Identification of a de novo PUF60 variant associated with craniofacial microsomia.

Craniofacial microsomia (CFM), also known as the oculo-auriculo-vertebral spectrum, is a congenital disorder characterized by hypoplasia of the mandible and external ear due to tissue malformations originating from the first and second branchial arches. However, distinguishing it from other syndromes of branchial arch abnormalities is difficult, and causal variants remain unidentified in many cases. In this report, we performed an exome sequencing analysis of a Brazilian family with CFM. The proband was a 12-month-old boy with clinical findings consistent with the diagnostic criteria for CFM, including unilateral mandibular hypoplasia, microtia, and external auditory canal abnormalities. A heterozygous de novo nonsense variant (c.713C>G, p.S238*) in PUF60 was identified, which was predicted to be pathogenic in silico. PUF60 has been reported as a causal gene in Verheij syndrome, but not in CFM. Although the boy showed craniofacial abnormalities and developmental delay that overlapped with Verheij syndrome, the facial asymmetry with unilateral hypoplasia of the mandible observed in this case did not match the previously reported phenotypes of PUF60 variants. Our findings expand the phenotypic range of PUF60 variants that cover CFM and Verheij syndrome.

A cross-sectional study on three-dimensional compensatory characteristics of maxillary teeth in patients with different types of skeletal Class III malocclusion with mandibular asymmetry.

OBJECTIVE: The purpose of this study was to analyze three-dimensional dental compensation in patients with different types of skeletal Class III malocclusion with mandibular asymmetry, using cone-beam computed tomography (CBCT) and three-dimensional reconstruction measurement technology, thereby providing clinical guidance and reference for combined orthodontic and orthognathic treatment. METHODS: 81 patients with skeletal Class III malocclusion with mandibular asymmetry were selected in accordance with the inclusion criteria. According to a new classification method based on the direction and amount of menton deviation relative to ramus deviation, patients were divided into three groups called Type 1, Type 2, and Type 3. In Type 1, the direction of menton deviation was consistent with that of ramus deviation and the amount of menton deviation was greater than that of ramus deviation. In Type 2, the direction of menton deviation was consistent with that of ramus deviation and the amount of menton deviation was smaller than that of ramus deviation. In Type 3, the direction of menton deviation was inconsistent with that of ramus deviation. The maxillary occlusal plane (OP), anterior occlusal plane (AOP), and posterior occlusal plane (POP) were measured on reconstructed CBCT images. The vertical, transverse, and anteroposterior distances from maxillary teeth to reference planes and the 3D angles between the long axis of these teeth and reference planes were measured. These dental variables measured from the deviated and non-deviated sides were compared within each group, as well as among each other. RESULTS: Of the 81 patients with asymmetrical Class III malocclusion, 52 patients were categorized in Type 1, 12 patients in Type 2, and 17 patients in Type 3. There were significant differences between deviated and non-deviated sides in Type 1 and Type 3 (p < 0.05). In Type 1, the vertical distances of maxillary teeth on the deviated side were lower than those on the non-deviated side, and AOP, OP, and POP on the deviated side were larger than those on the non-deviated side (p < 0.05). In Type 3, the vertical distances of the maxillary teeth on the deviated side were lower (p < 0.05), and the AOP and OP on the deviated side were larger than those on the non-deviated side. In all three groups, the transverse distances of the maxillary teeth from the mid-sagittal plane on the deviated side were larger than those on the non-deviated side (p < 0.05), and the angles between the long axis of maxillary teeth and the mid-sagittal plane on the deviated side were larger, respectively (p < 0.05). CONCLUSIONS: The maxillary teeth on the deviated side were observed to have smaller eruption heights in Type 1 and Type 3. In Type 1, AOP, POP, and OP were greater on the deviated side, while in Type 3, only AOP and OP were greater on the deviated side. The maxillary teeth of patients in all three groups on the deviated side were buccal and buccally inclined. Larger sample observations are still needed to further verify these findings.

Occlusal function and electromyographic activity of masticatory muscles in skeletal Class III patients with different patterns of mandibular asymmetry.

BACKGROUND: Although jaw asymmetry is commonly seen in skeletal Class III patients, its correlation with occlusal function and masticatory muscle activity has not been fully elucidated. OBJECTIVES: The purpose of this study was to investigate the occlusal function and masticatory muscle activity in skeletal Class III patients with various patterns of mandibular asymmetry. METHODS: Forty-two patients and 10 normal participants were examined. The patients were categorised into three groups. Groups 1 and 2 exhibited menton and ramus deviation to the same side. Menton deviation was larger than ramus deviation in Group 1, whereas Group 2 showed the inverse relation. Group 3 patients showed menton and ramus deviation in opposite directions. Occlusal contact area (OCA), relative bite force (RBF), and temporalis anterior (TA) and masseter muscle (MM) activity at maximum clenching were measured using T-Scan Novus system and Bio-EMG-III. Statistical analysis was performed using the t-test, one-way analysis of variance with Bonferroni correction and Spearman correlation (α = .05). RESULTS: Compared with normal participants, the patients had smaller OCA and greater asymmetry in the distribution of masticatory muscle activity. Greater ramus deviation was associated with smaller OCA in Group 1 but with larger OCA in Group 3. In Group 1, greater menton deviation was related to stronger TA activity on the non-deviation side. In Group 2, greater ramus deviation was related to stronger MM activity on the deviation side. CONCLUSION: Deviation of the menton and ramus was individually related to OCA and masticatory muscle activity, and this relationship varied according to the pattern of mandibular asymmetry.

Type of mandibular asymmetry affects changes and outcomes of bimaxillary surgery for class III asymmetry.

OBJECTIVES: Various methods have been used to classify class III asymmetry. There is little information on the use of an asymmetry index to examine soft tissue changes and outcomes for patients with class III asymmetry. This study aimed to (1) evaluate soft tissue changes and outcomes for three types of mandibular asymmetry and (2) determine if measures are associated with type of asymmetry. MATERIALS AND METHODS: Adults who consecutively underwent bimaxillary surgery using surgery-first approach for correction of class III asymmetry were divided into three groups based on type of mandibular asymmetry. This previously reported classification system is simple and mutually independent, categorizing mandibular asymmetry according to the amount and direction of ramus asymmetry relative to menton deviation: patients with a larger transverse ramus distance on the menton deviation side were divided into group 1 and group 2; group 1 (n = 45) exhibited a menton deviation larger than ramus discrepancy; group 2 (n = 11) exhibited a menton deviation less than ramus discrepancy; group 3 (n = 22) had larger transverse ramus distance contralateral to the side of the menton deviation. Soft tissue facial asymmetry indices, calculated from cone beam computed tomography images, assessed midline and contour asymmetry presurgery, changes postsurgery, and outcomes. RESULTS: Compared with groups 1 and 2, the presurgery index for contour and midline asymmetry was smallest for group 3. All the three groups had significant improvement in midline asymmetry postsurgery, and outcome measures were good; there were no differences between groups. However, contour asymmetry only improved significantly for groups 1 and 2. The outcome for contour asymmetry was fair for groups 1 and 3 and poor for group 2. CONCLUSIONS: Bimaxillary surgery significantly improved facial midline asymmetry. The type of mandibular asymmetry was associated with postsurgical changes and outcomes for contour asymmetry. CLINICAL RELEVANCE: Understanding the types of mandibular asymmetry could help clinicians to develop treatment plans and predict treatment changes and outcomes.

Is the pattern of mandibular asymmetry in mild craniofacial microsomia comparable to non-syndromic class II asymmetry?

OBJECTIVES: To compare the characteristics of mandibular asymmetry in patients with unilateral craniofacial microsomia (CFM) and class II asymmetry. MATERIALS AND METHODS: Pretreatment cone-beam computed tomography of consecutive adults with Pruzansky-Kaban type I and IIA CFM (CFM group) was analyzed by 3D cephalometry. Fourteen mandibular landmarks and two dental landmarks were identified. The mandibular size and positional asymmetry were calculated by using landmark-based linear and volumetric measurements, in terms of asymmetry ratios (affected/non-affected side) and absolute differences (affected - non-affected side). Results were compared with non-syndromic class II with matched severity of chin deviation (Class II group). Statistical analyses included independent t test, paired t test, chi-square test, and ANOVA. RESULTS: CFM group (n, 21; mean age, 20.4 ± 2.5 years) showed significantly larger size asymmetry in regions of mandibular body, ramus, and condyle compared to Class II group (n, 21; mean age, 27.8 ± 5.9 years) (p < 0.05). The curvature of mandibular body was asymmetric in CFM. Regarding the positional asymmetry of mandibular body, while a comparable transverse shift and a negligible yaw rotation were found among the two groups, the roll rotation in CFM was significantly greater as well as the occlusal (6.06° vs. 4.17°) and mandibular (7.84° vs. 2.80°) plane cants (p < 0.05). CONCLUSIONS: Mild CFM showed significantly more severe size asymmetry and roll rotation in mandible than non-CFM class II asymmetry. CLINICAL RELEVANCE: To improve the mandibular size and positional asymmetry in CFM, adjunct hard tissue augmentation or reduction in addition to OGS orthodontics with a meticulous roll and yaw planning is compulsory, which is expected to be distinct from treating non-CFM class II asymmetry.

Vertical growth pattern as a determinant of mandibular asymmetry.

Objectives: To determine normal mandibular linear values in three vertical groups, to compare right and left side to highlight a prevalent pattern towards mandibular asymettry. Methods: This is a descriptive cross sectional study in which pre-orthodontic treatment panoramic radiographs and lateral cephalograms of 224 patients (between 18 to 34 years) undergoing treatment in Orthodontic Department of Bahria University Medical and Dental College were used and traced on an acetate sheet. There were 74 patients in high angle,76 and 78 in low angle and normal angle group respectively based on their vertical growth pattern using SNMP angle. Condylar height (CH) and Ramal height (RH), and condylar plus ramal height (CH+RH) measurements were done as previously described by Habets. Results: There was no statistically significant difference between the three groups as determined by one way ANOVA. Condylar height and Gonial angle showed statistically significant difference when right and left side was compared, with increased values on the right side. Conclusion: There was no statistically significant difference in condylar, ramal, and total asymmetry index between different vertical groups. Between the right and left sides, condylar height and gonial angles were significantly increased on the right side. However, Ramal height showed no significant difference. Ramal index has a strong linear correlation with total asymmetry index.

Mandibular asymmetry as a possible etiopathologic factor in temporomandibular disorder: a prospective cohort of 134 patients.

OBJECTIVES: The present study aimed to investigate mandibular asymmetry as a possible etiopathologic factor in temporomandibular disorder (TMD). MATERIALS AND METHODS: A prospective cross-sectional study of patients with dentofacial deformities seeking corrective orthognathic surgery was conducted. The pre-operative prevalence of TMD in patients with mandibular asymmetry and other dentofacial deformities was assessed using the Diagnostic Criteria for TMD (DC/TMD) Axis I protocol. RESULTS: A total of 134 patients were recruited - 82 with mandibular asymmetry and 52 without. There was a significantly higher prevalence of TMD in those with mandibular asymmetry (67.1%; 95% CI 59 to 75%) compared to those without (40.4%; 95% CI 32 to 49%, p = 0.002). The overall pre-operative prevalence of TMD in this population of patients was 56.7% (95% CI 48 to 65%). Pain disorder only was present in 9.7%, TMJ disorder only in 29.9%, and both pain and TMJ disorders in 17.2%. The most prevalent type of TMD is disc displacement with reduction (77.6%), followed by myalgia (35.5%) and arthralgia (21.1%). CONCLUSION: The prevalence of TMD in those with mandibular asymmetry was significantly higher than those without, suggesting that mandibular asymmetry could be a possible etiopathologic factor in TMD. CLINICAL RELEVANCE: The significantly higher prevalence of temporomandibular disorder in those with mandibular asymmetry suggests that we need to be especially cognizant of this condition in our pre-operative, surgical, and post-operative management of this group of orthognathic patients.

Automated Real-Time Evaluation of Condylar Movement in Relation to Three-Dimensional Craniofacial and Temporomandibular Morphometry in Patients with Facial Asymmetry.

The aim of this study was to investigate the correlation between craniofacial morphology, temporomandibular joint (TMJ) characteristics, and condylar functional movement in patients with facial asymmetry using an up-to-date automated real-time jaw-tracking system. A total of 30 patients with mandibular asymmetry and prognathism were included. Three-dimensional (3D) craniofacial and TMJ morphometric variables were analyzed in images captured using cone-beam computed tomography. Three-dimensional condylar movements were recorded during the opening, protrusion, and laterotrusion of the jaw and divided into those for deviated and non-deviated sides. Overall functional and morphometric variables were compared between the sides by a paired t-test. Pearson's correlation analysis and factor analysis were also performed. As a result, significant differences were found between the sides in morphometric and functional variables. The condylar path length was significantly longer and steeper on the deviated side during protrusion and lateral excursion. TMJ morphometric asymmetry, more so than the craniofacial morphologic asymmetry, seemed to be reflected in the functional asymmetry, representing different correlations between the sides, as supported by factor analysis. This study provides evidence explaining why the asymmetric condylar path remained unchanged even after orthognathic surgery for the correction of craniofacial asymmetry.

Effect of facial profile convexity on the perception of mandibular asymmetry using three-dimensional stereophotogrammetric images.

OBJECTIVE: The aim of this study was to test the hypothesis that sagittal anomalies have an effect on the perception of mandibular asymmetry. Secondly, it aimed to determine the asymmetry perception threshold of orthodontist and laypeople. SETTING AND SAMPLE POPULATION: A total of 90 individuals were included in the study from different professions (Orthodontist: n:45, layperson: n:45). MATERIALS & METHODS: The reference image was obtained with 3dMD device and selected from among the individuals with class I soft tissue relationship. In the sagittal direction, the chin area has been moved as to produce 5 and 10 degrees of change in facial convexity angle. Similarly, 0, 2, 4, 6, 8 and 10 mm changes were made and recorded in video format. Manipulated images were scored by participants with VAS method. RESULTS: When differences between the groups were evaluated, the reference image was scored similarly by orthodontists and layperson (P: .017). No statistically significant difference was observed between the groups in other parameters (P > .05). Asymmetry in 0-2 mm range was evaluated by orthodontist and layperson and statistically insignificant (P > .05). Similarly, the change between 8 mm and 10 mm was different in both groups and statistically insignificant (P > .05). Also, when there was no asymmetry, the sagittal direction was differently scored by the participants in both groups and statistically insignificant (P > .05). CONCLUSIONS: It was observed that the effect of sagittal direction changes on asymmetry perception was not statistically significant.

Three-dimensional characterization of mandibular asymmetry in craniofacial microsomia.

OBJECTIVES: This study aimed to investigate the three-dimensional (3D) mandibular asymmetry in craniofacial microsomia (CFM) and its association with the Pruzansky-Kaban classification system. MATERIALS AND METHODS: Cone-beam computed tomography images of 48 adult CFM cases were collected. The asymmetry of the mandibular body and ramus was analyzed with 3D landmarks. The mirrored mandibular model was registered on the original model, yielding a color-coded distance map and an average distance (i.e., asymmetry score) to quantify the overall mandibular asymmetry. RESULTS: The lengths of the mandibular body and ramus were significantly shorter on the affected than the contralateral side (p < 0.001). The ANB (p = 0.009), body and ramal lengths (both p < 0.001), and body and ramal length asymmetry (both p < 0.05) were significantly different between mild (types I/IIA) and severe (types IIB/III) cases. The mandibular asymmetry score correlated with mandibular body length asymmetry (r = 0.296, p = 0.046). CFM mandibles showed high variability in shape asymmetry. CONCLUSIONS: CFM patients showed distinct body and ramal length asymmetries. In severe cases, mandibles were smaller, more retruded, and more asymmetric in length. The mandibular shape asymmetry was highly variable regardless of the Pruzansky-Kaban types, being a determinant in the extent of overall mandibular asymmetry. CLINICAL RELEVANCE: The 3D morphologic analysis provides better insights into real mandibular asymmetry. Although the Pruzansky-Kaban classification was applied, high individual variability of the mandibular morphology still existed within the types. Therefore, individualized analyses and treatment plans for CFM patients are highly recommended.

Disruption of the ERK/MAPK pathway in neural crest cells as a potential cause of Pierre Robin sequence.

Disrupted ERK1/2 signaling is associated with several developmental syndromes in humans. To understand the function of ERK2 (MAPK1) in the postmigratory neural crest populating the craniofacial region, we studied two mouse models: Wnt1-Cre;Erk2(fl/fl) and Osr2-Cre;Erk2(fl/fl). Wnt1-Cre;Erk2(fl/fl) mice exhibited cleft palate, malformed tongue, micrognathia and mandibular asymmetry. Cleft palate in these mice was associated with delay/failure of palatal shelf elevation caused by tongue malposition and micrognathia. Osr2-Cre;Erk2(fl/fl) mice, in which the Erk2 deletion is restricted to the palatal mesenchyme, did not display cleft palate, suggesting that palatal clefting in Wnt1-Cre;Erk2(fl/fl) mice is a secondary defect. Tongues in Wnt1-Cre;Erk2(fl/fl) mice exhibited microglossia, malposition, disruption of the muscle patterning and compromised tendon development. The tongue phenotype was extensively rescued after culture in isolation, indicating that it might also be a secondary defect. The primary malformations in Wnt1-Cre;Erk2(fl/fl) mice, namely micrognathia and mandibular asymmetry, are linked to an early osteogenic differentiation defect. Collectively, our study demonstrates that mutation of Erk2 in neural crest derivatives phenocopies the human Pierre Robin sequence and highlights the interconnection of palate, tongue and mandible development. Because the ERK pathway serves as a crucial point of convergence for multiple signaling pathways, our study will facilitate a better understanding of the molecular regulatory mechanisms of craniofacial development.

Description of Mandibular Improvements in a Series of Infants With Congenital Muscular Torticollis and Deformational Plagiocephaly Treated With Physical Therapy.

BACKGROUND: Many infants with congenital muscular torticollis (CMT) have deformational plagiocephaly (DP), and a small cohort also demonstrate mandibular asymmetry (MA). The aim of this retrospective study was to evaluate mandibular changes in these infants with previous computed tomography (CT) scans who underwent physical therapy (PT) to treat CMT. METHODS: A retrospective study included patients presenting to a pediatric plastic surgery clinic from December 2010 to June 2012 with CMT, DP, and MA. A small subset of these patients initially received a 3D CT scan due to concern for craniosynostosis. An even smaller subset of these patients subsequently received a second 3D CT scan to evaluate for late-onset craniosynostosis. Patients were treated with PT for at least 4 months for CMT. Initial CT scans were retrospectively compared to subsequent CT scans to determine ramal height asymmetry changes. Clinical documentation was reviewed for evidence of MA changes, CMT improvement, and duration of PT. RESULTS: Ten patients met inclusion criteria. Ramal height ratio (affected/unaffected) on initial CT was 0.87, which significantly improved on subsequent CT to 0.93 ( P < .05). None of the patients were diagnosed with craniosynostosis on initial CT. One patient was diagnosed with late-onset coronal craniosynostosis on subsequent CT. CONCLUSIONS: We identified a small cohort of infants with MA, CMT, and DP. These patients uniformly demonstrated decreased ramal height ipsilateral to the affected sternocleidomastoid muscle. Ramal asymmetry measured by ramal height ratios improved in all infants undergoing PT.

Cone Beam Computed Tomographic Evaluation of Mandibular Asymmetry in Patients with Cleft Lip and Palate.

OBJECTIVE: The purpose of the present study was to compare mandibular vertical asymmetry in patients with unilateral and bilateral cleft lip and palate and subjects with normal occlusion. MATERIALS AND METHODS: Cone beam computed tomography scans of three groups consisting of 20 patients with unilateral cleft lip and palate, 20 patients affected by bilateral cleft lip and palate, and a control group of 20 subjects with normal occlusion were analyzed for this study. Condylar, ramal, and condylar plus ramal asymmetry indices were measured for all subjects using the method of Habets et al. Kruskal-Wallis and Mann-Whitney tests were used to determine any significant differences between the groups for all indices at the 95% level of confidence. RESULTS: There were no significant differences regarding sex for all mandibular asymmetry indices in all three groups. All Asymmetry indices (condylar, ramal, and condylar plus ramal asymmetry) were significantly higher in the unilateral cleft group compared with the other two groups. CONCLUSION: Cone beam computed tomography images showed that patients with cleft lip and palate suffered from mandibular asymmetry. Subjects with unilateral cleft lip and palate had a more asymmetric mandible compared with the bilateral cleft lip and palate and control groups. Therefore, the mandible appears to be the leading factor in facial asymmetry in subjects with unilateral cleft lip and palate.

Mandibular asymmetry in patients with the crouzon or apert syndrome.

The aim of this study was to describe directional and fluctuating mandibular asymmetry over time in children with Crouzon or Apert syndrome. Mandibular asymmetry of children between 7.5 and 14 years of age with Crouzon syndrome (n = 35) and Apert syndrome (n = 24) were compared with controls (n = 327). From panoramic radiographs, mandibular directional and fluctuating asymmetry was determined for the three groups. Multilevel statistical techniques were used to describe mandibular asymmetry changes over time. Patients with Crouzon and Apert syndromes showed statistically significant more fluctuating asymmetry for mandibular measures than did controls. Between the Crouzon and Apert syndromes groups, no statistical differences were found in directional and fluctuating asymmetry. The control group showed statistically significantly more directional asymmetry than did patients with Crouzon or Apert syndrome. The controls showed no change over time for the directional asymmetry of condylar-ramal height; however, the directional asymmetry of the gonial angle increased. Patients with Crouzon syndrome showed side dominance for only condylar-ramal height; whereas, patients with Apert syndrome did not show dominance for any of the measurements. Apert and Crouzon syndromes showed developmental instability, in contrast to the controls. No statistically significant longitudinal differences were found for either the directional or the fluctuating asymmetry between Crouzon and Apert syndromes. Findings for fluctuating and directional asymmetry for both syndromes may indicate an inability to cope with genetic and environmental stress during development and treatment, compared with untreated nonsyndromic individuals.

Condylar process contributes to mandibular asymmetry: In vivo 3D MRI study.

The purpose of this study was to investigate the differences in mandibular morphology between the deviated and nondeviated sides in patients with noncongenital skeletal mandibular asymmetry. Divergences from control values were assessed to determine which region of the mandible contributes most to mandibular asymmetry. We measured various dimensions of the mandible in 20 young patients and 20 controls using noninvasive high-quality three-dimensional (3D) volumetric magnetic resonance imaging. Mandibular dimensions including the length of the condylar process were significantly greater on the nondeviated side of patients than the deviated side. Measurements of the deviated side were similar to control values, but measurements of the nondeviated side including condylar process length differed significantly from control values. These findings strongly suggest that overgrowth of the condylar process on the nondeviated side in these patients results in mandibular asymmetry, and therefore needs attention in orthodontic treatment, orthognathic surgery, and follow-up.

Radiographic and diagnostic approaches for mandibular asymmetries in orthodontic practice: a narrative review.

Mandibular asymmetry refers to dimensional differences between the left and right sides of the mandible in terms of size, form and volume. This condition may result in problems with functionality as well as appearance. Early intervention is often deemed optimal for addressing mandibular asymmetry; however, there is a lack of consensus regarding the diagnostic approach and strategy for identifying asymmetries in developing individuals. The purpose of this narrative review (NR) is to provide a clinician-focused update on the radiographic techniques for identifying mandibular asymmetries in orthodontic patients. Selective database searches were conducted until November 2023 to assess the available literature on mandibular asymmetry diagnosis. A health-sciences librarian developed a search strategy utilizing appropriate terms associated with mandibular asymmetry diagnosis. The databases used were Web of Science, Embase, Scopus, Liliacs and PubMed. Fifty-two studies were included in this review and data regarding the evaluation of mandibular asymmetries were presented with a narrative approach delineating clinical indications based on retrieved findings. There is no unanimous consensus on the method for diagnosing mandibular asymmetries. Cone beam computed tomography emerges as the preferred examination method for diagnosing mandibular asymmetry, thanks to the assessment of a 3D structure with a 3D image. However, the use of only orthopantomography could be advisable as a first-line diagnostic tool in children due to less radiation exposure.

Prevalence of mandibular asymmetries in the pediatric population of Jazan: A radiographic analytical study.

Background: Facial asymmetry results from variation in mandibular linear and angular dimensions on the right and left sides of the face. Mandibular asymmetry is of great significance to oral surgeons and orthodontists as it directly impacts the facial profile of an individual. Aim: The present study aimed to measure the prevalence of mandibular asymmetry and its fluctuations during the mixed dentition growth phase in healthy children aged 6-8 years in the Jazan region of Saudi Arabia. Method: This retrospective observational study was conducted by measuring linear asymmetrical measurements of mandible on orthopantomograms of 390 healthy children (182 boys and 208 girls, aged 6-8 years) with mixed dentition. Linear measurements from orthopantomograms were obtained using a standardized digitizer. Two sets of mandibular measurements were recorded, alongside subjective assessments of mandibular first molar development. An independent t-test was employed to assess the significance between measurements on both sides, while one-way ANOVA was used to demonstrate facial asymmetry significance among different age groups. Result: The result of this study revealed a significant statistical difference (p-value≤ 0.05) for both sides of the mandible across two dimensions: condylar and ramus height (p value = 0.03) and mandibular length (p value = 0.04). The asymmetry index resulted in no asymmetry among most of the included subjects. However, compared to the other three linear measurements, many seven-year-old participants possess mandibular asymmetry on condylar height (54.5 %). Conclusion: Within the limitation it could be concluded that children in growing age have a significant mandibular asymmetry (mainly 7 years), which, however, is only seldom clinically significant. Hence, treatment plan should be cautiously planned.

Vertical mandibular asymmetry and hand measurements in patients in growth: cross-sectional study.

Objectives: The aim of this study was to determine the relationship between the vertical mandibular ramus asymmetry and the hand measurements asymmetry in growing patients. Material and Methods: Panoramic radiographs and comparative radiographs of the right and left hands of 40 patients (14 males and 26 females) between 6 and 16 years old (mean age of 11.35±1.99 years) were evaluated. The total height of the mandibular ramus was measured, and the asymmetry index was calculated. The lengths of the proximal, middle and distal phalanges and the metacarpals of the five digits of both hands were measured and the absolute differences R-L were calculated for each one. Results: A statistically significant association between the presence of vertical mandibular ramus asymmetry and the presence of phalanges asymmetry FPII (p=0.016), FPIII (p=0.016), FPIV (p=0.033), FMIII (p=0.031) and FMIV (p=0.016) was observed. Conclusions: Mandibular asymmetry appears not to be isolated but also present in other body districts such as the phalanx bones. The total vertical asymmetry of the mandibular ramus showed an association with the asymmetry of the lengths of the FPIII, FMIII, FPIV, FMIV and FPII in growing individuals, with association between the side of mandibular asymmetry and the side of the phalanx's asymmetry. The asymmetry of this phalanges increases with increasing index of vertical mandibular ramus asymmetry.

Mandibular condyle volumes are associated with facial asymmetry in patients with cleft lip and palate: A retrospective cohort study.

This study compares condylar volumetric asymmetry and facial asymmetry in patients with cleft lip and/or palate (CLP) and controls. The mandibular condyle is important to facial growth, but its role in facial asymmetry for those with CLP has not been described. Condylar volumes and mandibular asymmetry were retrospectively calculated using Mimics Version 23.0 (Materialise, Leuven, Belgium) from patients with CLP undergoing computed tomography (CT) imaging and a cohort of controls. A total of 101 participants, 60 with CLP and 41 controls, had mean condylar volumetric asymmetry of 16.4 ± 17.4 % (CLP) and 6.0 ± 4.0 % (controls) (p = 0.0002). Patients with CLP who had clinically significant chin deviation (>4 mm) had more asymmetric condyles than those without significant chin deviation (p = 0.003). The chin deviated toward the smaller condyle in patients with facial asymmetry more often than in patients without facial asymmetry (81 % vs. 62 %, p = 0.033). While controls had some degree of condylar asymmetry, it tended to be milder and not associated with facial asymmetry. There is a greater degree of condylar volumetric asymmetry in patients with CLP compared to individuals in the general population. Clinically significant facial asymmetry in CLP is associated with a higher degree of condylar asymmetry, with the facial midline deviating toward the smaller condyle.

Hanna's Modified Sagittal Split Osteotomy (HSSO): An Alternative to Inverted L Osteotomy-Merging Function and Aesthetics for Enhanced Stability, Attractiveness, and Nerve Protection.

Background: The current high standards in orthognathic surgery demand surgical solutions that are both ⁠ functionally ⁠ effective and aesthetically pleasing. Our approach offers one for enhanced stability, attractiveness, and nerve protection ⁠ with improved accessibility ⁠ in the majority of orthognathic scenarios ⁠ compared to an inverted L osteotomy. Methods: A case series is presented to illustrate the application and outcomes of HSSO, an optimised approach that combines the advantages of a transoral inverted L osteotomy with specific enhancements and increased versatility, ⁠ with accessibility and exposure similar to a BSSO. Results: HSSO as a completely transoral technique, demonstrate the ability to perform significant counterclockwise rotations of the mandible, eliminating the need for trocars or skin incisions. We experinced high postoperative stability when HSSO was performed in conjunction with a three-piece LeFort 1 osteotomy on a dynamic opposing arch. In comparison to an inverted L approach, we postulated that HSSO offers advantages in stability, due to the increased segmental overlap of the proximal and distal segments of the mandible. This approach is designed to enhance the safety of the inferior alveolar nerve compared to traditional sagittal split methods. Furthermore, HSSO represents an alternative to total joint replacement in select cases of idiopathic condylar resorption and is effective for correcting mandibular asymmetries while maintaining jawline aesthetics. This is achieved through the manipulation of the mandibular angle, ramus height, and inferior border without creating a step deformity in the soft tissue. Conclusions: The outcomes of HSSO highlight its capacity to deliver predictable, functional, and aesthetically pleasing results, offering a viable alternative to more traditional orthognathic techniques.