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Background and objective The genetic basis of dentoalveolar characteristics has been investigated by several studies, however, the findings are equivocal. The objective of this systematic review and meta-analysis was to evaluate the heritability of dental arches and occlusal parameters in different stages of human dentition. Search methods Electronic databases PubMed, Embase, Scopus, Web of Science, and Dentistry and Oral Science Source were searched up to August 2023 without the restriction of language or publication date. Selection criteria Empirical studies investigating the heritability of dentoalveolar parameters among twins and siblings were included in the review. Data collection and analysis Study selection, data extraction, and risk of bias assessment were performed independently and in duplicate by two authors and a third author resolved conflicts if needed. Joanna Briggs Institute's critical appraisal tool was used to evaluate the risk of bias among studies and the certainty of evidence was assessed using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria. Results Twenty-eight studies were included in the systematic review, of which 15 studies reporting heritability coefficients in the permanent dentition stages were deemed suitable for the meta-analysis. Random-effects meta-analyses showed high heritability estimates for maxillary intermolar width (0.52), maxillary intercanine width (0.54), mandibular intermolar width (0.55), mandibular intercanine width (0.55), maxillary arch length (0.76), mandibular arch length (0.57), and palatal depth (0.56). The heritability estimates for the occlusal parameters varied considerably, with relatively moderate values for crossbite (0.46) and overbite (0.44) and low values for buccal segment relationship (0.32), overjet (0.22), and rotation and displacement of teeth (0.16). However, the certainty of evidence for most of the outcomes was low according to the GRADE criteria. Conclusions Based on the available evidence, it can be concluded that the dental arch dimensions have a high heritability while the occlusal parameters demonstrate a moderate to low heritability. Registration PROSPERO (CRD42022358442). [ABSTRACT FROM AUTHOR]

Background Orthodontic therapy aims to treat misaligned teeth and jaws to improve dental occlusion as well as the function and aesthetics of the masticatory system. Continuous data collection to check treatment quality is of great importance for the constant optimization of orthodontic care. Objective The aim of this retrospective multicentre cohort study was to systematically determine the outcome and quality of orthodontic treatment by applying the internationally established Index of Orthodontic Treatment Need (IOTN) and Peer Assessment Rating (PAR) index in multiple clinical settings for a representative number of patient cases. Materials and methods A total of 1509 consecutive orthodontic patient cases (treatment completion between January 2018 and December 2020) from three representative orthodontic centres (University clinic, city office, small town office) were analysed in a multicentre study. The pre- and post-treatment casts were scanned, digitally measured, and partially automatically evaluated using the IOTN and PAR indices. Results A statistically significant improvement in occlusion was observed for medically necessary treatment of IOTN grades 4 and 5 in 97.30 per cent of the analysed cases and for treatment-requiring grades 2 and 3 in 94.08 per cent of the analysed cases. The average percentage PAR improvement was 76.51 per cent. 72.50 per cent of cases showed improvement of more than 70 per cent. The mean PAR index score was reduced from 28.19 ± 9.49 to 6.22 ± 5.41 points. Conclusion The present data demonstrate that orthodontic treatment is efficient in inducing significant improvement of malocclusions in general and has a high success rate with severe dysgnathia. [ABSTRACT FROM AUTHOR]

Background: This study aims to verify Bolton's values for tooth size ratios and to evaluate possible relationships to different occlusal traits using precise digital measurement methods., Materials and Methods: Including 1000 consecutively selected patients from three study centres a digital, partially automated model analysis was performed utilizing the software OnyxCeph. The measurements comprised tooth width for calculation of anterior (AR) and overall ratio (OR) as a percentage, arch width, length, perimeter, overjet, overbite, space analysis in millimetre and the assessment of the angle classification., Results: AR and OR were significantly increased compared to Bolton's ratios of 77.2% (AR) and 91.3% (OR). In the gender comparison, male patients showed larger tooth size ratios, especially in the OR. Patients with Angle Class II/1 and II/2 had smaller tooth size ratios than patients with Angle Class III and I. Thus, patients with Angle Class II/1 had the largest tooth diameters in all maxillary teeth and with Angle Class II/2 the smallest tooth sizes in the mandible. The largest tooth widths in the lower jaw were observed in the Angle Class III patient group. Furthermore, a negative correlation from AR/OR to overjet, overbite, and available space in lower jaw as well as a positive correlation to available space in upper jaw was detected., Conclusions: There is a clear correlation between the tooth size ratios and the present dysgnathia as well as other orthodontically relevant occlusal traits. This prior knowledge about our patients is extremely important to create an individualized treatment plan and enable sufficient occlusion. To achieve a functionally good occlusion with correct overjet and overbite, it is essential that the maxillary and mandibular teeth are proportional in size. Any deviation from the ideal patient in terms of tooth size, number, shape, or arch must be considered in the pre-therapeutic treatment plan in combination with the existing dysgnathia in order to be able to achieve a stable anterior and posterior occlusion with appropriate adjustments to the therapy post-therapeutically., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background Whether precise orthodontic detailing of occlusion impacts masticatory function is unknown. In this study, we aimed to assess the impact of post-orthodontic dental occlusion on masticatory performance and chewing efficiency. Materials and methods Fifty-four adults who completed orthodontic treatment were categorized into two groups using the American Board of Orthodontics (ABO) model grading system: one meeting ABO standards (ABO, N = 29), the other failing to meet them (non-ABO, N = 25). The electromyographic (EMG) signals of the anterior temporalis (AT) and superficial masseter muscles were recorded bilaterally during static (clenching) and dynamic (gum chewing) tests. Chewing efficiency was measured by calculating the median particle size (MPS) and broadness of particle distribution (BPD) after five chewing trials of experimental silicone food at a standardized chewing rate. Results Participants of the ABO group had a slightly more symmetric activation of the AT muscles during clenching (P = 0.016) and chewed a gum at a slower rate (P = 0.030). During the standardized chewing test with silicone food, ABO subjects had slightly greater EMG potentials at all muscle locations than non-ABO individuals (all P < 0.05). MPS and BDP did not differ significantly between groups (all P > 0.05). Limitations The severity of the initial malocclusion of the study participants was not in the statistical model as a potential confounder on the outcome measures. Conclusions Meeting ABO standards contributes to a slightly more balanced activation of the temporalis muscles during clenching and more efficient muscle recruitment during chewing but does not improve chewing efficiency. [ABSTRACT FROM AUTHOR]

Background The Scandcleft international multicenter study is a prospective clinical trial of the long-term outcome after four different surgical protocols for palatal closure in patients born with unilateral cleft lip and palate (UCLP). This paper is one of a series of follow-up studies in 8-year olds. Objectives To evaluate the dental occlusion of 8-year-old patients after four different protocols of primary surgery for UCLP. Trial design Ten cleft centres in five countries tested three different surgical procedures for primary palatal repair in three parallel trials (Arms B, C, and D) against a common procedure (Arm A). Methods Initially 448 children born with non-syndromic UCLP were included in the project. At 8 years of age, 428 children remained in the study. Dental casts of 411 patients (270 boys, 141 girls), mean age 8.1 years (range 7.0–10.0) were taken. The casts were blindly assessed with the Modified Huddart and Bodenham (MHB) index by four orthodontists. The main outcome measures were anterior (+2 to −6) and posterior (0 to −8) mean scores. Comparisons were made with previous data in 5-year-olds. Results The inter- and intra-examiner reliability was good to excellent (0.75–0.90; 0.73–0.97), respectively. The mean total scores varied from −7.09 (Trial 2C) to −10.13 (Trial 3D). The mean anterior scores varied from −1.75 (Trial 2C) to −3.18 (Trial 1A). The mean posterior cleft-side scores varied from −4.32 (Trial 1B) to −5.21 (Trial 3D) and the mean non-cleft-side scores varied from −0.88 (Trial 2C) to −2.40 (Trial 3A). No significant differences were found within the trials. A significant difference was found between Trials 2 and 3 (Arm C/D) for the total score (P = 0.004). Conclusions There was no evidence of clinically significant differences in occlusion between the two surgical methods in each trial or between the trials. All mean scores showed more negative values in 8-year-olds compared with previously reported values in 5-year-olds. Trial registration ISRCTN29932826 [ABSTRACT FROM AUTHOR]

Background As there are very few long-term studies on the effects of head orthosis on deformational plagiocephaly (DP), we investigated the outcomes of patients, including facial symmetry and dental occlusion. Methods Forty-five infants with DP [cranial vault asymmetry index (CVAI) > 3.5 per cent] were divided into two groups: one treated with head orthosis (32 infants) and another without (13 infants). Another group without head asymmetry (CVAI ≤ 3.5 per cent) served as control. Using 3D-stereophotogrammetry, cranial asymmetry was analysed using symmetry-related variables [CVAI, posterior cranial asymmetry index (PCAI), and ear offset]. Data acquisition was performed before (T1) and at the end of treatment (T2), and at the age of 4 years (T3) for the treated group and at T1 and T3 for the remaining groups. Parameters of facial symmetry and dental occlusion were assessed at T3 for infants with DP. Results Symmetry-related variables (∆T1−T3) improved significantly more in the treated than the control group, whereas these parameters did not differ significantly between the untreated and control group. Comparing the treated and untreated groups between T1 and T3, the reduction in the asymmetry at the treated group was significantly higher for the CVAI and PCAI. In follow-up, the untreated group showed higher incidences of facial asymmetries than the treated group. Seventy-five per cent of all lateral crossbites found in patients with DP were contralateral to the posterior flattening. Limitations Due to ethical reasons, the investigation is a non-randomized study. Parameters of facial symmetry were only assed for the treated and untreated groups. Conclusion Head orthosis therapy in patients with DP leads to significantly better long-term outcomes. Facial asymmetries are more frequent in patients with DP who do not receive this treatment. [ABSTRACT FROM AUTHOR]

Background/objective The aim of this study was to evaluate the efficacy of tooth alignment with conventional and self-ligating labial and lingual orthodontic bracket systems. Materials/methods We tested labial brackets (0.022″ slot size) and lingual brackets (0.018″ slot size). The labial brackets were: (i) regular twin brackets (GAC-Twin [Dentsply]), (ii) passive self-ligating brackets including (Damon-Q® [ORMCO]; Ortho classic H4™ [Orthoclassic]; FLI®SL [RMO]), and (iii) active self-ligating brackets (GAC In-Ovation®C [DENTSPLY] and SPEED™[Strite]). The lingual brackets included (i) twin bracket systems (Incognito [3M] and Joy™ [Adenta]), (ii) passive self-ligating bracket system (GAC In-Ovation®LM™ [Dentsply]), and (iii) active self-ligating bracket system (Evolution SLT [Adenta]). The tested wires were Thermalloy-NiTi 0.013″ and 0.014″ (RMO). The archwires were tied to the regular twin brackets with stainless steel ligatures 0.010″ (RMO). The malocclusion simulated a displaced maxillary central incisor in the x -axis (2 mm gingivally) and in the z -axis (2 mm labially). Results The results showed that lingual brackets are less efficient in aligning teeth when compared with labial brackets in general. The vertical correction achieved by labial bracket systems ranged from 72 to 95 per cent with 13″ Thermalloy wires and from 70 to 87 per cent with 14″ Thermalloy wires. In contrast, the achieved corrections by lingual brackets with 13″ Thermalloy wires ranged between 25–44 per cent and 29–52 per cent for the 14" Thermalloy wires. The anteroposterior correction achieved by labial brackets ranged between 83 and 138 per cent for the 13″ Thermalloy and between 82 and 129 per cent for the 14″ Thermalloy wires. On the other hand, lingual brackets corrections ranged between 12 and 40 per cent for the 13″ Thermalloy wires and between 30 and 45 per cent for the 14″ Thermalloy wires. Limitation This is a lab-based study with different labial and lingual bracket slot sizes (however they are the commonly used ones in clinical orthodontics) and study did not consider saliva, periodontal ligament, mastication and other oral functions. Conclusions The effectiveness of lingual brackets in correcting vertical and anteroposterior displacement achieved during the initial alignment phase of orthodontic treatment is lower than that of the effectiveness of labial brackets. [ABSTRACT FROM AUTHOR]

Aim To investigate the outcome quality and the long-term (≥15 years) post-treatment (Tx) changes after Class II:2 Herbst-multibracket appliance (MBA) Tx. Subjects and Methods In this longitudinal observational study, a recall of Class II:2 patients who had been treated by a Herbst-MBA during adolescence was conducted. Study models from before and after active Tx, after retention and after recall were assessed using standard occlusal variables and the peer assessment rating index (PAR). These data were compared to historical untreated Class I controls. Results Twenty out of 33 patients (61%) could be located and participated at age 33.9 ± 2.7 years. When comparing their data to the 13 patients who did not participate, the pre- and post-Tx occlusal findings did not differ systematically; however, the PAR scores of the non-participants were by 3.3–8.2 points higher at all times and the non-participants were 2.1–2.5 years older. Pre-Tx at age 14.4 ± 2.7 years, the participants showed the following mean values: PAR = 15.0 ± 7.0, Class II molar relationship (MR) = 0.8 ± 0.3 cusp widths (cw), overbite = 5.3 ± 1.3 mm. After Tx, a PAR score of 2.9 ± 1.3 and a super Class I MR (−0.1 ± 0.1 cw) with normal overbite (1.2 ± 0.8 mm) existed. At recall, a PAR score increase to 5.9 ± 3.6 points had occurred, mainly caused by an increase of overbite to 2.5 ± 1.5 mm. The average MR remained Class I (0.0 ± 0.2 cw). For all variables, the untreated controls exhibited similar findings. Conclusion The occlusal outcome of Class II:2 Herbst-MBA Tx exhibited very good long-term stability. While mild post-Tx changes occurred, the long-term findings are similar to untreated Class I controls. [ABSTRACT FROM AUTHOR]

Background: A Kloehn-type cervical headgear (CH) aims to correct skeletal jaw discrepancy in Class II children. A few studies have reported CH treatment effects on airway dimensions, but none of them have been randomized according to timing. Objectives: To evaluate related craniofacial structures and pharyngeal airway dimensions in children with a Class II occlusion treated with CH and randomized into early and late treatment groups. Trial design: Randomized, parallel-group, prospective controlled trial. Methods: The material comprised 67 seven-year-old children with a Class II occlusion. Sealedenvelope randomization in 1:1 ratio was used to divide the children into two equal groups. In the early group (EG, n = 33), CH treatment was started immediately or after eruption of the first maxillary molars. In the second, late group (LG, n = 34), the active CH treatment was started about one and half year later. The active CH treatment was continued in both groups until normal Class I occlusion on first molars was achieved. Cephalometric radiographs were taken from both groups at the beginning of follow-up (T0), at the beginning of CH treatment of the second group (T1), and at the end of CH treatment of the second group (T2). Changes in cephalometric measurements were used as primary outcomes. Blinding was applicable for outcome assessment. Results: Fifty-six children completed the study. The posterior change in the position of the maxilla was significant for early treatment males at T0-T1 (SNA; P < 0.001, ANB; P = 0.009) and T0-T2 (SNA; P = 0.012). The palato-mandibular angle (PL-ML) decreased during T0-T1 in early treatment females (P = 0.018) and early treatment males (P = 0.037). The retroglossal airway increased (P = 0.010) in early treatment males at T0-T1. Highly significant positive correlations (P < 0.001) between skeletal and upper airway dimensions during early CH treatment were found in males. No harms were encountered. Conclusions: Despite the effective CH treatment, no harmful upper airway changes were found. [ABSTRACT FROM AUTHOR]

Objective: We studied longitudinally the associations of craniofacial morphology, mouth breathing, orthodontic treatment, and body fat content with the risk of having and developing sleep disordered breathing (SDB) in childhood. We hypothesized that deviant craniofacial morphology, mouth breathing, and adiposity predict SDB among children. Materials and methods: The participants were 412 children 6-8 years of age examined at baseline and 329 children aged 9-11 years re-examined at an average 2.2-year follow-up. An experienced orthodontist evaluated facial proportions, dental occlusion, soft tissue structures, and mode of breathing and registered malocclusions in orthodontic treatment. Body fat percentage was assessed by dual-energy X-ray absorptiometry and SDB symptoms by a questionnaire. Results: Children with SDB more likely had convex facial profile, increased lower facial height, mandibular retrusion, tonsillar hypertrophy, and mouth breathing at baseline and convex facial profile, mandibular retrusion, and mouth breathing at follow-up than children without SDB at these examinations. Male gender and body adiposity, mouth breathing, and distal molar occlusion at baseline were associated with SDB later in childhood. Adipose tissue under the chin, mandibular retrusion, vertically large or normal throat and malocclusion in orthodontic treatment at baseline predicted developing SDB during follow-up of among children without SDB at baseline. Limitations: We could not conduct polysomnographic examinations to define sleep disturbances. Instead, we used a questionnaire filled out by the parents to assess symptoms of SDB. Conclusions: The results indicate that among children, deviant craniofacial morphology, mouth breathing, body adiposity, and male gender seem to have implications in the pathophysiology of SDB. [ABSTRACT FROM AUTHOR]

Aim: To investigate the long-term (≥15 years) post-treatment (Tx) occlusal changes and outcome quality after Class II:1 Tx. Subjects and Methods: Herbst-MBA Tx had been performed at age 12.8 ± 2.7 years in 119 patients. A recall was conducted and study models from before and after active Tx, after retention as well as after recall were evaluated using standard occlusal variables and the PAR index. These data were compared to 31 untreated Class I controls. Results: 52 out of 119 patients could be located and participated at 33.6 ± 3.1 years. Compared to the 67 patients who did not participate in the recall, the pre- and post-Tx occlusal data of the participants did not differ systematically; however, the PAR scores were higher by 3.0-4.7 points at all times. Pre-Tx, the mean values of the 52 participants were: PAR = 27.2 ± 7.6, Class II molar relationship (MR) = 0.7 cusp widths (cw), overjet = 8.2 mm, overbite = 4.1 mm. After Tx, the PAR score was 3.4 ± 2.2. A Class I MR (0.0 ± 0.1 cw) with normal overjet (2.3 ± 0.7 mm) and overbite (1.3 ± 0.7 mm) existed. At recall, a mild PAR score increase to 8.2 ± 5.5 points had occurred; this was mainly due to increased overjet and overbite values (3.6 ± 1.1 and 2.8 ± 1.6 mm) while the MR was stable (0.0 ± 0.2 cw). For all these variables, similar findings were made in the untreated controls. Conclusion: The occlusal outcome of Class II:1 Tx showed very good long-term stability. While mild changes occur post-Tx, the long-term result is similar to untreated Class I controls. [ABSTRACT FROM AUTHOR]

Background: Although post-treatment changes are almost inevitable, and retention has long been recognized as one of the most critical and routine problems faced by orthodontists, there remains a lack of certainty regarding the parameters of any definitive retention protocol following orthodontic treatment. Objective: To investigate the performance of the Hawley-type retainers. Search methods: Search without restrictions in 15 databases and hand searching until December 2016. Selection criteria: Randomized clinical trials comparing the performance of Hawley-type retainers to other removable appliances or comparing different Hawley-type retainers' wearing schedules. Data collection and analysis: Following study retrieval and selection, data extraction and individual study risk of bias assessment using the Cochrane Risk of Bias Tool took place. The overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach. Results: Finally, 10 studies were identified involving 854 individuals, followed for up to 1 year after debonding. Eight studies compared subjects using Hawley and clear thermoplastic retainers; another compared Hawley to positioner and, finally, one trial involved individuals allocated to different Hawley appliance wearing schedules. Three studies were considered as being of low, four of unclear, and three of high risk of bias. In general, few differences were observed between the Hawley and other removable retainers regarding outcomes relevant to maxillary and mandibular dental arch measurements, dental arch relationships and occlusal contacts, speech evaluation, patient reported outcomes, adverse effects, and problems related to the appliances, as well as economic evaluation related outcomes. Moreover, no differences were observed between the compared Hawley wearing schedules. Overall, the quality of the available evidence was considered low. Conclusions: Given the overall quality of the available evidence and the multitude of parameters, which may have affected the results of the included trials, good practice would suggest further research in the respective field in order to increase both the quantity and quality of information available. Registration: PROSPERO (CRD42015029279) Funding: No funding was received for the present systematic review. [ABSTRACT FROM AUTHOR]

Objectives: This 10-year prospective study aimed to measure and evaluate the teeth position and occlusion following 10-year nocturnal use of a mandibular protruding device (MPD) in subjects with obstructive sleep apnoea (OSA) or snoring. Materials and methods: Seventy-seven consecutive patients diagnosed with OSA/snoring were treated with an MPD. Fabrication of dental casts with jaw registration indexes in the intercuspal position was carried out at baseline and at follow-up, a construction bite was made, and an MPD was fitted. At the 10-year follow-up, all subjects (n = 74) were invited to participate. The dental casts were analysed in a series of measurements. Results: Sixty subjects were included in the follow-up examination--41 were still using the device and 19 had ceased using the MPD. The MPD users showed significant changes in all analysed variables--decrease of overjet (-1.8 mm), overbite (-1.5 mm)--except the mandibular intercanine width and the maxillary anteroposterior relationship. Subjects who had ceased using their MPD retained their initial values, with the exception of a decreased overbite. The MPD users also showed an increased number of subjects with mesio-occlusion and posterior infra-occlusion; those who had ceased using their MPD mostly retained their initial status. Conclusions: Long-term nocturnal use of an MPD may cause both favourable and unfavourable occlusion changes, such as a decrease of the overjet and overbite or posterior infra-occlusion, and these changes may continue to develop during treatment with an MPD. Subjects with a Class III relationship may not be a suitable group for treatment with an MPD due to the mesial drift of the mandibular teeth. [ABSTRACT FROM AUTHOR]

Background: Hypofunctional occlusion is known to lead to changes in the length of roots over time. The mechanisms that drive such changes, however, are poorly understood, with most studies concentrating on juvenile rats prior to the arrest of root development. In this article, we investigated the response of the upper and lower first molar roots to lack of occlusion concentrating on timepoints after the development of the roots has ceased using the mouse as a model. Mouse molar roots finish development at weaning, much earlier than rat molars, and display a similar pattern of roots in the lower and upper jaw to humans. Methods: Hypofunctional occlusion was achieved in adult mice at 5 and 9 weeks of age by flattening the cusps of the upper first molar. Mice were then sacrificed after 6 and 2 weeks, respectively, along with control littermates. microCT was used to measure root length, alveolar bone height, and the amount of tooth eruption, followed by sectioning to understand the mechanisms behind the changes at the histological level. Results: In the lower first molar, the response to hypofunctional occlusion was characterized by elongation of both the mesial root and its surrounding alveolar bone, while the distal root was unaffected. In contrast, the response of the upper first molar was characterized by over-eruption of the mesial side of the tooth without any significant change in the alveolar bone or root length. From histologic sections, it was clear that increased deposition of cellular cementum played an important role in the changes that occurred in the lower mesial root. Conclusions: In a mouse model, upper and lower molars responded differently to hypofunctional occlusion, with adult mice showing a different response to that previously reported for juvenile rats, highlighting the importance of considering age and tooth position in cases of hypofunction. [ABSTRACT FROM AUTHOR]

Background/objectives: Facial soft tissues changes during growth roughly tend to mimic the underlying hard tissues, but not completely. The aim of this mixed longitudinal study was to assess facial growth among pre-pubertal and pubertal subjects without malocclusion using a noninvasive three-dimensional laser scanning system. Subjects/methods: Fifty-nine subjects (30 females and 29 males) aged at baseline 5.4-8.9 years with normal occlusion were clustered into the younger, older pre-pubertal, and pubertal groups according to age and the absence/presence of a standing height growth spurt. Three-dimensional facial images were obtained using laser scanners for five consecutive years. Several transversal, sagittal, and vertical parameters were assessed for between and within group comparisons. Results: Significant overall changes of almost all parameters were seen within each group (P < 0.05) without any group differences (P > 0.05). The younger pre-pubertal group showed greater annual growth rates of lip prominence; both pre-pubertal groups showed greater rates in facial middle third height. The pubertal group showed greater annual rates in facial profile angle changes during the growth peak. Limitations: A high standing height increment (7 cm) was used as the threshold for subject allocation in the pubertal group. Conclusions: Soft tissue facial growth has generally similar amounts and rates irrespective of the pubertal growth spurt. Pre-pubertal subjects show greater annual rates of facial middle third height changes while pubertal subjects show greater annual rates of chin protrusion. [ABSTRACT FROM AUTHOR]

Background: The minimally important difference (MID, the smallest difference that patients perceive as beneficial) has been proposed to assess whether study results are clinically meaningful, reducing the shortcoming of P-values-based approaches in the assessment of clinical outcomes. The post-treatment changes and the MID in Oral Health-Related Quality of Life (OHRQoL) among adults undergoing fixed orthodontic treatment were investigated., Methods: Ninety-two patients (29.1 ± 6.3 years old, 18 males and 74 females) were prospectively included. Oral Health Impact Profile (OHIP-14) and United Kingdom Oral Health-related Quality of Life (OHQoL-UK) were used to assess OHRQoL at baseline and post-treatment (50.8 ± 15.7 months). Global Transition Rating (GTR) was used to assess oral health/well-being, Peer Assessment Review (PAR), and Index of Complexity, Outcome and Need (ICON) were used to assess occlusion. Wilcoxon signed-rank test was used to assess changes in OHRQoL and occlusion, Kruskal-Wallis one-way ANOVA and Mann-Whitney U-test were used to assess associations between OHRQoL and oral health/well-being or occlusion. MID for OHIP-14 and OHQoL-UK was estimated via anchor-based (PAR, ICON, GTR) and distribution-based approach (effect size, standardized response mean, standard error of measurement)., Results: The median OHIP-14 and OHQoL-UK post-treatment scores were significantly changed, indicating improved OHRQoL. Based on the agreement between different methods, the MID of OHIP-14 and OHQoL-UK were at least 15 and 6 scale points, corresponding to a large effect size (1.5-1.7)., Conclusions: Orthodontic treatment had a positive long-term impact on OHRQoL. MID for the OHIP-14 and OHQoL-UK provide guidance to interpreting the impact of orthodontic treatment on the OHRQoL of patients., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: The aim of this study was to investigate whether the addition of records can influence intra- and inter-rated agreement on torque choices made to treat a group of patients with various malocclusions. Methods: Forty-eight patients were presented to five orthodontic specialists in three different occasions. During the first session, the participants were shown only the models and intraoral photos of the patients; extraoral photos were added during the second session, and cephalometric X-rays were further supplemented during the third session. Mean weighted kappa coefficients were calculated to measure agreement. Results: The inter-observer agreement was low with the mean coefficients measured:κ1 = 0.34 (SD ± 0.09), κ2 = 0.57 (SD ± 0.12), and κ3 = 0.54 (SD ± 0.28) for the three attempts, respectively. The mean kappa coefficients for the intra-rater agreement were also low ranging from 0.18 to 0.66 and the mean coefficients were 0.27 (SD ± 0.11) between first and second, and 0.53 (SD ± 0.11) between second and third attempt, respectively. Conclusions: This study shows that the addition of extraoral photographs, and subsequently cephalograms to plaster models and intraoral photos, does affect intra-, and inter-rater agreement on torque selection. It seems that the addition of extraoral photos plays a more important role in torque selection decisions than lateral cephalograms. Different clinicians do not have a uniform opinion on the size of torque required to treat cases. Further research is required to define rules on torque choices. [ABSTRACT FROM AUTHOR]

Objective: To assess the treatment effects of fixed functional appliances (FFAs) in treated versus untreated Class II patients by means of lateral cephalometric radiographs. Search methods: Unrestricted electronic search of 18 databases and additional manual searches up to October 2014. Selection criteria: Prospective randomized and non-randomized controlled trials reporting on cephalometric angular measurements of Class II patients treated with FFAs and their matched untreated controls. Data collection and analysis: Skeletal, dental, and soft tissue cephalometric data were annualized and stratified according to the time of evaluation in effects. Following risk of bias evaluation, the mean differences (MDs) and 95 % confidence intervals (CIs) were calculated with random-effects models. Patient- and appliance-related subgroup analyses and sensitivity analyses were performed with mixed-effects models. Results: Nine studies were included (244 patients; mean age: 13.5 years and 174 untreated controls; mean age: 12.8 years) reporting on cephalometric effects directly after the removal of FFAs. FFAs were found to induce a small reduction of SNA angle (MD = -0.83 degree/year, 95 % CI: -1.17 to -0.48), a small increase of SNB angle (MD = 0.87 degree/year, 95 % CI: 0.30-1.43), and moderate decrease of ANB angle (MD = -1.74 degree/year, 95 % CI: -2.50 to -0.98) compared to untreated Class II patients. FFA treatment resulted in significant dentoalveolar and soft tissue changes. Several patient- or appliance-related factors seem to affect the treatment outcome. Long-term effectiveness of FFAs could not be assessed due to limited evidence. Conclusions: According to existing evidence, FFAs seem to be effective in improving Class II malocclusion in the short term, although their effects seem to be mainly dentoalveolar rather than skeletal. [ABSTRACT FROM AUTHOR]

Objective: The aim of this prospective longitudinal investigation was to compare the relationship between the temporomandibular joint (TMJ) condyles and the temporal fossae by means of tomography before and after the orthodontic correction of Class II, division 1 malocclusion using the activator appliance. Materials and methods: The final sample consisted of 26 consecutively treated Class II, division 1 patients (19 boys and 7 girls with an average pre-treatment age of 11 years) who underwent orthodontic treatment by means of an activator appliance. Before treatment all patients were free of signs and symptoms associated to TMJ disorders. Bilateral tomographic records before and after treatment were taken and analyzed. Outlines of the condyle and temporal fossa were automatically determined by an edge-detection protocol, and the minimum joint space dimension was automatically measured every 2 degrees. For further analysis, the joint space was divided into anterior, superior, and posterior joint spaces. Results: The average treatment time with the activator appliance was 366 days. In all subjects, activator treatment resulted in a Class I dental arch relationship. After activator treatment, no differences were found in the joint space measurements in any direction. Comparisons between the right and left condyles were not significantly different. Conclusions: Joint space dimension in Class II division I children was similar before and after treatment in both TMJs. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to analyse residual orthodontic treatment need in Finnish municipal health centres. Subjects and methods: A random sample of two age groups, 16- and 18-year-olds (n = 2212), from seven municipalities was invited for a clinical examination, and 1041 adolescents participated. Two calibrated orthodontists blindly examined the participants for residual treatment need, applying the Dental Health Component (DHC) and Aesthetic Component (AC) of the Index of Orthodontic Treatment Need. Self-perceived treatment need, satisfaction with occlusal function, and dental appearance were evaluated with a questionnaire. Differences between objective and self-perceived treatment need and between treated and untreated adolescents were analysed using the chi-square test. Results: A total of 18.8 per cent of all adolescents had DHC grade 4 or 5 and/or AC category 8-10, indicating a definite need for treatment. In the analysis between treated and untreated adolescents, orthodontic treatment history or gender had no statistically significant association with the objectively defined need (P > 0.05). Self-perceived treatment need was reported by 9.6 per cent of adolescents. This need was more common among treated (13.9 per cent) than untreated (4.6 per cent) adolescents (P < 0.001). Among all adolescents, satisfaction with occlusal function was high, 91.3 per cent; 78.9 per cent of adolescents were satisfied with their dental appearance. The main reasons for dissatisfaction and self-perceived need were visible contact point displacements. Conclusions: The observed proportion of residual orthodontic treatment need is in line with earlier findings. The high satisfaction with occlusal function reflects the applied selection criteria; orthodontic treatment of displacements causing only aesthetic concern is not prioritized. [ABSTRACT FROM AUTHOR]

Objectives: The current parallel group, randomized controlled trial aimed to compare the dentoalveolar and skeletal changes resulting from treatment using two popular functional appliances: the Bite-Jumping Appliance (BJA) and the Twin-Block Appliance (TBA). Study design: This study is designed as a parallel-group, randomized controlled trial. Materials and methods: Patients were screened from the patients who were seeking treatment at the Department of Orthodontics, Al-Baath University. Eligibility criteria included skeletal Class II division 1 malocclusion resulting from the retrusion of the mandible. A computer-generated randomization list was used to randomly divide the patients into two equal groups to be treated with either the BJA or the TBA. Blinding was applicable for outcome assessment only. Forty-four patients (22 male and 22 female) aged 10.2-13.5 years were randomized in a 1:1 ratio to either the BJA or the TBA groups, and four patients were lost to follow-up (two from each group). Lateral cephalometric radiographs were obtained before treatment and after 12 months of active appliance therapy. Inter-group differences were evaluated with two-sample t-tests, and intra-group differences were assessed with paired-sample t-tests at the P<0.05 level. Results: Forty patients (20 in each group) were available for the statistical analysis. Baseline characteristics were similar between groups. Similar changes were observed in the sagittal plane, including a significant increase in the SNB angle. No significant changes were observed in the maxilla. The lower incisors were significantly proclined, and the upper incisors significantly retruded. In the vertical plane, BJA induced mandibular clockwise rotation, and the SN:MP angle increased by 2.14±2.97° (P = 0.002). Conversely, no significant changes took place in this angle in the TBA group 0.75±2.37° (P = 0.096). Similarly, Jarabak ratio decreased significantly in the BJA group by -1.78±0.85% (P = 0.002) and increased significantly in the TBA group by 1.26±0.76% (P= 0.032), with significant differences between the two groups (P< 0.001). No serious harm was observed. Limitations: A limitation of this research is a lack of an untreated control group. However, the resulting differences between the two groups can be attributed to the appliance differences, which fulfil the aim of the current research. Conclusions: Each of the two appliances is recommended for the functional treatment of skeletal Class II malocclusion resulting from the retrusion of the mandible. The BJA is recommended when clockwise rotation is desired, whereas the TBA is recommended to inhibit vertical development. [ABSTRACT FROM AUTHOR]

Objective: To analyze the effects on vertical dentoskeletal dimension produced by cervical headgear (CHG) or Pendulum (P) both followed by full fixed appliances in growing patients with Class II malocclusion. Material and Methods: The CHG group (CHGG) consisted of 40 patients (25 females, 15 males) with a mean age of 11.5 years. The P group (PG) comprised 40 patients (21 females, 19 males) with a mean age of 11.6 years. Mean treatment duration with the CHG and P appliances were 1.5 years and 8.2 months, respectively. Lateral cephalograms were available before treatment (T1) and at the end of fixed therapy (T2) with a mean interval of 3.5 years. The effects of the 2 protocols were compared with a matched control group (CG) of 25 untreated Class II subjects (13 females, 12 males). The ANOVA with Tukey's post hoctests was used to evaluate between-group differences at T1 and during the T1-T2 interval (P< 0.05). Results: CHGG showed significantly greater decreases in both Sella-Nasion to A point angle and A-Nasion-B point anglel when compared with both PG (-1.2 and -0.9 degrees, respectively) and CG (-1.9 and -1.5 degrees, respectively). No significant between-group differences were recorded for any of the vertical skeletal measurements. Both CHGG and PG showed significantly greater improvement in molar relationships with respect to CG (+2.5 mm). Conclusions: Both distalizing protocols were effective in the correction of Class II malocclusion without increasing the vertical dimension at the end of comprehensive treatment. [ABSTRACT FROM AUTHOR]

Background: Among child and adolescent patients, persistent but untreated malocclusions may or may not have psychological and social impacts on the individual's quality of life. Objectives: To gain knowledge of malocclusions and its impact on oral health-related quality of life (OHRQOL), we conducted a systematic review of quantitative studies for evidence regarding the influence of malocclusions on OHRQOL in children and adolescents. Materials and methods: Five databases (MEDLINE via PubMed, EMBASE, Psychinfo, CINAHL, and the Cochrane Library) were searched using specified indexing terms. The following inclusion criteria were used: child or adolescent study population; healthy study participants without syndromes such as cleft lip/palate or severe illness; no previous or ongoing orthodontic treatment among participants; a focus on malocclusions and quality of life; controlled or subgrouped according to malocclusions/no malocclusions; malocclusions and/or orthodontic treatment need assessed by professionals using standardized measures; self-assessed OHRQOL estimated using validated questionnaire instruments; full-text articles written in English or Scandinavian languages. Quality of evidence was classified according to GRADE guidelines as high, moderate, or low. Results: The search produced 1142 titles and abstracts. Based on pre-established criteria, the full-text versions of 70 articles were obtained, 22 of which satisfied the inclusion criteria. After data extraction and interpretation, six publications were deemed eligible for full inclusion. All six were of cross-sectional design, and the quality of evidence was high in four cases and moderate in the remaining two. The four studies with a high level of quality reported that anterior malocclusion had a negative impact on OHRQOL, and the two with a moderate level of quality reported that increased orthodontic treatment need had a negative impact on OHRQOL. Conclusion: The scientific evidence was considered strong since four studies with high level of quality reported that malocclusions have negative effects on OHRQOL, predominantly in the dimensions of emotional and social wellbeing. [ABSTRACT FROM AUTHOR]

Background/Objectives: Because polymer-based materials typically exhibit viscoelastic properties, the objective was to determine if commercially available, aesthetic, fibre-reinforced composite archwires maintain continuous forces without undergoing force decay when deflected continuously. Materials/Methods: Quasi force decay was evaluated by comparing three-point bending profiles of nickel-titanium (NiTi) and fibre-reinforced composite archwires (BioMers) prior to and after 30 days of continuous deflection of either 1 or 2 mm. Paired t-tests or non-parametric signed rank tests were used to statistically compare pre- and post-deflection bending forces. A control group consisting of wires not subject to the 30-day constant deflection was tested to check whether the initial testing altered the second three-point bend test. Results: Significant (P < 0.01) differences in the pre- and post-deflection deactivation force delivery were most evident in the composite 2 mm deflection group and all of the NiTi groups. The composite 2 mm deflection group failed to deliver consistent forces as the majority of the wires experienced crazing during the 30-day deflection period. The decrease in force delivery in the NiTi groups may be attributed to the small standard deviations. Conclusions: The composite 1 mm deflection group demonstrated that fibre-reinforced composite archwires are able to deliver a consistent force after 30 days of deflection. However, the clinical applicability of these fibre-reinforced composite archwires may be limited as they are unable to sustain deflections of 2 mm without experiencing crazing and loss of force delivery. Limitations: Clinical efficacy of the aesthetic, fibre-reinforced composite orthodontic archwires remains to be observed. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To investigate the different effects of changes in the occlusal plane, incisors inclination, and maxillary intercanine width on the curvature of the smiling line. MATERIALS: Records of 46 subjects (28 females and 18 males, mean age 16.6±4.2 years) with incisor class II division 1 malocclusions were selected. All subjects had four premolar extractions and were treated with preadjusted edgewise appliances. METHODS: Pre- and post-treatment maxillary dental digital models were virtually aligned via corresponding landmarks to the respective lateral cephalograms. Subsequent two-dimensional superimposition of the aligned cephalograms facilitated the three-dimensional superimposition of the pre- and post-treatment models. This process allowed the quantification of the curvature from a frontal perspective of the models. The change in curvature was then correlated with changes in the cephalometric inclination of the anterior occlusal plane (AOP), functional occlusal plane (FOP), maxillary central incisor (U1), and the intercanine width. RESULTS: Orthodontic correction in this sample resulted in the clockwise rotation of the anterior occlusal plane (5.84 degrees), reduction in proclination of the incisors (−14.39 degrees), increase in intercanine width (2.48mm), and a corresponding increase in the curvature of the smiling line (6.83 degrees). CONCLUSIONS: The change in curvature of the smiling line in these subjects was found to be related more significantly to the magnitude of difference in the inclination between the pre-treatment AOP and FOP than to the change in the inclination of the maxillary incisors. With orthodontic treatment, the smiling line can be correlated with cephalometric data to improve or maintain the curvature. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate facial morphology in 25 Class III and 46 non-Class III children aged 5–6 years using three-dimensional (3D) laser imaging; 3D facial images were obtained, two average facial templates were constructed for the non-Class III male and female groups, each individual face was superimposed on the corresponding average template and group comparisons were evaluated (facial height, facial convexity, mandibular position and facial surface morphology). Differences between parameters were evaluated by using an analysis of variance and colour deviation maps. The results showed that Class III children had less mid-face prominence and a concave facial profile when compared to non-Class III children (P = 0.002 and P = 0.018). The position of the pg point in the z-axis just failed to reach statistical significance when comparing the two groups (P = 0.051). A vertical analysis showed no statistical significance between the groups, when evaluating middle (n–sn) and lower (sn–pg) facial height. Coincidence of the Class III faces to normal templates with a tolerance set as 0.5 mm was low (less than 30%). The soft tissue characteristics of a Class III face differ significantly from the non-Class III face in the mid-face region and in the facial profile. A 3D laser imaging method evaluated and identified morphological characteristics of Class III children in deciduous dentition, which could in the future become an important diagnostic tool in small children. The most important clinical advantage of this study is the non-invasiveness of the method. [ABSTRACT FROM PUBLISHER]

Summary This prospective study investigated the skeletal, dental, and soft-tissue effects of a mini maxillary protractor appliance in class III subjects with maxillary retrusion and mandibular protrusion and compared these changes with those of untreated, well matched control sample with normal occlusions. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Several indices are now available to assess the severity of the malocclusion in cleft lip and/or palate (CLP) patients; and although it has been quite some time since the introduction of these indices, there is no consensus as to which index should be used for CLP populations. OBJECTIVE: To systematically review the available literature on the indices used to assess the occlusal schemes in dental models of CLP patients, with respect to the most commonly used index and the index that most fulfils the World Health Organization (WHO) criteria. SEARCH METHODS: Ten electronic databases, grey literature, and reference list searches were conducted. SELECTION CRITERIA: The inclusion criteria consisted of studies that aimed to assess a particular malocclusion index on study models of patients with CLP. DATA COLLECTION AND ANALYSIS: Full articles were retrieved from abstracts/titles that appeared to have met the inclusion -exclusion criteria which were subsequently reviewed using more detailed criteria for a final selection decision. The Quality Assessment of Diagnostic Accuracy Studies tool was used to appraise the methodological quality of the finally included studies. Due to the heterogeneity of the data, only a qualitative analysis was performed. RESULTS: A total of 13 studies met the inclusion -exclusion criteria. These studies revealed seven utilized indices, namely the GOSLON Yardstick, Five-Year-Old, Bauru-Bilateral Cleft Lip and Palate Yardstick, Huddart -Bodenham, Modified Huddart -Bodenham, EUROCRAN Yardstick, and GOAL Yardstick. The GOSLON Yardstick was the most commonly used index, and the Modified Huddart -Bodenham performed the best according to the WHO criteria. CONCLUSIONS: Current evidence suggests that the Modified Huddart -Bodenham Index equalled or outperformed the rest of the indices on all the WHO criteria and that the GOSLON Yardstick was the most commonly used index, possibly due to a longer time in use. Therefore, the Modified Huddart -Bodenham could be considered as the standard to measure outcomes of patients with CLP. [ABSTRACT FROM PUBLISHER]

Conflicting data have been reported in dentistry regarding the diagnostic potential of monitoring body sway while in a static standing bipedalic position. This systematic review reappraises previously reported effects of mandibular position, asymmetric occlusion, and temporomandibular disorders (TMDs) on body sway to determine whether there is sufficient evidence for such correlations and to define the potential diagnostic applications in orthodontics.A literature survey was performed using the Medline, LILACS, and SciELO databases, and the Cochrane Library, covering the period from January 1980 to December 2011.Twelve articles qualified for the final analysis. All of these studies investigated the effects of mandibular position, two focussed also on asymmetrical occlusion, and three on TMDs. Only two studies were judged to be of medium or medium/high quality, with all of the rest classified as low-quality design; no study included follow-up. According to the conclusions of these reports, four studies saw significant correlations between body sway and mandibular position or TMDs. After a reappraisal of the full data set, generally no clinically relevant correlations were uncovered in the comparisons.While more investigations with improved levels of scientific evidence are needed, according to current evidence, the static monitoring of body sway as a diagnostic aid in orthodontics may not be indicated. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate the influence of prolonged sucking habits and mouth breathing on palatal vault morphology in a group of subjects with unilateral functional crossbite [crossbite (CB) group] compared with a group of subjects with normal occlusion [non-crossbite (NCB) group]. A sample of 80 Caucasian subjects (51 CB and 29 NCB; aged 5.3±0.8 years) in the deciduous dentition was selected. A questionnaire regarding the subject’s sucking habits was answered by the parents. Any sucking habit that lasted more than 24 months was considered as a prolonged sucking habit. The breathing pattern was assessed by an experienced otorinolarygologist and was classified either mainly nose or mouth breathing. Intercanine and intermolar distances and palatal surface area and volume were recorded three dimensionally on study casts. Univariate and multivariate analyses were employed. Posterior CB was negatively correlated with all the dental and palatal parameters (P < 0.01) with the exception of the palatal surface area that did not reach the statistical significance. Only prolonged sucking habits (but not mouth breathing) was a significant risk indicator for unilateral functional CB (P < 0.001). However, the prolonged sucking habits were not significantly correlated with any of the investigated parameter, and mouth breathing was negatively correlated with the intermolar distance only. Therefore, maxillary constriction in unilateral functional CB might not be influenced by the presence or absence of prolonged sucking habits or mouth breathing. [ABSTRACT FROM PUBLISHER]

The aim of the study was to establish the prevalence of dental features that indicate a need for early orthodontic treatment (EOT). A group of schoolchildren in the mixed dentition stage (7–11 years old) (n = 432) was clinically screened for indications for EOT. Over 1/3 of the youngsters (34.7 per cent) presented at least one of the indications for EOT: anterior and posterior crossbites (including edge to edge occlusion) were found in 9.5 and 23.3 per cent, respectively; Angle Class III was found in 3 per cent; increased overjet (≥7 mm) prevailed in 3.7 per cent and was significantly related to risk for dental trauma (P = 0.001); while oral habits were practiced by 10.9 per cent, open bite was found only in 6.5 per cent, both predominantly among girls (P = 0.006 and P = 0.012, respectively); impinging overbite was present in 5.2 per cent, mainly in boys (P = 0.006); crowding >5 mm was found in 6.9 per cent for the maxilla and in 6 per cent for the mandible. Loss of tooth material affecting tooth position was found in 15.3 per cent. Normal occlusal relationships were found in 10.9 per cent only. The findings indicate that almost 1/3 of the examined children in the mixed dentition stage require EOT. Sexual dimorphism was demonstrated for several occlusal features. [ABSTRACT FROM PUBLISHER]

The aim of the present study was to evaluate the association of tongue posture with the dentoalveolar maxillary and mandibular morphology in a group of Class III subjects in comparison to a group of Class I subjects. Twenty Class III subjects (9 males, 11 females, 19.2 ± 4.6 years) and 20 Class I subjects (6 males, 14 females, 17.4 ± 1.7 years) were included in the present study. Maxillary and mandibular morphology was defined by the intermolar and intercanine distances, at both the cusps and gingival levels, and by measuring surface area and volume of the palatal vault and mouth floor assessed on three-dimensional digital models. Tongue-to-palate distances were measured on lateral cephalograms. The groups were compared using the Mann–Whitney U-test and correlations between each morphological parameter and the tongue-to-palate distances were calculated using the Spearman correlation coefficient. The mandibular intermolar width at the gingival level was significantly greater in the Class III group (P < 0.01), while the maxillary intercanine widths were significantly smaller in the Class III group (P < 0.05). The mouth floor area and volume and the respective ratios between the mouth floor and palate were significantly greater in the Class III group (P = 0.01). The tongue-to-palate distances were generally greater, i.e. lower tongue posture, for the Class III subjects. Significant correlations were seen between tongue-to-palate distances in the posterior region with the area ratio (rho = 0.44, P < 0.05). Tongue posture is significantly lower in Class III subjects and is associated with the dentoalveolar characteristics of the maxilla and mandible. [ABSTRACT FROM PUBLISHER]

The purpose of this retrospective study was to assess the relationship between the initial position of palatally displaced canines (PDCs) on panoramic radiographs and the duration of the orthodontic treatment and further to estimate the costs of the treatment. Data from panoramic radiographs and patient records of 66 consecutive patients (mean age 14.9 ± 1.7 years) with PDC were analysed. The initial position of the canine, the distance between the canine cusp tip and the occlusal plane, and the inclination of the canine were significantly associated with treatment duration both unadjusted and adjusted for background characteristics. The average estimated cost of the treatment of PDC was €3200 per case. The total annual cost for treatment of PDC in Sweden may therefore be estimated at €600 0000. In this study, duration of treatment averaged 17 months for canines displaced in impaction zone 1 or 2, 2.6 [95% confidence interval (CI) −1.0 to 6.2] months longer for those in impaction zone 3, and 7.6 (95% CI 4.1–11.1) months longer for canines displaced in impaction zone 4 or 5. This information makes it easier, through study of the panoramic radiograph, to estimate the duration of treatment and to give patients more precise information about the expected length of their treatment. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate the relationship between occlusal characteristics and oral health-related quality of life in adults who underwent orthodontic or orthodontic–surgical treatment. The study group consisted of 51 adult patients (35 women, 16 men) with severe malocclusion and considerable functional disorders. Thirty-six of the patients underwent combined orthodontic–surgical treatment, while 15 underwent orthodontic treatment. Data were collected before and after treatment. Mean follow-up period was 5.0 years (range 2.2–6.7 years). Occlusal characteristics were measured from dental casts by using Peer Assessment Rating (PAR) index. A self-completed Oral Health Impact Profile (OHIP-14) was used to measure oral impacts. The changes in PAR and OHIP-14 were measured, and correlation between PAR and OHIP tested before and after treatment and in the changes during the follow-up. Statistical significance was evaluated with the paired samples t-test and Mann–Whitney U-test, and the correlation between PAR and OHIP scores assessed using Pearson’s and Spearman’s correlation coefficient. The occlusion was significantly improved in all subjects, mean PAR reduction being 78.1 per cent. The prevalences of oral impacts at threshold `fairly often’ or `very often’ before and after treatment were 70.6 per cent and 9.8 per cent, respectively (P < 0.001). The PAR and OHIP scores correlated after treatment but not before treatment or in the changes. The treatment of severe malocclusion reduced the reported oral impacts to the level of general population and significantly improved oral health-related quality of life. [ABSTRACT FROM PUBLISHER]

It is well established that patients with a unilateral posterior crossbite exhibit reverse-sequencing chewing patterns when chewing on the affected side. The aim of the study was to compare the prevalence of reverse-sequencing chewing cycles in patients with anterior versus posterior unilateral crossbite during chewing soft and hard boluses. Eighty-six children (39 boys, 47 girls) were included in the study: 26 (10.4 ± 2.7 years) with unilateral anterior crossbite, 43 (10.2 ± 4.2 years) with unilateral posterior crossbite, and 17 (10.6 ± 2 years) with normal occlusion were selected for the study. Mandibular movements were measured with a kinesiograph (K7, Myotronics Inc. Tukwila). The kinematic signals were analyzed using custom-made software. The results showed a low prevalence of reverse-sequencing chewing cycles in patients with anterior crossbite, without any significant difference between sides and with the control group, with both soft (P = 0.33) and hard (P = 0.29) bolus. The patients with posterior unilateral crossbite showed a significant higher prevalence of reverse-sequencing chewing cycles during chewing on the crossbite side with respect to the non-crossbite side (P < 0.001) and to the control group (P < 0.001). Comparing the patients with anterior versus posterior unilateral crossbite, a significant difference (P < 0.001) in the prevalence of reverse chewing cycles was demonstrated during chewing on the posterior crossbite side only with both soft and hard bolus. In conclusion, patients with anterior versus posterior unilateral crossbite show different functional characteristics depending on which dental region is involved. [ABSTRACT FROM PUBLISHER]

A thorough understanding of the intraoral pressure conditions of patients with different forms of malocclusion may help to characterize their aetiology in more detail and improve orthodontic treatment approaches by adding strategies to achieve a normalization of intraoral pressure levels. These pressure curve analyses should not only provide information on intraoral activity or during rest but also detail characterization of swallowing features and pressure plateau stages. For this purpose, algorithms for extracting swallowing peaks and plateau stages were developed and evaluated. Established curve characteristics such as the average or maximum pressure as well as the number of swallowing peaks or resting phases were compared between each other. Their usefulness and correlation (Kendall’s τ) were evaluated in a data example of different occlusal groups (Angle Class I: n = 30; Angle Class II division 1: n = 12; and Angle Class II division 2: n = 13). Curve characteristics were compared among these groups using the Kruskal–Wallis test. Some of the derived curve characteristics were found to be uncorrelated, thus providing different information concerning the intraoral pressure condition of subjects. Based on these findings, it is recommended to employ the curve characteristics described in this study to obtain a holistic image of factors that may affect the formation of the dentition. [ABSTRACT FROM PUBLISHER]

The aim of this study was to examine the pathways between temporomandibular disorders (TMDs), occlusal characteristics, facial pain, and oral health-related quality of life in patients with severe malocclusion. The study comprised 94 (34 men and 60 women, mean age 38 years) adult patients who were referred for orthodontic or surgical–orthodontic treatment. All the patients had severe malocclusion. Oral health-related quality of life was measured with the Oral Health Impact Profile-14 scale (OHIP-14), the intensity of facial pain using a Visual Analogue Scale (VAS), TMD with Helkimo’s clinical dysfunction index (Di), and occlusal characteristics with the Peer Assessment Rating (PAR). A hypothetical model of the interrelationships between these factors was constructed based on the conceptual model of biological, behavioural, and psychosocial consequences of oral diseases. The associations were studied with path analysis. Women reported poorer oral health-related quality of life, higher pain levels, and had more severe TMD than men, but the gender difference was statistically significant only in pain and TMD. In contrast to the hypothetical model, among women the occlusal characteristics were not directly associated with oral health-related quality of life or facial pain. Among men, the occlusal characteristics were directly associated with oral health-related quality of life. In conclusion, patients with severe malocclusion who also have TMD and facial pain more often have impaired oral health-related quality of life. The associations of the occlusal characteristics with oral health-related quality of life differ between genders. Therefore, these associations should be studied separately among genders. [ABSTRACT FROM PUBLISHER]

The aims of the present study were to provide data on growth changes in the dental arches from age 7 to 32 in Finns with untreated normal Angle Class I occlusions. The material consisted of 33 series of dental casts of 18 women and 15 men. The subjects had been examined and study models taken at the ages of 7, 10, 12, 15, and 32. Dental arch width, overbite, and overjet were measured. Our longitudinal findings show that both the dental arches of young adults are slightly narrowed from adolescence to 32 years of age. All increases in width dimensions took place before 15 years of age. The means of the changes were mostly small, in the order of 0.5 to a few millimetres. Variability in age changes was considerable. In both genders, each variable increased in some subjects and decreased in others during every age interval. Differences between growth changes in the mesial, distal, and gingival intermolar widths indicate that both the maxillary and the mandibular first molars rotate mesiolingually and that the maxillary first molars also become more upright during late occlusal development.We expect the present findings of the changes occurring in the arch dimensions of subjects with untreated normal occlusions to help clinicians in following up occlusal development, choosing an optimal treatment time, and making orthodontic treatment and retention plans. However, because of the wide variability, accurate prediction of future development cannot be made on the individual level. [ABSTRACT FROM PUBLISHER]

Developmental dysplasia of the hip (DDH) has been associated with other congenital postural deformities and associated with asymmetric features in the body. The aim of this study was to examine the associations between developmental DDH and malocclusions in preschool and school children.The subjects were 60 children (40 girls and 20 boys) born during 1997–2001 in Northern Ostrobothnia Hospital District and having developmental DDH and treated by Von Rosen method. The control group consisted of 71 Finnish children (46 girls and 25 boys) matched by age and gender. Children participated the cross-sectional study at the age of 5–10 years; the mean age of the DDH children was 8.0 (SD 1.4) and controls 7.9 (SD 1.4) years. Dental examinations, intra-oral photographs, and clinical examination including growth measurements were carried out.The DDH children had significantly more lateral crossbites than controls (30/9.9 per cent; P < 0.003). Overall, 77.8 per cent of cases were unilateral crossbites and found more on the right side (50 per cent) compared to the left side (22.2 per cent). Girls had more crossbite compared to boys (77.8/22.2 per cent; odds ratio 2.53).Children with congenital hip dislocation are more predisposed to the asymmetric growth of occlusion and the development of crossbite. The genetic and environmental factors including intrauterine conditions in addition to the splint therapy may be possible influencing factors. This study will give additional information of the development of occlusal asymmetries and the multifactorial nature of the aetiology of lateral malocclusions. [ABSTRACT FROM PUBLISHER]

This study evaluated cephalometric differences between 113 Japanese (43 males and 70 females, aged 14.1 ± 5 years) and 106 European subjects (36 males and 70 females, aged 13.5 ± 7.3 years) using two compound angular measurements and their single components: the overbite depth indicator (ODI) for the assessment of vertical skeletal relationships and the antero-posterior dysplasia indicator (APDI) for an evaluation of sagittal dysgnathia. Both populations were assigned to groups representing Angle Classes I, II, and III, and an anterior open bite (AOB) group. Two sample t- and Wilcoxon signed-ranks tests were performed (P < 0.05).The ODI values showed no statistically significant differences between the Japanese and European samples. The Japanese sample showed a significantly smaller APDI but only in the Class II group. In the Japanese Class II and III subjects, the malocclusion patterns were more pronounced than those in the Caucasian sample (overbite, overjet, and APDI). [ABSTRACT FROM PUBLISHER]

Identifying risk factors is important to prevent a wide range of health-damaging behaviours and to improve the quality of life of young people. The aim of this study was to investigate the relationship between impacts on daily performance attributed to malocclusion and psychological stress in healthy young Japanese adults.Medical and oral health data were collected during a cross-sectional examination conducted by the Health Service Center of Okayama University. Systemically healthy non-smoking students aged 18 and 19 years (n = 641; 329 males and 312 females) were included. Malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need (IOTN). The impacts on daily performance attributed to malocclusion and psychological stress were assessed using self-reported questionnaires, the condition-specific oral impacts on daily performances (CS-OIDP), and the Hopkins Symptoms Checklist. Mann–Whitney U- and chi-square tests and structural equation modelling (SEM) were used for statistical analysis.Forty per cent of subjects had a malocclusion (n = 255). Subjects with impacts on daily performance had a significantly higher prevalence of malocclusion than those without impacts (P < 0.001). SEM showed that psychological stress, especially interpersonal sensitivity and depression, was significantly correlated with CS-OIDP and malocclusion. Negative impacts on daily performance attributed to malocclusion may contribute to psychological stress in young Japanese adults. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to compare the effects of a differently designed functional appliance (the R-appliance) with a twin-block (TB)-treated group.Thirty patients (18 girls and 12 boys) with a mean age of 10.5 ± 0.7 years were treated with the R-appliance for 16.2 ± 0.3 months and 25 (11 boys and 14 girls) with a mean age of 11.2 ± 1.3 years with a TB for 16.1 ± 1.4 months (control). All had a Class II division 1 malocclusion due to mandibular deficiency. Lateral cephalograms obtained at the beginning (T1) and end (T2) of the study were analysed.Paired t-tests showed that SNB significantly increased in both groups. The incisor mandibular plane angle (IMPA) was reduced in the R-appliance group by 1.9 ± 4.9 degrees (P < 0.04) but increased by 0.5 ± 5.1 degrees (P < 0.6) in the TB group. SNA in the R-appliance group showed an increase of 0.2 ± 1.8 degrees (P < 0.5), while it was decreased by 0.2 ± 1.3 degrees (P < 0.3) in the TB group.Both treatment modalities were successful in moving the mandible forward. However, with the R-appliance, this was achieved without retroclination of the lower incisors. [ABSTRACT FROM PUBLISHER]

Careful attention to malocclusion in children with special needs leads to a considerable improvement in the quality of life. The present study analysed the prevalence of malocclusion in children with Down syndrome (DS) and cerebral palsy (CP) as well as associations with individual, socio-economic, and behavioural factors.A cross-sectional study was carried out that included 181 mothers and their children with DS and CP (aged 3–12 years) at two institutions for individuals with special needs in Rio de Janeiro, Brazil. Data were collected using a questionnaire administered to the mothers and a dental examination of the children. Clinical examination recorded the following: anterior/posterior crossbite and anterior openbite (AOB). The control variables were the mother’s level of education as well as the gender and age of the child. Statistical analysis of the data was performed using the chi-square test and multiple logistic regression.An anterior crossbite was present in 20.4 per cent, a posterior crossbite in 21.5 per cent, and an AOB in 29.8 per cent. The presence of DS, bottle feeding, and non-nutritive sucking habits for 24 months or more was determinant factors for an anterior crossbite and the presence of DS, bottle feeding and non-nutritive sucking habits for 24 months or more, and respiratory infection in the previous 6 months was determinant factors for a posterior crossbite. The presence of CP and non-nutritive sucking habits for 24 months or more was determinant factors for an AOB. Thus, the prevalence of malocclusion in children with special needs was associated with the type of disability, use of bottle feeding and non-nutritive sucking habits for 24 months or more, and respiratory infection in the previous 6 months. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to evaluate the craniofacial growth of Colombian mestizos. Four age cohorts, including a total of 458 children and adolescents (262 males and 216 females), were included in this mixed-longitudinal study. The cohorts were first measured at ages 6, 9, 12, and 15 and every year thereafter for 3 years. Eight anthropometric measurements were taken, including three cranial (head perimeter, head width, and head length), two craniofacial (maxillary and mandibular length), and three facial (face height, bizygomatic width, and bigonial width).Multilevel analyses showed that all dimensions increased between 6 and 17 years of age. The cranium grew less than the craniofacial, which in turn grew less than the facial dimensions. In addition, vertical dimensions showed more growth than antero-posterior dimensions, which in turn grew more than transverse dimensions. None of the measurement showed statistically significant growth differences between subjects with normal occlusion and Class I or Class II malocclusions. Males were generally larger than females and showed greater growth rates. Except for facial width, whose yearly velocities decreased regularly with age, an adolescent growth spurt was evident for most of the male measurements. Yearly velocities for females followed a simpler decelerating pattern.The results provide reference data for Colombian mestizos, for whom normative data of other ethnic groups are not applicable. While occlusion had little or no effect, there were gender differences, as well as important growth differences between cranial and facial measurements. [ABSTRACT FROM PUBLISHER]

The aims of this investigation were to determine whether stabilization of maximum voluntary bite force (MVBF) occurs between 15 and 18 years of age in subjects with a normal occlusion, and to assess the influence of gender, body mass index (BMI), morphological occlusion, and jaw function measured by the number of occlusal contacts, overjet, overbite, maximal mouth opening, mandibular deflection during opening, sagittal slide between the retruded contact position and the intercuspal position, and number of dental restorations.The sample comprised 60 Caucasian subjects aged 15 (15 males and 15 females) and 18 (14 males and 16 females) years with a neutral occlusion, balanced facial profile, and absence of a previous orthodontic history. Bite force measurements were undertaken using a portable occlusal force gauge on both the left and the right sides of the jaw in the first molar region during maximal clenching. Two independent samples t-tests and multiple regression were used for statistical analysis.MVBFs were age and gender related (P < 0.05). Males showed a significant increase in bite force between 15 and 18 years of age (P = 0.002), but gender differences were significant only in the 18-year-olds (P = 0.003). In subjects with a neutral occlusion, MVBF could best be predicted using multiple regression from age and gender. The regression model accounted for 31.3 per cent of the variance in MVBF (P = 0.031), with gender contributing 17.9 per cent and age 7.9 per cent. Morphological occlusion, jaw function, and BMI explained the remaining 5.5 per cent of variance. While controlling for all other parameters, the independent contribution of gender to the prediction of MVBF was 16.2 per cent, age 6 per cent, number of occlusal contacts 3.2 per cent, and BMI 1.3 per cent. [ABSTRACT FROM PUBLISHER]

This study aimed to evaluate the malocclusions of patients with a cleft lip and/or palate (CLP) and to compare malocclusion characteristics between subjects with a pre-foramen incisor cleft (PIC) and a trans-foramen incisor cleft (TIC).A cross-sectional study was conducted of 117 cleft patients (53 per cent male) aged 6–37 years (mean age 14.7 ± 7.4 years) who attended the Dental Specialty Center in the city of Fortaleza, Brazil, between 2004 and 2007. Oral clefts were classified and radiographic examinations and dental casts were analysed to determine malocclusions and facial patterns. Malocclusion measurements were compared between the PIC and TIC groups by Mann–Whitney and Fisher's exact tests.The percentage of subjects with PIC, TIC, post-foramen incisor cleft, and rare cleft were 20.5, 73.5, 5.1, and 0.9 per cent, respectively. The prevalence of malocclusions in subjects with a CLP was 82.1 per cent (molar relationships Classes II and III) in 6- to 12-year-olds, and a severe malocclusion [dental aesthetic index (DAI)] was observed in all patients aged 13 years and above. The frequency of patients with a normal canine relationship, open bite, and anterior crossbite was higher in the PIC group than in the TIC group (6–12 years). Patients aged 13 years and above in the PIC group showed lower means for the largest anterior maxillary irregularity, higher means for positive anterior mandibular overjet, a lower frequency of crowding in the anterior incisal segments, and a normal antero-posterior molar relationship compared with the TIC group.Severe malocclusions were prevalent in subjects with a CLP. Subjects with a TIC have higher prevalence of malocclusions than those with a PIC. [ABSTRACT FROM PUBLISHER]

The aim of the study was to test the hypothesis that there is no difference between the soft tissue profile of Croatian and white North American adults. Facial profile photographs were taken of 110 Croatians (52 males and 58 females) with normal occlusions and well-balanced faces (age 22–29 years). The findings were also compared with a white Brazilian group. An independent Student's t-test (P < 0.05) was used to compare the soft tissue parameters of Croatians with those of North Americans and to assess gender differences.The soft tissue profile measurements that showed significant gender dimorphism (P < 0.001) were the true vertical line [(TVL)-nasal tip (NT)] and TVL-point B, indicating that the males had slightly greater nasal prominence (mean difference: 1.32 mm) and deeper labial sulci (mean difference: 2.04 mm) compared with the females. The upper lip was the same for both genders (1.25 mm), while the lower lip was 0.97 mm more prominent in females than in males. All soft tissue variables, except TVL-NT showed significant differences between Croatian and white American female subjects (P = 0.096). For male subjects, nasolabial angle was the only variable that showed no statistically significant difference between the two populations.A universal standard of facial aesthetic is not applicable to diverse white populations. These differences should be considered in diagnosis and treatment planning for Croatians, together with their individual characteristics. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to systematically review the orthodontic literature to assess the effectiveness of a prediction of outcome of orthodontic treatment in subjects with a Class III malocclusion. A structured search of electronic databases, as well as hand searching, retrieved 232 publications concerning the topic. Following application of inclusion and exclusion criteria, 14 studies remained. Among other data, sample ethnicity, treatment method, age at the start and completion of treatment, age at follow-up, outcome measures, and identified predictors were extracted from the relevant studies. A subjective assessment of study quality was performed.The heterogeneity of the samples and treatment methods prevented carrying out a meta-analysis. Thirty-eight different predictors of treatment outcome were identified: 35 cephalometric and three derived from analysis of study casts. Prediction models comprising three to four predictors were reported in most studies. However, only two shared more than one predictor. Gonial angle was identified most frequently—in five publications. The studies were of low or medium quality.Due to the large variety of predictors and differences among developed prediction models, the existence of a universal predictor of outcome of treatment of Class III malocclusions is questionable. [ABSTRACT FROM PUBLISHER]

The aim of this retrospective study was to determine differences between the outcomes of treatment using implant anchorage compared with straight-pull headgear and intermaxillary elastics in bimaxillary protrusion patients.The lateral cephalograms of 28 adult orthodontic patients (3 males and 25 females; age, 24.9 ± 5.0 years) who had an Angle Class I malocclusion with bimaxillary protrusion were selected. Group 1 (14 patients; 1 male and 13 females; age, 25.0 ± 5.1 years) received sliding mechanics with implant anchorage and group 2 (14 patients; 2 males and 12 females; age, 24.8 ± 5.1 years) a straight-pull headgear and intermaxillary elastics. Lateral cephalometric radiographs obtained before and after treatment were traced, 13 landmarks identified, and differences in the skeletal and dental changes compared between the groups. Wilcoxon's signed-rank test was used to determine changes within the treatment groups and a Mann–Whitney U-test to evaluate significant differences.More anchorage loss occurred at the maxillary posterior teeth in group 2 (2.1 mm) than in group 1 (0.1 mm). Closing rotation of the mandible occurred in group 1, while opening rotation of the mandible was observed in group 2. These results suggest that sliding mechanics with implant anchorage may provide absolute anchorage and could control mandibular rotation more than the conventional technique. [ABSTRACT FROM PUBLISHER]