Construction of tooth positioners with LTV vinyl silicone rubber and some case reports.
In the orthodontic field, attention has recently begun to center on active treatment with tooth positioners, appliances with elasticity made of rubber materials used for orthodontic force in place of conventional metal wires[1-7]. Tooth positioners were contrived by KESLING as retainers to be used after the use of metal wires in active treatment[8,9]. Nowadays, it is used for closing the spaces due to band removal after active treatment, for the minute regulation of the occlusal relationship and for aftercare as a retainer. Not only that, as it is possible to regulate malocclusion by moving teeth with rubberlike elasticity applied in place of metal wires or brackets, it is beginning to draw attention as a new active treatment appliance to be substituted for conventional metal wires. With regard to the materials for tooth positioners to be used as active treatment appliances, various kinds of materials have been applied since KESLING contrived them[10-12], but few materials satisfy the necessary conditions for tooth positioners[10]; 1) easy manipulability, 2) elasticity and hardness, 3) tastelessness and odorlessness in the oral cavity and 4) durability. Polyurethane rubber and heatvulcanized silicone (HTV) rubber which are tasteless, odorless and superior in elasticity, have recently been developed[1,4-7], but these materials require special mold materials and equipment in the preparation process which is also very complicated, so their use has not been widespread as yet. Therefore, for several years the authors have been studying their practical application and trying to develop a material that is easy to manipulate and superior in physical properties[2,3,13]. As a result, the authors have developed a clinically applicable method of tooth positioners with low temperature vulcanized (LTV) vinyl silicone rubber. The following is an outline of its physical properties, the method for its preparation and some case reports.
The philosophy of the tooth positioning appliance
Abstract It is not necessary or desirable to treat every case of malocclusion that is presented. Many, if not most, of these children of 3 to 6 years can be safely put under observation in order that the tendency of growth can be noted. A fair percentage will be seen to improve as Nature seeks to correct some earlier period of retarded growth. Others may require the correction of a habit which is obstructing the normal course of development. Still others, such as the cases shown here, require slight mechanical corrections before normal function can be established and the forces of normal occlusion can exert their influence. Practically all of these cases suffer from low and improperly balanced muscle tone, and myofunctional therapy is used both during treatment and afterward to overcome this deficiency. As the span of attention is short in these younger cases, appointments must be kept brief and appliances simple; however, if these conditions are observed, the preschool children will be found to be among our most cooperative patients.
Studies on the New Orthodontic Rubber Materials
矯正治療では, 歯を移動するための矯正力を主として金属線材料やゴム材料に求めている。特に, 近年Full band techniqueが矯正治療に盛んに採用されるようになってからは, 更に, ゴム材料の使用頻度が急速に高まってきている。しかし, 従来用いられていたゴム材料は, 矯正治療上要求される苛酷な条件を充分満たすものとはいい難かった。そこで, よりよい弾性高分子材料を開発する目的で, 種々な検討を行なってきたが, その結果, 現時点で注入型ポリオール硬化ポリウレタンゴム材料が矯正用弾性材料として最も望ましい性質をもっていることを知った。その要旨は, 第1報 (歯科理工学会雑誌第12号25巻1971年) ならびに第2報 (日矯歯誌31巻第1号1972年) において報告した。そこで, この優れた材料を矯正治療面に応用すべく, まずtooth positionerを採り上げ, この材料による製作法を検討し, 製作したtooth positionerを実際の患者に用いたところ極めてよい成績を得たので, ここに本材料によるtooth positionerの新製作法の特徴とそれによるtooth positionerの特性について報告する。要旨は次の通りである。1) Face-bowの使用によりset-upmodelと顔面頭蓋の位置的関係を正確に咬合器上に再現すうことができる。2) 歯の排列にあたっては, indicatorにより再排列時の歯の移動量を量的に把握することができる。3) 患者の口腔内で採得した咬合挙上位を咬合器上に再現し, set-up model完成後の咬合挙上位に適用することができる。4) ゴム材料填入には, 流し込み法を用い, 重合には加圧法を用いた。これにより本材料の物理的性質を損なうことなく正確且つ容易に装置を製作できる。5) 仕上げ操作は, 表面処理材を用いたことにより容易となり, これにより材料の透明度を保持できるので歯への適合性や移動経過の直視が可能である。6) この製作法によって作られたtooth positionerを他の材料によるそれと比べたところ, 無味無嗅で患者に不快感を与えないばかりでなく, 長期の使用で変色せず, 且つ亀裂に対する抵抗性もすぐれていた。7) この方法によるtooth positionerを40症例余の矯正患者に適用したところ充分満足できる治療成績が得られた。8) 材料の物理的性状を活用して更に, 積極的な動的矯正治療面にも使用できる可能性を認めた。