Prevalence of Lingual Concavities in the Posterior Mandible Using Cone Beam Computed Tomography in a Tertiary Care Hospital in Pakistan

Abstract

Background: Lingual cortical plate perforations during implant placement are more likely to occur in the posterior mandible where there are lingual concavities. However, Cone beam computed tomography (CBCT) allows for detailed analysis of this anatomy and local data do not exist.

Objective: To assess the prevalence of lingual concavity in posterior mandible, its depth and angle in CBCT images of adult population aged 18-45 years in a Tertiary Care Hospital Lahore and to compare its frequency, depth and angle according to sex and age group.

Methods: This cross sectional study was conducted in Fatima Memorial Dental Hospital, Lahore, Pakistan from December 2023 to May 2024. The subjects were 95 patients (18–45 years of age) who had lost some or all of their posterior mandibular teeth, and were recruited via non-probability consecutive sampling. A lingual concavity depth and lingual concavity angle was measured by one observer on cross-sectional CBCT images, which were referenced to 2 mm above the inferior alveolar canal. Pearson's chi-square and Welch's t-test (p < 0.05) were used for group comparisons.

Results: The mean age was 30.67 ± 7.83 years (51.58% female). Lingual concavity was present in 43 participants (45.26%; 95% CI 35.6–55.3); overall mean depth was 3.79 ± 1.87 mm and mean angle 62.89 ± 8.74°. Concavity was more frequent in males than in females (60.87% vs 30.61%; p = 0.003) and deeper (4.21 ± 1.84 vs 3.40 ± 1.82 mm; p = 0.033), but angle did not differ (p = 0.96). Frequency (43.75% vs 46.81%; p = 0.76), depth (p = 0.54) and angle (p = 0.56) were similar in the 18–30-year and 31–45-year groups.

Conclusion: Lingual concavity was seen in nearly 50% of this one centre sample, more frequently and more severely in males, and was not significantly different across the age groups.