CBCT analysis of mandibular incisor area and feasibility of immediate implant placement. An alveolar housing study.

Background: Immediate implant placement (IIP) has shown predictable outcomes when specific requirements are met. The aim of the present study was to radiographically evaluate the dimensions of mandibular incisors and the alveolar bone to further determine the feasibility of IIP in this area.

Materials and methods: A total of 404 intact mandibular incisor CBCT images from 101 patients (42 males, 59 females; mean age 49 ± 16.84 years) were analyzed. The mesiodistal tooth width and the distance between the incisal edge (IE), cementoenamel junction (CEJ), facial bone crest (BC), root apex (RA), and fenestration point (F) were registered, together with the alveolar bone width at 1 and 3 mm below BC. Finally, the angular discrepancy between the dental and the alveolar bone long axis (BLA) was recorded as the tooth torque (TT).

Results: The CEJ to BC distance was 3.23 ± 1.67 mm. The RA to F mean distance was 15.02 ± 3.97 mm. The mean alveolar bone buccolingual widths at 1 and 3 mm below the facial BC were 7.12 ± 0.82 and 6.32 ± 0.71 mm in the lateral and central incisors, respectively (P 0.001). The buccolingual width was less than 6 mm in more than 33% of the central incisors, but only in 3% of the lateral incisors, displaying increased alveolar width. The average was 165.66 ± 7.47 degrees.

Conclusions: The results presented in this study point toward the need for careful consideration of the requirements for anterior mandibular IIP for success and predictability purposes.