Investigation of acoustic and nasalans change of sounds after orthognathic surgery

Bilateral bone surgery in the jawbone (BSSO) is a type of surgery that covers the lower and upper jaws used in the deformity of the lower jawbone. When we look at the old reviews, when we look at the speech events in maxillofacial surgery, there are differences between various studies on the effects on speech. Our aim in this study is to see how the voice and speech quality will be affected in patients before and after maxillofacial surgery. It examines the changes in voice and differences in the structure of the nose. The patients participating in our study in this study were selected between the ages of 26 and 40. The patients were 12 female and 11 male. All of these patients were asked to say vowels, respectively. These letters are respectively a, e, i. After examining the patient records with the electroglottography device, the patient was called again and the same test was performed within 7-8 weeks. Vocal shimmer and vocal jitter percentages, as well as fundamental frequency (F0) and harmonics, were evaluated by voice analysis using the Multi Dimensional Voice Program (MDVP). MDVP is a method used to objectively evaluate sound properties. While this analysis evaluates the vibration properties of the sound over the percentages of shimmer and jitter, it also examines the fundamental frequency (F0) and harmonic structure of the sound. When we look at the studies obtained in the studies performed both before and after the surgery, conflicting studies contradict each other. And there is no significant difference. Differences in resonance were observed in only 5 of the patients in our study. When another patient was looked at, resonance was observed, and after a short time, he was transformed back to his pre-operational state. Speech disorder, especially the change in vowels, is not 100% successful in jaw surgery. Although minor changes are observed in the sound quality according to the examinations, it can be recovered after the surgery and revert to its former state.