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Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a case of a 13‐year‐old adolescent male patient who started orthodontic treatment at the age of 12. Before treatment, he was diagnosed with narrow maxilla, proclination of upper incisors, deep overbite, distal occlusion bilaterally with significant sagittal overjet in frontal area, skeletal Class II, and hypodivergent growth pattern. During treatment, the patient is in his pubertal growth spurt. About 2 months after intermaxillary Class II elastics (1/4 heavy, 6.5 Oz) were applied, he complained of pain during mastication, wide opening of the mouth, and sometimes during protrusive and lateral movements in the right TMJ. The TMJ X‐ray examination did not reveal abnormal morphological changes. Occlusion was evaluated by an electromyographic device, Teethan. The result was typical for Class II malocclusion. During the bilateral palpation of the zones of TMJ and opening of the mouth and chewing, the patient reported pain on the right side. There was no clicking in the joint. The elastic wear was stopped, and soon afterwards, the pain disappeared. These complaints point to a possible relationship between orthodontic treatment and TMJ pain. However, the disappearance of complaints after the removal of the Class II elastics points that the temporomandibular joint disorder (TMD) symptoms are reversible and resolved. [ABSTRACT FROM AUTHOR]

Copyright of Dental Press Journal of Orthodontics is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to examine the relationship between the presurgical maxillomandibular transverse index and post-surgical stability one year after mandibular advancement. For the material and methods, twenty-two subjects who were treated with mandibular advancement were enrolled in this study. Postsurgical stability was defined as the horizontal mandibular position change of <2 mm in lateral cephalogram 1 year after surgery. Subjects were divided into two groups according to the maintenance of postsurgical stability: a stable group (group S) and a less stable group (group LS). Presurgical maxillomandibular transverse index was determined as Yonsei transverse index (YTI) one month before surgery. A logistic analysis was performed on the postsurgical stability according to the YTI value. The presurgical, post-expansion target YTI value was obtained using receiver operating characteristic (ROC) curve. There were no notable differences in the baseline characteristics of the two groups except for vertical positions of point A, B, and gender distribution. Before surgery, however, there was a significant difference in YTI at both the fossa and CR level between the groups. The amount of mandibular advancement did not show a significant difference. The odds ratio for YTI was 0.35 (p = 0.024). The prediction of stability of presurgical YTI yielded an area under the ROC curve of 0.88. The cut-off value for YTI was 1.45 mm. It can thus be concluded that presurgical transverse index showed a correlation with postsurgical stability, and correcting it in the presurgical phase to a certain level appears to aid in securing postsurgical stability. [ABSTRACT FROM AUTHOR]

Aim-background: In the treatment of obstructive sleep apnoea (OSA), oral appliances are now being recognized as a valuable alternative to continuous positive airway pressure (CPAP). Various static imaging techniques of the upper airways allow for assessment of bone and soft tissue structures. However, static images do not capture dynamic airway characteristics. The aim of this paper was to review 4D imaging techniques in patients with OSA. Methods: PubMed/MEDLINE, Web of Science and Embase were systematically searched for studies published before June 2022. The review was compliant with the PRISMA guidelines. The quality of each eligible study was critically evaluated by all four authors independently. Four unique articles with qualitative analyses were retrieved. All included studies had a clear objective/aim, an appropriate endpoint and sufficiently described eligibility criteria. Results: With dynamic imaging (4D) evaluation of the upper airway, the incidence of upper airway collapsibility due to use of a mandibular advancement device (MAD) was reduced, extraluminal tissue pressure was decreased and the space in the upper airway was increased, notably in the retropalatal and retroglossal areas of the airway. These findings suggest that MADs may be effective for OSA regardless of whether or not the obstruction site is in the velopharynx or oropharynx. However, further investigation of dynamic changes in the upper airway is required to explain the efficacy of OSA treatment and the underlying mechanisms. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction: Mandibular advancement surgery corrects bone bases while establishing patients’ functional and aesthetic rehabilitation. However, little is known about the results of this procedure in the structures that make up the stomatognathic system, as the condyles. Objective: This study aimed to evaluate the structural and positional changes of mandibular condyles in ortho-surgical patients who underwent mandibular advancement surgery. Material and Methods: A prospective investigation was conducted with cone-beam computed tomography images. Using Dolphin Imaging® software, seven ortho-surgical patients with Angle Class II malocclusion and mandibular deficiency were evaluated. The images assessed were obtained at pre-surgical phase and after, at least, 1 year of the procedure. To study the structural and positional changes of condyles, linear and angular measurements were obtained, and the right and left sides of patients were compared. Descriptive statistical analysis was performed and, in order to verify possible significant differences, normality tests (Kolmogorov-Smirnov) were applied, followed by a paired t-test to define significance. Results: For all measures evaluated in this study, no statistically significant differences were found. Conclusion: The ortho-surgical procedure performed did not change the structure and position of the condyles of patients who underwent surgical mandibular advancement. Right and left mandibular condyles behaved similarly, suggesting stability and condylar adaptation after surgery.

Objective: This study evaluated the dentoskeletal and soft tissue changes for Class II malocclusion patients treated with Invisalign clear aligners with mandibular wings (IAMW). Methods: This retrospective study included 50 skeletal Class II patients treated with Invisalign clear aligner with mandibular wings. Records of 20 subjects were collected from the AAOF Legacy Collection (The Case Western Bolton Brush Growth Study) and were used as a control. The dental, skeletal, and facial soft tissue changes were assessed by digitizing and analyzing lateral cephalograms using Dolphin Imaging software (version 11.95 Premium; Dolphin Imaging & Management Solutions, Chatsworth, Calif). Paired t-tests and independent t-tests were used to assess the changes before and after and to compare between the IAMW and control groups. Results: The different measurements of the maxilla have shown that IAMW effect on the maxilla included minimal, non-significant retraction compared to the control group. The SNB and mandibular base position increased by 1.17° (±2.63) and 3.79 (±8.13), respectively. The mandible advanced significantly in the treatment group compared to the control group. Dentally, the lower incisors tipped slightly buccally, but the change was not significant (p > 0.05). The facial convexity angle decreased by 1.16° (±4.36). Conclusion: Invisalign clear aligner with mandibular advancer wings was able to correct the Class II malocclusion. This correction was mainly skeletal with some dental changes. This device can be used to address the growth modification problem in Class II malocclusion at the same time as addressing the other occlusal problems.

This study analyzed the biomechanical behavior under simulated conditions between a novel modification of the Low Z plasty (NM-Low Z) technique and the conventional Hunsuck–Epker (HE) technique on mandibular advancement surgery. The NM-Low Z technique was developed with the purpose of reducing post-operative complications by facilitating the operative method of lower jaw surgery. The models were investigated under physiological muscular and occlusal loads at 1, 2, 4, 6, and 8 weeks post-operation. Finite element analysis was used to analyze stress distribution, elastic strain, and model displacement. Maximum equivalent von Mises stresses were observed on the fixation system and bone. The elastic strain at the fracture site represented the optimal bone-healing capacity. The NM-Low Z model showed lower stress than the HE model at the 2-week post-operation stage and onwards. The elastic strains observed in both models were situated within the normal range for bone healing. The ranges of displacement for the NM-Low Z model were less than those in the HE model. Based on the data sets studied, the biomechanical study of the NM-Low Z technique can be favorably compared to the conventional HE technique. The NM-Low Z technique promotes post-operation skeletal stability by lowering stress on fixation and bone, with less displacement of the segment during bone-healing periods. [ABSTRACT FROM AUTHOR]

Modified maxillomandibular advancement (MMMA) has been proposed as an alternative to the classic maxillomandibular advancement (MMA) in East and Southeast Asian populations in which bimaxillary protrusion is a prevalent trait. The key difference between MMMA and MMA is the inclusion of anterior segmental osteotomies to reduce the protrusion of the perioral region. The aim of this scoping review was to identify the variations in MMMA and treatment outcomes. A search was conducted in the PubMed, Embase, and Cochrane electronic databases for articles published up to January 2023. Ten articles were included in this review. Three variations of MMMA have been reported in the literature. Treatment outcomes have mostly been favourable for all of these variations. Mandibular advancement of >10 mm and a greater than 50% reduction in the apnoea–hypopnoea index (AHI) have been well reported. Improvements in other outcome measures, such as enlargement of the airway dimension on computed tomography and the Epworth Sleepiness Scale score, have also been shown. Despite additional surgical procedures, complications have been uncommon and mostly minor in nature. It is necessary to be cognizant of MMMA and its variations when providing sleep surgery for East and Southeast Asian patients, tailoring this to the patient's profile and needs. [ABSTRACT FROM AUTHOR]

This study evaluated the dentoskeletal and soft tissue changes for Class II malocclusion patients treated with Invisalign clear aligners with mandibular wings (IAMW). This retrospective study included 50 skeletal Class II patients treated with Invisalign clear aligner with mandibular wings. Records of 20 subjects were collected from the AAOF Legacy Collection (The Case Western Bolton Brush Growth Study) and were used as a control. The dental, skeletal, and facial soft tissue changes were assessed by digitizing and analyzing lateral cephalograms using Dolphin Imaging software (version 11.95 Premium; Dolphin Imaging & Management Solutions, Chatsworth, Calif). Paired t-tests and independent t-tests were used to assess the changes before and after and to compare between the IAMW and control groups. The different measurements of the maxilla have shown that IAMW effect on the maxilla included minimal, non-significant retraction compared to the control group. The SNB and mandibular base position increased by 1.17° (±2.63) and 3.79 (±8.13), respectively. The mandible advanced significantly in the treatment group compared to the control group. Dentally, the lower incisors tipped slightly buccally, but the change was not significant (p > 0.05). The facial convexity angle decreased by 1.16° (±4.36). Invisalign clear aligner with mandibular advancer wings was able to correct the Class II malocclusion. This correction was mainly skeletal with some dental changes. This device can be used to address the growth modification problem in Class II malocclusion at the same time as addressing the other occlusal problems. [ABSTRACT FROM AUTHOR]

Background: This study aimed to determine the skeletal and dental effects in pediatric and adolescent Korean patients with Class II Division 1 malocclusion treated using the Invisalign Mandibular Advancement (MAⓇ) appliance. Methods: The study included patients aged 6 to 18 years who received orthodontic treatment with the MAⓇ appliance for Class II Division 1 malocclusion at the Department of Pediatric Dentistry, Wonkwnag University Daejeon Dental Hospital, between July 1, 2018, and December 31, 2021. The treatment group consisted of 20 patients, 10 boys and 10 girls. The control participants were also 10 boys and 10 girls. Lateral cephalometric radiographs were taken before and after treatment, and 41 measurements of skeletal and dental changes were measured and analyzed using the V-CephTM 8.0 (Osstem Implant). All analyses were performed using SPSS software (IBM SPSS for Windows, ver 26.0; IBM Corp.), and statistical significance was tested using paired and independent samples t-tests for within-group and between-group comparisons, respectively. Results: The patients in the treatment group showed significant decreases in ANB (A point, Nasion, B point), maxillary protrusion, maxillary anterior incisor labial inclination, and maxillary protrusion after treatment. However, when compared with the growth changes observed in the control group, only ANB and maxillary protrusion decreased, with no significant differences in SNA, SNB, and mandibular length. Conclusion: Collectively, the results of this study confirm that the use of MAⓇ appliance in pediatric and adolescent Korean patients with Class II Division 1 malocclusion results in a reduction of anteroposterior skeletal and dental disharmony.

Introduction: Full arch reconstruction with dental implants is considered as a reference for dental rehabilitation. However, there are some limitations with patient affected by severe maxilla, mandible atrophy and dento-skeletal-disharmony. These defaults can be corrected with orthognathic surgery and several bone grafts. Observations: A partially edentulous 65-year-old female patient with a skeletal class II by mandibular retrognathia was treated with mandibular advancement osteotomy and simultaneous insertion of four fully guided implants with immediate screwed zirconia prostheses loading in just one session. Conclusion: Simultaneous bilateral sagittal split osteotomy with a full arch rehabilitation by implant with immediate loading by zirconia prosthesis seems to be a reliable and predictable approach to treat skeletal class II patient with a fixed solution. Virtual planning was compulsory to be able to perform this surgery with accuracy. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the virtually planned position to the postoperative position of the maxilla, having performed the maxilla-first sequence or mandible-first sequence orthognathic surgery. An audit of 64 patients who underwent bimaxillary surgery between 2017 and 2020 was performed. Thirty patients had maxilla-first surgery and 34 had mandible-first surgery. The planned and post-surgical positions were analyzed using specific skeletal landmarks. Differences were calculated and the two-sample t -test was used to compare the groups. Measured differences between the planned and postoperative results differed significantly between the mandible-first and maxillary-first surgery groups (P < 0.001). The maxillary central incisors were under-advanced in the anterior–posterior direction in both groups. Most data points showed deviation from the surgical plan ≤ 2 mm and ≤ 4°. Secondarily, maxillary under-advancement in the mandible-first cohort was evaluated; these patients were subdivided into rigid and non-rigid fixation groups. The non-rigid fixation group showed less accuracy compared to the rigid fixation group, which was statistically significant (P = 0.014). The findings of this study demonstrate that virtual surgical planning can be less accurate in predicting the maxillary incisor position when performing mandible-first surgery, but this inaccuracy is within the acceptable range and can be mitigated by rigid fixation of the mandible. [ABSTRACT FROM AUTHOR]

The main objective of this prospective study was the evaluation of 1 mm step titration of mandible advancement in the success of treating obstructive sleep apnea (OSA). For that, a multicenter prospective study was designed to recruit patients with OSA who were eligible to receive a mandibular advancement device. Gradual titration of mandibular advancement (steps of 1 mm) from maximum intercuspidation was performed to determine the optimal mandibular advancement (highest reduction in the apnea-hypopnea index (AHI)). The principal variable was the percentage of patients where a reduction ≥50% of the AHI was achieved at the end of the titration phase. A total of 102 patients participated in this study. Fifty-six percent of the participants were males and 67% had a BMI ≥ 25 kg/m2. Most of the patients (79%) had an age ≥ 50 years and the majority (74%) were either non-smokers or ex-smokers. Excessive daytime sleepiness was reported by 40% of the patients. The mean AHI at baseline was 20.6 ± 12.7 events/h. The mean advancement of the mandible was 3.1 ± 1.6 mm. The device achieved a reduction in the AHI in 93% of the patients and success (≥50% reduction in the AHI) in 69% of the patients. Success was achieved in 50%, 81.6%, and 73.3% of the patients with mild, moderate, and severe OSA, respectively. Decreasing the magnitude of mandibular advancement could be possible by controlling the vertical mouth opening and step-by-step titration. [ABSTRACT FROM AUTHOR]

Objective: To identify the value of head rotation in the supine position and oral appliance (OA) use in drug‐induced sleep endoscopy (DISE). Study Design: Eighty‐three sleep apnea adults undergoing target‐controlled infusion‐DISE (TCI‐DISE) were recruited from a tertiary academic medical center. Setting: During DISE, 4 positions were utilized: supine position (position 1), head rotation (position 2), mandibular advancement using an OA (position 3), and head rotation with an OA (position 4). Methods: Polysomnography (PSG) data and anthropometric variables during DISE were analyzed. Results: Eighty‐three patients (65 men and 18 women; mean [standard deviation, SD], 48.5 [11.0] years) who underwent PSG and TCI‐DISE were included. The mean (SD) apnea–hypopnea index (AHI) was 35.5 (22.4) events/h. Twenty‐three patients had persistent complete concentric velopharyngeal collapse in the supine position, even with concurrent head rotation and OA (position 4). Their mean (SD) AHI was 54.7 (24.6) events/h, significantly higher than that of the 60 patients without such collapse in position 4 (p <.001). Their mean (SD) body mass index (BMI) was 29.0 (4.1) kg/m2, also significantly higher (p =.005). After adjustment for age, BMI, tonsil size, and tongue position, the degree of velum and tongue base obstruction was significantly associated with sleep apnea severity in positions 2, 3, and 4. Conclusion: We showed the feasibility, safety, and usefulness of using simple edge‐to‐edge, reusable OA in DISE. Patients who are not responsive to head rotation and OA during TCI‐DISE may need upper airway surgery and/or weight control. [ABSTRACT FROM AUTHOR]

Objectives The aim was to analyse the costs and duration of orthodontic-surgical treatment with mandibular advancement in the public health care sector in Finland. Materials The study was conducted as a retrospective registry study in a public district hospital on all nonsyndromic patients that were ethnic Finns and treated with full fixed appliances and mandibular advancement surgery in 2016–2020. Results The mean treatment duration of the included 45 patients was 28.1 months, including 18.9 months pre and 9.2 months postoperative orthodontics. The median number of visits was 27, including 17 visits before and 9 visits after surgery. The mean total treatment time was 14.5 h. The mean total direct costs per course of treatment were 7574 € to the municipality and 947 € to the patient. The costs positively correlated with the duration of the treatment (rho = 0.71, P  = .000), but were not associated to gender or age of patient. The mean surgery time was 78 minutes, and significantly less with an experienced surgeon (P  = .002). It was calculated that the mean minimum treatment costs would be 45% of the present total, achievable with a patient with optimum dental arches at the start of treatment. Limitations The major limitation of the study is the relatively small number of study subjects. Conclusion A 55% share of the costs is influenced by case- and operator-dependent factors. This indicates that the complexity and performance of the orthodontic phases of treatment are important determinants in the cost structure. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the relationship between the presurgical maxillomandibular transverse index and post-surgical stability one year after mandibular advancement. For the material and methods, twenty-two subjects who were treated with mandibular advancement were enrolled in this study. Postsurgical stability was defined as the horizontal mandibular position change of p = 0.024). The prediction of stability of presurgical YTI yielded an area under the ROC curve of 0.88. The cut-off value for YTI was 1.45 mm. It can thus be concluded that presurgical transverse index showed a correlation with postsurgical stability, and correcting it in the presurgical phase to a certain level appears to aid in securing postsurgical stability.

This study aimed to compare the condylar head displacement (CHD) after bilateral sagittal split ramus osteotomy (BSSO) between different degrees of mandibular advancement in skeletal class II patients and to evaluate whether the temporomandibular joint (TMJ) function would be affected. Fifty-nine patients (118 condyles) were included in this retrospective study and were divided into three groups based on the distance of mandibular advancement. The CHD in three directions, x (sagittal direction), y (coronal direction), and z (axial direction), was measured before operation (T0), immediately after operation (T1), and at least 6 months after operation (T2), and the TMJ function of patients was followed up and scored using the Helkimo index system. All the abovementioned data were statistically analyzed, and p < 0.05 was considered the statistical difference standard. During the BSSO surgery, the condyle was predominantly displaced in a lateral, posterior, and superior direction whenever in T1 and T2, even though the degree of CHD was different. Regarding the amount of CHD, the large advancement group was higher than the other two groups in T1 and T2 (p＜0.01). The Helkimo index scores of the three groups were evaluated, and there was no significant statistical difference between the Ai and Di index of the three groups. In our center, CHD occurred in lateral, posterior, and superior directions following mandibular advancement in skeletal class II patients, with a positive correlation between the CHD and the mandibular advancement; however, the TMJ function of the three groups did not show significant differences. [ABSTRACT FROM AUTHOR]

Objectives: This study was aimed at resolving the controversy over the wearing time of mandibular advancement (MA) appliances by comparing the differences between part-time and full-time MA (PTMA and FTMA) from the perspective of promoting H-type vessel coupling osteogenesis in the condylar heads. Materials and methods: Thirty 30-week-old male C57BL/6J mice were randomly divided into 3 groups: the control (Ctrl), PTMA, and FTMA groups. The mandibular condyles were analyzed by morphology, micro-computed tomography, histological staining, and immunofluorescence staining to investigate the changes of the condylar heads in the PTMA and FTMA groups after 31 days. Results: Both PTMA and FTMA models promoted condylar growth and achieved stable mandibular advancement at day 31. However, compared with PTMA, FTMA has the following characteristics. First, new bone formation in the condylar head was detected in the retrocentral region in addition to the posterior region. Second, the condylar proliferative layer was thicker, and the number of pyknotic cells in the hypertrophic and erosive layers was higher. Moreover, endochondral osteogenesis of the condylar head was more active. Finally, the retrocentral and posterior regions of the condylar head had more vascular loops or arcuate H-type vessel coupling Osterix+ osteoprogenitors. Conclusions: While both PTMA and FTMA induced new bone formation in the condylar heads of middle-aged mice, FTMA promoted more osteogenesis by volume and region. Furthermore, FTMA presented more H-type vessel coupling Osterix+ osteoprogenitors in both the retrocentral and posterior regions of the condylar head. Clinical relevance: FTMA is better at promoting condylar osteogenesis, especially in non-growing patients. We suggest that enhancing H-type angiogenesis could be an effective strategy to achieve favorable MA outcomes, especially for patients unable to meet the FT-wearing requirement or being non-growing. [ABSTRACT FROM AUTHOR]

Fixed functional appliances are used at either the fag end of the growth spurt or after the completion of the same. We orthodontists are yet to come across an appliance which satisfies all the ideal requirements for a fixed functional appliance. Most disadvantages of the fixed functional appliances such as increase in lower anterior facial height, proclination of lower anteriors, constant breakages, and huge expenses were taken into consideration in the basic designing of this ingenious appliance. In this article, a simple fixed functional appliance was designed to function along with fixed appliance therapy to stimulate mandibular growth. After the initial leveling and aligning, 0.019 × 0.025 stainless steel posted arch wires were placed. The bite jumping blocks were fabricated in the upper and lower arches with light cure blue composite. Using indirect bonding trays they were bonded in position. The case finished in an ideal overjet and overbite with a balanced face. Cephalometric values demonstrate an advancement of the mandible. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Obstructive sleep apnea (OSA) is an underdiagnosed and potentially serious disorder that is accentuated by edentulism. The overclosure of the mandible and a potential upper airway collapse during sleep creates challenges in treating edentulous sleep apneic patients.Purpose: To evaluate complete dentures and mandibular advancement devices as potential oral appliances in the management of sleep apnea in completely edentulous patients.Materials and Method: The study design was a systematic review with meta-analysis. The search criteria complied with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and the keywords in population, intervention, control, and outcomes (PICO) format was systematically searched for relevant research articles published till August 2021 in an electronic database (PubMed, Cochrane, Science Direct, Ovid). Randomized controlled trials and cohort studies were included that compared the effectiveness of oral appliances on apnea-hypopnea index (AHI), airway space, and quality of sleep in edentulous sleep apneic patients.Results: 1785 articles were derived from the initial search and based on inclusion criteria, 10 articles were systematically filtered for qualitative analysis and assessed for risk of bias using the Cochrane risk of bias tool and ROBINS-I tool. Out of the 10 articles, 5 articles were taken for quantitative analysis. The use of a mandibular advancement device (MAD) showed a decrease in AHI score, but the available data was heterogeneous to conduct a meta-analysis. The mean difference of AHI for the random effect model between the non-complete denture and complete denture wearers at sleep was -0.49[95% CI (-1.47,0.48)] events per hour, but the change was non-significant (p>.05).Conclusion: The complete dentures as an oral appliance had reduced apneic episodes in completely edentulous sleep apneic patients, but the effectiveness cannot be solely attributed to the prosthesis in the treatment of OSA. MAD showed greater improvement in reducing AHI, however, the level of evidence was inadequate to provide a conclusive statement.

• Herbst therapy was effective using sagittal and transverse dental changes. • After fixed appliances treatment, there was maintenance in sagittal dental changes. • After fixed appliances treatment, the transverse dental changes relapsed. Herbst therapy is an effective treatment for Class II malocclusions. However, the maintenance of the effects after fixed appliances treatment remains questionable. This retrospective study aimed to assess, using digital dental models, the sagittal and transverse dental arch changes in young patients during two Class II Division 1 treatment phases, first with modified Herbst appliance (HA) and then with fixed appliances. The treated group (TG) comprised 32 patients (17 boys, 15 girls; mean age, 12.85 ± 1.16 years) treated with HA and fixed appliances. The control group comprised 28 patients (13 boys, 15 girls; mean age, 12.21 ± 1.35 years) with untreated Class II malocclusions. Digital models were obtained immediately before and after HA therapy and after fixed appliances. Data were statistically analyzed. Compared with the control group, the TG showed an increase in maxillary and mandibular arch perimeters and in intercanine and intermolar arch widths, a decrease in overjet and overbite, and an improvement in canine and molar relationships. In the time after HA therapy until the end of fixed appliances treatment, the TG showed a decrease in maxillary and mandibular arch perimeters, overjet, upper and lower intermolar widths; an increase in molar Class II relationship; and no changes in canine relationship, overbite, and upper and lower intercanine widths. In this sample of patients treated with HA, on average, there was an improvement in the Class II relationship, which seemed to remain after fixed appliances. The transverse dental changes achieved in HA phase relapsed after treatment with fixed appliances. [ABSTRACT FROM AUTHOR]

Purpose: Sleep-disordered breathing (SDB) is common in pregnancy and is associated with adverse health consequences for both mother and child. Mandibular advancement splints (MAS) have been shown to improve sleep quality, daytime sleepiness and snoring in non-pregnant women. The effectiveness of MAS for treating SDB in pregnancy is unknown. This pilot study aimed to evaluate the efficacy and adherence to MAS in pregnant women with SDB. Methods: Women with mild-moderate SDB (apnea–hypopnea index (AHI) 10–29/h) on level 2 polysomnography (PSG) performed at 22.0 ± 5.5 weeks' gestation were treated with a MAS during pregnancy to 6 months postpartum. An embedded micro-recorder measured adherence. PSG was repeated while on titrated treatment, and off treatment in the postpartum period. Results: Among 17 women completing the study, MAS was worn ≥ 4 h/night for 57.5 ± 36.7% of nights during the antepartum period. While using MAS, nightly snoring time decreased from 25.9 ± 24.5% at baseline to 6.4 ± 7.8% when treated during pregnancy (p =.003). AHI decreased from 17.6 ± 5.1 to 12.9 ± 6.3 (p =.02) and fell by ≥ 30% and below 15/h in 60% of participants. During the postpartum period, MAS was used for ≥ 4 h/night on 24.8 ± 27.9% of nights. Moreover, the mean AHI off MAS was 17.9 ± 13.1; 88% of women had persistent SDB (AHI ≥ 10). Conclusions: In this cohort, treatment efficacy and objective adherence were variable. Device use was less frequent in the postpartum period even though a substantial number of women had persistent SDB after delivery. Clinical trial registered with www.clinicaltrials.gov number: NCT03138291. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction. Mandibular advancement devices are used in the treatment of mild to moderate obstructive sleep apnea. We have created different types of devices over the years and come up with a design of an acrylic two-part adjustable device as the best one so far. New design of the mandibular advancement device. A 36-year-old male patient has been referred for polysomnography to the Sleep Medicine Center of the Institute of Pulmonary Diseases of Vojvodina due to primary problems in the form of drowsiness during the day, reduced concentration and witnessed cessation of breathing during sleep. By evaluating respiratory parameters, the patient was diagnosed with mild obstructive sleep apnea with an Apnea-Hypopnea Index of 10.3. Hygienic-dietary regimen of life and the use of mandibular advancement device were prescribed to the patient. Control polysomnography was performed six months after the use of the mandibular advancement device. Evaluation of respiratory parameters has registered the apnea-hypopnea index of 6.2 with predominant hypopneas. The average oxygen blood saturation was 94.4%. Snoring was mild and rare. Patient did not have any long-term side effects of the device and he got used to it easily. Conclusion. Mandibular advancement device is an effective way to treat obstructive sleep apnea in clearly indicated cases. Dentists who indicate and make it must be well educated, informed and they must cooperate with the sleep medicine centers to monitor the effectiveness of the therapy. [ABSTRACT FROM AUTHOR]

Bilateral sagittal split osteotomy (BSSO) mandibular advancement can cause mandibular lower border notching (MLBN). The objective of this study was to calculate the incidence of MLBN and identify risk factors. This single-centre, retrospective study was performed between January 2018 and November 2020, in the Maxillofacial Surgery Department, Centre Hospitalier Universitaire, Caen. Patients who underwent BSSO advancement and had cone beam computed tomography (CBCT) scans obtained preoperatively, immediately postoperative (within 1 week), and late postoperative (≥1 year) were included. Measurements were made on the CBCT images. A total of 113 patients (226 operated sides) were enrolled. Mean age at the time of surgery was 17 years; 66.4% of patients were female and 33.6% were male. MLBN was observed on 35 operated sides (15.5% of sides). Advanced age (P = 0.002) and the degree of mandibular advancement (P = 0.008) were determined to be risk factors for developing MLBN. Sex, the operated side, third molar removal, and genioplasty were not associated with an increased occurrence of MLBN. Older patient age at the time of surgery and the requirement for a large advancement should be taken into consideration by the surgeon in order to reduce the risk of MLBN by using a modified BSSO procedure or bone grafting. [ABSTRACT FROM AUTHOR]

Background: Mandibular advancement device (MAD) is a good alternative for patients with obstructive sleep apnea (OSA). However, the treatment response varies amongst individuals. Objective: This study aimed to explore the role of craniofacial features in the response to MADs to improve prognostication and patient selection. Methods: The retrospective trial contained 42 males aged 41.5 ± 9.0 years, and with an apnea‐hypopnea index (AHI) of 21.5 ± 13.8 events/h. According to the mandibular plane angle, participants were divided into three groups: low angle (n = 13), average angle (n = 14) and high angle (n = 15). Under the monitoring of home sleep testing, adjustable MADs were used to titrate the mandible forward from 0 mm with an increment of 0.5 mm every day. The polysomnography outcomes, mandibular protrusion amounts, changes in upper airway MRI measurements and nasal resistance were compared amongst the three groups. Results: The normalisation rate (AHI <5 /h) was 92.3%, 57.1% and 46.7%, respectively, in the low‐, average‐ and high‐angle groups (p =.027). The effective protrusion where AHI was reduced by half was 20 (11.3 ~ 37.5) %, 31.3 (23.6 ~ 50) % and 50 (36.9 ~ 64.9) % of the maximal mandibular protrusion, in the low‐, average‐ and high‐angle groups (p =.004). Multivariate logistic regression revealed that increased gonion angle (OR = 0.878) and baseline AHI(OR = 0.868) can reduce the probability of normalisation. Conclusion: The high mandibular plane angle might be an unfavourable factor to MAD treatment and more protrusion was needed to achieve a 50% reduction in AHI. Vertical craniofacial pattern (gonion angle) and baseline AHI constituted the model for predicting the effect of MADs. [ABSTRACT FROM AUTHOR]

Background: The effect of functional orthopaedic treatment for mandibular deficiency relies on mandibular advancement (MA)‐induced condylar new bone formation. However, this is not easy to achieve, especially in non‐growing patients. Therefore, how to obtain reliable MA‐induced condylar osteogenesis is a subject much worthy of study. Objective: To investigate whether deferoxamine mesylate (DFM) enhances MA‐induced condylar osteogenesis in middle‐aged mice. Methods: Forty 30‐week‐old male C57BL/6J mice were randomly divided into 4 groups: the control (Ctrl), DFM, MA + Ctrl and MA + DFM groups. After a 4‐week experimental period, femurs, tibias and condyles were collected for morphological, micro‐computed tomography and histological evaluation. Results: For long bones, DFM reversed osteoporosis in middle‐aged mice by promoting H‐type angiogenesis. For mandibular condyles, MA promoted condylar osteogenesis in middle‐aged mice, thereby allowing the mandible to achieve a stable protruding position. In addition, DFM enhanced the volume and quality of MA‐induced condylar new bone formation. Furthermore, histological analysis revealed that DFM enhanced MA‐induced condylar subchondral ossification. Mechanistically, it was confirmed that DFM increased the number of H‐type vessels and their coupled Osterix+ osteoprogenitors by upregulating the hypoxia‐inducible factor (HIF)‐1α signalling pathway, thereby enhancing MA‐induced condylar osteogenesis. Conclusion: Applying DFM to enhance MA‐induced condylar osteogenesis through H‐type angiogenesis is expected to be an effective strategy to achieve favourable functional orthopaedic treatment effectiveness in non‐growing patients. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Obstructive sleep apnea (OSA) is an underdiagnosed and potentially serious disorder that is accentuated by edentulism. The overclosure of the mandible and a potential upper airway collapse during sleep creates challenges in treating edentulous sleep apneic patients. Purpose: To evaluate complete dentures and mandibular advancement devices as potential oral appliances in the management of sleep apnea in completely edentulous patients. Materials and Method: The study design was a systematic review with meta-analysis. The search criteria complied with the preferred reporting items for systematic reviews and meta analyses (PRISMA) guidelines and the keywords in population, intervention, control, and outcomes (PICO) format was systematically searched for relevant research articles published till August 2021 in an electronic database (PubMed, Cochrane, Science Direct, Ovid). Randomized controlled trials and cohort studies were included that compared the effectiveness of oral appliances on apnea-hypopnea index (AHI), airway space, and quality of sleep in edentulous sleep apneic patients. Results: 1785 articles were derived from the initial search and based on inclusion criteria, 10 articles were systematically filtered for qualitative analysis and assessed for risk of bias using the Cochrane risk of bias tool and ROBINS-I tool. Out of the 10 articles, 5 articles were taken for quantitative analysis. The use of a mandibular advancement device (MAD) showed a decrease in AHI score, but the available data was heterogeneous to conduct a meta-analysis. The mean difference of AHI for the random effect model between the non complete denture and complete denture wearers at sleep was -0.49[95% CI (-1.47,0.48)] events per hour, but the change was non-significant (p>.05). Conclusion: The complete dentures as an oral appliance had reduced apneic episodes in completely edentulous sleep apneic patients, but the effectiveness cannot be solely attributed to the prosthesis in the treatment of OSA. MAD showed greater improvement in reducing AHI, however, the level of evidence was inadequate to provide a conclusive statement. [ABSTRACT FROM AUTHOR]

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We performed a systematic review on literature associated with meta‐analyses to elucidate whether (I) low‐level laser therapy (C) compared to placebo accelerates (O) bone neoformation in the region of the midpalatal suture in (P) patients undergoing transverse maxillary expansion. Two reviewers blindly performed targeted searches using the selection criteria (PICOS) in seven major databases and three grey literature databases, employing specific terms and their entrenchments. The RevMan® software (Review Manager, version 5.3, Cochrane Collaboration) was used to adapt the RoB summary illustration to the Cochrane 2.0 tool questions. Meta‐analysis was performed using standardized mean difference (SMD) and Cohen's d calculation on random effects, tests for heterogeneity (I2) and publication bias (Egger and Begg), and one‐of‐out sensitivity analysis. GRADE (Grading of Recommendations Assessment, Development and Evaluation) was used for evidence quality analysis. Among the five studies included in the qualitative synthesis, three were included in the meta‐analysis. All analysed studies were prospective randomized clinical trials. The risk of bias was such that the Egger (P =.1991) and Begg (P =.024) tests showed no significant risk of publication bias. The meta‐analysis showed high heterogeneity (I2 = 81%, P <.00001), and 3 months after the operation, there was no significant difference between the photobiomodulation (PBMT) group and control group (P =.850) or between the subgroups of the periods evaluated after 3 months (P = 0.490). GRADE showed an SMD of 0.62. Photobiomodulation as an adjuvant therapy in patients undergoing transverse maxillary expansion has few benefits and is limited in shape, as it contributes to bone healing in the midpalatal suture region after a period of 3 months. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea syndrome is a conceivably hazardous ailment. Most end up with non-reversible surgical techniques, such as the maxillomandibular advancement (MMA) procedure. MMA is an amazingly obtrusive treatment, regularly connected to complexities and facial change. Computational fluid dynamic (CFD) is broadly utilized as an instrument to comprehend the stream system inside the human upper airways (UA) completely. There are logical inconsistencies among the investigations into the utilizations of CFD for OSAS study. Thus, to adequately understand the requirement for OSAS CFD investigation, a systematic literature search was performed. This review features the necessary recommendations to accurately model the UA to fill in as an ideal predictive methodology before mandibular advancement surgery. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to provide a structured overview of three-dimensional airway volume changes in relation to various orthognathic surgeries. Clinical human studies performing pre- and postoperative three-dimensional airway volume assessments to investigate volumetric changes of the airway after orthognathic surgery were included. Pre-determined inclusion and exclusion criteria were applied in an extensive search of the PubMed, Embase, and Web of Science electronic databases. The cut-off date was set to January 1, 2022. Forty-one articles reporting retrospective and prospective case–control and case series studies were included. All studies were determined to be of medium quality (moderate risk of bias). The included studies were categorized by type of intervention. Pre- and postoperative volumes were extracted from the available data, and volume changes as a percentage of the preoperative levels were calculated. Isolated mandibular setback surgery generally decreased the airway volume. Isolated maxillary or mandibular advancement, bimaxillary advancement, and surgically assisted maxillary expansion generally increased the airway volume in the total airway and oropharynx, among which the effect of bimaxillary advancement surgery appeared most significant. High heterogeneity exists in the terminology and definitions of the airway and its segments. A more uniform methodology for airway volume measurement is needed to provide an insight into the impact on the airway of specific types of surgical intervention. In conclusion, airway volumes are affected after orthognathic surgery, which may be of clinical significance, especially in patients who are predisposed to obstructive sleep apnoea. [ABSTRACT FROM AUTHOR]

The aim of this study was to perform a three-dimensional evaluation of Herbst appliance effects on the mandibular canines.The subjects consisted of 23 Class II:1 patients (12 men, 11 women), mean age of 15.76± 1.75 years, consecutively treated with a Flip-Lock Herbst®appliance (TP Orthodontics, Inc., La Porte, IN, USA). The lower anchorage unit for the Herbst appliance consisted of two anchor bands connected by a lingual arch with 3mm distance from the incisor’s lingual surface. Treatment changes in mandibular canine inclination and mandibular intercanine width at the cusp and apex levels were evaluated by means of cone-beam computed tomography images (i-CAT® Classic unit, Imaging Sciences International, Hatfield, PA, USA) obtained before and after treatment with the Herbst appliance. There were no statistical differences between genders. Herbst appliance treatment did not result in any statistically significant changes for mandibular canine inclination and mandibular intercanine width. There were associations between mandibular canine inclination and mandibular intercanine width at the cusp (/r/ = 0.43 to 0.66) and apex levels (/r/ = 0.34 to 0.60). The three-dimensionalcone-beam computed tomography analysis of the mandibular canine segment revealed that the Herbst appliance with a mandibular anchorage unit distant from the incisor’s lingual surface does not change mandibular canine inclination and mandibular intercanine width significantly during treatment. However, large interindividual differences may result in undesired amount of mandibular canine anchorage loss in individual patients.

The main objective of this prospective study was the evaluation of 1 mm step titration of mandible advancement in the success of treating obstructive sleep apnea (OSA). For that, a multicenter prospective study was designed to recruit patients with OSA who were eligible to receive a mandibular advancement device. Gradual titration of mandibular advancement (steps of 1 mm) from maximum intercuspidation was performed to determine the optimal mandibular advancement (highest reduction in the apnea-hypopnea index (AHI)). The principal variable was the percentage of patients where a reduction ≥50% of the AHI was achieved at the end of the titration phase. A total of 102 patients participated in this study. Fifty-six percent of the participants were males and 67% had a BMI ≥ 25 kg/m2. Most of the patients (79%) had an age ≥ 50 years and the majority (74%) were either non-smokers or ex-smokers. Excessive daytime sleepiness was reported by 40% of the patients. The mean AHI at baseline was 20.6 ± 12.7 events/h. The mean advancement of the mandible was 3.1 ± 1.6 mm. The device achieved a reduction in the AHI in 93% of the patients and success (≥50% reduction in the AHI) in 69% of the patients. Success was achieved in 50%, 81.6%, and 73.3% of the patients with mild, moderate, and severe OSA, respectively. Decreasing the magnitude of mandibular advancement could be possible by controlling the vertical mouth opening and step-by-step titration.

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Purpose: The aim of this study was to evaluate fixation resistance in mandibular sagittal split ramus osteotomy in standardized polyurethane hemimandibles with two types of advancement (6 and 12 mm), with or without mandibular plane rotation, using a 2.0-mm plate/screw system. Methods: Seven groups were evaluated using a vertical compressive load in the first molar region, and the applied force in Newtons was recorded in 1 mm, 5 mm, and 10 mm displacements, as well as the maximum force. Results: There was a statistical intergroup difference and it was observed that increasing the advancement decreased fixation resistance with a single plate, and inserting an additional plate significantly increased osteosynthesis resistance. Conclusion: In the 12 mm advancements, clockwise rotation proved to be more resistant when fixed with only one plate. By contrast, counterclockwise rotation was significantly more resistant in stabilizing the mandibular sagittal ramus osteotomy when two plates were used. [ABSTRACT FROM AUTHOR]