PROBLEM TO BE SOLVED: To provide an orthodontic appliance that facilitates improvement of false dentition requiring forward expansion of anterior teeth when performing teeth alignment treatment efficiently and precisely.SOLUTION: A forward expansion device is formed such that the tip of a circle diameter alloy elastic wire of the device is folded and bent to the inside in the side of a cervical part and a gingival side to make a form of an oval-shaped loop from 3 mm to 5 mm in diameter. As a result, the tip portion of an oval-shaped loop form comes into contact in many points in a tooth back uneven part to become a gentle surface contact, and the propagation of orthodontic force is performed precisely and stably, and therefore the tooth movement of a distance from 4 mm to 5 mm per one month can be performed by gentle translation. Also, it comes into contact in many points even if the orthodontic force applied to the crown is great, and therefore a load to a tooth root surface by the orthodontic force transmitted to a tooth root is dispersed to many distribution points, and a large load is not applied only in one point. As a result, the optimal orthodontic force can be acquired, and also the risk of damage of an alveolar bone, radicular absorption and pulpal deactivation due to the orthodontic force is evaded.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】歯並び治療を行う際、前歯部の前方拡大を必要とする不正歯列の改善を効率良く、又的確にそして容易な矯正装置を提供する。【解決手段】前方拡大装置は装置の丸径合金弾線の尖端部を歯頚部、歯肉側寄りに内側へ折り返し屈曲し3ミリから5ミリ径の楕円状ループの形態にした。結果、楕円状ループ形態の尖端部分が歯背面凸凹部で多数点で接触、緩やかな面接触となり矯正力の伝播が的確に又、安定的に行われる為、緩やかな歯体移動で一ヶ月4ミリから5ミリの距離の歯の移動が行えるようになった。又、歯冠にかかる矯正力が多大であっても多数点で接触する為、歯根に伝播された矯正力の歯根面への負荷は多数の分布点に分散され、一点のみに多大の負荷がかかることはなく、結果、最適な適正力が獲得できるのみならず、矯正力による歯槽骨の損傷、歯根の吸収、歯髄の失活のリスクは回避される。【選択図】図1
