To investigate the anatomical features of alveolar bone in gummy smile patients with cone beam computed tomography (CBCT), and provide the reference for miniscrews implanted in anterior alveolar crest.

A total of 63 cases of adults with gummy smile were selected for the study and the CBCT data of jaw bones were obtained. The mesiodistal interradicular distances, buccal-lingual thickness and buccal cortical bone thickness were measured at three different level which included 4 mm, 6 mm and 8 mm above the alveolar crest.

The mesiodistal interradicular distances increased along with distance between measure level and alveolar crest. (P ＜ 0. 05). The interradicular distance were the least when measured between central incisor and lateral incisor (P ＜ 0. 05). The interradicular space between central incisors presented the least buccal-lingual thickness (P ＜ 0. 05). No significant differences were observed between the other thicknesses of anterior interradicular spaces (P ＞ 0. 05). The buccal cortical bone thickness increased along with distance between measure level and alveolar crest (P ＜ 0. 05). The thicknesses were the least between central incisors while the most between lateral incisor and canine (P ＜ 0. 05).

The mesiodistal interradicular distances, buccal-lingual thickness and buccal cortical bone thickness are found increased with the height level. Given the most bone mass and cortical bone thickness, canine and lateral incisor interval can be recommended as the place for the miniscrews inserting.