Classification of osseous housing and the incidence of labial bone perforation for virtual implant surgery by CBCT in the edentulous maxillary

Abstract Objectives This study aimed to classify the alveolar ridge of the anterior maxillary edentulous and investigate the incidence of perforation and associated risk factors via virtual implant placement using cone beam computed tomography (CBCT). Methods The morphology of 85 patients who have lost a single tooth in the maxillary esthetic zone was assessed by CBCT. The width and height of the residual crest alveolar bone were measured. Root form implants (3.3 mm*10 mm and 3.3 mm*12 mm) were placed virtually in the edentulous area, and the risk factors associated with perforation were analyzed. Results Class Ib was the most common type of ridge (n = 26; 30.6%). Concavity bone thickness (CT) was significantly different (P < 0.05) among the four types of alveolar bone. The long axis angle of alveolar bone (LAAB) and the differences between the LAAB and implant placement angle (IPA) in the nonperforation areas were significantly lower compared with those in the perforation areas. After implantation, the overall occurrence of labial bone perforation was 56.5%, and perforation mostly occurred in Class II ridges. Conclusions Class II ridges and lateral incisors were at relatively high risk for labial perforation after implant placement. We thus recommend that clinicians determine the ridge classification, tooth type, CT, LAAB and IPA.