抜歯を伴う矯正治療中の中切歯の歯根および歯槽骨の形態変化のコーンビームCT計測

[Cone-beam CT measurement of morphological changes of the root and alveolar bone of the central incisor during orthodontic treatment with extraction].

抄録

目的:

成人患者における抜歯を伴う矯正治療が中切歯の歯根吸収および歯槽骨の形態に及ぼす影響を検討する。

PURPOSE: To study the effect of orthodontic treatment with extraction on root resorption and alveolar bone morphology of the central incisor in adult patients.

方法:

矯正治療を受けている成人患者 11 名を登録し、治療前後にコーンビーム CT（CBCT）撮影を依頼した。治療後の上下中切歯の歯根吸収、歯槽骨の厚さの変化、歯槽骨の高さを測定し、比較した。統計解析は、SPSS 23.0 ソフトウェアパッケージを使用して行った。

METHODS: Eleven adult patients receiving orthodontic treatment were enrolled, and asked to take cone-beam CT(CBCT) scanning before and after treatment. Root resorption of the upper and lower central incisors after treatment, changes in alveolar bone thickness and height of alveolar bone were measured and compared. Statistical analysis was performed using SPSS 23.0 software package.

結果:

歯と歯根の長さはある程度短くなった．上顎切歯は下顎切歯に比べ，歯根長の変化が大きかった．中切歯の舌側および口蓋頚部の歯槽骨幅はある程度減少し，上顎中切歯の口蓋頚部と下顎中切歯の中舌側 の歯槽骨幅はある程度変化していた．下顎中切歯の中唇側の歯槽骨幅は増加したが，舌側と口蓋側の歯槽骨は矯正治療後に増加し，上顎中切歯のそれよりも明らかであった．

RESULTS: The length of the tooth and root was reduced to a certain degree. The change in root length of the maxillary incisor was larger than that of the mandibular incisor. The alveolar bone width of the lingual and palatal neck of the central incisor showed some reduction, and alveolar bone width of the palatal neck of the upper central incisor and the middle lingual side of the mandibular central incisor changed to a certain extent. The width of the alveolar bone in the middle labial side of the mandibular central incisor increased, but the alveolar bone on the lingual and palatal side increased after orthodontic treatment, which was more obvious than that of the maxillary central incisor.

結論:

抜歯を伴う矯正治療では、中切歯の歯根吸収と舌側・口蓋側の歯槽骨の吸収がある程度進行する。しかし、口唇側の歯槽骨の量も増加する。下顎では、より多くの柵状突起と脱落が観察される。

CONCLUSIONS: Orthodontic treatment with tooth extraction is accompanied by a certain degree of root resorption of the central incisor and alveolar bone on the lingual and palatal side. However it is also accompanied by an increase in the amount of alveolar bone on the labial side. More fenestration and dehiscence are observed in the mandible.