THE DETERMINATION OF SAFE ZONE FOR HORIZONTAL RAMUS CUT IN SAGITTAL SPLIT RAMUS OSTEOTOMY WITH CONE BEAM COMPUTED TOMOGRAPHY: A RETROSPECTIVE PILOT STUDY

ABSTRACT Aim: Bilateral sagittal split ramus osteotomy (BSSRO) is commonly used to correct mandibular deformities. The first cut for this osteotomy is performed on the medial aspect above the lingula. During this procedure; The most feared intraoperative complication, the undesired fracture. Most of the BSSRO complications consist of condyle fracture or buccal/lingual plate fracture. The aim of this study was to determined the distance between the lingula and the sigmoid notch which is a surgical importance for BSSRO. Material and Methods: This retrospective study composed of the cone beam computed tomography images that were obtained at the our clinic. The sample compromised 70 patients (32 males and 38 females, with an age range of 12 to 28 years). The perpendicular distance between the fixed plane and upper limit of lingula was measured. The sample comprised 70 subjects (32 males and 38 females, with an age range of 12 to 28 years). The obtained data were statistically evaluated. Results: The minimum distance of the between fixed plane passing from sigmoid notch with lingula was found as a minimum of 4.80mm and a maximum of 19.20mm (mean±std. dev.= 11.99mm±2.40, n=140). The right and left side measurement ranged from 4.80mm to 16.4mm (mean±std. dev=11.34mm±2.26, n=70) and 7.72mm to 19.20mm (mean±std. dev.= 12.64mm±2.39, n=70), respectively. Conclusion: The findings obtained in this study provide a guideline for surgeons performing BSSRO on young populations in Turkey. Pre-procedural three-dimensional evaluation provides valuable information to prevent undesirable fractures. Keywords : Horizontal Ramus Osteotomy, CBCT, Sagittal Split Osteotomy SAGITTAL SPLIT RAMUS OSTEOTOMISINDE RAMUS KESISI ICIN GUVENILIR SINIRLARIN KONIK IŞINLI BILGISAYARLI TOMOGRAFI ILE BELIRLENMESI: RETROSPEKTIF PILOT CALIŞMA OZ Amac : Bilateral sagittal split ramus osteotomisi, mandibular deformiteleri duzeltmek icin siklikla kullanilan cerrahi bir yontemdir. Bu osteotomi icin ilk kesi lingula uzerinden gecen bir hat uzerinde gerceklestirilir. Bu cerrahi sirasinda en korkulan intraoperatif komplikasyon istenmeyen kirik olusumudur. Operasyon esnasinda hem proksimal hem de distal segmentlerde kirik olusabilir. Bu calismanin amaci, guvenli bir bilateral sagittal split ramus osteotomisi icin cerrahi onemi olan lingula ve sigmoid centik arasindaki mesafeyi belirlemektir. Gerec ve Yontem: Bu retrospektif calisma, klinigimizde cesitli dental sebeplerle elde edilen konik isinli bilgisayarli tomografi goruntuleri uzerinde gerceklestirildi. Aksiyel duzlem, sigmoid centikten gececek sekilde konumlandirilarak, olusturulan sabit duzlem ile lingula ust siniri arasindaki dikey mesafe olculdu. Orneklem 70 kisinin (12-28 yas araliginda, 32 erkek, 38 kadin) verilerini icermekteydi. Veriler istatistiksel olarak degerlendirildi. Bulgular: Minimum mesafe 4.8 mm maksimum mesafe 19 mm olarak bulundu (ort±std sapma=11,99 mm±2.40, n=140). Sag ve sol taraf olcumleri sirasiyla 4.80 mm’den16.4mm’ye (ort±std. sapma= 11.34mm± 2.26, n=70), 7.72mm’den 19.20mm’ye (std. dev.= 12.64mm±2.39, n=70) degismekteydi. Sonuc : Bu calismada elde edilen bulgular genc Turk populasyonuna bilateral sagittal split ramus osteotomisi icin cerrahlara bir rehber olabilir. Prosedur oncesi uc boyutlu degerlendirme, istenmeyen frakturlerin onlenmesinde degerli bilgiler saglar. Anahtar Kelimeler: Horizontal Ramus Kesisi, KIBT, Sagittal Split Osteotomisi