- 期刊
乳牙牙根吸收的研究1.光學顯微鏡的觀察
The Study of Root Resorption of Human Deciduous Teeth I. Histological Observatino by Light Microscope
摘要
人類乳牙在換牙時牙根吸收的研究，以光學顯微鏡觀察。總共收集了64顆人類無齲齒的乳牙，年齡由5歲2個月到11歲4個月。在乳牙生理性的吸收過程，可見有多數大型多核破齒細胞及單核細胞位在牙根牙骨質及牙本質的似扇形皺摺的豪攝氏陷凹區。且在牙根管內及牙髓腔處亦可見到此種吸收陷凹及破齒細胞，表示有內吸收發生。這種破齒細胞有的直接貼附在吸收陷凹處，有些則游離，其形狀大小不一，有不規則的細胞質突起。 脫落期乳牙牙根吸收依其恆繼齒所在部位不同而有差異。在乳前齒，牙根舌側的吸收較唇側明顯。於乳甘齒則牙根分叉處及牙根間牙骨質的吸收較明顯。並可見細胞性牙骨質及牙周韌帶附著到吸收陷凹處。
關鍵字
無資料並列摘要
Sixty-four human non-carious deciduous teeth were used to observe the root resorption of deciduous teeth by means of light micro –scope. The extent of root resorption was clas-sified into 6 grades: Res. O, Res. I, Res. 1/4, Res. 1/2, Res. 3/4, Res. Co. In the physiolo-gical root resorption of deciduous tooth, there are numerous, large multinucleated odontoclasts and mononuclear fibroblasts or macrophages residing at the Howship’s lacunae. The odontoclasts resorbed hard dental tissues, including cementum, dentin A characteristic of active or “resorbing” odontoclasts, but not in free or inactive odontoclasts is cytoplasmic projections, or brush borders, which were found near the underlying hard dental tissues. The deciduous root resorption was found to be most advanced in the apical areas. Because of the different eruption path of the permanent successors, the position of deci-duous root resorption varied. Generally, the lingual surface was resorbed more extensively than the labial surface in the deciduous an-terior teeth; the resorption of the furcal area and interradicular cementum surface of the roots were more advanced in the deciduous molars. Predentin can be resorbed by odonto-clasts, too. However, it seems more resistant to resorption than dentin. Resorption lacunae could be observed in the root canal and pulp chamber. This means that the internal root resorption probably oc-cur simultaneously. Periodontal fiber attach-ment was observed in some Howship’s lacunae of the root surface. Inflammatory changes oc-curred in the pulp of deciduous teeth during the shedding process, especially when the deciduous root was resorbed more than one half way. The appearance of the repairing cellular cementum and periodontal fiber attachment was clearly observed in some deciduous roots.