• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.35-42
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• 2003

Purpose: This study was aimed to investigate the relationship between the mandibular asymmetry and the internal derangement of temporomandibular joint. Materials and methods: One hundred and sixty eight patients had been assessed through clinical examinations, panoramic radiographs and magnetic resonance imagings (MRIs), were selected. The samples were classified into three subgroups according to the severity of the mandibular asymmetries in the panoramic radiographs and the status of TMJ discs on the MRI were compared among each groups. Results: In an apparent asymmetry group, there was a significant difference in the number of temporomandibular disk displacement without reduction between the long and short side (66.7%, 18/27 joints on the short side) when the ratio of condylar process and coronoid process was used (p<0.05), but there was no statistically significant difference when the ratio of condyle and ramus was used. Conclusion: The probability of the disc displacement without reduction was higher at the side with relatively shorter condylar process on the panoramic radiograph, and also it might be more effective to use ratio of condylar process and coronoid process in the assessment of mandibular asymmetry. Therefore, a careful assessment on the temporomandibular disorders is necessary to diagnose and establish the treatment plans for the patients with a mandibular asymmetry and the panoramic radiograph can be used effectively on that way.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권5호
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• pp.259-264
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• 2015

We describe our experience with conservative condylectomy for the correction of facial asymmetry in five patients with osteochondroma of the mandibular condyle. All five patients presented with malocclusion and facial asymmetry, which are common clinical findings of osteochondroma involving the mandibular condyle. We performed conservative condylectomy without additional orthognathic surgery for all five patients, preserving the vertical height of the condylar process as much as possible. Following surgery, intermaxillary traction using a skeletal anchorage system with rubber elastics was performed on all patients to improve occlusion, and, when necessary, additional minimal orthodontic treatment was performed. The mean follow-up period was 42 months. At the last follow-up visit, all patients exhibited satisfactory facial symmetry and remodeling of the remaining condyle, with stable health and no signs of recurrence. In conclusion, conservative condylectomy alone, without subsequent orthognathic surgery, is adequate for the restoration of facial symmetry and the preservation of vertical condylar height in select patients with condylar osteochondroma.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권2호
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• pp.151-159
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• 2005

The purpose of this study was to evaluate the nasal deviation in mandibular prognathism with mandibulo-facial asymmetry. There were 40 patients whose mandibular prognathism with/without facial asymmetry were treated with orthognathic surgery from March 2002 to October 2003. The Group A(n=20) had a mandibulo-facial asymmetry over 6mm menton deviation in cephalogram PA and the Group B(n=20) had a mandibular prognathism. The preoperative frontal photograph, cephalogram PA and three dimensionalcomputed tomography(divided in hard tissuse image and soft tissue image) of two group was evaluated NDA(nasal deviation angle) and MDA(mandibular deviation angle). The NDA was statistical difference between asymmetry Group A and symmetry Group B(p<0.01), and was deviated in affected side of asymmetry. The MDA were also statistical difference between Group A and Group B(p<0.01), however the measurements of MDA between the frontal photograph, 3D-CT and cephalogram PA were similar to each others. The low correlation of NDA between frontal photograph and cephalogram PA in Group A and B demonstrate that we couldn't assess nasal deviation in cephalogram PA. It could be concluded that patients with mandibulo-facial asymmetry have a nasal deviation and clinician must remember this fact when they assess and treat patients.

• 대한치과의사협회지
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• 제51권6호
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• pp.302-312
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• 2013

It has been established that disk displacement of the temporomandibular joint(TMJ) can cause mandibular asymmetry in growing subjects. One of the causes of internal derangement of TMJ seems to be the result of poor positioning of the joint structure in unilateral cross bite, and the subsequent occlusal trauma transferred to the functioning unit of the mandible, the joint and disc. Transverse discrepancy of the maxillary and the mandibular posterior dentoalveolar units was often found in mandibular asymmetric subjects. Most of the asymmetry in growing subjects becomes worse with further growth if left untreated. However once sufficient posterior overjet is gained through orthodontic treatment, many cases have shown improvement in facial asymmetry. Furthermore, the position of condyles in computed tomogram(con-beam CT) changed from anatomically unfavorable position to more concentric position.

• 대한치과교정학회지
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• 제47권5호
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• pp.277-288
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• 2017

Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

• 대한두개안면성형외과학회지
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• 제15권3호
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• pp.109-116
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• 2014

Background: Infants with deformational plagiocephaly (DP) usually present with cranial vault deformities as well as facial asymmetry. The purpose of this study was to use three-dimensional anthropometric data to evaluate the influence of cranial deformities on facial asymmetry. Methods: We analyzed three-dimensional computed tomography data for infants with DP (n=48) and without DP (n=30, control). Using 16 landmarks and 3 reference planes, 22 distance parameters and 2 angular parameters were compared. This cephalometric assessment focused on asymmetry of the orbits, nose, ears, maxilla, and mandible. We then assessed the correlation between 23 of the measurements and cranial vault asymmetry (CVA) for statistical significance using relative differences and correlation analysis. Results: With the exception of few orbital asymmetry variables, most measurements indicated that the facial asymmetry was greater in infants with DP. Mandibular and nasal asymmetry was correlated highly with severity of CVA. Shortening of the ipsilateral mandibular body was particularly significant. There was no significant deformity in the maxilla or ear. Conclusion: This study demonstrated that the cranial vault deformity in DP is associated with facial asymmetry. Compared with the control group, the infants with DP were found to have prominent asymmetry of the nose and mandible.

• 대한치과교정학회지
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• 제48권6호
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• pp.357-366
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• 2018

Objective: The purpose of this study was to analyze the transverse dental compensation in reference to the maxillary and mandibular basal bones using cone-beam computed tomography (CBCT) and evaluate the correlations between transverse dental compensation and skeletal asymmetry variables in patients with skeletal Class III malocclusion and facial asymmetry. Methods: Thirty patients with skeletal Class I (control group; 15 men, 15 women) and 30 patients with skeletal Class III with menton deviation (asymmetry group; 16 men, 14 women) were included. Skeletal and dental measurements were acquired from reconstructed CBCT images using OnDemand3D 1.0 software. All measurements were compared between groups and between the deviated and nondeviated sides of the asymmetry group. Correlation coefficients for the association between skeletal and dental measurements were calculated. Results: Differences in the ramus inclination (p < 0.001), maxillary canine and first molar inclinations (p < 0.001), and distances from the canine and first molar cusp tips to the midmaxillary or midmandibular planes (p < 0.01) between the right and left sides were significantly greater in the asymmetry group than in the control group. In the asymmetry group, the ramus inclination difference (p < 0.05) and mandibular canting (p < 0.05) were correlated with the amount of menton deviation. In addition, dental measurements were positively correlated with the amount of menton deviation (p < 0.05). Conclusions: Transverse dental compensation was correlated with the maxillary and mandibular asymmetry patterns. These results would be helpful in understanding the pattern of transverse dental compensation and planning surgical procedure for patients with skeletal Class III malocclusion and facial asymmetry.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.539-544
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• 2011

Maxillary canting and vertical shortening of the unilateral mandibular ramus height is common in cases of severe facial asymmetry. Normally, mandibular distraction osteogenesis (DO) with horizontal osteotomy at the ascending ramus is used for vertical lengthening of the mandibular ramus to correct facial asymmetry with an absolute shortened ascending ramus. In this case report, vertical lengthening of the ascending ramus was performed successfully with unilateral DO and sagittal split ramus osteotomy (SSRO), where the posterior part of the distal segment can be distracted simultaneously in an inferior direction with maxillary DO, resulting in a lengthening of the medial pterygoid muscle. This case describes the acquired unilateral mandibular hypoplasia caused by a condylar fracture at an early age, which resulted in abnormal mandibular development that ultimately caused severe facial trismus. The treatment of this case included two-stage surgery consisting of bimaxillary distraction osteogenesis for gradual lengthening of the unilateral facial height followed by secondary orthognathic surgery to correct the transverse asymmetry. At the one year follow-up after SSRO, the vertical length was maintained without complications.

• 대한치과보철학회지
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• 제30권1호
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• pp.15-24
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• 1992

The purpose of this study was to analyze the mandibular asymmetry of the patients with the temporomandibular dysfunction. In this study, 20 dental students aged between 22 and 27 years, Chosun University, who did not possess any restoration and symptoms like the temporomandybular joint click, pain, and opening limitation of the mandible were selected as the normal group. And 80 patients who were analyzed into the patients with the temporomadibular dysfunction(TMD) were divided into group I as the internal derangement and group II as external derangement. Both the normal group and the TMD Group were faked submento-vertex cephalogram by routine methods after that the unilateral mandibular length(L) and the amount of mandibular asymmetry and deviation were measured and analyzed. The results were as follows : 1, Unilateral mandibular length(L) of the normal group and the TMD group were $112.7{\pm}10.20mm\;and\;102.65{\pm}8.10mm$ respectively (P<0.01). 2. The amount of mandibula asymmetry of the normal group and the TMD group were $5.95{\pm}4.63mm\;and\;5.68{\pm}4.35mm$ respectively (P<0.5). 3. The amount of mandibular deviation of the normal group and the TMD group were $6.00{\pm}4.07\;and\;4.67{\pm}3.40mm$ respectively (P<0.3). 4. In the TMD group, unilateral mandibular length(L) in the affected site and the non-affected site were $102.73{\pm}8.68mm\;and\;102.53{\pm}7.68mm$ respectively (P<0.5).

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.57.1-57.8
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• 2019

Background: The relationship between the lateral deviation of chin and the upper and middle facial third asymmetry is still controversial. The purpose of this study is to evaluate the correlation of upper and middle facial third asymmetry with lateral deviation of chin using 3-dimensional computed tomography. The study was conducted on patients who underwent orthognathic surgery from January 2016 to August 2017. A total of 40 patients were included in this retrospective study. A spiral scanner was used to obtain the 3-dimensional computed tomography scans. The landmarks were assigned on the reconstructed 3-dimensional images, and their locations were verified on the axial, midsagittal, and coronal slices. The Pearson correlation analysis was performed to evaluate the correlation between chin deviation and difference between the measurements of distances in paired craniofacial structures. Statistical analysis was performed at a significance level of 5%. Results: In mandible, the degree of chin deviation was correlated with the mandibular length and mandibular body length. Mandibular length and mandibular body length are shorter on the deviated-chin side compared to that on the non-deviated side (mandibular length, r = -0.897, p value < 0.001; mandibular body length, r = -0.318, p value = 0.045). In the upper and middle facial thirds, the degree of chin deviation was correlated with the vertical asymmetry of the glenoid fossa and zygonion. Glenoid fossa and zygonion are superior on the deviated-chin side than on the non-deviated side (glenoid fossa, r = 0.317, p value = 0.046; zygonion, r = 0.357, p value = 0.024). Conclusion: Lateral deviation of chin is correlated with upper and middle facial third asymmetry as well as lower facial third asymmetry. As a result, treatment planning in patients with chin deviation should involve a careful evaluation of the asymmetry of the upper and middle facial thirds to ensure complete patient satisfaction.