Investigation of the effect of impacted third molar position and orientation on bad split fractures in sagittal split ramus osteotomy using finite element analysis

TL;DR

This study uses computer modeling to show how the position and angle of impacted wisdom teeth affect the risk of jaw fractures during a specific surgical procedure.

Contribution

The study introduces a finite element analysis to evaluate how third molar orientation and position influence bad split fractures during SSRO.

Findings

Vertically oriented and buccally positioned molars showed the highest stress concentrations.

Mesioangular and centrally positioned molars were associated with lower stress and lower risk.

Extraction of high-risk molars before surgery is recommended to reduce complications.

Abstract

This study aims to evaluate the impact of different angular orientations and buccolingual positions of impacted third molars on the incidence of bad splits during sagittal split ramus osteotomy using finite element analysis.

A total of 12 mandibular models were constructed, each representing a unique combination of third molar orientations (vertical, distoangular, horizontal, mesioangular) and positions (buccal, lingual, central). A force of 20 N was applied from the osteotomy line toward the proximal and distal segments to simulate the working principle of the Smith Spreader instrument.

The maximum principal stress followed the order: vertical > distoangular > horizontal > mesioangular. In terms of positional stress distribution, the buccal position generated the highest stress, followed by lingual and central positions. Similar trends were observed across all stress criteria evaluated.

The orientation and position of impacted third molars have a direct effect on the risk of bad splits during SSRO. Mesioangular and centrally positioned teeth were associated with lower stress levels, indicating lower risk, while vertically oriented and buccally or lingually positioned molars showed significantly higher stress concentrations. Thus, extraction of high-risk impacted third molars prior to surgery is recommended to reduce the likelihood of complications.

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