Speech and Swallowing Changes Associated with Sagittal Osteotomy: A Report of Four Subjects

he purpose of the study was to determine the im· mediate and possible long-term effects of a mandibular osteotomy upon speech and tongue thrust (where pre­sent). To explore this, four subjects who exhibited a Class Ill malocclusion or skeletal underbite, in addition to a lisp, were evaluated before and after undergoing a sagittal osteotomy. The evaluation consisted of identical speech and tongue thrust assessments completed within two weeks of and nine weeks after the scheduled surgery. Both evaluations were completed by a panel of three speech-language pathologists. The speech evalua­tion required the subject to read ten /s/ and ten /z/ phoneme sentences taken from the McDonald Deep Test of Articulation. Each subject was judged as either ex­hibiting or not exhibiting a lisp on each sentence read. The tongue thrust evaluation utilized a quantitative tongue thrust baseline measurement in which the subject's tongue position was ranked during the swallowing of food, liquid, and saliva. ostsurgical speech results indicated that there was a marked improvement of articulation scores for three of the four subjects. Two of the subjects demonstrated complete correction of lisping behavior. Postoperative tongue thrust measurements suggested that there was no change in tongue thrusting patterns. Three of the four subjects demonstrated a tongue thrust. The benefits of oral and maxillofacial surgery are varied. Some benefits are emphasized when surgical remedia­tion of a skeletal deformity or malocclusion are con­sidered. Jaw surgery may provide more favorable occlu­sion which may, in turn, result in an improved profile or cosmetic appearance, improved temporomandibular function, and improved chewing and eating habits. An important consideration of jaw surgery should also be the immediate and possible long-term effects upon speech and/or oral habits, particularly swallowing and resting tongue posture. One can clearly see that by surgically altering the size and configuration of the oral cavity, there may be significant changes not only in an individual's ability to produce specific speech sounds, but also in their habitual swallowing patterns. Little research has been done to investigate these changes. These issues are important to consider for two reasons: Effects on speech intelligibility may be a factor to con­sider when contemplating jaw surgery, and surgical results may facilitate speech and/or orofacial myofunctional therapy. The purpose of the study was to determine the im­mediate and possible long-term effects of a mandibular osteotomy upon speech and tongue thrust (where pre­sent). To demonstrate this, four subjects with a Class Ill malocclusion or skeletal underbite, in addition to a lisp, were evaluated before and after undergoing a sagittal osteotomy (a surgical procedure to reposition the man­dible in a normal relationship). This examination consisted of both a speech and tongue thrust assessment.