Skeletal Malocclusion Research Articles

Comparative evaluation of the reliability of MNG angle with other anteroposterior skeletal dysplasia indicators – A retrospective cephalometric study

The aim of the study was to evaluate the reliability of the MNG angle for various skeletal malocclusions and to compare and correlate it with ANB angle, Beta angle, Yen angle and W angle in Gujarati population. Lateral cephalograms of 50 Gujarati adults, were divided into three groups based on the ANB angle and the Beta angle measurements. The Yen angle, W angle and MNG angle were measured for all the cephalograms. The mean value for MNG angle was derived for each group. The one-way analysis of variance (ANOVA) and Bonferroni post hoc tests were used to compare the differences between the mean values of the 3 groups. Spearman’s correlation analysis was used to determine correlations among the five skeletal parameters. Analysis of the obtained data revealed a mean MNG angle of -1.22° ± 3.9°, 3.11° ± 2.8° and -6.0° ± 1.5° for Class I, II and III respectively. Spearman’s correlation analysis demonstrated a significant co-relation between ANB angle, Beta angle and MNG angle with a p value of ≤ 0.05 for skeletal Class I and Class II malocclusions. The MNG angle can be used as a dependable maker to assess the antero-posterior discrepancy, especially for Class II skeletal pattern.

The Relationship Between Orthodontic Malocclusion and Morphological Features of Sella Turcica Bridging and Ponticulus Posticus

Background and Objectives: Recent years have been marked by a search for new relationships between malocclusions and the morphological features of the cranial base and upper cervical spine. The aim of this study was to evaluate the relationship between skeletal orthodontic malocclusions and the morphological features of sella turcica bridging (STB) and ponticulus posticus (PP). Materials and Methods: The study sample consisted of 300 randomly selected pre-orthodontic treatment patients aged 7–40 years. Cephalometric analysis was performed twice by two researchers. The patients were divided into three groups according to the type of skeletal malocclusion. Statistical analysis was performed using SPSS 29.0 software. Results: The prevalence of incomplete PP was 40%, and the prevalence of complete PP was 11.33% and was significantly more common in males (56.7%). STB had a prevalence of 52.67% (15.67% complete, 37.0% partial), with a significantly higher prevalence in females (60.1%, p < 0.001). PP and STB were more common in Class II patients, followed by Class I and Class III. However, only PP showed a statistically significant difference (p = 0.042). According to logistic regression, men were twice as likely to have an open groove of PP (p = 0.015), while females had higher odds of partial and complete STB (p < 0.05). Class II malocclusion increases the odds of type 2 and type 4 PP as well as partial STB. However, it was not statistically significant (p > 0.05). Conclusions: The morphological features of sella turcica bridging and ponticulus posticus were related to sex and the orthodontic skeletal pattern. Ponticulus posticus was more prevalent in males, while sella turcica bridging was more prevalent in females; both conditions were more common in patients with a Class II skeletal pattern. Males were more likely to have an open groove of ponticulus posticus, whereas females were twice as likely to have both forms of sella turcica bridging.

Comparison Change of Pre and Post-Treatment in Vermilion Height and Lip Area in Adult Class II Division I Malocclusion Treated with Premolar Extraction

Aim: This study aimed to evaluate the alterations in vermilion height and lip area before and after fixed orthodontic treatment in adult patients with Class II Division I malocclusion who underwent premolar extractions. Assessments were conducted using frontal photographs and measurements from lateral cephalograms focusing on dentoalveolar and soft tissue parameters. Methods: Twenty-three adult patients with Class II skeletal malocclusion were selected from the records of the Department of Orthodontics and Dentofacial Orthopedics at AJ Institute of Dental Sciences, Mangalore. Pre-treatment and post-treatment lateral cephalograms and frontal photographs were obtained. Cephalograms were captured using a standardized KODAK 8000c digital cephalostat (69 kVp, 12 mA, 2 s), ensuring accurate patient positioning. The same investigator manually traced the cephalograms to minimize observer variability. Measurements were computed both manually and digitally for comparison purposes. Results: The study found a significant increase in the thickness from the cervical portion of the upper incisors to the upper lip after treatment (mean post-treatment: 15.77±2.28 mm; pre-treatment: 14.95±1.90 mm; P=0.006). Conversely, the thickness from the lower incisors to the upper lip decreased significantly post-treatment (mean post-treatment: 15.46±2.72 mm; pre-treatment: 17.26±2.19 mm; P<0.001). Additionally, there was a significant increase in vermilion height (St-Me) and lower facial height (N-Me) after treatment, with mean differences of 3.58 mm (P<0.001) and 1.18 mm (P=0.04), respectively. Conclusion: Orthodontic treatment involving premolar extractions in Class II Division I malocclusion patients led to significant soft tissue changes, particularly in lip thickness and vermilion height. Other parameters did not exhibit statistically significant differences.

Quantum of incisal compensation in skeletal class III malocclusion: a cross-sectional study.

Skeletal class III malocclusion presents either with maxillary retrognathism, mandibular excess, or a combination. Dentoalveolar compensations occur with maxillary incisor proclination and mandibular incisor retroclination. The aim of this study is to quantify the amount of incisal compensation in class III skeletal malocclusion and correlate it to the severity of the skeletal base. Eleven angular and 7 linear cephalometric measurements were digitized from 57 patients. Axial inclination of the upper and lower incisors was evaluated for compensation. Pearson's correlation coefficient was used to determine the dentoalveolar parameter among those measuring upper and lower incisor position and inclination that correlated most highly with the severity of class III. Linear regression analysis was used to identify the quantum of the incisal compensation. Upper incisors were proclined and placed anteriorly. However, correlation analysis suggested a less responsive incisor with progressive change in skeletal base. Lower incisors began to compensate only as the severity of class III increased. For every degree of reduction of ANB angle from normal, the incisor mandibular plane angle (IMPA) and L1-GoMe decreased by 0.79° and the L1-GoGn decreased by 0.81°. The upper incisors contributed more to compensation compared to the lower incisors in a class III skeletal base. As class III severity increased, the upper incisor compensation decreased while that of lower incisors increased. For every degree of reduction in ANB angle, the IMPA and L1-GoMe decreased by 0.79° and the L1-GoGn decreased by 0.81°.

TGF-β signaling in the cranial neural crest affects late-stage mandibular bone resorption and length.

Malocclusions are common craniofacial malformations that cause quality of life and health problems if left untreated. Unfortunately, the current treatment for severe skeletal malocclusion is invasive surgery. Developing improved therapeutic options requires a deeper understanding of the cellular mechanisms responsible for determining jaw bone length. We have recently shown that neural crest mesenchyme (NCM) can alter jaw length by controlling the recruitment and function of mesoderm-derived osteoclasts. Transforming growth factor beta (TGF-β) signaling is critical to craniofacial development by directing bone resorption and formation, and heterozygous mutations in the TGF-β type I receptor (TGFBR1) are associated with micrognathia in humans. To identify the role of TGF-β signaling in NCM in controlling osteoclasts during mandibular development, the mandibles of mouse embryos deficient in the gene encoding Tgfbr1, specifically in NCM, were analyzed. Our laboratory and others have demonstrated that Tgfbr1 fl/fl ;Wnt1-Cre mice display significantly shorter mandibles with no condylar, coronoid, or angular processes. We hypothesize that TGF-β signaling in NCM can also direct late bone remodeling and further regulate late embryonic jaw bone length. Interestingly, analysis of mandibular bone based on micro-computed tomography and Masson's trichrome revealed no significant difference in bone quality between the Tgfbr1 fl/fl ;Wnt1-Cre mice and controls, as measured by the bone perimeter/bone area, trabecular rod-like diameter, number and separation, and gene expression of collagen type 1 alpha 1 (Col1α1) and matrix metalloproteinase 13 (Mmp13). Although there was not a difference in localization of bone resorption within the mandible indicated by tartrate-resistant acid phosphatase (TRAP) staining, Tgfbr1 fl/fl ;Wnt1-Cre mice had approximately three-fold less osteoclast number and perimeter than controls. Gene expression of receptor activator of nuclear factor kappa-β (Rank) and Mmp9, markers of osteoclasts and their activity, also showed a three-fold decrease in Tgfbr1 fl/fl ;Wnt1-Cre mandibles. Evaluation of osteoblast-to-osteoclast signaling revealed no significant difference between Tgfbr1 fl/fl ;Wnt1-Cre mandibles and controls, leaving the specific mechanism unresolved. Finally, pharmacological inhibition of Tgfbr1 signaling during the initiation of bone mineralization and resorption significantly shortened jaw length in embryos. We conclude that TGF-β signaling in NCM decreases mesoderm-derived osteoclast number, that TGF-β signaling in NCM impacts jaw length late in development, and that this osteoblast-to-osteoclast communication may be occurring through an undescribed mechanism.

Efficacy of the Coronoid Notch and Occlusal Plane As Predictable Landmarks for Determining the Medial Cut Height in Bilateral Sagittal Split Osteotomy: A Split-Mouth Observational Study.

This split-mouth observational study was conducted to assess the reliability and safety of using the coronoid notch and occlusal plane as landmarks to aid surgeons during bilateral sagittal split osteotomy(BSSO). Thirteen patients between the ages of 18 and 30 years, with class II and class III mandibular skeletal malocclusion requiring BSSO, were randomly selected and assigned to each of the study and control groups. A split-mouth study was chosen to conduct this research. Cone beam computed tomography (CBCT) imaging was conducted before the surgery to evaluate the anatomical structure, and three predefined points were marked at the superiormost point of the mandibular foramen, the inferiormost point of the mandibular foramen, and the deepest point of the sigmoid notch. A conventional sagittal split osteotomy was carried out in the control group. Preoperative values were obtained in the study group using the CBCT imaging technique by drawing an imaginary line from the inferiormost part of the mandibular foramen to the line corresponding to the occlusal plane that extended beyond the last molar. The lingual flap reflection was restricted to the internal oblique ridge. The posterior border of the mandible was not reflected. The measurements acquired via CBCT imaging were accurately transferred to the intraoperative surgical site using a vernier caliper. This facilitated the precise completion of the horizontal osteotomy, ascending ramus cuts, and vertical osteotomies. BSSO was performed, the mandibular setback or advancement was done with intermaxillary fixation, and the procedure was completed by rigid fixation. Types of lingual splits, types of lateral bone cut ends (LBCEs), any unfavorable split, and the time taken for the surgery (in minutes) were assessed. The surgery time in the control group (20.1538 ± 2.85325 min) was found to be higher than that in the study group (17.6154 ± 3.59487 min), with a p-value of 0.02. No significant differences were observed when assessing the presence of unfavorable splits in both groups (p = 0.500). Buccal LBCEs were the most prevalent, followed by inferior types. Type I lingual split was the most common in the study group (70%). This technique offers a dependable anatomical reference and significantly reduces surgical time for beginners. Additionally, the patterns of the lingual split were correlated with the types of lateral bone cut ends.

Surgical Orthodontic Correction for Class III Skeletal Malocclusion: Case Report

Surgical Orthodontic Correction for Class III Skeletal Malocclusion: Case Report

Evaluation of masticatory muscles in patients with different sagittal direction skeletal anomalies by ultrasonography and ultrasonographic elastography.

The aim of this study was to evaluated the masseter, anterior digastric and geniohyoid muscles of individuals with similar growth and developmental periods but different sagittal skeletal malocclusions using ultrasonography and ultrasonographic elastography and to make interclass assessments. In this study, ultrasonography and ultrasonographic elastography records of 30 Class I individuals (17 females, 13 males), 30 Class II individuals (14 females, 16 males), and 27 Class III individuals (12 females, 15 males) in the normodivergent and growth development periodwere used. The masseter, anterior digastric, and geniohyoid muscles of individualswere examinedusing ultrasonography and ultrasonographic elastography, andcomparisons were madebetween the classes. Statistical analysis was accomplished by Mann Whitney U, One-way ANOVA, Kruskal Wallis H tests. Interclass differences were foundin ultrasonography and elastography measurements of the masseter muscle. However, no differences were observed in ultrasonography measurements of the auxiliary masticatory muscles, whereas differences were seen only in the geniohyoid muscle in elastography measurements among the classes (p<0.05). Individuals with different sagittal skeletal malocclusions during growth and development exhibited similar muscle sizes and elasticities, approximately close to each other.

Retrospective analysis of the upper airway anatomy and Sella turcica morphology across different skeletal malocclusions: a computerized technique

ObjectiveThis study aimed to investigate the normal volumetric space and variations in the measurements of different landmarks in adults with different skeletal relations of the maxilla and the mandible based on CBCT data. The study also analyses these landmarks to locate any correlations.BackgroundNumerous studies in orthodontics have found a relationship between orthodontic treatment and changes in the anatomy and function of the airway. Severe changes in airway morphology can cause breathing difficulties, lower quality of life, and even result in life-threatening conditions such as obstructive sleep apnoea. Consequently, orthodontic diagnosis and treatment planning require a thorough understanding of the airway space and its function.MethodsThe present retrospective study was conducted using CBCT records of 120 adult patients, containing 40 samples of each skeletal class (20 males and 20 females). The boundaries were defined for the 3 major regions: the nasopharynx, the oropharynx, and the hypopharynx. Various measurements were recorded across these regions, as well as selective cephalometric landmarks. The obtained data was used to calculate average and standard deviation, while regression analysis was used to evaluate correlations and t-test was used to test statistical significance of gender differences.ResultsThe results demonstrate that skeletal Class III individuals exhibit a reduced airway volume in the nasopharynx compared to other groups, whereas skeletal Class II individuals displayed a diminished airway volume in the hypopharynx. A strong correlation was observed for Sella turcica parameters. There were no significant differences in skeletal parameters across genders. Nasopharynx cavity volume demonstrated significant differences between skeletal Class I–Class III as well as between skeletal Class II–Class III. Hypopharynx cavity volume also demonstrated significant differences between skeletal Class I–Class II and between skeletal Class II–Class III.ConclusionThe major findings are the presence of a reduced nasopharyngeal volume in skeletal Class III malocclusions while skeletal Class II individuals displayed a diminished hypopharyngeal volume, making these critical areas to consider during the diagnostic and orthodontic treatment planning stages. This study also revealed a consistent correlation between Sella turcica parameters across various facial skeletal profiles, with skeletal Class II patients exhibiting a distinct pattern and skeletal Class I and Class III demonstrating an average relationship.

The impact of breastfeeding on facial appearance in adolescent children.

Evidence that breastfeeding impacts the facial features of children is conflicting. Most studies to date have focused on dental and skeletal malocclusion. It currently remains unclear whether such effects are of sufficient magnitude to be detectable on outward facial appearance. Here, we evaluate the extent to which maternally reported breastfeeding is associated with 3D facial shape in a large adolescent cohort. After extracting 3D facial surfaces from MR scans in 2275 9- and 10-year-old children and aligning the surfaces in dense correspondence, we analyzed the effect of breastfeeding on shape as a dichotomous (no/yes) and semi-quantitative (to assess duration in months) variable using partial least squares regression. Our results showed no effect (p = 0.532) when breastfeeding was dichotomized. However, when treated as a semi-quantitative variable, breastfeeding duration was associated with statistically significant changes in shape (p = 3.61x 10-4). The most prominent facial changes included relative retrusion of the central midface, zygomatic arches, and orbital regions along with relative protrusion of forehead, cheek, and mandible. The net effect was that as breastfeeding duration increased, the facial profile in children became flatter (less convex). The observed effects on the face, however, were subtle and likely not conspicuous enough to be noticed by most observers. This was true even when comparing the faces of children breastfed for 19-24 months to children with no reported breastfeeding. Thus, breastfeeding does appear to have detectable effect on outward facial appearance in adolescent children, but its practical impact appears to be minimal.

Open-mouth jaw locking in a 5-year-old Persian cat: a case report.

Open-mouth jaw locking is an uncommon condition in feline patients. A 5-year-old neutered male Persian cat was evaluated for an acute inability to close its mouth and ptyalism. The general physical examination was unremarkable. A complete oral examination revealed a reduced vertical range of motion, as well as an asymmetric malocclusion with severe displacement of the mandibles to the left. Advanced diagnostic imaging included computed tomography (CT), which revealed a typical brachycephalic conformation, skeletal malocclusion and a bilateral temporomandibular joint (TMJ) subluxation, with the left coronoid process of the mandible abnormally positioned ventrolateral to the zygomatic arch. The open-mouth jaw locking was manually reduced and resolved. Once the coronoid process was repositioned, a second CT scan was performed and confirmed complete reduction of the TMJ subluxation. Supportive treatment with meloxicam was administered and a loose-fitting tape muzzle and Elizabethan collar were applied for two weeks. There was no recurrence of open-mouth jaw locking at long-term follow-up. This case report highlights the relevance of CT imaging and 3-dimensional reconstruction in the diagnosis of this unusual condition.

Development and validation of predictive models for skeletal malocclusion classification using airway and cephalometric landmarks

ObjectiveThis study aimed to develop a deep learning model to predict skeletal malocclusions with an acceptable level of accuracy using airway and cephalometric landmark values obtained from analyzing different CBCT images.BackgroundIn orthodontics, multitudinous studies have reported the correlation between orthodontic treatment and changes in the anatomy as well as the functioning of the airway. Typically, the values obtained from various measurements of cephalometric landmarks are used to determine skeletal class based on the interpretation an orthodontist experiences, which sometimes may not be accurate.MethodsSamples of skeletal anatomical data were retrospectively obtained and recorded in Digital Imaging and Communications in Medicine (DICOM) file format. The DICOM files were used to reconstruct 3D models using 3DSlicer (slicer.org) by thresholding airway regions to build up 3D polygon models of airway regions for each sample. The 3D models were measured for different landmarks that included measurements across the nasopharynx, the oropharynx, and the hypopharynx. Male and female subjects were combined as one data set to develop supervised learning models. These measurements were utilized to build 7 artificial intelligence-based supervised learning models.ResultsThe supervised learning model with the best accuracy was Random Forest, with a value of 0.74. All the other models were lower in terms of their accuracy. The recall scores for Class I, II, and III malocclusions were 0.71, 0.69, and 0.77, respectively, which represented the total number of actual positive cases predicted correctly, making the sensitivity of the model high.ConclusionIn this study, it is observed that the Random Forest model was the most accurate model for predicting the skeletal malocclusion based on various airway and cephalometric landmarks.

Changes in mandibular width and frontal-lower facial profile after orthognathic surgery using sagittal split ramus osteotomy with removal of internal bone interference in patients with class III skeletal malocclusion

BackgroundThe purpose of this study is to analyze changes in mandibular width and frontal view ramus inclination using cone beam CT in patients with skeletal class III malocclusion who underwent BSSRO, with the removal of bone interference between segments. MethodsFor all 20 subjects, cone-beam CT imaging was performed prior to surgery (T1), immediately post-surgery (T2), and 6 months after surgery (T3). Reorientation was performed using R2GATE software (MegaGen, Seoul, Korea). The gonion and antegonial notch were used as reference points in the sagittal view, and the most lateral point of the condyle head was used as the reference point in the frontal view. All measurements were recorded in the frontal view.ResultsInter-gonial width decreased by 2.64 mm at T3-T2 (P < .001) and by 2.58 mm at T3-T1 (P < .05). Inter-antegonial width decreased by 1.75 mm at T3-T2 (P < .05) and by 3.5 mm at T3-T1 (P < .001). In the frontal view, the right ramus inclination based on the gonion increased by 2.07° at T3-T1 (P < .05). The left ramus inclination based on gonion increased by 2.45° at T2-T1 (P < .05) and by 3.94° at T3-T1 (P < .001). The right ramus inclination based on antegonial notch increased by 2.35° at T2-T1 (P < .05) and by 3.04° at T3-T1 (P < .01). The left ramus inclination based on antegonial notch increased by 2.73° at T2-T1 (P < .001) and by 3.18° at T3-T1 (P < .001).ConclusionsDuring bilateral sagittal split osteotomy, removing bone interference between the proximal and distal segments results in a reduction of postoperative mandibular width and an increase in frontal view ramus inclination.

Effects of clear aligners combined with maxillary protractor on mixed dentition patient with skeletal class Ⅲ malocclusion: a finite element study

Objective: To compare the effects of expansion screw with maxillary protractor and clear aligners combined with maxillary protractor on the maxilla and maxillary dentition of mixed dentition patients with class Ⅲ skeletal malocclusion using finite element analysis, further providing clinical guidance for clear aligner treatment. Methods: A finite element model was established based on maxillofacial cone-beam CT data of a 10-year-old boy with mixed dentition, class Ⅲ skeletal malocclusion, who visited Department of Orthodontics, School of Stomatology, The Fourth Military Medical University in January, 2024. The expander with protractor group (group A) and the clear aligners with protractor group (group B) were divided. The arch was extended by 0.25 mm in both groups, and the forward pull force was 2.94 N (working condition 1) and 4.90 N (working condition 2), respectively. The initial displacement trend of maxilla and maxillary dentition in two groups under two working conditions were evaluated. Results: Under two working conditions, the maxilla of both groups showed clockwise rotation and labial inclination. The labial inclination of maxilla was more significant in clear aligners with protractor group, about 2.2-3.0 times that of expander with protractor group under the same working condition. Maxillary dentition showed mesial and buccal displacement, with anterior teeth extrusion and posterior teeth intrusion in two groups under two working conditions. Under the working condition 1 and 2, the labial displacement of central incisor of clear aligners with protractor group (-0.065, -0.089 mm) were greater than that in expander with protractor group (-0.024, -0.024 mm). Under two working conditions, the posterior teeth of expander with protractor group moved close to the buccal bodily direction, while those of clear aligners with protractor group moved tilted towards the buccal direction in the horizontal direction. The forward displacement trend of maxilla and maxillary dentition in clear aligners with protractor group was more obvious than expander with protractor group with the increase of the forward pull force. Under two working conditions, the anterior teeth' s hydrostatic stress of periodontal membrane and the equivalent stress of alveolar bone in clear aligners with protractor group were higher than those in expander with protractor group, mainly concentrated on the labial cervical region of the incisor. Conclusions: Clear aligners combined with maxillary protractor can produce forward force on the maxilla, but labial inclination occurs in the anterior teeth. It can be an effective orthopedic treatment strategy for mixed dentition patients with class Ⅲ skeletal malocclusion.

Correlation of the Upper Nasolabial Angle With Skeletal Patterns and Nasal Morphology in Indian Adults: An Observational Study.

The upper nasolabial angle (UNLA) is an important determinant in clinical diagnosis and treatment planning. Therefore, the primary objective of this study was to assess the correlation between various skeletal parameters and nasal morphology in an Indian cohort, particularly UNLA. The secondary objectives were to evaluate sex differences in nasal morphology, optimal cut-off values of the UNLA for skeletal malocclusions, and differences in nasal morphology in different skeletal malocclusions. This retrospective study used 162 pre-treatment lateral cephalometric records of patients with skeletal Class I, Class II, and Class III relationships. Group 1 consisted of 68 skeletal Class I patients (ANB angle of 2-40), Group 2 consisted of 68 skeletal Class II patients (ANB angle > 40), and Group 3 consisted of 26 skeletal Class III patients (ANB angle of less than 20). Each group was further subdivided according to the growth pattern into low (horizontal), average, and high (vertical) growers. The angle between the sella-nasion plane and mandibular plane (SN-GoGn angle) was used to further divide the groups according to their growth pattern into a horizontal growth pattern (SN-GoGn angle < 280), an average growth pattern (SN-GoGn angle of 28-360), and a vertical growth pattern (SN-GoGn angle > 360). The study sample was also divided into males and females to assess gender differences. Spearman's correlation coefficient, multinomial logistic regression analysis, Mann-Whitney U test, and Kruskal-Wallis tests were used. Receiver operating characteristic curves were used to obtain the optimal cut-off values for UNLA. The UNLA showed a positive correlation with the sagittal position of the maxilla and a negative correlation with the sagittal position of the mandible and palatal plane (PP) inclination angle. Statistically significant sex differences were observed in nasal length, nasal depth, and lower anterior facial height. The optimal cut-off values for the UNLA angle in the class II skeletal pattern were ≥ 200, 16-200 for skeletal class I, and ≤ 160 for skeletal class III patients. None of the skeletal and nasal parameters were reliable predictors of the skeletal pattern type. The present study showed that the UNLA increased in the skeletal class II pattern with the downward inclination of the PP. Patients with skeletal class III malocclusion had an upward-canted nasal tip.

Evaluation of the presence of nasal septum deviations in individuals with different skeletal malocclusions

OBJECTIVE: The aim of this study was to evaluate the presence of deviated septum in individuals with different skeletal malocclusions. MATERIALS AND METHOD: The study was performed on cone beam computed tomography images of a total of 159 individuals, 53 in each Class I, Class II, and Class III skeletal malocclusion. Nasal septum deviation was analysed in three groups as mild (type 1; &amp;lt;9°), moderate (type 2; 9-15°), and severe (type3; &amp;gt;15°). In addition, the presence of concha bullosa in different skeletal malocclusions was evaluated. The data were analyzed statistically using the Chi-square test and One-way Analysis of Variance (ANOVA). The relationship betweenskeletal malocclusions and types of deviation was determined using Cramèr’s V analysis. RESULTS: There are statistically significant differences between type 2 and type 3 in individuals with Class I skeletal malocclusion and between type 1 and type 3 in individuals with Class II skeletal malocclusion (p=0.046; p&amp;lt;0.01 respectively). In individuals with Class III skeletal malocclusion, no difference was observed between deviation types. In addition, a weak correlation was found between skeletal malocclusion and deviation types (Cramèr’s V = 0.213). No significant difference was observed between the groups in terms of concha bullosa and deviation side (p=0.215). CONCLUSION: Although a significant difference was observed in terms of deviation type in individuals with Class I and II skeletal malocclusion, a weak correlation was observed between the increase in deviation severity and skeletal malocclusions.

Lateral cephalometric parameters among Arab skeletal classes II and III patients and applying machine learning models

BackgroundThe World Health Organization considers malocclusion one of the most essential oral health problems. This disease influences various aspects of patients’ health and well-being. Therefore, making it easier and more accurate to understand and diagnose patients with skeletal malocclusions is necessary.ObjectivesThe main aim of this research was the establishment of machine learning models to correctly classify individual Arab patients, being citizens of Israel, as skeletal class II or III. Secondary outcomes of the study included comparing cephalometric parameters between patients with skeletal class II and III and between age and gender-specific subgroups, an analysis of the correlation of various cephalometric variables, and principal component analysis in skeletal class diagnosis.MethodsThis quantitative, observational study is based on data from the Orthodontic Center, Jatt, Israel. The experimental data consisted of the coded records of 502 Arab patients diagnosed as Class II or III according to the Calculated_ANB. This parameter was defined as the difference between the measured ANB angle and the individualized ANB of Panagiotidis and Witt. In this observational study, we focused on the primary aim, i.e., the establishment of machine learning models for the correct classification of skeletal class II and III in a group of Arab orthodontic patients. For this purpose, various ML models and input data was tested after identifying the most relevant parameters by conducting a principal component analysis. As secondary outcomes this study compared the cephalometric parameters and analyzed their correlations between skeletal class II and III as well as between gender and age specific subgroups.ResultsComparison of the two groups demonstrated significant differences between skeletal class II and class III patients. This was shown for the parameters NL-NSL angle, PFH/AFH ratio, SNA angle, SNB angle, SN-Ba angle. SN-Pg angle, and ML-NSL angle in skeletal class III patients, and for S-N (mm) in skeletal class II patients. In skeletal class II and skeletal class III patients, the results showed that the Calculated_ANB correlated well with many other cephalometric parameters. With the help of the Principal Component Analysis (PCA), it was possible to explain about 71% of the variation between the first two PCs. Finally, applying the stepwise forward Machine Learning models, it could be demonstrated that the model works only with the parameters Wits appraisal and SNB angle was able to predict the allocation of patients to either skeletal class II or III with an accuracy of 0.95, compared to a value of 0.99 when all parameters were used (“general model”).ConclusionThere is a significant relationship between many cephalometric parameters within the different groups of gender and age. This study highlights the high accuracy and power of Wits appraisal and the SNB angle in evaluating the classification of orthodontic malocclusion.

Assessing masseter muscle volume and activity in relation to craniofacial morphology: a 3D CBCT study.

Understanding the factors influencing craniofacial structure growth is crucial for addressing craniofacial deformities. This study evaluates masseter muscle volume, activity, and maximum bite force across different skeletal malocclusion groups and aims to evaluate the masseter muscle volume, activity, and maximum bite force (BF) according to different skeletal malocclusion groups. This study aimed to assess masseter muscle volume, activity, and maximum bite force (BF) across different skeletal malocclusion groups in 60 young adults (18-30 years) seeking treatment at Kirikkale University Faculty of Dentistry. Cone-Beam Computed Tomography (CBCT) imaging, radiological measurements, surface electromyography (sEMG), and force sensor measurements were employed. Results revealed significant differences in sEMG measurements based on sagittal classification. Vertical direction groups showed notable results in muscle volume and BF, though no significant differences were observed in sEMG values. A correlation was identified between BF and sEMG, but no correlation was found between muscle volume and other parameters. The findings obtained in this study suggest that the significant relationship between EMG and sagittal skeletal classification could be a valuable diagnostic tool. However, concerns about reliability were raised due to uneven distribution in muscle volume and BF among vertical direction groups. The lack of significant results in muscle volume, sEMG, and BF was attributed to CBCT limitations in soft tissue imaging and the small sample size, emphasizing caution in interpreting the findings.

Are zygomatic implants an alternative to orthognathic surgery in the treatment of a vertical discrepancy ? A case series to describe an open bite treatment protocol

IntroductionThis report aims to present case series to describe a treatment protocol for correction of severe open bite in non-growing patients MethodologyPatients diagnosed with skeletal open bite malocclusion (overbite range: -3 to -6 mm) were treated using a bonded appliance and skeletal anchorage. Intrusive force was applied between buccal bars of appliance and zygomatic multipurpose implants (MPI). Intrusion was continued until positive overbite occurred. Treatment progressed with conventional fixed orthodontic treatment for alignment and settling. MPIs were retained until the end of treatment for retention of intrusion ResultsClinically effective open bite correction was achieved by intrusion of maxillary buccal segment and mandibular counterclockwise autorotation ConclusionThis protocol includes zygomatic anchorage and an appliance that aims triple intrusion effect through combination of orthodontic and physiological forces. Achieving significant maxillary intrusion, controlling mandibular eruption and maximizing mandibular counterclockwise autorotation are the main outcomes of this protocol.

Comprehensive treatment approach for hemifacial microsomia: Integrating orthognathic surgery with sequential customized implantation

ObjectiveThis study aims to evaluate the clinical outcomes of combining orthognathic surgery with staged patient-specific implants (PSIs) for comprehensive craniofacial asymmetry reconstruction in adult hemifacial microsomia (HFM) patients. MethodsSix adult HFM patients (1 Type I and 5 Type IIa) underwent orthognathic surgery to correct skeletal malocclusion and chin deviation. Sequential PSIs were implanted to address craniofacial asymmetry. Digital lateral cephalograms and cranial CT scans were obtained at four time points: pre-orthognathic surgery (T0), within three months after orthognathic surgery (T1), one year after orthognathic surgery and just before personalized implantation (T2), and after personalized implantation (T3). Evaluation parameters included skeletal and dentoalveolar measures, occlusal cant, chin deviation, skeletal stability, and facial contour symmetry. ResultsAt T1, no significant differences were observed in skeletal movements compared to planned surgical movements (p > 0.05). Similarly, at T2, skeletal movements did not significantly differ from those observed at T1 (p > 0.05), indicating surgical precision and stability. Analysis of skeletal and dentoalveolar parameters, occlusal cant, and chin deviation revealed significant increases in SNB, FH-NPo, and ST N vert-Pog at T1 compared to T0 (p < 0.05), along with notable improvements in chin deviation and occlusal cant (p < 0.05). Comparison of T2 to T1 showed no significant changes in SNB, FH-NPo, ST N vert-Pog, chin deviation, or occlusal cant (p > 0.05), indicating substantial postoperative stability. Following personalized implantation (T3), further significant improvements were observed in skeletal symmetry. ConclusionCombining orthognathic surgery with staged PSIs effectively reconstructs craniofacial asymmetry in adult HFM patients, achieving significant improvements in skeletal alignment, occlusal cant, and chin deviation, with stable outcomes over time.