• 대한치과교정학회지
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• 제24권1호
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• pp.199-220
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• 1994

This study was conducted to determine the electromyographic features in the perioral muscles of class II division 1 malocclusion with incompetent lips, and to grope the correlation between its activities and craniofacial morphology. Tn this study, 14 subjects with class II division 1 malocclusion with incompetent lips(mean age of 20.5 years) and 20 subjects with normal occlusion(mean age of 23.9 years) were investigated. Electromyographic data were recorded from orbicularis oris, mentalis, buccinator and suprahyoid muscles durig rest lip posture, lip position at sealing, maximum sealing, maximal blowing, maximal biting, sipping milk, sipping and swallowing milk, chewing gum, masticating almond, swallowing almond and phonation utilizing the Medelec MS-25 electromyographic apparatus. Lateral cephalometric radiographs were taken with the mandible in intercuspal position on all subjects. All data were recorded statistically processed. The findings of this study can be summerized as follows : 1. In class II division 1 malocclusion with incompetent lips, the overall augmentations of perioral muscle activities during various functionel movements set for lip sealing were manifested and particular swelling in mentalis activity at rest was detected. 2. On the other hand remarkable diminution of upper lip acitivities at lip sealing movements was drawn. 3. In Class II division 1 malocclusion with incompetent lips, negative correlations existed between the diversity of upper lip activities and upper incisor position and overjet as well in contrast to positive correlations in the lower lip. 4. It was suggested that the abnormal function of lower lip and mentalis muscle contributed somewhat the revelation of the characteristics of Class II division 1 malocclusion.

• 대한소아치과학회지
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• 제27권2호
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• pp.246-250
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• 2000

Oral screen은 가장 기본적인 기능성 장치로서, 근육의 변화를 도모하여 비정상적인 근육형태와 연관된 초기부정교합의 개선에 적합하다. 이것은 혀와 buccinator mechanism사이의 근평형을 향상시켜, 정상적인 성장이 가능하도록 한다. Oral screen은, (1) 손가락빨기 혀내밀기, 입술깨물기 등의 구강습관, (2) 기도가 열려있을 때의 구호흡, (3) 상악전돌경향을 동반한 경미한 원심교합, (4) 유치열과 혼합치열에서의 개방교합, (5) 무력순 등을 개선하는데 사용된다. Oral screen은 매일 밤, 그리고 가능하다면 낮에도 장착하여야 한다. 장치의 효과는 구순폐쇄훈련을 시행함으로써 발휘된다. 장치를 장착하는 동안, 입술은 장치의 효과를 높이고 구순폐쇄를 향상시키기 위해 항상 접촉한 상태로 유지되어야 한다. 본 증례는 구호흡과 무력순을 보이며 각각 상악절치의 순측경사와 치은비대, 개방교합 양상을 보이는 2명의 어린이환자에게 구순폐쇄훈련을 병행하면서 oral screen을 장착한 결과, 구호흡경향이 줄어들어 치은부종이 감소하였고 구순의 근력과 길이는 증가하여 구순폐쇄가 원활해졌다. 아울러 상악 절치의 경사도가 감소되어 개방교합의 치료에 효과적임을 알 수 있었다.

• 대한치과교정학회지
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• 제53권4호
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• pp.276-285
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• 2023

Objective: The aim of this retrospective study was to compare changes in hard tissue and soft tissue after the four first premolars were extracted with anterior teeth retraction according to the presence or absence of lip incompetence. Methods: Patients who underwent the four first premolars were extracted with anterior teeth retraction were divided into competent (n = 20) and incompetent lip (n = 20) groups. Cephalometric measurements for hard tissue and soft tissue changes were performed pre-treatment and post-treatment. Results: In the competent group, the upper and lower lips retreated by 2.88 mm and 4.28 mm, respectively, and in the incompetent group by 4.13 mm and 5.57 mm, respectively; the differences between the two groups were significant (p < 0.05). A strong positive correlation between retraction of the upper lip and upper incisors was observed in both groups (p < 0.05), whereas a correlation between retraction of the lower lip and lower incisors was only found in the incompetent group. A simple linear regression analysis showed that the pattern of lip retraction following the retraction of the anterior teeth was more predictable in the incompetent group than in the competent group. Conclusions: These findings suggest that the initial evaluation of lip incompetence in patients with skeletal Class II is essential for the accurate prediction of the soft tissue changes following retraction of the anterior teeth in premolar extraction treatment. Therefore, sufficient explanation should be provided during patient consultations.