Craniofacial risk factors for obstructive sleep apnea-systematic review and meta-analysis.

Obstructive sleep apnea (OSA) is caused by temporary partial or complete constriction of the upper airway during sleep which leads to reduced blood oxygen and cardiovascular risks. Main symptoms vary between adults and children leading to misdiagnosis or delayed patient identification. To improve early diagnosis, lateral cephalograms can provide craniofacial measurements associated with a higher risk of OSA. In order to identify the most relevant craniofacial measurements, a systematic literature review with meta-analysis was conducted combining the terms 'orthodontic*', 'craniofacial', 'cephalometr*', 'cephalogram', 'OSA*', 'UARS', 'SDB', 'sleep disordered breathing', 'sleep apnea' and 'sleep apnoea'. Of 3016 publications, 19 were included in the systematic review and meta-analysis, 15 with adult patients and four with children. A total of 16 measurements (six angles, 10 distances) were compared, nine showed a possible influence in patients with OSA compared to controls: NSBa angle (-0.28°), ANB angle (+0.33°), ML-NSL angle (+0.34°), Me-Go-Ar angle (+0.33°), SN distance (-0.70 mm), N-ANS distance (-0.36 mm), MP-H distance (+1.18 mm), uvula length (+1.07 mm) and thickness (+0.96 mm). Posterior airway measurements were not sufficiently described or comparably measured to be statistically analysed. There is some evidence for altered craniofacial anatomy in patients with OSA compared to controls. Lateral cephalograms should be screened for these aspects routinely to improve early diagnosis of OSA and craniofacial orthopaedics should complement the interdisciplinary treatment plan for young patients with OSA.

Exploratory analysis of new craniometric measures for the investigation of biological sex using open-access statistical and machine-learning tools on a cone-beam computed tomography sample.

Investigation of the biological sex of human remains is a crucial aspect of physical anthropology. However, due to varying states of skeletal preservation, multiple approaches and structures of interest need to be explored. This research aims to investigate the potential use of distances between bifrontal breadth (FMB), infraorbital foramina distance (IOD), nasal breadth (NLB), inter-canine width (ICD), and distance between mental foramina (MFD) for combined sex prediction through traditional statistical methods and through open-access machine-learning tools. Ethical approval was obtained from the ethics committee, and out of 100 cone beam computed tomography (CBCT) scans, 54 individuals were selected with all the points visible. Ten extra exams were chosen to test the predictors developed from the learning sample. Descriptive analysis of measurements, standard deviation, and standard error were obtained. T-student and Mann-Whitney tests were utilized to assess the sex differences within the variables. A logistic regression equation was developed and tested for the investigation of the biological sex as well as decision trees, random forest, and artificial neural networks machine-learning models. The results indicate a strong correlation between the measurements and the sex of individuals. When combined, the measurements were able to predict sex using a regression formula or machine learning based models which can be exported and added to software or webpages. Considering the methods, the estimations showed an accuracy rate superior to 80% for males and 82% for females. All skulls in the test sample were accurately predicted by both statistical and machine-learning models. This exploratory study successfully established a correlation between facial measurements and the sex of individuals, validating the prediction potential of machine learning, augmenting the investigative tools available to experts with a high differentiation potential.

Impaired head circumference growth and behavioural problems in childhood: Longitudinal findings from the MINA-Brazil birth cohort.

BACKGROUND: Previous evidence on the relation between early head circumference (HC) growth and behavioural outcomes in preschoolers has been inconsistent. OBJECTIVE: We aimed to investigate whether HC growth from birth to 5 years of age was related to internalising or externalising behavioural problems at 5 years of age in a sex-specific manner. METHODS: Among 303 girls and 318 boys from the MINA-Brazil birth cohort, we examined the associations between changes in HC from birth to 5 years of age and internalising and externalising behaviour problem scores at 5 years according to the Strengths and Difficulties Questionnaire for parents. HC values were transformed into sex- and age-specific z-scores (HCZ) using World Health Organisation standards, and the differences between values at 5 years of age and birth were classified into quintiles. We estimated adjusted mean differences with 95% confidence intervals in behavioural problem scores between HCZ change quintiles using multivariable linear regression by sex. To examine nonlinear associations, we included cubic spline terms. RESULTS: Head circumference growth from birth to 5 years of age was inversely and nonlinearly associated with internalising problems in girls. Compared with girls at the lowest quintile of HC growth, those above had an adjusted 1.27 (95% confidence interval 0.28, 2.27) points lower mean internalising problems score. This association was mostly driven by HC growth during the first 2 years. We found no association between HC growth and externalising behaviour in either sex. CONCLUSIONS: Impaired HC growth was related to higher mean internalising problem scores at 5 years of age in girls but not in boys. HC growth was not associated with externalising problems.

Accuracy and clinical validity of automated cephalometric analysis using convolutional neural networks.

BACKGROUND: This study aimed to assess the error range of cephalometric measurements based on the landmarks detected using cascaded CNNs and determine how horizontal and vertical positional errors of individual landmarks affect lateral cephalometric measurements. METHODS: In total, 120 lateral cephalograms were obtained consecutively from patients (mean age, 32.5 ± 11.6) who visited the Asan Medical Center, Seoul, Korea, for orthodontic treatment between 2019 and 2021. An automated lateral cephalometric analysis model previously developed from a nationwide multi-centre database was used to digitize the lateral cephalograms. The horizontal and vertical landmark position error attributable to the AI model was defined as the distance between the landmark identified by the human and that identified by the AI model on the x- and y-axes. The differences between the cephalometric measurements based on the landmarks identified by the AI model vs those identified by the human examiner were assessed. The association between the lateral cephalometric measurements and the positioning errors in the landmarks comprising the cephalometric measurement was assessed. RESULTS: The mean difference in the angular and linear measurements based on AI vs human landmark localization was .99 ± 1.05°, and .80 ± .82 mm, respectively. Significant differences between the measurements derived from AI-based and human localization were observed for all cephalometric variables except SNA, pog-Nperp, facial angle, SN-GoGn, FMA, Bjork sum, U1-SN, U1-FH, IMPA, L1-NB (angular) and interincisal angle. CONCLUSIONS: The errors in landmark positions, especially those that define reference planes, may significantly affect cephalometric measurements. The possibility of errors generated by automated lateral cephalometric analysis systems should be considered when using such systems for orthodontic diagnoses.

Long-term effects produced by early treatment of Class III malocclusion with rapid maxillary expansion and facemask followed by fixed appliances: A multicentre retro-prospective controlled study.

OBJECTIVE: To assess the short- and long-term dentoskeletal effects of early Class III treatment with rapid maxillary expansion and facemask (RME/FM) followed by fixed appliances. MATERIALS AND METHODS: A total of 44 patients (27 females, 17 males) treated consecutively with RME/FM were included from the archives of 3 centres. Three lateral cephalograms were available: T0 (before the start of RME/FM therapy, mean age 8.1 ± 1.8 years), T1 (immediately after RME/FM, mean age 9.8 ± 1.6 years), and T2 (long-term observation, mean age 19.5 ± 1.6 years). A control group of 17 untreated Class III subjects (12 females and 5 males) also was selected. Between-group statistical comparisons were performed with ANCOVA. RESULTS: No statistically significant differences for any of the cephalometric variables were found at T0. In the short term, the treated group showed significant improvements in ANB (+2.9°), Wits appraisal (+2.7 mm), SNA (+1.8°) and SNB (-1.1°). A significant closure of CoGoMe angle (-1.3°) associated with smaller increments along Co-Gn (-2.4 mm) also was found together with a significant increase in intermaxillary divergence (+1.3°). In the long-term, significant improvements in ANB (+2.6°), Wits appraisal (+2.7 mm) and SNB (-1.7°) were recorded together with a significant closure of the CoGoMe angle (-2.9°). No significant long-term changes in vertical skeletal relationships were found. CONCLUSIONS: RME/FM therapy was effective in improving Class III dentoskeletal relationships in the short term. These changes remained stable in the long-term due mainly to favourable mandibular changes.

Craniofacial morphological variability in orthodontic patients with non-syndromic orofacial clefts: an approach using geometric morphometrics.

OBJECTIVES: Orofacial clefts are complex congenital anomalies that call for comprehensive treatment based on a thorough assessment of the anatomy. This study aims to examine the effect of cleft type on craniofacial morphology using geometric morphometrics. MATERIALS AND METHODS: We evaluated lateral cephalograms of 75 patients with bilateral cleft lip and palate, 63 patients with unilateral cleft lip and palate, and 76 patients with isolated cleft palate. Generalized Procrustes analysis was performed on 16 hard tissue landmark coordinates. Shape variability was studied with principal component analysis. In a risk model approach, the first nine principal components (PC) were used to examine the effect of cleft type. RESULTS: We found statistically significant differences in the mean shape between cleft types. The difference is greatest between bilateral cleft lip and palate and isolated cleft palate (distance of means 0.026, P = 0.0011). Differences between cleft types are most pronounced for PC4 and PC5 (P = 0.0001), which together account for 10% of the total shape variation. PC4 and PC5 show shape differences in the ratio of the upper to the lower face, the posterior mandibular height, and the mandibular angle. CONCLUSIONS: Cleft type has a statistically significant but weak effect on craniofacial morphological variability in patients with non-syndromic orofacial clefts, mainly in the vertical dimension. CLINICAL RELEVANCE: Understanding the effects of clefts on craniofacial morphology is essential to providing patients with treatment tailored to their specific needs. This study contributes to the literature particularly due to our risk model approach in lieu of a prediction model.

Gender differences in the upper airway, craniofacial morphological and polysomnographic parameters in patients with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common sleep disorder characterized by repetitive episodes of upper airway collapse during sleep associated with arousals with or without oxygen desaturation. OBJECTIVE: This study aims to assess and analyse the morphological and neurological factors associated with obstructive sleep apnoea using polysomnography study data and two-dimensional cephalometric analysis of airway and skeletal parameters and their correlation in the patients with varying severities of obstructive sleep apnoea. METHODS: This study included 892 patients who underwent a complete work up, including a thorough history, clinical examination, standard polysomnography study and 2D cephalometric analysis to diagnose obstructive sleep apnoea. This study divided the participants into two groups based on the AHI score from the PSG study: AHI < 15 and AHI > 15 groups. The groups were further divided into male and female groups to study the prevalence of OSA. The analysis involved 13 cephalometric parameters: Seven linear and six angular measurements. The airway parameters measured in this study were minimum posterior airway space (PAS_min), hyoid bone to the mandibular plane (H_MNP) and soft palate length (SPL). All the subjects in this study underwent a standard overnight polysomnography study at the sleep centre in Samsung Medical Center. RESULTS: A total of 892 adult participants (M: F = 727:165, mean age: 50.6 ± 13.2 years and age range: 18-85 years). AHI >15 group was significantly older with higher BMI, NC and WC compared to the AHI < 15 groups in both male and female groups. There was statistical significance observed in N1, N3, AI, ODI, lowest saturation (%) and apnoea max length between the groups (p < .001). The arousal index (AI), especially the respiratory arousal index was considerably higher in the male group. There were significantly higher values in all the PSG parameters in the male group. In the airway parameters, hyoid bone position and soft palate length showed significant differences (p < .001), whereas the PAS did not show any differences (p = .225) between the AHI <15 and AHI >15 groups. The overall skeletal cephalometric parameters showed no significant differences between the groups, whereas the gonial angle and AB to mandibular plane angle showed significant differences in the female group (p = .028, p = .041 respectively). CONCLUSION: The partial correlation of cephalometric parameters with AHI showed a stronger correlation between the H_MNP and AHI in both men and women. The position of the hyoid bone and the soft palate length influences the progression of OSA, especially in male patients. This study found no direct association between the minimum PAS and varying severities of OSA in men and women. We speculate that more than the craniofacial morphological factors such as the sagittal and vertical position of the maxilla and the mandible, the position of the hyoid bone might be more responsible for the severity of OSA.

Orthognathic surgery improves compromised natural head position and pharyngeal airway in patients with Skeletal Class II or III malocclusion.

BACKGROUND: Natural head position (NHP), pharyngeal airway and maxillofacial growth pattern are correlated. The author's previous studies proved that following surgical correction of Skeletal Class II malocclusion, the over-extended NHP returned upright, and the pharyngeal airway space (PAS) dimension expanded. OBJECTIVE: The present study compares the post-operative change in NHP and PAS after orthognathic surgery in Skeletal Class II and III malocclusion patients. METHODS: Patients receiving orthognathic procedures to correct Skeletal Class II or III malocclusions were reviewed in this retrospective study. Pre-operative and 6-week post-operative cone-beam computed tomography datasets were collected. Variables representing the craniofacial pattern, the NHP and the PAS were measured three-dimensionally. Post-operative variables were compared with their pre-operative counterparts using either repeat-measure 2-way analysis of variance or Wilcoxon matched-pairs signed rank test. RESULTS: Thirty cases of Skeletal Class II malocclusion and 13 cases of Skeletal Class III malocclusion were collected. Preoperatively, the inter-group differences were significant in craniofacial pattern (68.14 ± 3.552 degree vs. 79.63 ± 2.497 degree, p < .0001) and the NHP (68.77 ± 11.02 degree vs. 82.83 ± 7.738 degree, p = .0002) while not significant in PAS; after surgery, the intergroup differences in craniofacial pattern and the NHP between groups decreased, and the PAS increased in both groups. CONCLUSION: Orthognathic surgery may improve compromised NHP and increase PAS in Skeletal Class II and III malocclusion patients.

The Effect of Barrel-Stave Osteotomy Length in Sagittal Strip Craniectomy.

OBJECTIVE: In managing sagittal craniosynostosis, strip craniectomy of the affected suture is commonly paired with barrel-stave osteotomies to allow for additional cranial remodeling. However, the effect of these osteotomies is not well-established. This study aimed to evaluate the effect of the length of barrel-stave osteotomies on outcomes in patients with sagittal craniosynostosis. DESIGN: A retrospective review of operative records and pre-operative and one-year post-operative three-dimensional images. SETTING: Tertiary care pediatric institution. PATIENTS: Forty-five patients with sagittal craniosynostosis. INTERVENTIONS: Sagittal strip craniectomy and either long, medium, or short barrel-stave osteotomy lengths followed by helmet therapy. MAIN OUTCOME MEASURES: Operative and three-dimensional craniometric outcomes. RESULTS: Operative time, estimated blood loss, and hospital length of stay were significantly decreased in the short group (P = .003; 0.002; 0.027). The cranial index was normalized in all groups, but the long group was significantly lower (P = .007; 0.025). Head circumference was similar between groups. All indexes were within the normal percentiles in all groups. The medium group had a significantly decreased scaphocephalic index (P = .031; .035). The short group had significantly greater occipital bulleting than the medium group (P = .001). The long group had significantly greater narrowing than the short group (P = .036). CONCLUSIONS: Strip craniectomy with the addition of long, medium, or short barrel staves all resulted in clinically successful outcomes. Our findings suggest that increased barrel-stave osteotomy length may not be necessary for a successful outcome while avoiding more extensive dissection, potential risk, increased operative time, and hospital length of stay.

Accuracy of Cranial Shape Measurements Using Smartphones: A Prospective Study.

OBJECTIVE: Prospectively validate the accuracy of smartphone-based digital cranial measurements for the diagnosis and treatment of deformational plagiocephaly and/or brachycephaly (DPB), compared with calipers used in the standard of care. DESIGN/METHODS: Bird's-eye-view head photos were captured via smartphone, and their heads were measured with hand calipers by an expert user. CI/CVAI/CVA were calculated from photos and caliper measurements, and from 3D photogrammetry of the head as ground truth. Digital and caliper measurements were compared against 3D-based ground truth using mean absolute error, Spearman correlation coefficient, and Bland-Altman method. Statistical significance between methods was assessed using Wilcoxon Rank-Sum test. PARTICIPANTS: 71 infants aged 2-11 months (20 female, 51 male) with DPB. RESULTS: The mean absolute errors for CI, CVAI, CVA were 1.63 ± 1.44, 1.45 ± 1.29, 2.38 ± 1.86 mm for smartphone, and 2.60 ± 1.96, 1.43 ± 1.22, 2.04 ± 1.81 mm for calipers, respectively. The correlation coefficients for CI, CVAI, CVA between smartphone and ground truth were 0.90, 0.94, 0.80 (p < 0.001), and 0.87, 0.93, 0.84 (p < 0.001) between calipers and ground truth, respectively. Bland-Altman results were (0.08, [-4.18, 4.34]), (-0.05, [-3.85, 3.76]), (-0.82, [-6.52, 4.87]) for smartphone, and (1.41, [-4.34, 7.15]), (0.28, [-3.37, 3.94]), (0.16, [-5.18, 5.49]) for caliper measurements respectively. Digital and caliper measurements were similar (p = 0.12) except for CI, where digital measurements were more accurate (p = 0.04). CONCLUSION: Smartphone-based cranial measurements have very high correlation with 3D-based ground truth, and they are comparable or superior to caliper measurements. Digital measurements can be performed in pediatric offices or from home to help with the early detection and treatment of DPB.

Sagittal Growth Restriction of the Midface Following Isolated Cleft Lip Repair: A Systematic Review and Meta-Analysis.

Midface hypoplasia (MFH) is a long-term sequela of cleft lip and palate repair, and is poorly understood. No study has examined the aggregate data on sagittal growth restriction of the midface following repair of the lip, but not palate, in these patients.A systematic review of 3780 articles was performed. Twenty-four studies met inclusion criteria and 11 reported cephalometric measurements amenable to meta-analysis. Patients with Veau class I-III palatal clefts were included so long as they had undergone only lip repair. Groups were compared against both noncleft and unrepaired controls.Cephalometrics were reported for 326 patients (31.3% female). Noncleft controls had an average SNA angle of 81.25° ± 3.12°. The only patients demonstrating hypoplastic SNA angles were those with unilateral CLP with isolated lip repair (77.4° ± 4.22°). Patients with repaired CL had SNA angles similar to noncleft controls (81.4° ± 4.02°). Patients with unrepaired CLP and CL tended toward more protruding maxillae, with SNA angles of 83.3° ± 4.04° and 87.9° ± 3.11°, respectively. Notably, when comparing SNA angles between groups, patients with CLP with isolated lip repair had significantly more hypoplastic angles compared to those with repaired CL (P < .0001). Patients with CLP with isolated lip repair were also more hypoplastic than noncleft controls (P < .0001). In contrast, there was no significant difference between the SNA of patients with repaired CL and controls (P = .648).We found that cleft lip repair only appeared to contribute to MFH in the setting of concurrent cleft palate pathology, suggesting that scarring from lip repair itself is unlikely to be the predominant driver of MFH development. However, studies generally suffered from inadequate reporting of timing, technique, follow-up time, and cleft severity.

Occlusal Outcomes in Non-Robin Sequence Patients with Isolated Cleft Palate.

OBJECTIVES: 1. To assess the skeletal class occlusion and lateral cephalometry in children with isolated cleft palates (non-Robin sequence) and 2. to identify associations between these findings and pre-palatoplasty cleft palate measurements. STUDY DESIGN: Retrospective cohort study. SETTING: North American Institutional Tertiary Paediatric Center. PATIENTS: Our cleft database was reviewed, and patients were included if they had an isolated cleft palate without a Robin Sequence diagnosis, had a Furlow palatoplasty and had available per operative cleft palate measurements and available lateral cephalogram between 6 and 8 years old. Thirty-two patients matched to inclusion criteria. INTERVENTION: Furlow's Palatoplasty. MAIN OUTCOME AND MEASURES: Cleft size at palatoplasty, cephalometric measurements and skeletal occlusal classes were analysed. ANOVA was used to test the association between cephalometric measurements and occlusal classes. Results are presented as means with a 95% confidence interval. The association between cleft measurements and cephalometric parameters was tested with Spearman Correlation (rs). RESULTS: The skeletal occlusal outcome at 7 years old for this series of patients was: Class I: 19%; Class II: 59% and Class III: 22%. No single cleft measurement at palatoplasty was predictive of the skeletal occlusal outcome. A larger hard palate cleft was associated with a shorter antero-posterior maxilla. CONCLUSIONS: The skeletal occlusal class outcomes were similar to those found in a previous study in the literature. The occlusal prognosis appears to be better than in patients with Robin Sequence or with an associated cleft lip. No preoperative measurement was found to be associated with the occlusal outcome.

Cephalometric Pharyngeal Morphology in Adults with Unoperated Cleft Palate.

OBJECTIVE: The aim of this study was to cephalometrically evaluate the pharyngeal morphology in adults with unoperated Submucous Cleft Palate (SMCP), adults with unoperated Overt Cleft Palate (OCP), and adults without clefts. DESIGN: This study employed a retrospective cross-sectional design. Lateral cephalometric radiography was performed on three groups of adults: 1) 29 with unrepaired SMCP; 2) 41 with unrepaired OCP; and 3) 39 without clefts, who served as controls. One-way ANOVA and rank-sum tests were used for intergroup comparisons. P value was set at .05. RESULTS: The soft palate length and the ratio of soft palate length to pharyngeal depth were significantly lower in subjects with unoperated SMCP and OCP than in non-cleft controls. Significant differences were also observed in pharyngeal depth, nasopharyngeal depth, and posterior pharyngeal wall thickness between subjects with unoperated OCP and non-cleft controls. CONCLUSIONS: Pharyngeal morphology differs significantly between individuals with and without clefts, particularly in soft palate length and the ratio of soft palate length to pharyngeal depth.

Automatic Landmark Annotation and Measurement of 3D Mandibular Morphology Using Non-Rigid Registration: A Preliminary Exploration and Accuracy Assessment.

This study aimed to develop an automatic methodology for mandibular landmarking and measurement using non-rigid registration as well as analyze the accuracy of automatic landmarking and measurements.Statistical analysis.Digital technology center, tertiary hospital.130 healthy Chinese adults with equal gender distribution, average age 28.2 ± 5.6 years.Four mean shape mesh templates were generated from 100 head CT scans. Following manual indication of landmarks, these templates were applied for automatic landmark annotation and measurements on mandibles from another 30 head CT scans, using non-rigid iterative closest point registration.Differences of landmark coordinates and measurements between automatic and manual annotation were analyzed using mean difference, centroid size, Euclidean distances and intraclass correlation coefficient (ICC), assessing the accuracy and validity of automatic landmark annotation.The majority of automatic landmarks (16/22) did not exhibit consistent displacement to specific direction. ICCs of all landmark coordinates exceed 0.950, with 87.9% larger than 0.990. The average Euclidean distance between manual and automatic landmarks was 2.038 ± 0.947 mm. Most ICCs of linear and angular measurements between manual and automatic annotation (20/26) exceeded 0.900, with the average errors being 1.425 ± 0.973 mm and 2.257 ± 0.649 °, respectively.A novel and efficient method for automatic landmark annotation was established based on non-rigid registration. Its credibility and accuracy in mandibular annotation and measurements were demonstrated.

Can artificial intelligence-driven cephalometric analysis replace manual tracing? A systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to investigate the accuracy and efficiency of artificial intelligence (AI)-driven automated landmark detection for cephalometric analysis on two-dimensional (2D) lateral cephalograms and three-dimensional (3D) cone-beam computed tomographic (CBCT) images. SEARCH METHODS: An electronic search was conducted in the following databases: PubMed, Web of Science, Embase, and grey literature with search timeline extending up to January 2024. SELECTION CRITERIA: Studies that employed AI for 2D or 3D cephalometric landmark detection were included. DATA COLLECTION AND ANALYSIS: The selection of studies, data extraction, and quality assessment of the included studies were performed independently by two reviewers. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A meta-analysis was conducted to evaluate the accuracy of the 2D landmarks identification based on both mean radial error and standard error. RESULTS: Following the removal of duplicates, title and abstract screening, and full-text reading, 34 publications were selected. Amongst these, 27 studies evaluated the accuracy of AI-driven automated landmarking on 2D lateral cephalograms, while 7 studies involved 3D-CBCT images. A meta-analysis, based on the success detection rate of landmark placement on 2D images, revealed that the error was below the clinically acceptable threshold of 2 mm (1.39 mm; 95% confidence interval: 0.85-1.92 mm). For 3D images, meta-analysis could not be conducted due to significant heterogeneity amongst the study designs. However, qualitative synthesis indicated that the mean error of landmark detection on 3D images ranged from 1.0 to 5.8 mm. Both automated 2D and 3D landmarking proved to be time-efficient, taking less than 1 min. Most studies exhibited a high risk of bias in data selection (n = 27) and reference standard (n = 29). CONCLUSION: The performance of AI-driven cephalometric landmark detection on both 2D cephalograms and 3D-CBCT images showed potential in terms of accuracy and time efficiency. However, the generalizability and robustness of these AI systems could benefit from further improvement. REGISTRATION: PROSPERO: CRD42022328800.

The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

OBJECTIVE: To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. METHODS: The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. RESULTS: Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). CONCLUSIONS: The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

Late-forming supernumerary teeth: A case series.

The aim of this case series was to illustrate the development of late-forming supernumerary teeth (LFST) and highlight the implications for orthodontic treatment. There are limited studies relating to the aetiology, prevalence and treatment of LFST and the cases presented here demonstrate the management of LFST within a tertiary care centre. Five cases are presented, which show various presentations and chronological ages in the development of LFST. This case series emphasises the significance of maintaining a low threshold for suspecting LFST in patients where supernumerary teeth have previously been identified. It also highlights the importance of regular clinical and radiographic reviews. Timely identification can help prevent complications and optimise treatment outcomes.

Novel prediction models for pharyngeal-airway volume based on the cranial-base and midsagittal cross-sectional area of the airway in the pharyngeal region: A cephalometric and magnetic resonance imaging study.

OBJECTIVE: The objective of the study was to elucidate the association between cranial base (Bjork-Jarabak analysis), midsagittal cross-sectional area of the airway in the pharyngeal region (MCSA-PR) data and pharyngeal-airway volume (PAV) and develop a model that could help clinicians predict PAV using two-dimensional (2D) data (Bjork polygon and MCSA-PR). MATERIALS AND METHODS: Pre-treatment lateral cephalometric radiographs and magnetic resonance imaging (MRI) scans of 82 women were categorized into three anteroposterior skeletal groups based on ANB angle: Class I (n = 29), 1.5° ≤ ANB≤5.1°; Class II (n = 26), ANB >5.1°; Class III (n = 27), ANB <1.5°. The Bjork polygon, MCSA-PR data from cephalograms and PAV data from MRI scans were examined. Intergroup comparisons were performed using the Kruskal-Wallis test and one-way analysis of variance (ANOVA), with pairwise comparisons conducted using the Bonferroni-corrected Mann-Whitney U-test for the Kruskal-Wallis test and Bonferroni-corrected multiple comparison test for one-way ANOVA. Forward multiple linear regression was used to create model equations for predicting PAV. RESULTS: MCSA-PR and anterior (N-S) and posterior (S-Ar) cranial-base lengths were positively correlated with the PAV. We developed four models; three operated at the group level, and one encompassed the entire sample. Notably, all models could effectively explain the variance in the PAV data. The model for the Class I group was the strongest (adjusted R2 = 0.77). CONCLUSION: Our findings indicate the remarkable potential of the MCSA-PR, N-S and Bjork sum angles (BSA) as predictors of the PAV and the relevance of 2D cephalometric and cranial-base parameters in predicting the three-dimensional (3D) pharyngeal-airway size.

Craniofacial morphology in adults with osteogenesis imperfecta-A cross-sectional study.

OBJECTIVES: The aim of this study was to compare the craniofacial and neurocranial morphology of adults with osteogenesis imperfecta (OI) with controls and to elucidate whether osseous origin impacts on morphological deviations in OI. MATERIALS AND METHODS: Fifty-four adults (mean age 45.8) with OI type I, 14 adults (mean age 42.6) with OI types III/IV and 49 adult controls (mean age 41.0) were included. All participants had European ethnicity. Cranial morphology was assessed by 2D-cephalometry. Comparison between groups was made by multiple regression analyses. RESULTS: Comparison between OI groups and controls: (1) Dimension of the maxilla and mandible, respectively was reduced (P < .01), and in relation to the posterior cranial base, the maxilla was retro-positioned (P < .001), and the mandible was prognathic (P < .001). (2) The anterior face height was reduced (P < .04), and in OI types III/IV only, the maxilla was posteriorly inclined (P < .001). (3) Anterior cranial base (P < .001) and the dimension sella-frontale (P < .02) were short. (4) The sagittal dimension of the posterior cranial fossa was increased (P < .01), and the vertical dimension was reduced (P < .01). CONCLUSIONS: Adults with OI had a hypoplastic, retro-positioned and posteriorly inclined maxilla, a hypoplastic and forward-positioned mandible, and a reduced anterior face height. Deviations were seen in morphology of the posterior cranial fossa. The impact of OI on cranial morphology was generally more evident in OI type III/IV than in OI type I. OI impacts on osseous cranial structures irrespective of bony origin being intramembranous or endochondral.

Normal variation of mandibular asymmetry in children.

OBJECTIVE: To explore the normal variation of asymmetry in mandibles of children in the age group of 1 to 12 years. MATERIALS AND METHODS: The study group consisted of 92 cadaveric mandibles of children with a dental age of 1 to 12 years old in possession of ACTA (Academic Centre for Dentistry Amsterdam), Faculty of Dentistry, the Netherlands. 3D models of the mandibles were obtained from CT-scans and hemimandibular volumes of all mandibles were calculated. The condylar height, ramus height, mandibular body length and the gonial angle were bilaterally determined using a novel landmark-based method, and the degree of asymmetry was calculated. RESULTS: No relationship was found between dental age and asymmetry of the studied parameters (P < .05). The highest degree of asymmetry was found in the ramus height, whereas the gonial angle presented the lowest degree of asymmetry. A positive correlation was found between the asymmetry of the hemimandibular volume vs the height of the ramus (P < .05) and the length of the mandibular body (P < .05). An inverse correlation was found between the asymmetry of the ramus height vs the condylar height (P < .05), mandibular body length (P < .05) and gonial angle (P < .05). CONCLUSIONS: Mandibular asymmetries in children did occur (9.8% of the included mandibles presented with a relevant overall asymmetry of ≥3%) and were unrelated to age. The different segments of the mandible seem to compensate for each other, in order to maintain a functional equilibrium.