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

The sagittal split ramus osteotomy (SSRO) is commonly used to correct dentofacial deformities. This study compared fracture patterns, maximum tensile load, displacement, time, and thickness of ex-vivo mandibles subjected to the Epker or Wolford SSRO techniques. Sixty-one dried adult cadaveric mandibles were sectioned, with each hemimandible randomly assigned to one of two groups: Epker, which involved a horizontal beveled medial cut above the lingula, and Wolford, which added an additional cut along the inferior mandibular rim. Each hemimandible was mounted on a wooden base, and a metallic device similar to a Smith sagittal separator was used to stress the sagittal cut until failure. Fractures were classified as favorable (lingual split scale (LSS)1, LSS2, LSS3) or as unfavorable (LSS4). The Epker group had significantly more unfavorable fractures than the Wolford group (P = 0.027), with a 4.51-fold higher relative risk of unfavorable fractures. Hemimandible thickness did not significantly affect fracture patterns (P > 0.05). No significant differences were found between the techniques regarding tensile load, displacement, or fracture time (P > 0.05). Wolford's additional osteotomy along the inferior mandibular rim reduced the load required for the mandibular split and increased fracture predictability.