Roentgencraniometric evaluation of changes in skeletal and dental relationships after bimaxillary surgical correction of mandibular prognathism

Abstract

This study is dedicated to evaluating the results of bimaxillary osteotomies in the surgical correction of class III dentofacial deformities. The main objective of the research was to identify precisely the indication area for bimaxillary operations and to determine to what extent and in what way they change the skeletal and dental relationships typical of class III deformities. Material and methods The experimental group consisted of 20 patients male and female, mean age of 19.8±5.3 years with severe class III deformities. The control group consisted of 30 subjects with skeletal class I jaw relationships and physiological occlusion, mean age of 21.5±3.5 years. In subjects of the experimental group 2 series of cephalograms were made: Series A - before the orthodontic preparation and surgical intervention and series B - 6 months up to a year after surgery. The series C of cephalograms was taken in the control group. All images were converted into digital form. Using the computer program Dr Ceph® (FYI Technologies, GA, USA, version 9.7), the values of 30 skeletal and 12 dental variables were measured on every cephalogram. The measurements of variables in subjects of the experimental group were compared before and after surgery, as well as with the values of the same variables in the control group. In all patients of the experimental group the reposition of maxilla by LeFort I osteotomy and the mandibular set-back using the bilateral sagittal ramus osteotomy according to Obwegeser and Dal Pont were performed. Results The experimental group in this study included the patients with severe skeletal Class III deformities caused by deficiency and retrusion of the maxilla in 40% of patients, with normal mandible (25%), or prominent mandible with retruded or normal maxilla (75%)...

Ova studija je posvećena evaluaciji rezultata bimaksilarnih osteotomija u hirurškom korigovanju dentofacijalnih deformiteta III klase. Osnovni cilj istraţivanja je bio da se preciznije definiše indikaciono podruĉje bimaksilarnih osteotomija i da se utvrdi u kolikoj meri i na koji naĉin one menjaju skeletne i dentalne odnose tipiĉne za deformitete III klase. Materijal i metode Eksperimentalnu grupu je ĉinilo 20 pacijenata muškog i ţenskog pola proseĉne starosti od 19,8 ± 5,3 god. sa izraţenim oblicima deformiteta III klase. Kontrolnu grupu ĉinilo je 30 ispitanika sa I skeletnom klasom i fiziološkom okluzijom proseĉne starosti 21,5±3,5 god. Ispitanicima eksperimentalne grupe naĉinjene su 2 serije telerengenskih snimaka: serija A - pre ortodontske pripreme i hirurške intervencije i serija B - 6 meseci do godinu dana nakon hirurške intervencije. Serija C telerendgenskih snimaka naĉinjena je kod ispitanika kontrolne grupe. Svi snimci su prevedeni u digitalni oblik. Uz pomoć kompjuterskog programa Dr Ceph® (FYI Technologies, GA,USA,verzija 9.7) na svakom snimku izmerene su vrednosti 30 skeletnih i 12 dentalnih varijabli. Vrednosti izmerenih varijabli kod ispitanika eksperimentalne grupe su uporeĊene pre i nakon operacije, kao i sa vrenostima istih varijabli u kontrolnoj grupi. Kod svih pacijenata eksperimentalne grupe izvršena je repozicija maksile osteotomijom po tipu Le Fort I i distalizacija mandibule bilateralnom sagitalnom osteotomijom ramusa po Obwegeseru i Dal Pontu. Rezultati Eksperimentalnu grupu u ovoj studiji ĉinili su ispitanici sa izrazitim skeletnim deformitetom III klase koji je uzrokovan deficijencijom i retruzijom maksile kod 40% ispitanika uz normalnu mandibulu (25%) ili progenom mandibulom uz retrudiranu ili normalnu maksilu (75%)...