Preliminary data on the relationship between oral morphology and jaw movement patterns during speech

Abstract

The purpose of the present study is to compare jaw movement patterns during speech in persons with varying occlusion and to describe the changes in patterns which occur following surgical repositioning of the jaws (orthognathic surgery). Subjects are placed in a cephalostat and tape recorded using a videofluoroscopic procedure. Selected portions of the tapes are photographed with a 35-mm camera and enlarged to life size. Cephalometric measurements of lip, tongue and jaw position are made from each photograph. At present, data on sustained phonation of /s/ and /∫/ have been obtained from persons with varying occlusion. In addition, two subjects have been tested before and after orthognathic surgery. Preliminary data indicate that speakers tend to compensate for their malocclusion. Persons with excessive overjet move their mandibles forward and persons with deep overbite rotate their mandibles open during speech. Following surgery, these patterns are altered. [Work supported by a University of Minnesota Graduate School Grant and an NIDR fellowship.]