Evaluation of a Mandibular Canal Classification System to Predict the Incidence of Postoperative Complications Following Third Molar Removal

Objectives: Third molar removal is the most common intervention in oral and maxillofacial surgery. However, the removal of mandibular third molars is associated with complications that can result in pain, inconvenience, and morbidity. This study evaluates a novel mandibular canal classification system for predicting postoperative complications after mandibular third molar removal.

Methods: 466 mandibular third molar removal cases treated between 2004 and 2014 were analyzed in this retrospective longitudinal study. Age, preexisting conditions, retention type (Sailer and Pajarola classification), and the third molar`s proximity to the mandibular canal (SPMC) were considered as potential risk factors for surgical complications. Surgical complexity of the retention type and SPMC classification were delineated per the Simple-Advanced-Complex (SAC) classification. A multivariate logistic regression model was used to investigate the effect of these risk factors on the occurrence of postoperative complications.

Results: Out of the 7.9% cases with postoperative complications, 6.7% were associated with alveolar osteitis. The highest rate postoperative complications was in SPMC class D (25%), cases with the preexisting odontogenic cysts (29.41%) and in the old age group (47.6 to 75.59 years) (13.63%). Cases with SPMC class A or C demonstrated a higher risk of developing postoperative complications in comparison to cases with SPMC class S (13.1% versus 6.1%,Fisher`s Exact test p=0.01). The risk of developing postoperative complications increased with age, although not significantly (Fisher`s Exact Test p=0.23). In addition, preexisting odontogenic cysts further increased this risk by 4 times (29.4% versus 7.1%, Fisher`s Exact test p=0.007).

Conclusion: The mandibular canal classification system might provide clinicians with an additional tool for assessing anatomical risk factors related to mandibular third molar removal. However, more comprehensive evaluation of this classification system is necessary.