Estimating the Extraction Time of an Upper Third Molar: Proposal and Validation of Results

Abstract

Background: Numerous studies in the literature have aimed to evaluate the difficulty level of removing third molars. However, most of these studies have focused on the lower third molars, which can lead to complications. There is a lack of a method to determine the complexity of upper third molar extraction. Therefore, this study's objective was to develop an equation using multiple linear regression to estimate the extraction time of an upper third molar based on its complexity. Methods: This study involved patients enrolled in the Master of Oral Surgery program at the University of Seville. To determine their relationship with surgical time, the researchers analyzed various factors, such as depth, root morphology, and the need for odontosection. They then validated their findings by studying patients treated at Palmaplanas Hospital in Mallorca. Results: The cohort analysis from the University of Seville revealed significant associations between surgical time and the identified factors. A regression equation design was performed to predict the total duration of surgical intervention for wisdom teeth extraction. This equation incorporates several independent variables, represented by Xi, together with a constant term, C, and the corresponding coefficients, Bi, which weight the impact of each variable on the intervention time. The results are as follows: -0.312 (spatial relationship), 0.651 (depth), -0.443 (bone and mucosa integrity), 0.214 (roots), -0.745 (ostectomy), 0.713 (odontosection), and -0.426 (suture). Upon application of the statistical methodology to the Palmaplanas Hospital cohort, a regression coefficient of 0.770 was determined. This indicates a strong correlation between the input data and the estimated surgical time. Conclusions: In conclusion, the proposed formula demonstrates notable validity in predicting the surgical time required to extract upper third molars.

Keywords: classification; diagnostic procedure; difficulty indices; extraction; impacted third molars; validation; wisdom teeth.

Figure 1

Extraction of an upper level C deep wisdom tooth vertical, covered with mucosa but not bone with less than 2/3 of fused root without the need for osteotomy or odontosection and suture; Y = C + B1 × X1 + B2 × X2 + B3 × X3 + B4 × X4 + B5 × X5 + B6 × X6 + B7 × X7= 9.442 − 0.312 × 1 + 0.651 × 3 − 0.443 × 4 + 0.214 × 1 − 0.745 × 1 + 0.713 × 1 − 0.426 × 2 = 8.641 min of extraction. (a) Orthopantomography; (b) anesthesia; (c) full thickness flap; (d) exodontia without osteotomy or odontosection; (e) suture; (f) exo-donated third molar germ.