Three-dimensional analysis of mandibular morphology asymmetry and temporomandibular joint position in patients with unilateral Brodie bite

OBJECTIVE

Previous studies have shown unilateral posterior crossbite is associated with mandibular asymmetry in morphology and position. However, it remains unclear whether unilateral Brodie bite plays a similar role in mandibular development. Therefore, this study aims to investigate the morphological and positional symmetry of mandibles in patients with unilateral Brodie bite by three-dimensional anaylsis.

METHODS

Fourteen patients with unilateral Brodie bite (mean age 18.43 ± 4.24 years) and fourteen sex- and age-matched patients with normal occlusion (mean age 18.07 ± 5.48 years) underwent cone-beam computed tomography (CBCT) scans. 3D surface mesh models of their mandibles were established using Mimics Research 19.0. The surface matching percentage was compared between the original and mirrored mandible by Geomagic Control X software. Furthermore, the dimension and position of the temporomandibular joint (TMJ) were determined for both groups using InVivoDental 5.0.

RESULTS

For surface-to-surface deviation analysis, the percentage of mismatch in patients with unilateral Brodie bite was significantly higher than the control group at ±0.50 mm, ±0.75 mm, and ±1.00 mm tolerance (P < .001). In patients with unilateral Brodie syndrome, the condyles on the scissors-bite side showed a significantly more anterior position (P = .03), greater medial inclination (P < .01), and larger posterior TMJ space (P = .01) than the non-scissors-bite side.

CONCLUSION

Patients with unilateral Brodie bite exhibit a more asymmetrical mandibular morphology, with a greater anterior condylar position and posterior joint space on the scissors-bite side, indicating that early diagnosis and treatment may be necessary for patients with unilateral Brodie bite.

Internal structural analysis of the nasomaxillary complex in patients with skeletal class III asymmetry: A study on asymmetry patterns

OBJECTIVES

To investigate the internal structure of the nasomaxillary complex, including the maxillary sinus, nasal cavity and nasal septum according to the facial asymmetry pattern and to evaluate its correlation with external maxillomandibular asymmetry in Class III patients based on cone-beam computerized tomography (CBCT) images.

MATERIALS AND METHODS

Facial asymmetry was analysed in a total of 100 Class III patients aged 16 years or older using CBCT scans. Patients were categorized into subgroups based on asymmetry pattern. Measurements of the nasomaxillary complex were obtained from the CBCT scans, including the volume and width of the maxillary sinuses and nasal cavities on deviated and non-deviated sides, as well as the displacement of the nasal septum. Statistical analysis was performed to compare the internal nasomaxillary variables within and between groups, and regression analysis was conducted to evaluate the correlation between facial asymmetry and the internal nasomaxillary variables.

RESULTS

Group comparisons showed that there were no significant differences in the volume of the maxillary sinus and nasal cavity. However, the direction and extent of nasal septum deviation, as well as the width of the nasal cavity, varied depending on the maxillary asymmetry pattern. Regression analysis indicated a correlation between nasal septum deviation and the difference in maxillary height, while the difference in nasal cavity width was correlated with the difference in maxillary width.

CONCLUSION

A comprehensive evaluation of the internal nasal anatomy is vital for understanding the intricate relationship between nasal structure and maxillary growth.

A proposed protocol for correlation between bone density in hemimandibular hyperplasia radiography and histopathological findings - A retrospective study

The role of low-dose computed tomography (LDCT) in surgical planning can be assessed based on the correlation among bone density (BD/HU), radiographic values, and the histopathological appearance of hyperplastic overgrowth in mandibular condyles (hemimandibular hyperplasia/osteochondroma). The aim of this study was to evaluate the correlation between LDCT indices of bone-density measurements in surgical planning and histopathological specimens. The patients incuded in this study underwent detailed radiological evaluation as preparation for further clinical procedures. Excised condyles were evaluated in terms of bone density index using LDCT, and then histopathologically to investigate the accuracy of surgical procedures and set the basis for future surgical planning. An index value between both condyles' bone densities represented the relative difference between the healthy condyle and the side with hemimandibular hyperplasia (HH). Patients with unilateral condylar hyperplasia (UCH) showed a statistical correlation between condyle heads with increased bone density (BD) and scintigraphic (SCI) values (p < 0.001). On the other hand, correlation between BD and histopathological studies alone was significant (p < 0.001). With the increase in BD measured in HU in UCH condyles, the overall value of fibrous cartilage layer thickness decreased (p < 0.001). Furthermore, histopathological evaluation indicated that increased bone density on the UCH side resulted in increased total thickness (p > 0.001). The proposed index measurements in the mandibular condyles based on LDCT/BD can be used to estimate the degree of required surgical resection. Results from LDCT radiographic studies correlate with histopathological specimens more than scintigraphy.

The Role of Digital Surgical Planning and Surgical Guides in the Treatment of Unilateral Condylar Hyperplasia

Unilateral condylar hyperplasia (UCH) results in facial asymmetry, malocclusion, and temporomandibular joint dysfunction. Treatment consists of both surgical and orthodontic intervention. A review was performed for 4 patients with UCH who underwent digital surgical planning (DSP)-assisted condylectomy. All patients were female, aged 14 to 35 years at the time of operation with facial asymmetry and class III malocclusion. None of the patients had prior treatment and all had perioperative orthodontic appliances to provide fixation and postoperative elastic therapy. All patients underwent DSP-guided condylectomy, and intraoperative surgical cutting guides were used for 3 of the patients. All had significant improvement in facial symmetry and occlusion. None had recurrence, and additional intervention has not been required. If UCH is recognized before marked secondary changes in the maxilla, mandible, and occlusion, future orthognathic surgery may be potentially obviated. Craniomaxillofacial surgeons should consider using DSP and surgical guides in the treatment of UCH.

Treatment measures of hemimandibular hyperplasia and associated facial deformities

This study aims to show our institute's experience in the treatment of HH and its associated facial deformities in adults and growing adolescents and to investigate condylar remodeling and volumetric changes and long-term stability of orthognathic surgery in adults. The study included consecutive patients with clinical and radiological features of HH who underwent high condylectomy with or without simultaneous orthognathic surgery from 2013 to 2018. The clinical outcomes were assessed based on functional activities, TMJ pain, and recurrence. Postoperative 3D condylar remodeling and orthognathic stability were evaluated with the use of ITK-Snap and 3D Slicer. Thirteen patients (8 females and 5 males) with a mean age of 26.3 ± 5.79 years (range; 13-34 years) were included with facial asymmetry as the chief complaint. The patients were followed up for a minimum of 12 months and a maximum of 4 years (mean; 16.85 ± 10.04). There were no postoperative complications, and all patients achieved a satisfactory functional and aesthetic outcome using a one-stage surgical procedure. There was no incidence of recurrence or further asymmetries, with long-term stability at the selected points showing a mean difference of less than ±1 mm. The affected condylar volume was significantly reduced following high condylectomy, with mean changes between T1 and T2 of -144. 80 mm³ (p = .012). However, the contralateral condylar volume remained stable, with a mean change of 2.54 mm³ (p = .881). One-stage high condylectomy and orthognathic surgery is a viable measure for the treatment of HH and associated deformities in adults. High condylectomy in early adolescence could result in termination of the disease, and aesthetic improvement with further constant orthodontist-surgeon follow-up is required.

Minimally invasive intraoral proportional condylectomy with a three-dimensionally printed cutting guide

The aim of this study was to describe the steps of a minimally invasive surgical technique used to perform a proportional intraoral condylectomy with a three-dimensionally (3D) printed cutting guide. The technique consists of two steps: virtual surgical planning and intraoral condylectomy. During virtual surgical planning, the mandibular ramus was measured bilaterally, the height of the proportional condylectomy was planned virtually, and a cutting guide was 3D printed. In the intraoral condylectomy, the mandibular condyle was approached intraorally, the 3D printed cutting guide was positioned in the sigmoid notch, and the proportional condylectomy was performed. The protocol reported in this technical note is the sum of knowledge acquired from a series of studies published previously by the authors, who have jointly developed a surgical technique that is both minimally invasive and accurate for the treatment of condylar hyperplasia.

Pythiosis in cats in northeastern Brazil

The epidemiological, clinical and anatomopathological aspects of pythiosis in cats in northeastern Brazil are described. From January 2000 to December 2018 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1928 tissue samples of cats, three of which were diagnosed as pythiosis. Grossly, the cats showed a multinodular mass in the oral cavity associated with facial deformity (case 1), a large multinodular mass thickening the jejunum wall (case 2), and an ulcerated nodule in the skin at the base of the tail (case 3). Histologically, pyogranulomatous inflammation and necrosis, with intralesional predominantly negatively stained hyphae, were observed in all cases. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. The diagnosis of pythiosis was based on the epidemiological, clinical and anatomopathological findings, and was confirmed by immunohistochemistry. Although uncommon in cats, pythiosis should be readily considered as a differential diagnosis of chronic pyogranulomatous infections of the gastrointestinal tract and skin, especially in endemic areas, where the disease is often diagnosed in other animal species.

Three-dimensional evaluation of skeletal and dental changes in patients with skeletal class III malocclusion and facial asymmetry after surgical-orthodontic treatment

OBJECTIVE

To evaluate skeletal and dental changes in patients with skeletal Class III malocclusion and facial asymmetry after surgical-orthodontic treatment using cone-beam computerized tomography (CBCT).

METHODS

This study included forty adult patients diagnosed with skeletal Class III malocclusion and asymmetry who underwent either isolated mandibular surgery or bimaxillary surgery. CBCT scans were taken before treatment (T0), at the completion of presurgical orthodontic treatment (T1) and after treatment (T2). Mimics 17.0 and 3-Matics 7.0 were used to measure skeletal and dental parameters. Skeletal and dental changes within each group from pretreatment to posttreatment were assessed, and Pearson correlation analysis was used to analyze the correlations among skeletal changes.

RESULTS

The three-dimensional changes in condylar position were insignificant after surgical-orthodontic treatment in either group (P > 0.05). However, in the one-jaw surgery group, there were significant backward rotations of the condyle and ramus on the nondeviated side (P < 0.05), and the condyle on the deviated side rotated inward and forward significantly in the two-jaw surgery group (P < 0.05) at T2. There were no significant differences in the changes in the total alveolar bone thickness of bilateral first molars during dental decompensation (P > 0.05). The ratio between the buccal and the total bone thickness around the maxillary first molar on the deviated side decreased significantly at T1, as did those around the mandibular first molar on the nondeviated side (P < 0.05).

CONCLUSIONS

Condylar angulations were less stable after treatment (7 to 9 months after surgery) in both the one-jaw and the two-jaw surgery groups, while condylar displacements were insignificant. In addition, orthodontists should keep a watchful eye to the relative position of the root in the alveolar bone during tooth decompensation.

Measuring asymmetry from high-density 3D surface scans: An application to human faces

Perfect bilateral symmetry is the optimal outcome of the development of bilateral traits in the absence of developmental perturbations. Any random perturbation in this perfect symmetrical state is called Fluctuating Asymmetry (FA). Many studies have been conducted on FA as an indicator of Developmental Instability (DI) and its possible link with stress and individual quality in general and with attractiveness, health and level of masculinity or femininity in humans. Most human studies of facial asymmetry use 2D pictures and a limited number of landmarks. We developed a protocol to utilize high-density 3D scans of human faces to measure the level of asymmetry. A completely symmetric spatially dense anthropometric mask with paired vertices is non-rigidly mapped on target faces using an Iterative Closest Point (ICP) registration algorithm. A set of 19 manually indicated landmarks were used to validate the mapping precision. The protocol's accuracy in FA calculation is assessed, and results show that a spatially dense approach is more accurate. In addition, it generates an integrated asymmetry estimate across the entire face. Finally, the automatic nature of the protocol provides a great advantage by omitting the tedious step of manual landmark indication on the biological structure of interest.

Correction of Eyes and Lip Canting after Bimaxillary Orthognathic Surgery

Patients who have a lower facial asymmetry with compensatory head posture (developmental facial asymmetry) may have minor temporomandibular (T-M) joint problems and tend to mask their asymmetry by tilting the head for camouflage of their chin deviation. However, this compensatory head posture can give the impression of orbital dystopia and c spine deviation. When these patients undergo bimaxillary orthognathic surgery, orbital canting and head tilting improves gradually without the need for camouflage, and bleary eyes become clearer. We evaluated 13 patients who underwent LeFort I osteotomy combined with bilateral sagittal split osteotomy of the mandible for developmental facial asymmetry to quantitatively observe whole facial postural changes after surgery. Pre-operative and post-operative 1:1 full-face photographs of the patients were analyzed to compare the degrees of head tilting and orbital canting and the sizes of the eye opening. After bimaxillary orthognathic surgery, eye canting decreased from 2.6° to 1.5°, eye and lip lines came closer to parallel, and the degree of head tilting decreased from 3.4° to 1.3°. The eyes also appeared to open wider. Correction of lower facial skeletal asymmetry through bimaxillary orthognathic surgery improved head tilting and orbital canting gradually by eliminating the need of compensatory head posture. Facial expressions also changed as the size of the eyes increased due to the reduction of facial muscle tension caused by T-M joint dysfunction.

Comparative Assessment of Facial Asymmetry in Malocclusion using Posteroanterior View

AIM

The study was conducted to assess facial asymmetry in various dental malocclusions and to determine asymmetry in lower, mid, and upper face and jaws using posteroanterior cephalometric analysis.

MATERIALS AND METHODS

Overall, 120 posteroanterior cepha-lograms were taken of individuals between 12 and 25 years of both sexes, and were divided into four groups: Angle's class I excellent occlusion, Angle's class I malocclusion, Angle's class II malocclusion, and Angle's class III malocclusion. These cepha-lograms were traced and Grummon's analysis was performed.

RESULTS

In Angle's class I occlusion and Angle's class II malocclusion, the results obtained showed asymmetry present in the upper face. Correlation was found between occlusion, maloc-clusion, and facial asymmetry.

CONCLUSION

Facial asymmetry was found in all dental occlusions whether excellent or malocclusion group, with maximum asymmetry having upward trend toward upper face starting from lower.

CLINICAL SIGNIFICANCE

For the success of the orthodontic treatments in various types of malocclusion and to determine the facial asymmetry, posteroanterior view can be very helpful, as it gives additional information which can be utilized to augment treatment planning and improve prognosis in terms of relapse prevention.

Regional Odontodysplasia Crossing the Midline

Regional odontodysplasia is a non-hereditary development dental anomaly involving epithelial and mesenchymal-derived dental tissues. The condition affects both primary and permanent teeth. Clinically, affected teeth are hypoplastic, soft upon probing, have a yellow-brown discoloration and present high susceptibility to caries. Radiographically, the teeth show enlarged pulp chambers, open apices and no clear differentiation between enamel and dentin. The reduced radiopacity of the enamel and dentin gave rise to the term ghost teeth. We present the case of a three-year-old boy diagnosed with regional odontodysplasia involving more than one quadrant, showing facial asymmetry and missing primary and permanent teeth.

Collaborative treatment for a case of condylar hyperplastic facial asymmetry

Facial asymmetry can be caused by unilateral condylar hyperplasia. In such cases, it may be difficult to achieve symmetry since there is dentoalveolar compensation on the affected side, and the occlusal cant does not correspond to the frontal mandibular deviation. In the case presented, surgical orthodontic treatment and orthognathic surgery planning was accomplished for a patient with facial asymmetry due to condylar hyperplasia. The surgical plan was devised with particular attention to the severe dentoalveolar compensation. In this case, prior to the two-jaw surgery, the occlusal cant and frontal mandibular plane inclination was corrected through impaction of the left molar region by segmental osteotomy. Facial asymmetry and severe dentoalveolar compensation were successfully corrected after a unilateral segmental osteotomy and two-jaw surgery, resulting in a stable occlusal relationship and facial symmetry as well as good jaw function. Collaboration between the orthodontists and maxillofacial surgeons was essential for the successful treatment of the patient.

Congenital Temporomandibular Joint Ankylosis: Clinical Characterization and Natural History of Four Unrelated Affected Individuals

The objective of this study was to describe four unrelated patients affected by congenital temporomandibular joint ankylosis. Clinical delineation, natural history, and possible etiologies are discussed. Clinical aspects that are important for follow-up are outlined.

Maxillary and Sella Turcica Morphology in NewbornsWith Cleft Lip and Palate

Objective

The first aim was to examine maxillary developmental fields by analyzing bone size parameters within the maxillary bone complex in newborns with unilateral cleft lip (UCL) and unilateral cleft lip and palate (UCLP). The second aim was to evaluate sella turcica morphology in unilateral cleft lip and unilateral cleft lip and palate.

Subjects and Methods

Axial and profile radiographs from 40 newborns (boy–girl, 1:1) in each group (20 unilateral cleft lip and 20 unilateral cleft lip and palate) were randomly selected among radiographs taken for optimizing treatment planning. Analysis of maxillary bone size was performed on axial radiographs and size parameters were measured. Furthermore, analysis of sella turcica morphology was performed on profile radiographs. The results were divided into groups with normal morphology and severe deviations in the morphology.

Results

The maxillary areas were significantly shorter and broader in unilateral cleft lip and palate than in unilateral cleft lip. A profound asymmetry in the maxillary areas was seen in unilateral cleft lip and palate, but not in unilateral cleft lip. In both cleft types, approximately half of the individuals had deviations in sella turcica morphology. The most severe deviations occurred in newborns with unilateral cleft lip and palate.

Conclusions

In newborns with unilateral cleft lip and palate, the maxillary areas are significantly shorter, broader, and more asymmetric than in newborns with unilateral cleft lip. The present study showed that bone structures are a suitable parameter for characterizing the craniofacial developmental fields. Additionally, a high incidence of deviations in sella turcica morphology might indicate that this area is affected in individuals with clefts.

[Consideration of the shape of the teeth in facial hyperdivergency]

INTRODUCTION

The study examines how the shape of the teeth is taken into account in the context of facial hyperdivergency. One aim was to check out the widely-held belief that the hyperdivergent patient has long teeth.

DISCUSSION

Our study found no link between the shape of the teeth and facial hyperdivergency, thus confirming the results in the literature. We examined the issue of how to characterize dental shapes. We found three diversely-appreciated types of shape: rectangular, triangular and ovoid. Individualized management of tooth shape harmony enables the clinician to envisage recontouring the shape of a patient's teeth using interproximal enamel reduction. The anatomical demands of this type of tooth remodeling favor the less popular ovoid and triangular shapes. However, following treatment, they tend to adopt a more widely-accepted rectangular shape.

MATERIALS AND METHODS

Using a spreadsheet, we built a computational tool to perform the dimensional quantitative diagnosis and made drawings in order to approach the shapes from a qualitative point of view. This method enables us to determine the areas to be recontoured and to obtain a preview of our treatment objectives. The result is harmonious with respect to shapes, proportions and positions as well as from a functional and periodontal point of view.

Asymmetry in the Condylar Long Axis and First Molar Rotation

Asymmetric growth occurs frequently in the mandibulofacial region, but little attention has been given to asymmetry in the temporomandibular joint. The purpose of this study was to clarify the feature of asymmetry in the condylar long axis and its relation to upper first molar rotation. Records of 148 pre-orthodontic patients were used. The angle of the condylar long axis and that of the molar rotation were both larger on the left side than on the right side. Positive correlations were found between the corresponding bilateral measurements of condylar long axes and also between those of molar rotations, whereas no correlation was found between the condylar long axis and molar rotation. These findings were found in most subgroups classified by dental age, skeletal pattern, bite force balance, or gender. These results suggest that consistent left-right differences in the condylar long axis and first molar rotation are common.

Size and Orientation of Masticatory Muscles in Patients with Mandibular Laterognathism

Size measurements of jaw muscles reflect their force capabilities and correlate with facial morphology. Using MRI, we examined the size and orientation of jaw muscles in patients with mandibular laterognathism in comparison with a control group. We hypothesized that the muscles of the deviated side would be smaller than those of the non-deviated side, and that the muscles of both sides would be smaller than in controls. In patients, a comparison of deviated and non-deviated sides showed, in orientation, differences for masseter and medial pterygoid muscles, but, in size, differences only for the masseter muscle. Nevertheless, muscle sizes in patients were much smaller than in controls. Lateral displacement of the mandible can explain the orientation differences, but not the smaller muscle size, in patients. It is possible that the laterodeviation initiates an adaptive process in the entire jaw system, resulting in extensive atrophy of the jaw muscles.

Features in subjects with the frontal occlusal plane inclined toward the contralateral side of the mandibular deviation

INTRODUCTION

The frontal occlusal plane of the maxilla generally inclines toward the ipsilateral side of the mandibular deviation in subjects with facial asymmetry; however, a few patients with facial asymmetry have their frontal occlusal planes inclined toward the contralateral side. We aimed to investigate the morphologic and functional features of such patients.

METHODS

The subjects were 40 patients with facial asymmetry divided into 2 groups based on the inclination of the frontal occlusal plane toward the ipsilateral or the contralateral side. We analyzed lateral and posteroanterior cephalometric radiographs and occlusal variables and evaluated temporomandibular joint symptoms. Statistical comparisons were performed between the 2 groups (P <0.05).

RESULTS

The posteroanterior cephalometry significantly differed between the ipsilateral and contralateral groups. Occlusal force and occlusal contact area were significantly larger, and temporomandibular joint symptoms were more frequently found on the side of the upward-inclined frontal occlusal plane than on the opposite side in both groups.

CONCLUSIONS

The features in the contralateral group in terms of occlusal force and temporomandibular disorders were clinically significant. Clinicians should note that the conditions associated with the contralateral group require less presurgical decompensation.

Morphologic Analysis of the Temporomandibular Joint Between Patients With Facial Asymmetry and Asymptomatic Subjects by 2D and 3D Evaluation: A Preliminary Study

Signs and symptoms of temporomandibular joint (TMJ) dysfunction are commonly found in patients with facial asymmetry. Previous studies on the TMJ position have been limited to 2-dimensional (2D) radiographs, computed tomography (CT), or cone-beam computed tomography (CBCT). The purpose of this study was to compare the differences of TMJ position by using 2D CBCT and 3D model measurement methods. In addition, the differences of TMJ positions between patients with facial asymmetry and asymptomatic subjects were investigated. We prospectively recruited 5 patients (cases, mean age, 24.8 ± 2.9 years) diagnosed with facial asymmetry and 5 asymptomatic subjects (controls, mean age, 26 ± 1.2 years). The TMJ spaces, condylar and ramus angles were assessed by using 2D and 3D methods. The 3D models of mandible, maxilla, and teeth were reconstructed with the 3D image software. The variables in each group were assessed by t-test and the level of significance was 0.05. There was a significant difference in the horizontal condylar angle (HCA), coronal condylar angle (CCA), sagittal ramus angle (SRA), medial joint space (MJS), lateral joint space (LJS), superior joint space (SJS), and anterior joint space (AJS) measured in the 2D CBCT and in the 3D models (P < 0.05). The case group had significantly smaller SJS compared to the controls on both nondeviation side (P = 0.009) and deviation side (P = 0.004). In the case group, the nondeviation SRA was significantly larger than the deviation side (P = 0.009). There was no significant difference in the coronal condylar width (CCW) in either group. In addition, the anterior disc displacement (ADD) was more likely to occur on the deviated side in the case group. In conclusion, the 3D measurement method is more accurate and effective for clinicians to investigate the morphology of TMJ than the 2D method.

The effect of smiling on facial asymmetry in adults: a 3D evaluation

BACKGROUND/AIMS

Mild resting facial asymmetry exists in clinically symmetrical faces, but the effect of smiling on the magnitude of overall facial asymmetry in adults has not been assessed. The aim of the present study was to use stereophotogrammetry to quantify the effect of smiling on overall facial asymmetry in Caucasian adults who presented with Class I incisor relationships and no history of orthodontic treatment.

METHODS

Twenty male and 20 female Caucasians aged 1 8-30 years with no history of orthodontic treatment, a clinically symmetrical face and a Class I incisor relationship had 3D stereophotogrammetric images captured at rest and on natural and maximal smile (T1). The images were repeated 2-4 weeks later (T2) to assess expression reproducibility. Overall facial asymmetry scores were produced from 27 landmarks using partial Ordinary Procrustes Analysis (OPA) and assessed by an Analysis of Covariance (ANCOVA) model. A random sample of the images was re-examined two months later to calculate intraobserver landmark reproducibility.

RESULTS

Mean landmark error was low (0.41 ± 0.07 mm). Mean overall facial asymmetry scores were not significantly gender different (p = 0.5300); therefore, the male and female data were pooled. Mean overall facial asymmetry scores for maximal (0.91 ± 0.16) and natural smile (0.88 ± 0.18) were higher than at rest (0.80 ± 0.17) (p < 0.0001) and were reproducible across (T1-T2) sessions (p = 0.3204).

CONCLUSIONS/IMPLICATIONS

Overall 3D facial asymmetry scores for the sampled Caucasian adults with clinically symmetrical faces increased in magnitude from rest to natural and to maximal smile. Clinicians should assess overall facial asymmetry at rest and on natural and maximal smile at baseline, during treatment and as part of a core outcome assessment, particularly for cases with unilateral posterior crossbite, unilateral cleft lip and palate or skeletal asymmetry.

Cephalometric Analysis of the Facial Skeletal Morphology of Female Patients Exhibiting Skeletal Class II Deformity with and without Temporomandibular Joint Osteoarthrosis

Purpose

This study evaluated the differences in the facial morphological characteristics of female patients exhibiting skeletal class II deformity with and without temporomandibular joint osteoarthrosis.

Methods

Eighty-three female patients with skeletal class II deformity were included in this study; these patients were classified into three groups on the basis of the condylar features shown in cone-beam computed tomography scans: normal group, indeterminate for osteoarthrosis group, and osteoarthrosis group. The cephalometric differences among the three groups were evaluated through one-way ANOVA.

Results

Of the 83 patients, 52.4% were diagnosed with osteoarthrosis, as indicated by the changes in the condylar osseous component. The cephalometric measurements that represented skeletal characteristics, including mandibular position relative to the cranial base, mandibular plane angle (MP-SN), posterior facial height (S-Go), and facial height ratio, were significantly different among the three groups (p < 0.05). The patients in the osteoarthrosis group yielded the smallest S-Go, the highest MP-SN, and the most retruded mandible.

Conclusions

Temporomandibular joint osteoarthrosis is commonly observed in female patients with skeletal class II deformity. The morphological characteristics of the facial skeleton in patients with bilateral condylar osteoarthrosis may be altered.

Cone-Beam Computed Tomography Assessment of Lower Facial Asymmetry in Unilateral Cleft Lip and Palate and Non-Cleft Patients with Class III Skeletal Relationship

Introduction

To evaluate, using cone-beam computed tomography (CBCT), both the condylar-fossa relationships and the mandibular and condylar asymmetries between unilateral cleft lip and palate (UCLP) patients and non-cleft patients with class III skeletal relationship, and to investigate the factors of asymmetry contributing to chin deviation.

Methods

The UCLP and non-cleft groups consisted of 30 and 40 subjects, respectively, in mixed dentition with class III skeletal relationships. Condylar-fossa relationships and the dimensional and positional asymmetries of the condyles and mandibles were examined using CBCT. Intra-group differences were compared between two sides in both groups using a paired t-test. Furthermore, correlations between each measurement and chin deviation were assessed.

Results

It was observed that 90% of UCLP and 67.5% of non-cleft subjects had both condyles centered, and no significant asymmetry was found. The axial angle and the condylar center distances to the midsagittal plane were significantly greater on the cleft side than on the non-cleft side (P=0.001 and P=0.028, respectively) and were positively correlated with chin deviation in the UCLP group. Except for a larger gonial angle on the cleft side, the two groups presented with consistent asymmetries showing shorter mandibular bodies and total mandibular lengths on the cleft (deviated) side. The average chin deviation was 1.63 mm to the cleft side, and the average absolute chin deviation was significantly greater in the UCLP group than in the non-cleft group (P=0.037).

Conclusion

Compared with non-cleft subjects with similar class III skeletal relationships, the subjects with UCLP showed more severe lower facial asymmetry. The subjects with UCLP presented with more asymmetrical positions and rotations of the condyles on axial slices, which were positively correlated with chin deviation.

[Surgery on virtual model and 3-dimensional printing of a surgical wafer for the correction of a severe mandibular asymmetry]

Correction of a severe facial asymmetry presents a challenge due to the geometric complexity of the dentition, the bony structures and the soft tissues. In most asymmetric cases two-jaw surgery is recommended. Manual model surgery is an essential part of treatment planning but it can be complicated, time-consuming and may contain potential errors. We present a case of a 26-year-old male with a severe right-sided hemimandibular elongation when computerized simulation surgery was performed instead of manual model surgery. High-resolution computer tomography scan was done following presurgical orthodontics and the stack images were reformatted into a three-dimensional structure. The symmetry of the maxilla was corrected via a virtual Le Fort I osteotomy with the help of a three-dimensional planning software. A virtual intermediate surgical wafer was designed and fabricated with a three-dimensional printer. Virtual bilateral sagittal split osteotomy was performed and the mandible was rotated into the correct position to visualize the movements of the osteotomized segments. Real surgery was accomplished according to the virtual plan. The splint fitted well. There is a significant improvement in the facial symmetry; the occlusion is good and stable. This case supports the usage of computer-aided surgical planning and three-dimensional rapid prototyping for the correction of facial asymmetries.

[3D mandibular distraction planification in a case of severe temporomandibular ankylosis]

INTRODUCTION

When occurring in childhood, temporomandibular ankylosis joint is responsible for complex maxillofacial deformities, including mandibular growth deficiency. We present a case of temporomandibular joint ankylosis associated with severe mandibular asymmetry treated by mandibular bone distraction performed under computer assistance.

OBSERVATION

A 27-year-old patient presented with a severe facial asymmetry consisting in hypoplasia of the left hemi-mandible and maxilla. Mouth opening was non-existent. The CT-scan showed a left temporomandibular ankylosis. A left mandibular distraction was decided. The distraction characteristics (choice and positioning of the distractor, axis and amount of distraction) were determined preoperatively on the 3D CT-scan. The planning has been transferred to a navigation console (Kolibri®, Brainlab®). A combined intraoral and cutaneous was performed. Navigation allowed for an appropriate placement of the osteotomy line and fixation of the distractor. Distraction was started at the 5th postoperative day at the rate of 1mm per day and lasted 25 days without complication.

DISCUSSION

3D planning allows for better indication setting, better preparation of the procedure, reducing complications and operative time. It may help as an educational tool for young surgeons and for a better understanding from the patient. Navigation is an accurate method for the transfer of the planning in the operation room.

Perception of maxillary dental midline shift in asymmetric faces

PURPOSE

The purpose of this article is to determine whether certain facial asymmetries (nose and chin) have an impact on the perception of the maxillary dental midline shift.

MATERIALS AND METHODS

From a digitally created symmetric facial model (SFM) constructed in a previous study, a new asymmetric facial model (AFM) was created, with nose and chin deviated to the same side. Modifications were made on the AFM for shifts in the maxillary dental midline in both directions, resulting in a total of eight different images. Through a web survey, 112 randomly selected laypersons were asked to evaluate each image according to their own personal beauty and esthetic criteria using a visual Likert scale.

RESULTS

1 mm of dental midline shift to the left of the AFM was not noticed; 1 mm of dental midline shift to the right of the AFM had a negative impact on perception of facial attractiveness; 2 and 3 mm of dental midline shift to left or right of the AFM had a negative impact on perception of facial attractiveness.

CONCLUSIONS

Facial asymmetries such as nose and chin inclinations have an impact on the perception of maxillary dental midline shift. Direction of dental midline shift can be a major factor in this perception.

Upper airway cavities morphologic features in facial asymmetries

Facial asymmetries have an important impact on the cranio-facial structures morphology, being the result of the genetic, environmental and dysfunctional factors and their impact on the dento-maxillary complex. Asymmetries can be identified in all craniofacial structures, including the upper airway cavities. Craniofacial asymmetries can influence general growth and development by altering the respiratory function. The present study aimed to evaluate morphologic correlations of the upper airway cavities changes in facial asymmetries. Most of the cases included in the study showed on the underdeveloped side that the nostril and nasal fossa were narrowed, while the paranasal sinuses were frequently larger. However, no correlation could be established to answer whether these changes were determined by asymmetry, or if they appeared as compensatory, or if only some structures of the upper airway cavities changed morphologically in a compensatory manner.

Nodal pathway genes are down-regulated in facial asymmetry

PURPOSE

Facial asymmetry is a common comorbid condition in patients with jaw deformation malocclusion. Heritability of malocclusion is advancing rapidly, but very little is known regarding genetic contributions to asymmetry. This study identifies differences in expression of key asymmetry-producing genes that are down-regulated in patients with facial asymmetry.

METHODS

Masseter muscle samples were collected during bilateral sagittal split osteotomy orthognathic surgery to correct skeletal-based malocclusion. Patients were classified as class II or III and open or deep bite malocclusion with or without facial asymmetry. Muscle samples were analyzed for gene expression differences on Affymetrix HT2.0 microarray global expression chips.

RESULTS

Overall gene expression was different for asymmetric patients compared with other malocclusion classifications by principal component analysis (P < 0.05). We identified differences in the nodal signaling pathway, which promotes development of mesoderm and endoderm and left-right patterning during embryogenesis. Nodal and Lefty expression was 1.39- to 1.84-fold greater (P < 3.41 × 10), whereas integral membrane Nodal modulators Nomo1,2,3 were -5.63 to -5.81 (P < 3.05 × 10) less in asymmetry subjects. Fold differences among intracellular pathway members were negative in the range of -7.02 to -2.47 (P < 0.003). Finally Pitx2, an upstream effector of Nodal known to influence the size of type II skeletal muscle fibers was also significantly decreased in facial asymmetry (P < 0.05).

CONCLUSIONS

When facial asymmetry is part of skeletal malocclusion, there are decreases in nodal signaling pathway genes in masseter muscle. This data suggest that the nodal signaling pathway is down-regulated to help promote development of asymmetry. Pitx2 expression differences also contributed to both skeletal and muscle development in this condition.

[Contribution of three dimensional cephalometry in the study of determining morphological parameters for facial esthetics]

There have been numerous studies of facial esthetics, but few have benefited from the new techniques provided by 3D imaging. The aim of this study is to determine which are the most crucial cephalometric criteria for facial esthetics by identifying the strongest correlations between the esthetic rating and 3D Cephalometric values, the Cepha 3Dt. A group of 91 subjects (from 10 to 60 years of age) was rated by a jury of 50 randomly selected judges (from 12 to 65 years of age) using an analog scale. We then looked for the most important correlations between the esthetic ratings and the tridimensional cephalometric values by using 3D Cephalometric Analysis on a global sample, and on Class II and Class III sub-samples. Facial esthetics therefore appeared to be especially linked to: anterior-posterior dimension, maxillo-mandibular disharmony, relationships between the anterior areas (alveolar and basal), the alveolar region has a greater impact than the basal area on facial architecture. In the Class II group, sagittal discrepancies and mandibular divergence have an equal impact on the assessment of facial esthetics.

Asynchronicity of facial blood perfusion in migraine

Asymmetrical changes in blood perfusion and asynchronous blood supply to head tissues likely contribute to migraine pathophysiology. Imaging was widely used in order to understand hemodynamic variations in migraine. However, mapping of blood pulsations in the face of migraineurs has not been performed so far. We used the Blood Pulsation Imaging (BPI) technique, which was recently developed in our group, to establish whether 2D-imaging of blood pulsations parameters can reveal new biomarkers of migraine. BPI characteristics were measured in migraineurs during the attack-free interval and compared to healthy subjects with and without a family history of migraine. We found a novel phenomenon of transverse waves of facial blood perfusion in migraineurs in contrast to healthy subjects who showed synchronous blood delivery to both sides of the face. Moreover, the amplitude of blood pulsations was symmetrically distributed over the face of healthy subjects, but asymmetrically in migraineurs and subjects with a family history of migraine. In the migraine patients we found a remarkable correlation between the side of unilateral headache and the direction of the blood perfusion wave. Our data suggest that migraine is associated with lateralization of blood perfusion and asynchronous blood pulsations in the facial area, which could be due to essential dysfunction of the autonomic vascular control in the face. These findings may further enhance our understanding of migraine pathophysiology and suggest new easily available biomarkers of this pathology.

[Congenital hemifacially infiltrating lipomatosis]

Congenital infiltrating lipomatosis of the face is a rare condition with congenital facial asymmetry due to localized overgrowth and accumulation of mature lipocytes. We describe a boy, followed from the age of five months to ten years, with left facial overgrowth, ipsilateral macroglossia, ptosis of the left upper lip, typical asymmetric dental eruption and regional macrodontia in the left upper gumma. The hypertrophic asymmetry was proportionally unaltered with growth. Magnetic resonance imaging confirmed diffuse fatty infiltration with overgrowth of regional bony and soft tissue structures. Intracranial structures were normal as was the boy's cognitive development.

Clinical care in craniofacial microsomia: a review of current management recommendations and opportunities to advance research

Craniofacial microsomia (CFM) is a complex condition associated with microtia, mandibular hypoplasia, and preauricular tags. It is the second most common congenital facial condition treated in many craniofacial centers and requires longitudinal multidisciplinary patient care. The purpose of this article is to summarize current recommendations for clinical management and discuss opportunities to advance clinical research in CFM.

Autologous fat grafting for treatment of facial atrophy in Behcet's disease: a case report

Behcet's disease (BD) is an autoimmune & autoinflammatory disease of unclear etiology characterized by recurrent oral & genital ulcers as well as other systemic manifestations. A key pathogenesis is excessive inflammatory wound healing response. While descriptions of the cutaneous manifestations of disease are limited to short-term consequences such as extensive pustule and papule formation in response to minor tissue injury, the long-term consequences are significant fibrosis and scarring of epithelial tissue. We describe the case of a patient with Behcet's disease who presented with unilateral facial atrophy secondary to minor trauma to the oral mucosa. She was treated with autologous fat grafting. Though a rare disease, plastic surgeons should be aware of the entity of Behcet's disease and its complications of tissue atrophy that may require reconstructive surgery.

Unilateral condylar hyperplasia: a 3-dimensional quantification of asymmetry

Purpose

Objective quantifications of facial asymmetry in patients with Unilateral Condylar Hyperplasia (UCH) have not yet been described in literature. The aim of this study was to objectively quantify soft-tissue asymmetry in patients with UCH and to compare the findings with a control group using a new method.

Material and Methods

Thirty 3D photographs of patients diagnosed with UCH were compared with 30 3D photographs of healthy controls. As UCH presents particularly in the mandible, a new method was used to isolate the lower part of the face to evaluate asymmetry of this part separately. The new method was validated by two observers using 3D photographs of five patients and five controls.

Results

A significant difference (0.79 mm) between patients and controls whole face asymmetry was found. Intra- and inter-observer differences of 0.011 mm (−0.034–0.011) and 0.017 mm (−0.007–0.042) respectively were found. These differences are irrelevant in clinical practice.

Conclusion

After objective quantification, a significant difference was identified in soft-tissue asymmetry between patients with UCH and controls. The method used to isolate mandibular asymmetry was found to be valid and a suitable tool to evaluate facial asymmetry.

Symmetry of the face in old age reflects childhood social status

The association of socioeconomic status (SES) with a range of lifecourse outcomes is robust, but the causes of these associations are not well understood. Research on the developmental origins of health and disease has led to the hypothesis that early developmental disturbance might permanently affect the lifecourse, accounting for some of the burden of chronic diseases such as coronary heart disease. Here we assessed developmental disturbance using bodily and facial symmetry and examined its association with socioeconomic status (SES) in childhood, and attained status at midlife. Symmetry was measured at ages 83 (facial symmetry) and 87 (bodily symmetry) in a sample of 292 individuals from the Lothian Birth Cohort 1921 (LBC1921). Structural equation models indicated that poorer SES during early development was significantly associated with lower facial symmetry (standardized path coefficient -.25, p=.03). By contrast, midlife SES was not significantly associated with symmetry. The relationship was stronger in men (-.44, p=.03) than in women (-.12, p=.37), and the effect sizes were significantly different in magnitude (p=.004). These findings suggest that SES in early life (but not later in life) is associated with developmental disturbances. Facial symmetry appears to provide an effective record of early perturbations, whereas bodily symmetry seems relatively imperturbable. As bodily and facial symmetries were sensitive to different influences, they should not be treated as interchangeable. However, markers of childhood disturbance remain many decades later, suggesting that early development may account in part for associations between SES and health through the lifecourse. Future research should clarify which elements of the environment cause these perturbations.

Three-dimensional vector analysis of mandibular structural asymmetry

OBJECTIVES

The three-dimensional (3D) asymmetric structure of the mandible makes it necessary to analyze both its size and angle. Currently the developing 3D analysis techniques are not able to perform the simultaneous linear and angular measurements. Our aim was to evaluate mandibular asymmetry using a vector-based system by constructing 3D vectors for the mandibular functional units.

MATERIAL AND METHODS

We analyzed the 3D computed tomography images of normal control (N = 27) and asymmetric mandibles (N = 40). We created 3D vectors for the condylar, coronoid, body, gonial, and symphyseal functional units and compared the corresponding pairs of 3D vectors by calculating vector operations.

RESULTS

The vector difference and other vector components represented the individual 3D architectural pattern and severity of the asymmetric mandible. The body unit contributed most to mandibular asymmetry followed by the condylar unit.

CONCLUSIONS

The results indicate that 3D vector analysis can improve our understanding of the 3D architecture of asymmetric mandibles. This type of 3D vector analysis can be a useful tool for the comprehensive evaluation of its asymmetric mandibular structure.

Conservative management of unilateral condylar hyperplasia

OBJECTIVE

The purpose of this study was to eliminate orthodontic treatment in mild to moderate cases of condylar hyperplasia in its early stages by condylectomy.

PATIENTS AND METHODS

A total of five patients (two females and three males) aged between 17 and 40 years were treated with unilateral condylectomy of the involved side without orthodontic treatment. All patients underwent standardized clinical and radiological examination at initial consultation, before surgery, immediately after surgery, and follow-up. Objective and subjective evaluation of temporomandibular joint (TMJ) included maximal incisal opening, lateral excursions, correction of facial asymmetry, occlusal harmony, TMJ pain, and jaw function. Results were recorded at 5-year follow-up.

RESULTS

In all our cases, we achieved good mouth opening and near to normal occlusion. Good facial aesthetics was obtained after 3 months postoperative follow-up without secondary orthodontic treatment.

CONCLUSION

Thus, we conclude that treatment of mild to moderate cases of unilateral condylar hyperplasia during the inactive phase can be treated with condylectomy without orthodontic treatment, and it significantly improves long-term surgical outcomes.

A comparison of three methods to evaluate the position of an artificial ear on the deficient side of the face from a three-dimensional surface scan of patients with hemifacial microsomia

PURPOSE

Patients with hemifacial microsomia may have a missing ear on the deficient side of the face. The fabrication of an ear for such individuals usually has been accomplished by directly measuring the ear on the normal side to construct a prosthesis based on these dimensions, and the positioning has been, to a large extent, primarily operator-dependent. The aim of the present study was to compare three methods, developed from the identification of landmarks plotted on three-dimensional surface scans, to evaluate the position of an artificial ear on the deficient side of the face compared with the position of the natural ear on the normally developed side.

MATERIALS AND METHODS

Laser scans were undertaken of the faces of 14 subjects with hemifacial microsomia. Landmarks on the ear and face on the normal side were identified. Three methods of mirroring the normal ear on the deficient side of the face were investigated, which used either facial landmarks from the orbital area or a zero reference point generated from the intersection of three orthogonal planes on a frame of reference. To assess the methods, landmarks were identified on the ear situated on the normal side as well as on the face. These landmarks yielded paired dimensional measurements that could be compared between the normal and deficient sides. Mean differences and 95% confidence intervals were calculated.

RESULTS

It was possible to mirror the normal ear image on to the deficient side of the face using all three methods. Generally only small differences between the dimensional measurements on the normal and deficient sides were observed. However, two-way analysis of variance revealed statistically significant differences between the three methods (P = .005).

CONCLUSIONS

The method of mirroring using the outer canthi was found to result in the smallest dimensional differences between the anthropometric points on the ear and face between the normally developed and deficient sides. However, the effects of the deformity can result in limitations in relation to achieving a precise alignment of the ear to the facial tissues. This requires further study.

Assessing the influence of asymmeftry affecting the mandible and chin point on perceived attractiveness in the orthognathic patient, clinician, and layperson

PURPOSE

The purpose of this investigation was to undertake an objective and quantitative evaluation of how severity of asymmetries affecting the mandible and chin point influence perceived attractiveness.

MATERIALS AND METHODS

The mandible and chin point of idealized male and female frontal facial images were altered in 5-mm increments from 0 to 25 mm and to the left and right, to represent horizontal, vertical, and combined asymmetry affecting these regions. These images were rated on a 7-point Likert scale by a preselected group of orthognathic patients before treatment, clinicians, and laypeople.

RESULTS

In relation to a 5-mm asymmetry, observers progressively decreased attractiveness ratings and increased the desire for surgery for greater asymmetries. Clinicians and patients were found to be more critical than laypeople. The desire for surgery decreased by 3% for each year increase in age, was 53% less for men, and 45% greater for white observers.

CONCLUSIONS

Asymmetry of 10 mm is perceived as being significant; at 5 mm and below, it is largely unnoticed. The greater the degree of asymmetry greater than 10 mm, the more noticeable and the greater the desire was for correction. Clinician and patient ratings were similar and more critical than ratings of laypeople. A desire for surgery was negligible for 5 mm of asymmetry but increased considerably at 10 mm and continued to increase with greater degrees of asymmetry. The highest-rated images showed perfect bilateral symmetry, whereas the lowest-rated images showed significant degrees of mandibular and chin asymmetry.

Cellular damage markers in the temporal lobe of a patient with Dyke-Davidoff-Masson Syndrome

We studied the cellular damage in a patient with Dyke-Davidoff-Masson Syndrome and a history of chronic temporal lobe epilepsy resistant to treatment. The epileptogenic zone was localized to the right temporal lobe, and an extensive surgical removal of the temporal neocortex plus amygdala and hippocampus was performed. The specimens were immediately frozen in liquid nitrogen and stored at -75 degrees C for biochemical studies. Specimens were immersed and fixed in freshly prepared 4% paraformaldehyde for histopathological evaluation. Neurotransmitter levels were highest in the hippocampus compared to the temporal neocortex (T1, T2, and T3). In the amygdala, GABA was found whereas other amino acids were absent. We found marked dislamination in all areas of the cortex, neuronal loss, amylaceous bodies, and neuronal cytomegaly with cytoskeletal disorganization containing dense fibrillar cytoplasmic aggregates, nodular heterotopias, dysplastic and large neurons with high Nissl staining, intermixed with balloon cells with atypical nuclei, often with binucleation, and abundant glassy eosinophilic cytoplasm. Positive immunoreactive cells with nestin, vimentin, and enhanced expression of astrocytes were observed in all brain regions. This patient's syndrome should be considered as a postinfectious/post-stroke event that caused hemiparesis and later recurrent seizures. Higher expression of nestin and vimentin has been observed in proliferative neuronal cells, the expression in astrocytes may mainly reflect an early response of these cells to injury. Nestin may play a role in protecting the brain from injury. It has been proposed that re-expression of embryonic genes by mature cells is associated with morphological plasticity.

Assessment of the posteroanterior cephalograms of the parents of children with cleft lip and/or cleft palate in Latvia

OBJECTIVE

To compare the craniofacial morphology of parents of children with cleft lip with or without palate (CL±P), children with isolate cleft palate (CP) and individuals without family history of orofacial clefting in Latvia.

MATERIALS AND METHODS

Posteroanterior (PA) cephalograms were obtained from all participants: 37 couples of noncleft biological parents of children with nonsyndromic CL±P and 17 couples of noncleft biological parents of children with nonsyndromic CP (the parents groups were made dividing the parents after gender and children cleft type). The control groups consisted of 40 females and 42 males, who had no history of clefts in the family. A conventional cephalometric analysis was used to measure various measurements of facial widths.

RESULTS

Statistically significant differences (decreased facial and biorbital width) were found between fathers of children with CP and males from the control group. Results showed asymmetry of zygomatic width (left side dominance) in all parents groups compared with the control groups. The asymmetry was detected in maxillary part (left side dominance) in CP children mothers and females and males control groups.

CONCLUSION

Some statistical significant differences in the PA cephalometric measurements among parents groups of children with CL±P and CP, and control groups were found. However the differences among study groups and the control groups were small, often not larger than variations in the population.

Inner ear anomalies in congenital aural atresia

OBJECTIVES

To define the prevalence of inner ear anomalies in aural atresia patients and to recognize patterns of developmental anomalies in aural atresia patients.

STUDY DESIGN

Retrospective review.

SETTING

Academic medical center.

INTERVENTION

Physical exam, audiometry, and temporal bone CT in selected patients.

PATIENTS

Pediatric patients with aural atresia.

MAIN OUTCOME MEASURE

Prevalence of inner ear anomalies and coexisting facial paralysis or sensorineural hearing loss.

RESULTS

In this series of 118 patients with aural atresia, associated facial palsy was seen in 13%, whereas inner ear anomalies were present in 22%, including all patients with facial palsy. Interestingly, the inner ear anomalies often did not display a significant sensorineural hearing loss. Bilateral inner ear anomalies were frequently encountered despite unilateral atresia. Most anomalies involved the semicircular canals including several uncommon variants of posterior semicircular canal anatomy.

CONCLUSION

Inner ear anomalies are common in the presence of aural atresia, especially when there is concurrent congenital facial palsy. The presence of inner ear anomalies should be recognized as a common feature of craniofacial microsomia.

Assessing soft-tissue characteristics of facial asymmetry with photographs

INTRODUCTION

Precise diagnosis and treatment of facial asymmetry are important in orthodontics. The aims of this study were to determine the soft-tissue characteristics of patients perceived to have severe asymmetry requiring treatment and the soft-tissue factors affecting the subjective assessment of facial asymmetry.

METHODS

In the first part of this study, 5 observers examined 1000 photographs of patients receiving orthodontic treatment and selected 100 for further assessment. These photographs showed 50 patients who were considered to have little or moderate asymmetry and 50 who were considered to have severe asymmetry. A pilot study was performed to select the reference photographs representing the most symmetric (score of 0) and the most asymmetric (score of 100). A panel of 9 orthodontists then rated the facial asymmetry of the 100 patients on a 100-mm visual analog scale. The scale was divided into 3 equal regions. Region 1 included patients with the least facial asymmetry; according to the orthodontists, these patients did not require treatment. Region 2 included patients with moderate facial asymmetry who did not require treatment. Region 3 included patients with the most facial asymmetry who did require treatment.

RESULTS

One-way analysis of variance showed that lip canting, chin deviation, body inclination difference, and gonial angle difference had significant differences between the groups. Chin deviation and gonial angle difference were significant factors affecting the assessment of facial asymmetry, according to stepwise linear regression analysis.

CONCLUSIONS

These results will help in the diagnosis and treatment planning for patients with asymmetry.

Evaluation of facial asymmetry and masticatory muscle thickness in children with normal occlusion and functional posterior crossbite

AIM

The aim of this study was to evaluate facial asymmetry and the thickness of the masticatory muscles in young children with normal occlusion and functional posterior crossbite.

METHODS

The sample comprised 72 children of both genders (64.71±7.04 months) in the primary and early mixed stage of dentition, divided into four groups: primary-normal occlusion (PriN; N=19), primary-crossbite (PriC; N=19), mixed-normal occlusion (MixN; N=27), and mixed-crossbite (MixC; N=16). The thickness of the masseter and anterior portion of the temporalis muscle at rest and during maximal clenching were assessed by ultrasonography. Facial morphology and asymmetry were evaluated by standardized front-view photographs, in which the following measurements were recorded: anterior face height (AFH), bizygomatic facial width (BFW), angle of the eye (AE) and angle of the mouth (AM) (interpupillary and commissure planes in relation to mid-sagittal plane, respectively).

RESULTS

The results showed that muscle thickness did not differ significantly between the sides of the dental arches in all groups (paired t-test). Only the groups with normal occlusion presented significant positive correlation between AE and AM (Pearson's correlation test). In PriN, only body weight was significantly related to masseter thickness; in MixN, facial morphology contributed significantly to masseter thickness at rest and maximal clenching, while the covariates weight, height and age did not relate to muscle thickness (stepwise backward multiple regression).

CONCLUSION

In the studied sample, children with crossbite presented greater facial asymmetry than those with normal occlusion, and a greater masseter thickness was related to larger faces in the mixed dentition.

Analysis of facial skeletal characteristics in patients with chin deviation

BACKGROUND

This study was undertaken to investigate the facial skeletal features associated with chin deviation.

METHODS

Twenty-five patients (14 males and 11 females) diagnosed with chin deviations of more than 2 mm were recruited. Fifteen skeletal landmarks, including median and lateral points, were located on posteroanterior cephalograms. The CG-ANS (crista-galli of the ethmoid-anterior nasal spine) line and the perpendicular line through the CG were used as references. The differences between the distances from paired lateral points to reference lines were examined with intraclass correlation coefficients to analyze the symmetry of facial skeletal tissue. The factors associated with the amount or direction of chin deviation were analyzed by multiple regression analysis or by logistic regression analysis.

RESULTS

Seventeen subjects (68%) showed chin deviation to the left side and 8 subjects (32%) to the right side. Sixty-eight percent of subjects presented with Angle Class III malocclusion. Horizontal distances of all paired lateral points to the y-axis, in mandibular body length and effective length, showed a low grade of symmetry. Only vertical distances of paired zygomaticofrontal sutures and zygonion points to the x-axis were asymmetric. However, there were no significant asymmetries of the gonial angle, ramus height, and vertical distances from other paired lateral points to the x-axis. The amount of chin deviation was associated with the absolute differences of the left and right antegonion to the y-axis and zygomaticofrontal suture to the x-axis. The direction of chin deviation was significantly associated with the difference in the effective length of bilateral mandibular halves.

CONCLUSION

Facial skeletal asymmetry exists in patients with chin deviation. This should be considered when planning treatment for both the nonsurgical and surgico-orthodontic cases with chin deviation.