• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.159-169
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• 1995

The purpose of this study was investigating the effects of pivot splint on width of the temporomandibular joint space in order to get the basic data for clinical applications. Pivot splint could be used for treating the patients with temporomandibular disorders, especially for chronic closed lock which would not be reduced by joint manipulation or with other methods. So it is necessary to have a lot of underlying data for using pivot splint, but there is few available reports related to mechanical principle or clinical results of the splint. Healthy twenty dental students wee collected for this study and pivot splint with 2.5mm high right-side pivot was used. Next, transcanial projection was taken and width of joint space at there mandibular positions were measured : habitual occlusion position, clenching position with splint, and clenching position with splint and mandibular force. The data were processed with SAS statistical program. The obtained results were as follows : 1. Ipsilateral posterior joint space width was increased on clenching the pivot splint, but joint space widths of contralateral side were not significantly changed. 2. Superior and posterior joint space width were increased on clenching the pivot splint with mandibualr force on both ipsilateral and contralateral side. 3. Ipsilateral joint space widths were not significantly changed from habitual occlusion position to clenching the pivot splint with active mandibular force, but in case of with passive mandibular force, posterior joint space width was significantly increased. 4. Correlationships between mandibular positions were more significant at anterior joint space than at superior or posterior joint space. But the correlation between clenching and clenching with mandibular force was significant at all the three joint space.

• 대한치과교정학회지
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• 제23권3호
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• pp.295-309
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• 1993

The purpose of this study was to investigate the effect of jaw growth in a growing rabbits, when they are subjected to refractive force and after removal of refractive force. The experimental animals were Oryctolagus couniculus, male rabbits of 4 weeks of age. The mandible is retracted with 200gm in force of each side to the posterior and superior direction for 14 hours a day. Then rabbits were used as control group. First experimental group received refractive force for 4 weeks. Second experimental group received for 8 weeks. Third experimental group received for 12 weeks. True lateral films and dorso-ventral films were taken before wearing appliances, 4 weeks, 8 weeks, 12 weeks and 16 weeks after wearing appliance. The changes of rabbits jaw growth were observed radiographically. The findings were as follows : 1. Mandibular refractive force decreased total mandibular length, mandibular condylar length and angular length. 2. Mandibular refractive force increased nasal height, condylar width and angular width. 3. Mandibular refractive force decreased mandibular lenght growth but increased mandibular width growth. 4. There is no phenomena of catch-up growth after refractive force removal.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권3호
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• pp.238-243
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• 2001

Purpose : The purpose of this study was to determine radiologic variables affecting extraction of impacted mandibular third molar. Materials and Methods : This study was investigated on 44 consecutive extractions of unilateral impacted mandibular third molars (Male;34, Female;10, Mean age;24.98, Age range;19-35). Fourteen radiologic variables, which were actual value except only one, were evaluated to establish their relation to the operation time. The Pearson correlation coefficient and Stepwise procedures for regression analysis were carried out. Results : Eight variables (depth, angulation, ramus width, relationship to the second molar, distal ramus depth, mesial ramus depth, mesial periodontal ligament width and follicle) showed a statistically significant relation to the operation time(Pearson correlation coefficient, p<0.05). Two variables, depth and mesial periodontal ligament width, showed the most powerful and just relation to the operation time($r^2$ = 0.349, p<0.05). Conclusion : This study shows that our results can help general practioner to estimate the operation time of extraction of impacted mandibular third molars by measuring two radiologic variables ; depth and mesial periondontal ligament width.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권5호
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• pp.313-320
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• 2020

Objectives: The aim of this study was to evaluate the relationship between masticatory muscle thickness and mandibular morphology in young Korean adults with normal occlusion and mandibular prognathism. Patients and Methods: Multidetector computed tomography (MDCT) was used to measure the masticatory muscle thickness on the right side in 100 Korean young adults (50 normal occlusion group, 50 mandibular prognathism group). Cephalometric analysis was done to measure mandibular morphology. Pearson correlation analysis was done to investigate the relationship between the masticatory muscle thickness and mandibular morphometry. Results: The four masticatory muscles showed positive correlation with intergonial width in all subjects. All muscles, except temporalis, positively correlated with height of the ramus and mandibular length. Positive correlation was also observed in all muscles, except medial pterygoid, with thickness of the ramus. In the normal occlusion group, all four masticatory muscles showed positive correlation with intergonial width and ramus thickness. Positive correlation was also observed in all muscles (except lateral pterygoid) with mandibular length. Masseter and lateral pterygoid positively correlated with height of the ramus. In the mandibular prognathism group, all masticatory muscles, except lateral pterygoid, showed positive correlation with intergonial width. The masseter muscle showed negative correlation with ANB. Conclusion: The results suggest a positive correlation of the thickness of masticatory muscles with both horizontal and vertical dimensions of the mandible. However, thickness of the masseter was found to decrease in patients with increasing severity of mandibular prognathism.

• 한국임상수의학회지
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• 제16권1호
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• pp.57-64
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• 1999

It was performed to evaulate the effects of occlusion of mandibular gland and sublingual gland on the mandibular gland in dogs. The occlusion of mandibular gland and sublingual gland was induced by ligature in clinically normal dogs, and ultrasonograpic appearance, hematological changes and histological changes of the mandibular gland were observed daily during 6 days. The results were as follows. 1. The length, width, circumference and area of the mandibular gland in clinically normal dogs were 25.1 mm, 8.4 mm, 56.4 mm and 163.0 $\textrm{mm}^2$ in the left, and 23.4 mm, 8.0 mm, 53.3 mm and 141.6 $\textrm{mm}^2$in the right. 2. The length, width, circumference and area of the mandibular gland were gradually increased after ligature of the salivary duct, and revealed maximum values, as 33.4 mm, 10.9 mm, 73.0 mm and 287.2 $\textrm{mm}^2$, respectively, at 24 hours after ligature, and returned to normal size at 3 days after ligature. 3. The size of the opposite mandibular gland without ligature was also gradually increased until 24 hours, and returned to normal size at 3 days, similar to the changes of the mandibular gland with ligature. 4. There were no significant changes after ligature of the salivary duct in hematological findings. 5. In histopathological findings, the major of glandular alveoli was enlarged at 24 hours after ligature of the salivary duct, and neutrophils and monocytes were infiltrated at 6 days after ligature.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권2호
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• pp.204-210
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• 2000

The mandibular contour determines the shape of the lower part of the face and thus influences the appearance of the face. A patient with a large, squarish, or broad face who desires a small, round, or slender face can undergo mandibular contouring surgery to reduce the width of the lower face. The successful correction of a prominent mandibular angle by conventional angle ostectomy has been reported. But, in the majority of patients with a widened facial appearance, both the mandibular angle and part of the mandibular body anterior to it are protuberant laterally, so both must be resected. The purpose of this study is to introduce a new method of performing mandibular contouring surgery, more effectively and easily, and to reduce postoperative complication and evaluate its results. We treated 6 patients who has prominent mandibular angle using multiple step osteotomy with angle-splitting ostectomy. The advantages of this new method are as following. (1) easily performable (2) effective mandibular contouring surgery by reducing the width of lower face (3) producing a natural relief of the mandibular angle (4) low risk of soft tissue damage and complications (5) shortening of the operation time. etc.

• The Journal of Advanced Prosthodontics
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• 제4권2호
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• pp.72-75
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• 2012

PURPOSE. This study evaluated the existence of golden proportion between the widths of the maxillary and mandibular anterior teeth in Indian population. MATERIALS AND METHODS. The clinical tooth width measurements were recorded with the digital vernier calipers on 576 patients of both sexes in the age group of 21 - 30 years. Flexible ruler was used to determine the width of maxillary and mandibular anterior teeth on the patients by the same operator. The data obtained was statistically analyzed using paired student t-test (${\alpha}$=.05). RESULTS. The golden proportion was not found between the width of the right central and lateral incisors in 53% of women and 47% of men. The results revealed the golden percentage was rather inconstant in terms of relative tooth width. CONCLUSION. The golden proportion is an inappropriate method to relate the successive widths of the maxillary anterior teeth in Indian population.

• 대한치과교정학회지
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• 제37권3호
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• pp.220-230
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• 2007

골격성 I급이면서 수직적으로 정상인 환자 160명(남자 80명, 여자 80명)의 측모 두부방사선 계측사진을 대상으로 하악 전치부 치조골의 협설측 두께를 치축을 기준으로 계측하여 연령에 따른 차이를 조사하여 다음과 같은 결과를 얻었다. 하악전치부 치조골의 협설측 두께와 하악 전치부 설측 치조골의 두께는 연령이 증가함에 따라 여자의 CEJ 하방 2 mm 부위를 제외하고는 남녀 모두에서 유의한 감소를 보였다. 반면에, 하악 전치부 협측 치조골의 두께와 하악 이부 최대 풍융부의 두께는 연령이 증가함에 따라 유의한 차이를 보이지 않았다. 이상의 연구를 통하여 한국인에 있어서 수평적으로 I급의 골격형태이면서 수직적으로 정상인 환자에서는 성인보다는 성장기환자에서 하악 전치의 설측 치조골의 두께가 더 두꺼워 발치치료에서와 같은 하악 전치의 설측이동이 유리할 것으로 사료된다.

• 대한치과교정학회지
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• 제32권2호통권91호
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• pp.117-127
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• 2002

본 연구는 전후방적인 부조화가 폭경에 영향을 미치는지 알기 위해 I급 정상교합군과 III급 부정교합군을 비교하였고, III급 부정교합군내에서 수직적인 부조화가 폭경에 영향을 미치는지 알기 위해 Hyperdivergent군과 Neutral군으로 나누어 폭경의 차이를 비교하였다. 부산대학교병원 치과교정과에 내원한 골격성 III급(ANB< 0$^{\circ}$) 부정교합자 중측모 두부방사선 계측사진상에서 하악 평면각(SN-Mandibular plane; 정상인의 평균 32 ${\pm}$ 5$^{\circ}$)이 1.5 SD이상(39.5$^{\circ}$이상)인 환자 37명 (남자 18명, 여자 19명 )을 hyperdivergent군(Group B)으로, 하악 평면각이 정상치의 0.5 SD이내인(32 ${\pm}$ 2.5$^{\circ}$) 40명 (남자 20명, 여자 20명)을 neutral군(Group C)으로 분류하였고 11개의 치과대학 교정과에서 선별한 정상교합과 정상적인 안모를 가진 성인 24) 중 41명(남자 20명, 여자 21명)을 정상교합군(Group A)으로 하여 이 세 군을 대상으로 연구하여 다음과 같은 결론을 얻었다. 1. 골격성 III급 부정교합군내에서 수직적인 양상에 따른 폭경 비율은 유의할 만한 차이가 없었다. 2. 정상교합군과 III급 부정교합군의 상, 하악 기저골에 대한 치아간 폭경 비율의 비교에서 상악에서는 III급 부정교합군의 비율이 더 컸고(p<0.001), 하악에서는 제 1대구치 부분을 제외한 모든 항목에서 III급 부정교합군의 비율이 작아서(p<0.001) III급 부정교합군이 정상교합군에 비해 기저골에 대해 상악 치아가 더 협측으로 경사되고, 제1대구치를 제외하고 기저골에 대해 하악 치아가 설측 경사되어 횡적인 치성보상이 잘 되어 있는 것으로 나타났다(p<0.001). 3. 정상교합군과 III급 부정교합군의 상악에 대한 하악의 치아간 폭경 비율의 비교에서 모든 부분에서 유의할 만한 차이가 없었다. 4. 정상교합군과 III급 부정교합군의 상악에 대한 하악의 기저골 폭경 비율의 비교에서 모든 부위에서 III급 부정교합군이 정상교합군보다 더 커서(p<0.0001) III급 부정교합군의 상악 기저골 폭경이 하악보다 더 좁게 나타났다.

• The Journal of Advanced Prosthodontics
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• 제14권1호
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• pp.1-11
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• 2022

PURPOSE. The maximum width between the mesial and distal labial transitional line angles, described as "esthetic width" herein, could significantly influence the visual perception of the teeth and smile. This study aimed to conduct biometric research on esthetic width and to explore whether regular distribution exists in the esthetic width of human teeth. MATERIALS AND METHODS. A total of 4,264 maxillary and mandibular anterior teeth were measured using the Geomagic studio software program. The proportions of maxillary to mandibular homonymous teeth and proportions between the adjacent teeth were calculated. Bilateral symmetry and the correlation between the esthetic and mesiodistal widths were both accounted for during the measurement procedures. RESULTS. The mean esthetic widths were 6.773 ± 0.518 mm and 4.329 ± 0.331 mm for maxillary and mandibular central incisors, respectively, 5.451 ± 0.487 mm and 5.008 ± 0.351 mm for maxillary and mandibular lateral incisors, respectively, and 3.340 ± 0.353 mm and 5.958 ± 0.415 mm for maxillary and mandibular canines, respectively. Except for the mandibular canines, no significant difference in esthetic width was found among homonymous teeth from the same jaw. A high linear correlation was found between the esthetic and mesiodistal widths of the same tooth, except for the maxillary canines. Esthetic width proportions among different tooth categories showed some regular patterns, which were similar to those of the mesiodistal width. CONCLUSION. Esthetic width is regularly distributed among the teeth in the Chinese population. This could provide an important reference for anterior dental restorations and dimension recovery in esthetic reconstruction of anterior teeth.