Mandibular deformities present with infinite variation with different aesthetic and functional problems. Orthognathic surgery is required to achieve satisfactory results for functional and aesthetically in mandibular prognathism patient. Setback of the mandible to correct mandibular prognathism is a well-known procedure. The 2 most frequently used techniques are the intraoral vertical ramus osteotomy and the bilateral sagittal split ramus osteotomy (BSSRO). Bilateral sagittal split ramus osteotomy is an effective and commonly used method to correct mandibular prognathism. In this patient report, mandibular prognathism in female monozygotic twin patients was treated with BSSRO is presented.