Assessment of Anterior Maxillary Labial Bone Thickness Using Cone-Beam Computed Tomography: A Retrospective Analysis

Abstract

Background: The morphological variations observed in labial bone thickness (LBT) around maxillary anterior teeth can affect the three-dimensional placement of dental implants and its long-term outcomes; making it imperative for clinicians to thoroughly examine the LBT prior to tooth extraction.

Aim: To measure LBT in relation to the six anterior maxillary teeth at different levels along the long axis and the distance between cemento-enamel junction and bone crest (CEJ-BC) based on Cone-Beam Computed Tomography (CBCT) scans retrieved from patients’ records and identify any association with patients’ characteristics.

Materials and Methods: A total of 100 CBCT scans were evaluated by one calibrated examiner. The thickness of the labial bone was measured perpendicular to the long axis of the tooth at 1, 3 and 5 mm from the alveolar crest (LBT-1, LBT-3, LBT-5, respectively) and CEJBC using medical imaging viewer.

Results: CBCT scans of 58 females and 42 males with a mean age of 39.7 ± 9.5 years were included. A high variation of CEJ-BC was observed (range 0.55 – 3.90 mm). Statistically significant higher CEJ-BC values were associated with males and increased age (> 50 years). The overall means of LBT-1 were 0.76 ± 0.26, 0.79 ± 0.26 and 0.83 ± 0.37 mm; LBT-3: 0.92 ± 0.36, 1.05 ± 0.46 and 1.03 ± 0.48 mm; LBT-5: 1.17 ± 0.52, 0.80 ± 0.45 and 0.81 ± 0.40 mm for central-, lateral incisors and canines, respectively. The LBT was less than 1 mm in 74.2% ii of all maxillary anterior teeth with central incisor being the thinnest site (85%). No significant association between LBT and patient characteristics was observed.

Conclusion: The CEJ-BC distance is greater in males and increases with age, particularly in those older than 50 years. The LBT in the six maxillary anterior teeth is predominantly thin (< 1 mm) and has no correlation to age or gender. An increased LBT was observed at 3 mm level when compared with LBT-1 and LBT-5. Such variability should be taken into consideration when planning for immediate implant placement.