Positional changes of the lower and upper anterior teeth after surgical correction of mandibular prognathism

Abstract

Background/Aim. To establish the influence of surgical corrections of mandibular prognathism upon the position of the lower and upper anterior teeth (incisors). Methods. The changes in position of the lower and upper anterior teeth (incisors) after the surgical correction of mandibular prognathism were analyzed by means of x-ray craniometry in 183 patients (female: n = 110, male: n = 73) in which the correction had been made in accordance with the principles of sagital osteotomy of the mandibular ramus. There were 4 angular and 2 linear parameters determined in the pre- and postoperative tele-xray-pictures. The changes of these parameters were tested by means of the parametric statistic tests. Results. The performed surgical procedures did not cause statistically significant changes in the angular parameters. The changes of both linear parameters were thought highly statistically significant. Conclusion. Under the influence of the performed surgical procedures no changes were found in the position of anterior teeth (incisors) in relation to SN and the mandibular plane. They were actually moved along with the medium fragment of the lower jaw and that fragment was moved linearly backwards along the occlusal plane with a practically insignificant rotation in the cranial direction.

Uvod/Cilj. Utvrditi uticaj hirurške korekcije mandibularnog prognatizma na položaj donjih i gornjih sekutića. Metode. Promene položaja donjih i gornjih sekutića posle hirurške korekcije mandibularnog prognatizma analizirane su rendgenkraniometrijski kod 183 osobe (ž = 110; m = 73) kod kojih je korekcija izvršena po principima sagitalnih osteotomija ramusa mandibule. Na preoperativnim i postoperativnim telerendgenogramima određivana su četiri angularna i dva linearna parametra. Promene tih parametara testirane su pomoću parametrijskih statističkih testova. Rezultati. Sprovedene hirurške procedure nisu izazvale statistički značajne promene angularnih parametara. Promene oba linearna parametra bile su visoko statistički značajne. Zaključak. Pod uticajem sprovedenih hirurških korektivnih procedura ne dolazi do promene položaja sekutića u odnosu na SN i mandibularnu ravan, već se oni pomeraju zajedno sa središnjim fragmentom donje vilice. Taj fragment se kreće translatorno unazad duž okluzalne ravni, sa praktično zanemarljivom rotacijom u kranijalnom pravcu.