An in vitro comparison between two different designs of sagittal split ramus osteotomy

Area of Science:

• Oral and Maxillofacial Surgery
• Biomechanical Engineering
• Dental Implantology

Background:

• Mandibular fractures often require surgical intervention, with osteotomy techniques significantly impacting treatment outcomes.
• Sagittal split ramus osteotomy (SSRO) is a common procedure, but variations in osteotomy design may influence mechanical stability.
• Understanding the biomechanical implications of different osteotomy configurations is crucial for optimizing surgical results and patient recovery.

Purpose of the Study:

• To evaluate how different osteotomy types in the inferior mandible affect the mechanical performance of fixation.
• To compare the biomechanical stability of two distinct inferior mandibular osteotomy techniques within the SSRO framework.

Main Methods:

• The study utilized 20 polyurethane hemimandibles, divided into two groups (n=10 each) undergoing SSRO with either a straight or oblique basilar osteotomy.
• Osteosynthesis was performed using bicortical screws in an inverted L configuration, guided by a surgical guide.
• Vertical compression tests were conducted on photoelastic resin models, with data analyzed using Student's t-test (P <0.05 significance).

Main Results:

• No statistically significant difference was found in maximum displacements between the two osteotomy groups (P <0.05).
• Extensiometric analysis revealed significant differences only in the middle fixation screw.
• Photoelastic models demonstrated similar force dissipation patterns towards the inferior mandible in both SSRO configurations.

Conclusions:

• The specific type of osteotomy in the inferior aspect of the mandible does not appear to influence overall mechanical performance when using an inverted L screw fixation system.
• These findings suggest that surgeons may have flexibility in choosing inferior osteotomy techniques without compromising biomechanical stability in SSRO.