Long-term remodeling of anterior alveolar bone from treatment to retention / 实用口腔医学杂志

ABSTRACT

Objective: To investigate alveolar bone remodeling on both labial and lingual aspects of lower anterior teeth during treatment and retention stage. Methods: Forty-three cases with lower first premolars extracted (34 girls and 9 boys) and full records at three time points (pretreatment, posttreatment, follow-up) were collected as study sample. Displacement of lower incisor and bone thickness around its labial and lingual aspect were measured. Results:For the level of center of resistance(LC), there was statistically significant decrease of alveolar bone on lingual aspect (0.78?0.77) mm and no change on labial aspect, as the center of resistance(CR) was retracted lingually by (-3.02?1.13) mm during treatment. Analogous changes were found at the level of 3 mm apical to the center of resistance (L3C). In retention stage, with stable positioned lower incisor, no statistically significant change of alveolar bone was found on labial aspect at LC while a little amount of decrease of labial bone (0.20?0.58) mm was found at L3C. On the contrary, subsequential bone apposition could be detected with increase of lingual bone at both levels by (0.31?0.76) mm and (0.38?0.94)mm respectively. Conclusion:Speed of labial bone resorption is faster than that of lingual bone apposition during orthodontic treatment. In retention stage, sequential bone apposition on lingual aspect is presented with lower incisor in stable position.