Fracture patterns of two sagittal split ramus osteotomy techniques: a cadaveric study

Area of Science:

• Oral and Maxillofacial Surgery
• Biomechanical Engineering
• Anatomical Studies

Background:

• Sagittal split ramus osteotomy (SSRO) is a standard surgical procedure for correcting dentofacial deformities.
• Variations in SSRO techniques may influence surgical outcomes and fracture patterns.
• Understanding biomechanical differences is crucial for optimizing surgical predictability.

Purpose of the Study:

• To compare the Epker and Wolford techniques for sagittal split ramus osteotomy (SSRO).
• To evaluate differences in fracture patterns, biomechanical load, displacement, and time.
• To assess the impact of mandibular thickness on fracture outcomes.

Main Methods:

• Ex-vivo biomechanical testing of 61 adult cadaveric mandibles.
• Random assignment of hemimandibles to Epker or Wolford SSRO techniques.
• Application of tensile load using a modified Smith sagittal separator until fracture failure.
• Classification of fractures using the Lingual Split Scale (LSS).

Main Results:

• The Epker technique showed a significantly higher relative risk (4.51-fold) of unfavorable fractures (LSS4) compared to the Wolford technique (P = 0.027).
• No significant differences were observed between techniques in maximum tensile load, displacement, or fracture time (P > 0.05).
• Mandibular thickness did not significantly influence fracture patterns (P > 0.05).

Conclusions:

• The Wolford SSRO technique, with an additional inferior mandibular rim cut, demonstrates increased fracture predictability.
• This modification may reduce the biomechanical load required for mandibular splitting, potentially improving surgical outcomes.
• The findings suggest the Wolford technique offers advantages in controlling fracture patterns during SSRO procedures.