Positioning errors of dental implants and their associations with adjacent structures and anatomical variations: A CBCT-based study

The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α=0.05). The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors ( >0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r=0.232,