• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권2호
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• pp.148-156
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• 2007

Purpose: The aim of this study is the changes of upper respiratory airway space in patients with mandibular prognathism after 2-jaw orthognathic surgery in patients with skeletal classs III malocclusion. Method: We measured the lines between selected upper airway landmarks on lateral cephalometric x-ray films of skeletal class III 64 persons who had not been operated yet, were 6 months after operation. The test subjects were divided into 3 groups according to maxillary movement, as follows; maxillary advancement (MA) group, maxillary posterior impaction (MPI) group, maxillary posterior impaction and superior repositioning (MPI+MSR) group. Result: In this study, nasopharyngeal airway space in MPI+MSR group was significantly increased after operation (p<0.05). Oropharygeal and hypopharyngeal airway space in MA group and MPI group were significantly decreased after operation (p<0.05). From hyoid bone to anterior mandible point distance in MA group and MPI group were significantly decreased after operation (p<0.05). Conclusion: Oropharygeal and hypopharyngeal airway space were influenced more by mandibular set-back than maxillary movement. Maxillary movement surgery as well as mandibular setback surgery should be taken into consideration in order to minimize symptoms related to obstructive sleep apnea syndrome after operation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권2호
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• pp.141-147
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• 2007

The purpose of this study was to evaluate the effects of maxillary occlusal plane angle to postoperative skeletal stability by comparative analysis after two-jaw surgery of patients with skeletal CIII malocclusion. This study was made with lateral cephalometric radiography of 52 patients with skeletal class III malocclusion that were performed to Le Fort I osteotomy and BSSRO. And 52 patients were divided to Group A(n=30) and B(n=22). Maxillary posterior impaction was not conducted in Group A, which the pre-operative maxillary occlusal plane angle was in a normal range, and for Group B, which the pre-operative maxillary occlusal plane was low, the maxillary posterior impaction was conducted. The results were obtained as follows : 1. The relapse rate of Group A, which the pre-operative maxillary occlusal plane angle was in a normal range, was relatively stable compared to Group B, which the pre-operative maxillary occlusal plane was low. 2. The relapse rate of each measurement of Group B, which had the maxillary occlusal plane altered during the operation, was somewhat high, and of those, the post-operative relapse rate of overjet, overbite, mandibular plane angle appeared to be significantly high in the statistics. The analyzed results above, was thought to be indicating that the pre-operative maxillary occlusal plane angle was closely related to the post-operative skeletal stability, and that obtaining post-operative skeletal stability only through operative normalization of occlusal plane angle may meet limitations.

• 한국멀티미디어학회논문지
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• 제12권1호
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• pp.147-155
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• 2009

교합력 측정과 분석은 힘의 관계를 분석하여 치아의 역학적 관계를 진단하는 방법이다. 본 연구에서는 새로운 교합력 측정 및 분석 시스템 개발의 기초 연구로써 측정 소프트웨어를 설계 및 구현하고 유용성을 평가한다. 이를 위해 교합력의 정상, 비정상을 효과적으로 측정할 수 있는 다양한 도구들을 개발하였다. 첫째, 치아에 작용하는 힘의 중심 변화를 나타내는 표지의 경로와 14개로 나뉜 치아 영역별 교합력 분포를 정량적인 수치와 함께 가시화 하였으며, 둘째, 교합력이 어느 치아의 특정한 영역으로 치우쳐서 작용하는가를 판단할 수 있도록 하기 위해 좌 우 치아 영역의 힘의 균형을 비율로 측정할 수 있는 도구를 구현하였다. 또한 0.5초 단위로 측정된 교합력의 변화를 소프트웨어 상에서 기록할 수 있도록 하였다. 센서 시트 방식의 측정 하드웨어와 연동하여 테스트한 결과, 힘의 분포와 균형을 효과적으로 확인할 수 있었다.

• 대한치과교정학회지
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• 제46권6호
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권1호
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• pp.24-30
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• 2002

The facial patterns were expressed by the interrelation of variable factors such as heredity, function and environment. Such variable factors have an effect on the growth and development of maxillofacial bones. The malocclusions with skeletal discrepancies are caused by abnormal forms, sizes and positions of cranial base, maxilla and mandible. For the proper diagnosis and treatment planning, the analysis of such structures is necessary. Lateral cephalograms of 54 adults with class III malocclusion patients (test group) and 61 adults with normal occlusion (control group) were analyzed. Anteroposterior relations and sizes of cranial base, maxilla, mandible were estimated to compare with those of normal ones. In test group, the anterior cranial base length was within normal range, but posterior cranial base, maxilla and mandibular body were longer than those in control group, significantly. Based on the cranial base, the location of maxilla in test group was normal, but the location of mandible was more anterior than that in control. Based on the maxilla, the location of mandible was more anterior in test group than that in control. Both mandibular body and ramus anteroposterior lengths in test group were larger than those in control. Both mandibular plane angle and upper gonial angle were within normal range, but lower gonial angle was significantly high in test group.

• 대한두개안면성형외과학회지
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• 제9권1호
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• pp.17-22
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• 2008

Purpose: For several decades, open reduction has been a controversial issue in mandibular condyle fracture. The authors have successfully used the open reduction and internal fixation with retromandibular approach and have found it to be satisfactory for mandibular condyle fracture. Methods: A total of 10 patients with mandibular condyle fracture underwent open surgical treatment using retromandibular approach. The incision for the retromandibular approach was carried below the ear lobe and the facial nerve branches were identified. Dissection was continued until the fracture site was exposed and internal fixation was performed with miniplate following intermaxillary fixation. The average period of joint immobilization was 1 weeks and the arch bars were removed in 3 weeks on average. The preoperative and postoperative panoramic view and three-dimensional computed tomography were compared. During the follow up period, we evaluated the presence of malocclusion, chin deviation, trismus, pain, click sound, facial nerve palsy, hypertrophic scar and skin fistula. Results: According to the radiographic findings, the fractured condyle was reducted satisfactorily in all patients without any symptoms of facial palsy. During the follow up period ranged form 6 to 12 months, all clinical symptoms were improved except in one case with chin deviation and malocclusion. Conclusion: Using open reduction and internal fixation of mandibular condyle fracture with retromandibular approach, all results were satisfactory with good functional outcomes and minimal complication. We concluded that the open surgical treatment should be considered as the first choice for mandibular condyle fracture management.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권1호
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• pp.27-34
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• 2006

After orthognathic surgery in skeletal class III patients, the hyoid bone position and the upper airway dimension could be changed due to mandibular setback. There has been many studies about airway dimension of the patients with skeletal class II malocclusion or obstructive sleep apnea. but not with skeletal class III. The purpose of this study was to examine the change of position of the hyoid bone and the consequent change of airway space as the result of retrusion of mandible after orthognathic surgery in skeletal Cl III malocclusion patients. It is also to apply this results in predicting, diagnosing and treating the subsequent obstructive sleep apnea. Forty patients who were diagnosed as skeletal Cl III maloccusion, received orthoganthic surgery of both jaws including mandibular setback, and were followed up post-operatively for more than 6 months were selected. There were 10 male patients 30 female patients. The preoperative and postoperative lateral cephalograms were traced and the distances and angles were measured. The nasopharyngeal space increased postoperatively while the oropharyngeal space decreased. Except for the change of oroparyngeal space, the changes in male patients were greater than female patients. The hyoid bone moved in the posterior-inferior direction, and the change was greater in males than in females. If the postoperative mandibular setback is great, then a significant decrease of airway space and posterior and inferior movement of the hyoid bone were observed. This can result in symptoms related to obstructive sleep apnea. This result should be considered in the diagnosis and treatment planning of orthognathic surgery patients.

• 대한치과교정학회지
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• 제45권4호
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• pp.171-179
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• 2015

Objective: To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. Methods: Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, $12.2{\pm}1.5years$) were treated with the PA, and 19 patients (mean age, $11.3{\pm}1.9years$) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. Results: PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group ($3.2^{\circ}$ vs. $9.0^{\circ}$, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination ($5.0^{\circ}$) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor ($0.1^{\circ}$) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. Conclusions: PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA.

• 대한치과교정학회지
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• 제50권5호
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• pp.324-335
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• 2020

Objective: To compare postoperative positional changes in the mandibular proximal segment between the conventional orthognathic surgery (CS) and the surgery-first approach (SF) using intraoral vertical ramus osteotomy (IVRO) in patients with Class III malocclusion. Methods: Thirty-eight patients with skeletal Class III malocclusion who underwent bimaxillary surgery were divided into two groups according to the use of preoperative orthodontic treatment: CS group (n = 18) and SF group (n = 20). Skeletal changes in both groups were measured using computed tomography before (T0), 2 days after (T1), and 1 year after (T2) the surgery. Three-dimensional (3D) angular changes in the mandibular proximal segment, condylar position, and maxillomandibular landmarks were assessed. Results: The mean amounts of mandibular setback and maxillary posterior impaction were similar in both groups. At T2, the posterior portion of the mandible moved upward in both groups. In the SF group, the anterior portion of the mandible moved upward by a mean distance of 0.9 ± 1.0 mm, which was statistically significant (p < 0.001). There were significant between-group differences in occlusal changes (p < 0.001) as well as in overjet and overbite. However, there were no significant between-group differences in proximal segment variables. Conclusions: Despite postoperative occlusal changes, positional changes in the mandibular proximal segment and the position of the condyles were similar between CS and SF, which suggested that SF using IVRO achieved satisfactory postoperative stability. If active physiotherapy is conducted, the proximal segment can be adapted in the physiological position regardless of the occlusal changes.

• 치과방사선
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• 제19권1호
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• pp.105-121
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• 1989

The author analysed tomograms and submento-vertex radiograms of 90 temporomandibular joints from 45 asymptomatic young adults. 15 had Angle class Ⅰ malocclusion, 15 classⅡ and 15 class Ⅲ. Corrected lateral tomograms were obtained in three condylar positions; centric occlusion, centric relation and 1 inch mouth opening. The condylar angulation, depth of cut, joint spaces were analysed in each radiogram. The obtained results were as follows; 1. The mean condylar angulation in Angle class Ⅰ, Ⅱ, Ⅲ group was 17.55±5.51° 13.33±8.85° 16.25±6.60° respectively, and there was no significant difference in each group. The mean condylar angulation of right side (16.62±7.23°) was larger than left side (14.80±7.33°). 2. The mean depth of cut in Angle class Ⅰ, Ⅱ, Ⅲ group was 8.13±1.61㎝, 3.05±3.80㎝, 7.75±2.19㎝, respectively. Angle class Ⅰ and class Ⅱ group revealed significant difference in measurement (p<0.0l). 3. The mean height of articular fossa in Angle class Ⅰ, Ⅱ, Ⅲ group was 8.67±3.06㎜, 9.61±2.57㎜, 8.93±2.83㎜, respectively. And the mean width of articular fossa was 19.90±2.80㎜, 19.48±3.83㎜, 20.36±4.82㎜, respectively. 4. The mean height and width of condylar head was 5.11±1.16㎜, 11.20±2.26㎜, respectively. 5. In centric occlusion, the superior joint space was the largest (3.42±1.42㎜), followed by anterior joint space (2.94±1.95㎜) and the posterior joint space (2.64±1.19㎜. In centric relation, the anterior joint space was the largest (3.86±2.17㎜), followed by the superior joint space (3.64±3.68㎜) and the posterior joint space (1.18±0.77㎜). 6. The displaced measurement from centric relation to centric occlusion was 1.10±1.04㎜ anteriorly and 0.24±0.97㎜ inferiorly. In 1 inch mouth opening state, the condylar head displaced posteroinferiorly (2.49±2.49㎜ posteriorly, 1.17±1.34㎜ inferiorly) from the apex of articular eminence. And Angle class Ⅰ and Ⅱ group, Angle class Ⅱ and Ⅲ group revealed significant difference in posterior measurement, respectively (p<0.01).