Changes of the upper lip after surgical correction of mandibular prognathism

Abstract

The aim of this study was to establish and estimate the effects of surgical correction of mandibular prognathism on the height and position of the upper lip. The changes of the upper lip were analyzed on 115 patients between 16 and 30 year of age (71 females and 44 males) who were subject to surgical correction of mandibular prognathism using the sagittal split ramus osteotomy. The lateral cephalometric radiographs were taken of each patient before and six months after the surgical procedure. The soft tissue cephalometric analysis included the measurements of six linear and two angular parameters. The obtained data were statistically processed and evaluated. Statistical analysis revealed the significant changes in two linear cephalometric parameters after surgical procedure - the incisal step and the length of the upper lip. The changes in the length and position of the upper lip after surgical correction of mandibular prognathism by means of sagittal split ramus osteotomy seem to be minor and clinically insignificant. Only the length of the upper lip was significantly changed. It became longer. The upper lip advancement amounted approximately 15% of the complete mandibular set-back during operation.

Cilj istraživanja je bio da utvrdi i proceni efekte hirurške korekcije mandibularnog prognatizma na dužinu i položaj gornje usne. Promene gornje usne su kefalometrijski analizirane kod 115 osoba (f=71; m=44) kod kojih je mandibularni prognatizam korigovan metodom sagitalnih osteotomija grane donje vilice. Svakom pacijentu su načinjena po dva profilna telerendgenska snimka glave, jedan pre i jedan nakon hirurške intervencije. Kefalometrijska analiza mekog profila lica je obavljena merenjem i poređenjem šest linearnih i dva angularna parametra. Dobijene vrednosti su statistički obrađene i evoluirane. Primenjene hirurške korektivne procedure rezultirale su statistički značajnim promenama kod dva linearna parametra (incizalna stepenica i dužina gornje usne). Promene gornje usne posle hirurške korekcije mandibularnog prognatizma pomoću sagitalnih klizajućih osteotomija grane donje vilice su minimalne i gotovo neznačajne. Značajno se menja jedino dužina gornje usne - postaje duža. Gornja usna se pomera za 15% ukupnog pomeranja struktura donje vilice.