Optimal implantation site of orthodontic microscrew in maxillary anterior region based on CBCT

Objective To determine the optimal implantation site of orthodontic microscrew by cone beam computed tomography(CBCT)analysis in anatomical structure of the maxillary anterior region,and provide a theoretical basis for orthodontic implant placement and improve post-implantation stability. Methods Forty patients who underwent CBCT scanning in our department from January 2017 to June 2018 were selected for this study,with male to female ratio of 1:1 and age ranging from 20 to 40 years.The CBCT scanning was applied to measure the interradicular distances between neighboring roots,buccolingual dimension,labial cortical bone thickness and lingual cortical bone thickness between maxillary anterior teeth at planes of 2 mm,4 mm,6 mm and8 mm above the alveolar ridge crest.Data were measured to comprehensively evaluate the certain site condition of the alveolar bone. Results The interradicular distance,buccolingual dimension and labial cortical bone thickness between maxillary anterior teeth were positively correlated with the distance above the alveolar ridge crest(within 8 mm).The interradicular distances,buccolingual dimension,labial cortical bone thickness and lingual cortical bone thickness between lateral incisor root and canine incisor root at8 mm above the alveolar ridge crest were all greater than those between other maxillary anterior teeth. Conclusion The area between lateral incisor root and canine incisor root at 8 mm plane from alveolar ridge crest,can be used as an optimal site for implanting orthodotic microscrew.Though the interradicular distance and buccolingual dimension between maxillary central incisor roots are highest,implantation at this site still needs stability enhancement strategy to overcome the weakest labial cortical bone thickness and lingual cortical bone thickness.