垂直的寸法の増大--顎咬合関係への影響。臨床的アプローチ

Increase of vertical dimension--consequences for the maxillomandibular relationship. A clinical approach.

抄録

本研究の目的は、咬み合わせを開く装置を挿入することによって生じる切歯と臼歯部の垂直的変化を比較し、その後の治療期間中（平均4.3ヶ月）における回転と萌出の発生を分析することである。垂直的重なりが4mmを超える15～24歳の患者8名を対象に、前方咬合平面を有する上顎固定式舌側アーチ装置を用いて治療を行った。治療前、固定装置を挿入した直後、および装置を取り外した後に、下顎の後退位を冷硬化アクリルで記録した。第一大臼歯間の垂直的な重なりと離開は、これらの各時点で測定した。最後に、萌出中の歯の動きを第二大臼歯の領域の指標で測定した。その結果、咬み合わせの挙上量とは無関係に、前頭部と臼歯部の咬み合わせの挙上量の関係は、6人で約2：1、2人で約5：3であった。また、第二大臼歯部では、登録ⅠとⅢの指標の厚みに有意差があり、開咬治療中の萌出だけでなく、頬舌回旋も示唆された。

The purpose of the present study was to compare the vertical change in the incisor and molar areas caused by insertion of a bite opening appliance and to analyse the occurrence of rotation and eruption during the following treatment period (mean 4.3 months). Eight patients between 15 and 24 years of age with vertical overlaps > or = 4 mm were treated by means of a maxillary fixed lingual arch appliance with an anterior bite plane. The retruded mandibular position was recorded with cold cure acrylic before treatment, immediately after insertion of the fixed appliance, and after removal of it. Vertical overlap and separation between the first molars was measured at each of these occasions. Finally, tooth movements during eruption were measured on the indices in the area of the second molar. The results showed that, independent of the amount of bite raise, the relation between frontal and molar area bite raise was approximately 2:1 for six and 5:3 for two patients. There was a significant difference in thickness of indices from registrations I and III in the second molar area indicating not only eruption during bite opening therapy but also buccolingual rotation.