A cephalometric study on the hard and soft tissue changes by the rapid palatal expansion in Angle's Class III malocclusion / 대한치과교정학회지

ABSTRACT

This stydy was undertaken to evaluate the cephalometric changes of the soft tissue and skeletal profile subsequent to the palatal expansion in 25 Angle's Class III cases, ranging in age from six to fifteen years, with cross-bite of the anterior teeth, underdevelopment of maxilla and facial disharmony. Following results were obtained 1. ANS moved downward, Point A presented forward & downward movement increasing SNA and point B presented backward & downward movement decreasing SNB. 2. Mandible was rotated to backward & forward and maxilla moved forward & downward with the bite opening and improvement of anterior teeth cross-bite. 3. Soft tissue on inadible was rotated to backward & downward rotation of Point B', Pog'. 4. Respones of the upper lip was more significant in downward than forward direction, and correlated with the upper central incisor and mandible rotation. 5. Reaponse of the lower lip was mord significant in downward than backward direction, and correlated with the mandible rotation. 6. There was a rather high degree of correlation between skeletal porfile and soft-tissue profile,LS, 1Pog', PogLS, PogLIPog' in horizontal measurements and 1Pog', PogLI, PogPog' in vertical measurements.