Predictive Factors to Assess the Difficulty to Extract Retained Lower Third Molars

Background: Third molar eruption occurs in a very limited space. Several difficulty scales have been used to determine the complexity when extracting retained molars, which are key for surgical planning and prediction. A scale including indicators such as quality of mucosa and bone, as well as shape and number of roots is introduced. Purpose: Evaluate the difficulty in extracting retained lower third molars, using the scale proposed by Romero-Ruiz, and thus estimate the presence of intraoperative complications and surgical time. Methods: An observational descriptive cross-sectional study was carried out, with a sample of 100 extractions of retained lower third molars in patients between 16 and 40 years of age. The following variables were evaluated: spatial relationship, depth, relationship with mandible ramus/space, integrity of bone and mucosa, roots, dental follicle, and surgical time. The data were summarized in absolute frequency tables and analyzed with Pearson's Chi2 test (p < 0.05). Results: 71 % of third molars were classified as “difficult” on the scale. There were significant differences in terms of surgical time-age (p = 0.002), presence of complications-location of the third molar (p = 0.015), presence of complications-follicle size (p = 0.022), difficulty-sex (p = 0.011 ), difficulty-age (p = 0.068). Conclusions: This scale can be used to plan extraction treatments for retained lower third molars to reduce surgical times and anticipate complications.