골격성 제III급 부정교합 환자에서 상악골 전방 견인 장치 사용후 측모 변화에 대한 연구

Abstract

Cause of skeletal class Ⅲ malocclusion in growing parients can be classified into maxillary deficiency, mandibular overgrowth, and combination of the two. Use of Protraction Head Gear(P.H.G.) has been recommended for treatment of growing class Ⅲ malocclusion patients, for it results in forward & downward movement of maxilla and backward & downward rotation of mandible. Numerous animal experiments were preformed and clinical study data have been reported ; nevertheless, studies on soft tissue profile change and comparison of treatment effects among the patients who had undergone treatment are considred to be somewhat insuffcient. The author selected 93 patients, who had been diagnosed as skeletal Class Ⅲ malocclusion with maxillary deficiency and then treated with P.H.G. ; the sample group was divided according to sex, treatment beginning age, palatal suture opening(intaoral appliance), and facial growth pattern. For each group, changing patterns of hard and soft tissue profile observde, and comparision whth 20 normal group(Angle`s Class I) patients of statistical significance in amount of growth and treatment of hard and soft tissue was done. The following results were obtained. 1. Skeletal, dental, and soft tissue measurement indicatde that more growth changes was induced in the sample group that used P.H.G. compared to the growth amount of normal group. 2. No statistical significance was ovserved in the amounts of maxillart forward movement and madibular backward & downward rotation depending on treatment beginning age in both sex group. 3. R.P.E. showed mote significant maxillary forward movement and less protrusion and less protrusion of upper incisor than La-Li. 4. There was no statisitcal significance in the amount of maxillary forward movement dependig on facial growth pattern. On the other hand, measurements indicating mandibular downward & backward rotation indicated greater change in counterclockwise growth pattern group than the clockwise. 5. Changes in upper and lower lip thicknesses showed a close ralationshipp with positional changes in underlying bone tissue and upper and lower teeth, and upper lip height and nasolabial angle increased and mentilabial angle decreased.