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Unlabelled: The role of the third molars in lower arch crowding has been debated for more than a century., Objectives: The aim of this study was to determine the relationship between lower arch crowding and the presence of angulation and position of lower third molar., Methods and Materials: The measurements of the dental arch were made in 120 subjects aged 16 to 21 years, with average age to 18 years. The subjects were divided into two groups: Class I normal occlusion comprised 35 male and 25 female with mean age 18.87years, whereas Class I crowding comprised 27 males and 33 females with mean age 18.5 years. The dental pantomogram (DPT) were used to calculate the ratio of retromolar space (Ganss ratio), angulation of third molar to second molar and third molar to the base of the mandible., Results: The results showed that measurements of Ganss ratio, third molar angulation to the base of the mandible, and third molar to second molar inclination, was statistically significant between crowded and normal groups., Conclusion: It can be concluded that there was a strong relationship between angulation and position of third molars and lower arch crowding. Key words: Third molars, angulation, lower arch, crowding

A transverse dimension deficiency is most often the result of functional disorders. Poor tongue posture at rest and during function as well as digit-sucking give rise to deficiencies which are initially alveolar but which, with time, frequently end up becoming skeletal. The combination of functional rehabilitation and transverse dimension treatment is the best way to avoid many relapses. We need to monitor this anomaly closely, from diagnosis to retention. Otherwise, failure awaits us., (© EDP Sciences, SFODF, 2016.)

Background: A rodent occlusal hypofunction model has been widely established in jawbone-related studies. However, the effects of occlusal stimuli, with total elimination of molar contacts, and its rehabilitation on mandibular remodeling remain unclear., Materials and Methods: Forty-eight 5-wk-old Sprague-Dawley male rats were used. Twenty-four experimental rats underwent occlusal hypofunction by insertion of a bite-raising appliance. Twenty-four rats received no treatment (control group). Two weeks later, half the experimental rats (occlusal hypofunction group) were killed; the appliance was removed from the remaining experimental rats (recovery group) for two additional weeks before killing. Control animals were killed biweekly. Body weight and masseter muscle weight were measured, and the mandibles were subjected to micro-computed tomography to evaluate the mandibular morphology and cortical bone characteristics. The expressions of osteoblast- and osteoclast-related genes were evaluated with quantitative polymerase chain reaction., Results: No significant body weight differences were observed between the experimental and control rats. However, lighter masseter muscle, shorter mandibular incisor crown, mandibular body and ramus, and higher mandibular alveolar process and first molar fossae were observed in the occlusal hypofunction group. Moreover, the cortical bone characteristics associated with the expression of osteoblast- and osteoclast-related genes were remarkably different in the central and posterior mandible in the occlusal hypofunction group. At the 2-wk recovery time point after occlusal stimuli, the altered parameters in the masseter and mandible returned to normal levels., Conclusions: Mandibular remodeling via bone turnover is region specific for altered occlusal stimuli. Normal occlusion is an important determinant of the mandibular morphology and architecture., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: To assess whether a true knowledge of crowding alters treatment decisions compared with estimates of crowding., Materials and Methods: Thirty-six orthodontists were asked to estimate crowding using visualization on eight mandibular arch study models and to indicate possible extraction choices. For each model, the intermolar widths, intercanine widths, and clinical scenarios were identical, but the true crowding varied from 0.2 to 8.4mm as to a lesser extent did the curve of Spee. Eleven orthodontists repeated the visualization exercise after 2 weeks to assess reliability. All 36 of the orthodontists were asked to repeat the treatment planning exercise on the same models, but this time was provided with the true amount of crowding in each case., Results: When the 36 orthodontists used direct visualization of the models to assess crowding, the range of their estimates of crowding increased as the crowding increased. As might be expected, they also tended to move towards extraction treatments as the crowding increased (P = 0.013, odds ratio = 3). Although the reliability of the repeat estimates of crowding were moderate, the mean estimates were greater than the true crowding for each model. When orthodontists were presented with the true amount of crowding, rather than their estimate of crowding, it had a significant effect on the decision to extract, with fewer orthodontists recommending extractions., Limitations: The principal limitation of this study is that it was a laboratory-based study and utilized just the mandibular arch model for estimation and treatment planning., Conclusions: Direct visualization may overestimate the amount of crowding present. When the true amount of crowding is known, it can lead to more consistent treatment planning, with the decision to extract fewer teeth in the borderline cases. A formal space analysis is likely to assist with treatment planning., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Abstract Retrospective analysis was conducted in 78 patients of various age, who suffered the inborn lip and palate fissura, for estimation of the patients quality of life after uranostaphiloplasty. The operations were performed on clinical base of The Oral Cavity Surgery and The Jaw-Facial Surgery Cathedra in Department of The Jaw-Facial Surgery of Clinical Medical Center (Baku). There was established, that application of uranostaphiloplasty procedure, as well as timely initiated rehabilitation, influences a further establishment of the patient personality. A timely refer to a speech therapeutist and the treatment began also have great significance for further establishment of the patient personality. Disorders of speech, incorrect bite hampers obtaining of education, working, interferes with a family creation, hampers the employment and worsens a quality of life.

Introduction: The cervical vertebrae maturation (CVM) method is used to determine the timing of treatment of Class II malocclusion. Because its performance has not been tested in patients with Class II, the objective of this study was to evaluate the effectiveness of the CVM method in predicting craniofacial growth in Class II malocclusion., Methods: Twenty-nine untreated girls with Class II malocclusion were identified among participants of the Nijmegen Growth Study. Each girl had a series of cephalograms taken semi-annually from 9 to 14 years of age. The CVM status was established by five observers on a cephalogram taken at 9 years; mandibular and maxillary length and anterior face height were assessed on all available cephalograms. Method error was evaluated with kappa statistics and Bland-Altman (BA) plots. Regression analysis was used to determine if CVM grade can predict the amount of facial growth., Results: The mean kappa for intra-rater agreement during grading with CVM was 0.36 (fair agreement). BA plots demonstrated acceptable agreement for cephalometric measurements. The regression analysis demonstrated that the only chronologic age was associated with the facial growth. The largest effect of age was for condylion-gnathion (Cd-Gn) and articulare-gnathion (Ar-Gn)-for every additional 6 months the Cd-Gn increases by 1.8mm [95 per cent confidence interval (CI): 1.7, 1.9, P < 0.001] and Ar-Gn increases by 1.59mm (95 per cent CI: 1.52, 1.67, P < 0.001). The CVM grade could not predict the change of cephalometric variables., Conclusions: There is no evidence to support the hypothesis that the CVM method can predict the amount of craniofacial growth in girls with Class II malocclusion., (© The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The present study targeted patients with unilateral cleft lip and palate (UCLP) undergoing either one - (Wardill technique) or two-stage palatoplasty (Perko technique). Correlations between Goslon Yardstick scores and orthodontic appliances used and whether an osteotomy was performed were investigated. No differences were observed between the two types of palatoplasty in terms of Goslon Yardstick scores. A palatal expander and protraction facemask were used in Phase I of orthodontic treatment. The palatal expander was selected for most patients with UCLP in Phase I, regardless of the surgical technique used. A protraction facemask was used in patients undergoing the Wardill procedure who had a Goslon Yardstick score placing them in Group 3 or 4. In contrast, a protraction facemask was used in patients undergoing the Perko procedure who had a Goslon Yardstick score placing them in Group 4. No significant differences were observed in the Goslon Yardstick scores yielded by either type of procedure. The Goslon Yardstick score in relation to whether an osteotomy was performed in Phase II as part of orthodontic treatment was determined, focusing on the relationship between that score and the palatoplasty method used. A protraction facemask was used in patients undergoing the Perko procedure, which eliminated the need for an osteotomy at a future date. However, a protraction facemask was also used in patients undergoing the Wardill option, and those patients were likely to require an osteotomy. In other words, the results suggest that the type of palatoplasty selected will determine the effectiveness of any orthodontic appliances used.

Introduction: during the period of child growth airways and facial skeleton are developing in close relationship. Patients with upper dental arch narrowing and high gothic palet, tend to have narrowed nasal passages and are more vulnerable to violations of breathing during sleep - so-called obstructive sleep apnea (OSA, Obstructive Sleep Apnea), the occurrence of which is explained by a decrease of anteroposterior sizes of throat. The aim of the study was to evaluate the effect of orthodontic treatment in the period of mixed dentition on the state of the upper respiratory tract., Materials and Methods: there were examined 64 children (7-12 years) with class I malocclusion. Clinical examination was carried out according to the protocols of providing orthodontic care with assessment of the functional state of the maxillofacial region. Orthodontic correction had been carried with apparatus of Biobloc system. Before treatment and after its completion there had been performed morphometric analysis of dentition and assess patency of the upper airway by McNamara method., Results: prior to the beginning of orthodontic treatment in all patients had been found a significant decrease of upper and lower pharyngeal spaces 5.95±0.75mm, 8.1 8.}0.74 mm respectively (normal - 15-20mm and 11-14mm). After orthodontic treatment with Biobloc system the upper pharyngeal space increased in 2.5 times (P<0,01), lower pharyngeal space increased in 1.6 (p<0,01) times, and in average amounted to 13,3 ± 0,86 mm., Conclusions: thus found that after orthodontic treatment with Biobloc apparatus along with the expansion of the alveolar arches of both jaws there is a significant positive effect of increasing the volume of the upper respiratory tract. Consequently, orthodontic treatment in the period of mixed dentition, stimulates the growth not only of the dental arches, but also greatly improves the development nazomaxillary complex and prevents apnea syndrome, that increases the level patient's health and life quality.

Objectives: To provide an empirical test of the applicability of Locker's conceptual model of oral health for malocclusion patients, and to suggest alternative models of the effect of malocclusion on well-being., Materials and Methods: Data from a survey of 323 adolescents attending for orthodontic treatment were analyzed to develop a new oral health model for malocclusion patients. Oral health-related quality of life (OHRQoL) was measured using the 14-item Oral Health Impact Profile; malocclusion was measured using the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN). Using structural equation modeling, the relationship between conceptual domains in Locker's model was explored and three models of their interrelationship tested for goodness of fit., Results: Fit indexes for Locker's model indicated that it did not fit the data well. Therefore, a modified model was developed to incorporate additional paths between other levels to better fit the data. The best fit was provided by a model in which the direct effects of malocclusion on pain, discomfort, and handicapping-and the direct effect of pain on disability-were removed. A direct effect of functional limitation on disability was allowed. The modified Oral Health Impact Profile model proved to be a good fit to the data (root mean square error of approximation  =  0.069)., Conclusion: The pathways identified in Locker's (1988) conceptual model of oral health may not be appropriate for describing the relationships between OHRQoL constructs in individuals with malocclusion. An alternative model is proposed.

Objective: To compare the short-term skeletal and dental effects of two-phase orthodontic treatment including either a Twin-block or an XBow appliance., Materials and Methods: This was a retrospective clinical trial of 50 consecutive Class II cases treated in a private practice with either a Twin-block (25) or XBow (25) appliance followed by full fixed orthodontic treatment. To factor out growth, an untreated Class II control group (25) was considered., Results: A MANOVA of treatment/observation changes followed by univariate pairwise comparisons showed that the maxilla moved forward less in the treatment groups than in the control group. As for mandibular changes, the corpus length increase was larger in the Twin-block group by 3.9 mm. Dentally, mesial movement of mandibular molars was greater in both treatment groups. Although no distalization of maxillary molars was found in either treatment group, restriction of mesial movement of these teeth was seen in both treatment groups. Both treatment groups demonstrated increased mandibular incisor proclination with larger increases for the XBow group by 3.3°. The Wits value was decreased by 1.6 mm more in the Twin-block group. No sex-related differences were observed., Conclusions: Class II correction using an XBow or Twin-block followed by fixed appliances occurs through a relatively similar combination of dental and skeletal effects. An increase in mandibular incisor inclination for the XBow group and an increased corpus length for the Twin-block group were notable exceptions. No overall treatment length differences were seen.

Purpose: The present study aims to determine any existing association between airway dimensions, measured with cone beam computed tomography (CBCT), and the different patient craniofacial morphologies., Material and Methods: Sixty CBCT (Dental Picasso Master 3D) images, from patients treated at the Orthodontics Master at Valencia University were selected. The program InVivoDental 5.1 was used to visualize sections, analyze three-dimensional images, and perform airway measurements in the three planes of the space. Intra- and interobserver error methods were recorded. After that, measurements at three different levels of the airway (upper, medium, lower) were taken, in both the anteroposterior and transversal directions of the airway space. The area (mm(2)) of the airway space at the three levels was also measured., Results: In the anteroposterior airway measurements, there were differences between the measurements by level. The magnitude of these differences depended on the skeletal pattern of the individual. In the transversal airway measurements and in the area airway measurements, there were no differences according to the skeletal pattern. However, in the transversal direction, measurements in the lower level were significantly higher than in the superior level in all cases. When measuring the area, significantly higher measurements in the upper level were recorded. The homogeneity between medium and lower levels decreased gradually from class I to class III subjects., Conclusions: No statistically significant results were observed that related the anteroposterior and vertical skeletal craniofacial morphology with airway dimensions, although some specific associations have been detected for certain airway levels or for pattern combinations., (Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Temporomandibular joint (TMJ) displays a high remodelling capability. The current purpose was to investigate the differences between mandibular condylar remodelling responses of growing mice to installation and removal of unilateral anterior crossbite (UAC) prosthesis. Twenty-four mice were divided into one mock control group and two UAC groups. Unilateral anterior crossbite was created by installing a pair of prosthesis to left-side maxillary and mandibular incisors. Unilateral anterior crossbite was removed in removal group at 3 weeks but remained in UAC group. Temporomandibular joints were sampled at 7 weeks. Changes in condylar cartilage and subchondral bone were assessed by histology and in vivo micro-CT. Real-time PCR and immunohistochemistry were performed to evaluate expression changes in ADAMTS-5, MMP-3, MMP-9, MMP-13, IL-1, TNF-α, OPG and RANKL. Statistical analysis was performed at α = 0.05. Temporomandibular joint cartilage degradation was induced by UAC as previously reported but was reversed by removal of UAC. The dropped cartilage thickness, chondrocyte number and collagen II-positive area, the increased expression levels of Adamts-5, Mmp3, 9, 13, Tnf-α and Il-1β in cartilage, the decreased ratio of OPG/RANKL in both condylar cartilage and subchondral bone, the loss of TMJ subchondral bone and the increase in the TRAP-positive cells in subchondral bone were all reversed in the removal group (P < 0.05). The growing mouse TMJ condyle displays a high remodelling capability which can be degenerative and rehabilitative, respectively, in response to placement and thereafter removal of the aberrant prosthesis. Eliminating aberrant prosthesis is helpful to promote the degraded condyle to recover., (© 2015 John Wiley & Sons Ltd.)

Objective: Comparison of three different retention strategies 5 years or more postretention., Design, Setting, and Participants: Randomized, prospective, single-centre controlled trial. Forty-nine patients (33 girls and 16 boys) were randomly assigned to one of three retention methods during 2 years by picking a ballot shortly before start of retention treatment. Inclusion criteria were no previous orthodontics, permanent dentition, normal skeletal sagittal, vertical, and transversal relationships, Class I dental relationship, space deficiencies, treatment plan with extractions of four premolars followed by fixed straight-wire appliance. Maxillary and mandibular Little's irregularity index (LII), intercanine and intermolar width, arch length, and overbite/overjet were recorded in a blinded manner, altogether 10 measurements on each patient. Significant differences in means within groups assessed by t-test and between groups by one-way analysis of variance., Interventions: Retention methods: removable vacuum-formed retainer (VFR) covering the palate and the maxillary anterior teeth from canine-to-canine and bonded canine-to-canine retainer in the lower arch (group V-CTC); maxillary VFR combined with stripping of the lower anterior teeth (group V-S); and prefabricated positioner (group P)., Results: Maxillary mean LII ranged from 1.8 to 2.6mm, mean intercanine width 33.6-35.3mm with a significant difference between groups V-S and P, mean intermolar width 46.8-47.4mm and mean arch length 21.8-22.8mm. Mandibular mean LII ranged from 2.0 to 3.4mm with a significant difference between groups V-S and P, mean intercanine width from 25.4 to 26.6mm, mean intermolar width from 40.8 to 40.9mm and mean arch length from 16.9 to 17.3mm. Mean overbite ranged from 1.8 to 2.7mm and mean overjet from 3.7 to 4.1mm., Limitations: A single centre study could be less generalizable., Conclusions: The three retention methods disclosed equally favourable clinical results., Trial Registration: This trial was not registered., Protocol: The protocol was not published before trial commencement., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: To investigate whether individuals with high and low mandibular plane angles, respectively, have different patterns of long-term dental arch changes in adulthood., Subjects and Methods: The material comprised 16 low-angle (≤ 24.4 degree) and 10 high-angle individuals (≥38.7 degree). Mean age was 22.7 years when the first recordings were made (T1), and new recordings were made 10 (T2) and 20 (T3) years later. The individuals were orthodontically untreated except for three who had been out of retention for more than 5 years before T1. Lateral cephalograms and study casts were obtained on all three occasions., Results: For the total observation period, the greatest mean changes were observed as a 1mm decrease of lower intercanine width and arch depths in both groups. Intermolar widths increased less than 0.5mm. Upper and lower crowding increased in the range of 0.5-0.7mm in the two groups. Only small changes occurred in overjet and overbite. Differences between groups were not significant except for lower anterior arch depth which decreased more in the low-angle group, and overjet which increased in the high- and decreased in the low-angle group. During both periods the changes were generally in the same direction., Conclusion: Changes in dental arch dimensions from third to fifth decade of life are small and generally similar in individuals with high versus low mandibular plane angles. The changes are for most variables in the same direction in the two periods examined. The only significant differences between the groups are the changes in lower arch depth and overjet., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Computer-based digital orthodontic models are available for clinicians, supplemented by dedicated software for performing required diagnostic measurements. The purpose of this study was to evaluate the accuracy of measurements made on three-dimensional digital models obtained with a CBCT-scanner (DigiModel™, OrthoProof(®), Nieuwegin, The Netherlands)., Methods: 66 orthodontic dental casts of primary and early mixed dentitions were selected. Three-dimensional images were obtained on this CBCT-scanner and analyzed by means of the DigiModel™ software. Measurements were made with a digital caliper directly on the conventional casts and also digitally on the virtual models. 6 anatomic dental points were identified, and a total of 11 measurements were taken from each cast, including midline deviation, overjet, overbite and arch widths. Conformity of digital and manual measurements as well as intra-, inter- and repeated-measurement-reliability were evaluated by Lin's Concordance Correlation Coefficient, ICC and a Bland-Altman-analysis., Results: The agreement and conformity of digital and manual measurements was substantial for all parameters evaluated. Intra-, inter- and repeated-measurement-reliability was excellent., Conclusions: Measurements on digital models obtained by a CBCT scan of conventional casts (DigiModel™, OrthoProof(®)) are suited for reliable diagnostic measurements, which compare well to those obtained from plaster casts, the current gold standard., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Malocclusion, body posture, and breathing pattern may be correlated, but this issue is still controversial. The aim of the study was to examine the relationship between the type of malocclusion, body posture, and nasopharyngeal obstruction in children aged 7-14 years., Material and Methods: The study group comprised 94 patients aged 7-14 years (mean±SD: 11.9±2.1 years); 44 (46.8%) males and 50 (53.2%) females. All patients passed an examination performed by the same orthodontist (study model and cephalometric radiograph analysis), orthopedic surgeon (body posture examined from the front, side, and back), and otorhinolaryngologist (anterior and posterior rhinoscopy and pharyngoscopy) in a blind manner., Results: Postural disorders were observed in 72 (76.6%) patients. Hypertrophy of the adenoids was diagnosed in 54 (57.4%) patients, hypertrophy of the tonsils in 85 (90.3%), nasal septum deviation in 51 (54.3%), and allergic rhinitis in 19 (20.2%) patients. There was a statistically significant correlation between presence of kyphotic posture and a reduction in the SNB angle, representing sagittal position of the mandible. Also, there was a statistically significant association between kyphotic posture and nasopharyngeal obstruction (54.1% of patients with nasopharyngeal obstruction were kyphotic, compared with 25% of patients with no nasopharyngeal obstruction; p=0.02). Kyphotic posture and reduced SNB angle were more common among males., Conclusions: We concluded that: 1) there was a significant association between the sagittal position of the mandible (SNB angle) and a kyphotic posture; 2) kyphotic posture was significantly more common among patients with nasopharyngeal obstruction.

Unlabelled: This case report describes the importance of preventing more excessive transverse dental compensation during orthodontic treatment for a patient with severe transverse skeletal discrepancy., Summary: The patient, a 33-years-old Japanese woman, had severe transverse skeletal discrepancy involving the maxilla and mandible. In addition, she had an extreme transverse dental compensation of the posterior teeth in mandibular arch (i.e. excessive lingual inclination of mandibular molars)., Aim: Therefore, the main treatment objectives were to prevent more excessive transverse dental compensation by orthodontic treatment and improve the occlusal function., Method: We chose non-surgical orthodontic treatment. Because this patient did not think that the esthetic improvement with surgery would be worth the risk., Result: The orthodontic treatment resulted in sufficient elimination of the transverse dental compensation and movement of the teeth into their proper position where basal bone firmly support them. Anterior crossbite was corrected with remaining buccal crossbite, facial profile was improved and functional occlusion was obtained. At 2 years 2 months after the orthodontic treatment, the facial profile and occlusion remained favorable., Conclusion: This report would become an alternative to ideal treatment for a case with transverse skeletal discrepancy.

Aim: Whether or not the dental relationship correlates with skeletal relationship in the sagittal plane is an area of interest for orthodontic diagnosis and treatment planning. Thus, the aim of this study was to investigate the correlation of the dental malocclusion and the skeletal malocclusion in the sagittal plane among Saudi orthodontic patients., Materials and Methods: Orthodontic dental casts and cephalometric radiographs of 124 patients were investigated and analyzed. The dental casts were classified in relation to the molar relationship according to Angle's classification and to the incisal relationship according to the British Standards Institution (BSI) classification. The sagittal relation in the cephalometric radiographs was analyzed according to ANB angle and WITS appraisal., Results: The results show that the incisal relation had a very high significant association with WITS appraisal (p = 0.0045), whereas with ANB, the association was marginally significant (p =0.0528). No significant associations were found with molar relation neither at ANB (p = 0.2075) nor at the WITS (p = 0.4794) appraisal. Significant positive correlations between ANB and WITS appraisal were found at the three incisal classification classes (class I, r = 0.73; class II, r = 0.64; class III, r = 0.75) and no significant correlation was observed in all classes with the Angle's (molar) classification., Conclusions: The incisal classification had a significant association with WITS appraisal, whereas with ANB the association was marginally significant. No correlation was found between Angle's (molar) classification and ANB or WITS appraisal., Clinical Significance: The incisal relation could be considered as a good indicator of the skeletal malocclusion in the sagittal plane in the orthodontic practice.

Aim: To determine the features of the mandibular dental arch in subjects presenting with impacted permanent lower canines., Methods: The 'impaction group' consisted of 48 Indian subjects with mandibular canine impaction (Females:Males, 1.5:1; mean age, 15.03 ± 0.49 years). The 'control group' was comprised of 96 age-, gender- and malocclusion-matched Indians who were randomly selected from subjects initially screened but who had completely erupted mandibular canines. Arch width, arch length, arch shape and space status (total tooth size, arch-length--tooth-size discrepancy) were assessed using dental models and were compared between the groups using comparative measurements and statistics., Results: Statistically significant differences were demonstrated with respect to the arch length, arch shape, total tooth size and arch-length--tooth-size discrepancy (p = 0.03, 0.02, 0.04, 0.01; independent 2-sample t-tests, respectively). Crowding was more prevalent in subjects with impaction than in the controls, with the difference being statistically significant (chi-square = 13.202; degrees of freedom (df) = 4; p = 0.010)., Conclusion: Patients with permanent mandibular canine impaction have adequately wide but shorter lower dental arch forms along with wider mandibular total tooth size and greater arch-length--tooth-size discrepancy when compared with a control sample.

Aim: This study was undertaken to assess pre- and post-treatment upper and lower arch dimensions, and changes occurring in those dimensions, during orthodontic treatment without premolar extractions, when finishing wires of a particular material, size and arch form had been used., Methods: The records of 58 patients (31 male and 27 female) with a mean age of 13.52 (±1.60) years were selected for this study, with ethics approval gained from the Departmental Human Ethics Advisory Group of the University of Melbourne (DHEAG no: 1033997.1). All patients had been treated with fixed appliances (0.018 inch, pre-adjusted edgewise) in the early permanent dentition, without premolar extractions, by one experienced orthodontist. Pre- and post-treatment upper and lower arch dimensions were measured from study casts. Correlation coefficients were calculated between these measurements as well as pretreatment cast and vertical cephalometric measurements, gender and the amount of crowding that had been relieved., Results: Despite the use of finishing archwires of the same material, size and arch form (0.016 x 0.022 inch, heat-treated cobalt-chromium), there was considerable variation in dimensional changes that occurred during treatment within the total sample and its various subgroups, and in the final arch dimensions. All arch width changes were found to be strongly correlated with the amount of pretreatment crowding. Post-treatment arch dimensions and changes in those dimensions were also strongly correlated with pretreatment dimensions, suggesting that the final post-treatment arch dimensions were significantly influenced by other factors rather than simply the material, size and arch form of the finishing wires. In this treated sample, no statistically significant differences were found in the resultant arch widths and arch width changes occurring in the different vertical pattern sub-groups., Conclusion: The placement of finishing wires of a particular material, size and arch form is unlikely to result in exactly matching end-of-treatment arch forms and dimensions in all orthodontic patients. Instead, whether using a 0.018 or a 0.022 inch slot system, the clinician should expect considerable individual variation in final arch form and dimension, despite the placement of apparently very similar wires. The main determinants of final arch form and dimension appear to be the original muscular and occlusally-related arch form and dimension and the amount of crowding to be relieved. Final arch forms and dimensional changes with treatment are unlikely to be directly related to patient gender, age or underlying vertical pattern. The findings indicate that clinicians must decide whether they will accept the considerable lateral and antero-posterior expansion that is likely to occur when crowding is to be relieved in the permanent dentition without premolar extractions.

Malocclusions affect individuals worldwide, resulting in compromised function and esthetics. Understanding the etiological factors contributing to the variation in dentofacial morphology associated with malocclusions is the key to develop novel treatment approaches. Advances in dentofacial phenotyping, which is the comprehensive characterization of hard and soft tissue variation in the craniofacial complex, together with the acquisition of large-scale genomic data have started to unravel genetic mechanisms underlying facial variation. Knowledge on the genetics of human malocclusion is limited even though results attained thus far are encouraging, with promising opportunities for future research. This review summarizes the most common dentofacial variations associated with malocclusions and reviews the current knowledge of the roles of genes in the development of malocclusions. Lastly, this review will describe ways to advance malocclusion research, following examples from the expanding fields of phenomics and genomic medicine, which aim to better patient outcomes., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To compare the effectiveness of fixed and removable orthodontic appliances in correcting anterior crossbite with functional shift in the mixed dentition., Subjects and Methods: Consecutive recruitment of 64 patients who met the following inclusion criteria: early to late mixed dentition, anterior crossbite with functional shift, moderate space deficiency in the maxilla, i.e. up to 4mm, a non-extraction treatment plan, the ANB angle > 0 degree, and no previous orthodontic treatment. Sixty-two patients agreed to participate. The study was designed as a randomized controlled trial with two parallel arms. After written consent was obtained, the patients were randomized, in blocks of 10, for treatment either with a removable appliance with protruding springs or a fixed appliance with multi-brackets. The main outcome measures assessed were success rate, duration of treatment, and changes in overjet, overbite, and arch length. The results were also analysed on an intention-to-treat basis., Results: The crossbite was successfully corrected in all patients in the fixed appliance group and all except one in the removable appliance group. The average duration of treatment was significantly less, 1.4 months, for the fixed appliance group (P < 0.05). There were significant increases in arch length and overjet in both treatment groups, but significantly more in the fixed appliance group (P < 0.05 and P < 0.01)., Conclusion: Anterior crossbite with functional shift in the mixed dentition can be successfully corrected by either fixed or removable appliance therapy in a short-term perspective., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Our objectives were to assess the depth of the curve of Spee (COS) in different malocclusion groups, to relate this to the eruption of anterior or posterior teeth quantitatively, and to determine whether the depth of the COS is affected by the vertical eruption of anterior or posterior teeth., Methods: Two hundred conventional lateral cephalograms and 3-dimensional models of untreated patients (70 boys, mean age: 16.4 ± 1.4 years; 130 young women, mean age: 18.1 ± 1.8 years) were included and assigned to 4 malocclusion groups as Class I, Class II Division 1, Class II Division 2, and Class III. The depth of the COS, overjet, and overbite were measured on 3-dimensional models. The perpendicular distance between the incisal tip of the mandibular central incisor (L1-MP), the deepest point of the COS (S-MP), and the distobuccal cusp tip of the mandibular second molar (L7-MP) to the mandibular plane were calculated and proportioned with each other. The Pearson correlation coefficient was calculated, and multiple linear regression analysis was carried out. Also, multivariate analysis of variance was performed at the P <0.05 level., Results: The mesiobuccal cusp of the first molar was the deepest part of the COS in all groups, with a maximum depth of 2.44 ± 0.73 mm in the Class II Division 1 subjects and a minimum depth of 1.76 ± 0.94 in the Class III subjects. The depth of the COS changed as follows: Class II Division 1 > Class II Division 2 > Class I > Class III malocclusion groups. Statistically significant positive correlations were found between the depth of the COS and L1-MP/S-MP (r = 0.541) and L7-MP/S-MP (r = 0.269) in the Class I and Class III subjects, and between the depth of the COS and overjet (r = 0.483) and L7-MP/S-MP (r = 0.289) in the Class II Division 1 subjects. All variables except overjet had positive correlations with the depth of the COS in Class II Division 2 subjects. The multivariate analysis of variance showed statistically significant differences in overjet, overbite, L1-MP/S-MP, L7-MP/S-MP, and the depth of the COS (P <0.001) among the groups., Conclusions: Although the overjet differed, vertical eruption of the anterior teeth did not differ among the different malocclusion groups and had a significant contribution to the depth of the COS in subjects with Class I and Class III malocclusions., (Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: To compare and evaluate the stability of correction of anterior crossbite in the mixed dentition by fixed or removable appliance therapy., Material and Methods: The subjects were 64 consecutive patients who met the following inclusion criteria: early to late mixed dentition, anterior crossbite affecting one or more incisors, no inherent skeletal Class III discrepancy, moderate space deficiency, a nonextraction treatment plan, and no previous orthodontic treatment. The study was designed as a randomized controlled trial with two parallel arms. The patients were randomized for treatment with a removable appliance with protruding springs or with a fixed appliance with multibrackets. The outcome measures were success rates for crossbite correction, overjet, overbite, and arch length. Measurements were made on study casts before treatment (T0), at the end of the retention period (T1), and 2 years after retention (T2)., Results: At T1 the anterior crossbite had been corrected in all patients in the fixed appliance group and all except one in the removable appliance group. At T2, almost all treatment results remained stable and equal in both groups. From T0 to T1, minor differences were observed between the fixed and removable appliance groups with respect to changes in overjet, overbite, and arch length measurements. These changes had no clinical implications and remained unaltered at T2., Conclusions: In the mixed dentition, anterior crossbite affecting one or more incisors can be successfully corrected by either fixed or removable appliances with similar long-term stability; thus, either type of appliance can be recommended.

Background/objectives: Although it has been suggested that adult patients with facial asymmetry with posterior unilateral crossbite (PUXB) may have a more tilted mandibular hinge axis (MHA) than those without PUXB, whether craniofacial morphology is associated with the MHA remains unclear. The purpose of this study was to compare the craniofacial morphology and MHA in adult subjects with post-growth facial asymmetry with and without PUXB., Subjects/methods: Thirty pre-orthodontic patients (PUXB and non-PUXB groups, n = 15 each, 9 females and 6 males, mean age: 23.2 years) participated in the study. The MHA was measured by computerized axiography and duplicated on posteroanterior and submentovertex cephalometric radiographs. Morphological asymmetry was evaluated for both skeletal and dental components and positional deviation of the mandible by cephalometric analysis. The Mann-Whitney U-test and Spearman's correlation coefficient by rank were used for statistical analysis. The level of statistical significance was set at P < 0.05., Results: Significant differences in both skeletal and dental components were found between the PUXB and non-PUXB groups. In both the frontal and horizontal dimensions, the inclination of the MHA towards the mandibular shifted side was greater in the PUXB group than in the non-PUXB group., Conclusions/implications: The present findings suggest that facially asymmetric adult subjects with malocclusions associated with PUXB exhibit not only mandibular asymmetry but also remodelling of the condylar head and glenoid fossa that accompanies the three-dimensional shifting of the MHA., (© The Author 2014. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Backgroud: Normal occlusion is very important for physiological structure of mandible. However, the details of influences of occlusal hypofunction and its recovery on the three-dimensional architecture of mandibular alveolar bone in growing rats are still lacking., Materials and Methods: Forty-eight growing male Sprague-Dawley rats were randomly divided into normal (n = 24), hypofunctional (n = 12), and recovery (n = 12) groups. The hypofunction group was developed by inserting a bite-raising appliance between the maxillary and mandibular incisors of the rats. Two weeks after insertion, the appliance was removed to result in the recovery group; the experiment continued for two additional weeks. The experimental animals and control animals were killed weekly. In addition to measuring the body weight and masseter muscle weight of the rats, the histomorphology and microstructure of the mandibular alveolar bone were scanned using microcomputed tomography., Results: A lighter masseter muscle and a higher and narrower alveolar process were observed in the hypofunction group compared with the control animals (P < 0.05). Mandibular remodeling also occurred in the hypofunctional group, as demonstrated by a smaller trabecular cross-sectional area, looser trabecular bone, decreased bone volume fraction, trabecular thickness, trabecular number, and increased bone surface density and trabecular separation, especially at week 2 (P < 0.05). After removing the anterior bite-opening appliance, the altered masseter muscle weight and architecture of the mandibular alveolar bone were gradually reversed and reached normal levels at the end of the experiment (P > 0.05)., Conclusions: A loss of occlusal stimuli can lead into mandibular alveolar bone remodeling, and the recovery of occlusion can restore the altered mandibular architecture in growing rats., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The purpose of the present study was to conduct a longitudinal examination of changes in width, depth, anterior space, overjet, and overbite in the dental arch in men and women from 22 (T1) to 43 (T3) years of age and to explore any differences between the age periods 22-33 (T1-T2) and 33-43 (T2-T3) years as well as gender differences at T1 and changes within the two periods. The research material consisted of models of 32 men and 33 women. The parameters were measured with an electronic caliper. Repeated measurements of 20 pairs of randomly selected models were taken to check the reliability of our results. A significant decrease in intercuspid width, arch depth, and anterior space was observed in both arches of both genders. The changes were generally greater during the first observation period, and there were no significant gender difference. At T1 the men's arches were larger than those of the women.

Objective: To study progression of tooth wear quantitatively in a convenient sample of young adults and to assess possible correlations with occlusal conditions., Methods: Twenty-eight dental students participated in a three-year follow up study on tooth wear. Visible wear facets on full arch gypsum casts were assessed using a flatbed scanner and measuring software. Regression analyses were used to assess possible associations between the registered occlusal conditions 'occlusal guidance scheme', 'vertical overbite', 'horizontal overbite', 'depth of sagittal curve', 'canine Angle class relation', 'history of orthodontic treatment', and 'self-reported grinding/clenching' (independent variables) and increase of wear facets (dependent variable)., Results: Mean increase in facet surface areas ranged from 1.2 mm2 (premolars, incisors) to 3.4 mm2 (molars); the relative increase ranged from 15% to 23%. Backward regression analysis showed no significant relation for 'group function', 'vertical overbite', 'depth of sagittal curve', 'history of orthodontic treatment' nor 'self-reported clenching. The final multiple linear regression model showed significant associations amongst 'anterior protected articulation' and 'horizontal overbite' and increase of facet surface areas. For all teeth combined, only 'anterior protected articulation' had a significant effect. 'Self reported grinding' did not have a significant effect (p>0.07)., Conclusions: In this study 'anterior protected articulation' and 'horizontal overbite', were significantly associated with the progression of tooth wear. Self reported grinding was not significantly associated with progression of tooth wear., Clinical Significance: Occlusal conditions such as anterior protected articulation and horizontal overbite seem to have an effect on the progression of occlusal tooth wear in this convenient sample of young adults., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: The aim of this retrospective study was to identify which dental and/or cephalometric variables were predictors of long-term maxillary dental arch stability in patients treated with a transpalatal arch (TPA) during the mixed dentition phase followed by full fixed appliances in the permanent dentition., Methods: Thirty-six patients, treated with TPA followed up by full fixed appliances, were divided into stable and relapse groups based on the long-term presence or not of relapse. Intercuspid, interpremolar and intermolar widths, arch length and perimeter, crowding, and upper incisor proclination were evaluated before treatment (T 0), post-TPA treatment (T 1), post-fixed appliance treatment (T 2), and a minimum of 3 years after full fixed appliances' removal (T 3). A binary logistic regression was performed thereafter to evaluate the impact of the dental arch and cephalometric measurements at T 1 and the changes between T 0 and T 1 as predictive variables for relapse at T 3., Results: The proposed model explained 42.7 % of the variance in treatment stability and correctly classified 72.2 % of the sample. Of the seven predictive variables, only upper anterior crowding (p = 0.029) was statistically significant. For every millimeter of decreased crowding at T 1 (after TPA treatment/before starting the fixed orthodontic treatment), there was an increase of 3.57 times in the odds of having stability., Conclusions: The best predictor of relapse was maxillary crowding before treatment. The odds of relapse increase by 3.6 times for every millimeter of crowding at baseline.

This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton's method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.

The relationship of mandibular condyle dimensions and its association with unilateral posterior crossbite (UPXB) has been suggested in the literature. The purpose of this prospective study was to evaluate mandibular condyles on the left and right sides and between crossed and non-crossed sides in the sagittal and coronal planes, using cone-beam computed tomography (CBCT). Twenty CBCT images of 40 temporo mandibular joints (TMJs) in individuals in mixed dentition phase, which included 9 males (mean 7.9 years) and 11 females (mean 8.2 years), with unilateral posterior crossbite without premature contacts and functional mandibular shifts and with transverse maxillary deficiency. The criteria for sample exclusion included the presence of painful symptoms, facial trauma history, systemic diseases such as juvenile rheumatoid arthritis, mouth opening limitation (< 40 mm), congenital or genetic anomalies, and skeletal asymmetries that may result in TMJ disorders. Dimensional measurements of the condyles between the right and left sides and crossed and non-crossed sides in sagittal and coronal view were made. There was no significant difference between the measurements of the crossed and non-crossed sides in both sagittal and coronal view. These findings suggest that the presence of unilateral posterior crossbite in children with UPXB did not result in changes between the mandibular condyles in the right and left sides or between the crossed and non-crossed sides in the coronal or sagittal plane.

The aim of this study was to assess the influence of unilateral posterior crossbite on the electrical activity of the temporal and masseter muscles in patients with subjective symptoms of temporomandibular dysfunctions (TMD). The sample consisted of 50 patients (22 female and 28 male) aged 18.4 to 26.3 years (mean 20.84, SD 1.14) with subjective symptoms of TMD and unilateral posterior crossbite malocclusion and 100 patients without subjective symptoms of TMD and malocclusion (54 female and 46 male) aged between 18.4 and 28.7 years (mean 21.42, SD 1.06). The anamnestic interviews were conducted according to a three-point anamnestic index of temporomandibular dysfunction (Ai). Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Recordings were carried out in the mandibular rest position and during maximum voluntary contraction (MVC). Analysis of the results of the EMG recordings confirmed the influence of unilateral posterior crossbite on variations in spontaneous muscle activity in the mandibular rest position and maximum voluntary contraction. In addition, there was a significant increase in the Asymmetry Index (As) and Torque Coefficient (Tc), responsible for a laterodeviating effect on the mandible caused by unbalanced right and left masseter and temporal muscles.

Background: The objectives of this paper are to (1) study use of soft tissue analyses advocated by Steiner, Ricketts, Burstone, Sushner and Holdway to develop soft tissue cephalometric norms as baseline data for sagittal lip position in Northeast Chinese adult population, (2) compare the sagittal lip positions in different skeletal malocclusions and (3) compare the sagittal lip positions in Northeast Chinese adults with other reported populations., Methods: Lateral cephalometric radiographs of subjects were taken in natural head position. Radiographs were manually traced and five reference lines - Sushner, Steiner, Burstone, Holdway and Ricketts, were used. The linear distance between the tip of the lips and the five reference lines were measured. Statistical analysis was done using the Statistical Package for Social Sciences (SPSS) 21. Descriptive analysis was done for each variable for each subject. Coefficient of variation between lip positions as assessed by reference lines was determined. Post hoc Tukey's test was used for comparison of the mean cephalometric values of three skeletal malocclusions. The level of significance for the analysis was set at p < 0.05., Results: The findings showed significant difference in the sagittal lip positions in different skeletal malocclusions. There was variation in consistent reference line in each skeletal malocclusion. The S2 line was the most consistent reference line in skeletal class I and class II group. The B line was the most consistent line in skeletal class III. In skeletal class II group, upper lips were the most protrusive and lower lips were retrusive than in skeletal class I and class III groups. In case of skeletal class III group, upper lips were retrusive and lower lips were more protrusive than in skeletal class I and class II groups., Conclusions: The sagittal lip positions were found to be associated with the skeletal malocclusion pattern. Northeast Chinese population has protrusive upper and lower lip in comparison to Caucasians. Each skeletal malocclusion group showed different preferable reference lines for analysis of sagittal lip position.

Background: The purpose of this clinical longitudinal study was to investigate the effectiveness of indirect bonding technique evaluating the number of bond failures which occurred during treatment., Methods: Fifty-two patients were selected and divided into two groups: group A (33 patients) bonded with the direct technique and group B (19 patients) bonded with the indirect technique. The number and date of bracket failure were recorded for over 15 months. Moreover, also the effect of crowding level on bracket failures was calculated. Statistical analysis was performed by means of t-test, Kaplan-Meier survival estimates and chi-squared test., Results: No statistically significant differences were found in the total bond failure rate between direct and indirect techniques, also when comparing the upper and lower arches. The only significant difference was found comparing the posterior segment of the lower arches, in which a higher percentage of detachments were recorded in group B, bonded with the indirect technique. Moreover, no significant differences between direct and indirect bonding were found when evaluating crowding level., Conclusions: Orthodontic practitioners can safely use the indirect bonding technique, even in patients with severe crowding, because it does not influence the adhesive quality and the bracket survival rate.

Aims: To investigate the changes in condylar cartilage and subchondral bone of the temporomandibular joint (TMJ) in a mouse model of incisor malocclusion., Methods: By bonding a single (single group) or a pair (pair group) of metal tube(s) to the left incisor(s), a crossbite-like relationship was created between left-side incisors in mice. The morphological changes in the TMJ condyles were examined by hematoxylin and eosin and toluidine blue staining. Indices of osteoclastic activity, including tartrate-resistant acid phosphatase (TRAP) staining and macrophage colony stimulating factor (M-CSF) were investigated by histochemistry or real-time polymerase chain reaction (PCR). The osteoblastic activity was indexed by osteocalcin expression. Expressions of semaphorin 4D and its receptor, Plexin-B1, were detected by real-time PCR. Two-way analysis of variance was used to assess the differences between groups., Results: One week and 3 weeks after bonding the metal tube(s), cartilage degradation and subchondral bone loss were evident histologically. Both indices of osteoclastic activity (TRAP and M-CSF) were significantly increased in cartilage and subchondral bone after bonding the metal tube(s). Osteocalcin expression in cartilage was significantly increased at week 3, while its expression in subchondral bone was significantly increased at week 1 but decreased at week 3. The semaphorin 4D expression in cartilage and subchondral bone was significantly decreased at week 1 but significantly increased at week 3. For Plexin-B1 expression, a significant increase was detected in subchondral bone at week 3., Conclusion: Bonding a single or a pair of metal tube(s) to left incisor(s) is capable of inducing remodeling in the TMJ, which involved cartilage degradation and alteration of osteoclastic and osteoblastic activity.

Introduction: Mandibular angle resection is rarely used, but is a highly effective means of correcting facial defects. We report a mandibular angle resection technique associated with the removal of a part of hypertrophic masseter muscles and resection of buccal fat pad., Technical Note: Anatomical reminders: the most important entities are the facial artery and vein, crossing the lower margin of the jaw just in front of the anterior boarder of the masseter muscle and the temporomaxillary vein, passing through the temporomaxillary fossa; preoperative aspects: the preoperative examination included a radiological assessment of the shape and size of the mandibular angle; surgical technique: an intra-oral approach was usually used. The most effective and convenient method for the osteotomy was using a reciprocating saw. This technique allowed achieving a smooth contour of masseter muscles during masticatory movements or at rest., Our Experience: Eleven mandibular angle resections were performed from 2001 to 2009. The surgery was supplemented by remodeling the lower margin of the jaw for 5 other patients. No permanent facial palsy was noted. One patient presented a unilateral long-term loss of sensitivity of the lower lip and chin., Discussion: This surgical technique if simple even requires using good technical equipment, and observing a set of rules. Using these principles allows simplifying the surgical technique, and decreasing its morbidity. A part of the masseter muscles and the buccal fat pad can sometimes be resected to improve the morphological results., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Introduction: To investigate dentofacial characteristics of orthodontic patients with centric relation (CR)-maximum intercuspation (MI) discrepancy and to analyze changes in dentofacial characteristics between CR and MI positions in these patients using lateral cephalograms., Materials and Methods: Adult female patients were classified into two groups: large CR-MI discrepancy (greater than 2.0 mm horizontal or vertical mandibular incisor movements during CR to MI change, n  =  20) and small CR-MI discrepancy (less than 1.0 mm horizontal and vertical mandibular incisor movements during CR to MI change, n  =  22). All subjects underwent temporomandibular joint (TMJ) magnetic resonance imaging prior to treatment. Gnathological stabilizing splints were used to find a reliable CR position in patients with large CR-MI discrepancy. Sixteen variables from lateral cephalograms were analyzed to identify differences in cephalometric variables between CR and MI positions in patients with large discrepancy. Differences in dentofacial cephalometric variables at MI positions between patients with large and small CR-MI discrepancies were also analyzed., Results: Patients with large CR-MI discrepancy had backward positioning and rotation of the mandible at the MI position compared to the norm. In addition, the mandible moved more posteriorly and rotated more in a clockwise direction during MI to CR change. Interestingly, all patients with large CR-MI discrepancy had TMJ disk displacement. There were no significant differences in the cephalometric variables of the MI positions between patients with small and large CR-MI discrepancies., Conclusions: This study suggests that adult patients with backward positioning and rotation of the mandible should be carefully evaluated as a result of the potential CR-MI discrepancy.

Purpose: Facial asymmetry is a common comorbid condition in patients with jaw deformation malocclusion. Heritability of malocclusion is advancing rapidly, but very little is known regarding genetic contributions to asymmetry. This study identifies differences in expression of key asymmetry-producing genes that are down-regulated in patients with facial asymmetry., Methods: Masseter muscle samples were collected during bilateral sagittal split osteotomy orthognathic surgery to correct skeletal-based malocclusion. Patients were classified as class II or III and open or deep bite malocclusion with or without facial asymmetry. Muscle samples were analyzed for gene expression differences on Affymetrix HT2.0 microarray global expression chips., Results: Overall gene expression was different for asymmetric patients compared with other malocclusion classifications by principal component analysis (P < 0.05). We identified differences in the nodal signaling pathway, which promotes development of mesoderm and endoderm and left-right patterning during embryogenesis. Nodal and Lefty expression was 1.39- to 1.84-fold greater (P < 3.41 × 10), whereas integral membrane Nodal modulators Nomo1,2,3 were -5.63 to -5.81 (P < 3.05 × 10) less in asymmetry subjects. Fold differences among intracellular pathway members were negative in the range of -7.02 to -2.47 (P < 0.003). Finally Pitx2, an upstream effector of Nodal known to influence the size of type II skeletal muscle fibers was also significantly decreased in facial asymmetry (P < 0.05)., Conclusions: When facial asymmetry is part of skeletal malocclusion, there are decreases in nodal signaling pathway genes in masseter muscle. This data suggest that the nodal signaling pathway is down-regulated to help promote development of asymmetry. Pitx2 expression differences also contributed to both skeletal and muscle development in this condition.

Objectives: To objectively classify the nose-lip-chin profiles of adult women and identify any associations between the nose-lip-chin profile patterns and dentoskeletal patterns., Setting and Sample Population: Lateral facial photographs and lateral cephalograms were obtained for 229 Japanese women who were being assessed for orthodontic treatment., Methods: A feature vector that was effective in distinguishing differences in nose-lip-chin profiles was extracted for each photograph. To categorize the records into an optimum number of subclasses according to nose-lip-chin profile configurations, a vector quantization method was applied to the feature vectors of all samples. Dentoskeletal patterns that corresponded to the nose-lip-chin profile subclasses were compared., Results: Eight profile patterns were identified, and the differences among patterns were notably maximized by the nasolabial angle, configuration and vertical length of the subnasal region, vertical thickness of the lip vermilion borders, sagittal position of the upper- and lower-lip vermilion borders and their relation to each other, labiomental angle, depth of the labiomental sulcus, degree of prominence of the chin, and degree of protrusion of the mandible. The dentoskeletal patterns showed significant differences between the classified profile patterns (p < 0.01)., Conclusions: A method to objectively classify the nose-lip-chin profiles of adult women was established, and the nose-lip-chin profile patterns were found to be associated with the dentoskeletal patterns., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The aim of this study was to determine how sensitive dental specialists and laypeople are to maxillary incisor crowding when viewed from the front., Methods: Computer technology was used to create a series of photographs of the incisors of a smiling woman viewed from the front. The photographs showed varying degrees of maxillary incisor crowding classified according to Little's irregularity index (LII). The incisors illustrated in the photos were ranked on a scale from perfect alignment to severely crowded. The rating was done by 4 groups of people: orthodontists, general dentists, laypeople with experience of orthodontic treatment, and laypeople with no history of orthodontic treatment., Results: The orthodontists and the general dentists noted misalignment of 1 central incisor when the LII reached 1.5 mm, whereas the laypeople with or without experience of orthodontic treatment were sensitive to 2.0 mm of crowding. When the LII reached 2.0 mm for 1 lateral incisor, it triggered the orthodontists to consider providing orthodontic treatment, whereas this degree of irregularity was ignored by the general dentists and laypeople. When both central incisors were misaligned, the orthodontists were sensitive to the fact at 2.0 mm of LII, whereas the general dentists and the laypeople with experience of orthodontic treatment became sensitive at 3.0 mm of LII, and the laypeople with no history of orthodontic treatment were sensitive at 4.0 mm of LII. When both lateral incisors were misaligned, the orthodontists noted the crowding at an LII of 3.0 mm, the general dentists became sensitive at an LII of 4.0 mm, whereas both the laypeople with experience of orthodontic treatment and the laypeople with no history of orthodontic treatment ignored it. When the crowding of all maxillary incisors reached an LII of 4 mm, both the orthodontists and the general dentists were alerted to the fact, but both the laypeople with experience of orthodontic treatment and the laypeople with no history of orthodontic treatment were sensitive only to a total incisor crowding equal to an LII of 6.0 mm., Conclusions: Orthodontists are more critical than other groups when evaluating the misalignment of the maxillary incisors. It appears that the central incisors play a more important role than do the lateral incisors when dental crowding impacts smile esthetics. For all observer groups, it also appears that people are more sensitive to the misalignment of a single tooth than they are to the same level of crowding distributed over multiple teeth., (Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: In recent years, the golden proportions have been evaluated by various researchers in the general population and orthodontic patients to establish their correlation with facial attractiveness and esthetics, but with conflicting results. The present study aimed to analyze the frontal facial golden proportions for three groups of young adult females, an attractive group, and two malocclusion groups. Our null hypothesis stated that the golden proportions of attractive females were analogous with or closer to the golden number than those with an established malocclusion., Materials and Methods: Frontal facial photographs of 80 female dental students were scored for facial attractiveness by 10 dental specialists. Thirty females with scores greater than the median score of 48 formed the attractive group. Thirteen females with Class I malocclusion and 15 females with Class II division 1 malocclusion formed the two malocclusion groups. Ten landmarks and 19 golden proportions were calculated for all subjects. One-way ANOVA and unpaired Student's t-test was used to analyze the differences in golden proportions between the attractive and malocclusion groups., Results: Significant differences were observed for 10 proportions (P<0.04 to <0.0001). Five vertical proportions showed significant differences in both subgroups; Attractive versus Class I and Attractive versus Class II division 1; while one vertical and all transverse proportions showed significant differences only in Attractive versus Class II division 1 subgroup. The average values of these proportions varied both toward and away from the golden number for both attractive and malocclusion groups., Conclusion: Facial proportions of the attractive females were significantly different from those with malocclusion, but did not show a constant trend of being closer to the golden number. Furthermore, the golden proportions were not analogous with the facial esthetics of the attractive females.

Anchorage loss is very disturbing for orthodontists and patients during orthodontic treatment, which usually results in bad treatment effects. Despite the same treatment strategy, different patients show different tendencies toward anchorage loss, which influences the treatment results and should preferably be predicted before the treatment is begun. However, relatively little research has been conducted on which patients are more likely to lose anchorage. The mesial tipping of the first molar marks the onset of anchorage loss, and changes in the angulation of the first molar are closely related to anchorage loss. This cross-sectional study aimed to determine how the mesiodistal angulation of the upper first molars changes during general orthodontic treatment and to identify the individual physiologic factors leading to these changes in a large sample of 1403 patients with malocclusion. The data indicate that the upper first molars tend to be tipped mesially during orthodontic treatment, and this constitutes a type of anchorage loss that orthodontists should consider carefully. Compared to treatment-related factors, patients' physiologic characteristics have a greater influence on changes in the angulation of the upper first molars during orthodontic treatment. The more distally tipped the upper first molars are before treatment, the more they will tip mesially during treatment. Mesial tipping of the upper first molars, and therefore, anchorage loss, is more likely to occur in adolescents, males, patients with class II malocclusion and patients who have undergone maxillary premolar extraction. This finding is of clinical significance to orthodontists who wish to prevent iatrogenic anchorage loss by tipping originally distally tipped upper molars forward, and provides a new perspective on anchorage during orthodontic treatment planning.

Aim: To investigate the inter-examiner variability of contact point displacement measurements (used to calculate the overall Little's Irregularity Index (LII) score) from digital models of the maxillary arch by four independent examiners., Methods: Maxillary orthodontic pre-treatment study models of ten patients were scanned using the Lava(tm) Chairside Oral Scanner (LCOS) and 3D digital models were created using Creo(®) computer aided design (CAD) software. Four independent examiners measured the contact point displacements of the anterior maxillary teeth using the software. Measurements were recorded randomly on three separate occasions by the examiners and the measurements (n=600) obtained were analysed using correlation analyses and analyses of variance (ANOVA)., Results: LII contact point displacement measurements for the maxillary arch were reproducible for inter-examiner assessment when using the digital method and were highly correlated between examiner pairs for contact point displacement measurements >2mm. The digital measurement technique showed poor correlation for smaller contact point displacement measurements (<2mm) for repeated measurements. The coefficient of variation (CoV) of the digital contact point displacement measurements highlighted 348 of the 600 measurements differed by more than 20% of the mean compared with 516 of 600 for the same measurements performed using the conventional LII measurement technique., Conclusions: Although the inter-examiner variability of LII contact point displacement measurements on the maxillary arch was reduced using the digital compared with the conventional LII measurement methodology, neither method was considered appropriate for orthodontic research purposes particularly when measuring small contact point displacements., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged <12 years and least distally in cases aged >16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

Objective: Evaluate condylar, ramal, and condylar plus ramal vertical mandibular asymmetry in patients with unilateral posterior crossbite (UPCB) and in patients with unilateral cleft lip and palate (UCLP) compared with subjects having normal occlusion., Design: This cross-sectional study evaluated panoramic radiographs of three groups of subjects: UPCB, 20 patients; UCLP, 20 patients; and normal occlusion sample, 20 subjects. All subjects were picked at random from Rey Juan Carlos University, Madrid, and all films were traced and measured manually by the same author., Results: Kruskal-Wallis test revealed no statistically significant differences (P < 0.05) in condylar asymmetry index (CAI), ramal asymmetry index (RAI), and condylar plus ramal asymmetry index (C + RAI) among the three groups. The average CAI for group UPCB was 9.03 ± 7.65; 8.03 ± 6.89 for group UCLP; 6.93 ± 9.87 for normal group. Mean RAI for group UPCB was 2.53 ± 2.52; 2.61 ± 1.22 for group UCLP; 2.65 ± 1.90 for normal group., Conclusions: Condylar asymmetry was observed in all three groups (UPCB, UCLP and normal occlusion) because condylar asymmetry indexes were higher in each group at the 3 % threshold. No statistically significant differences were found among the three study groups for any of the asymmetry indexes.