The Effect of Bimaxillary Orthognathic Surgery on Nasalance, Articulation Errors, and Speech Intelligibility in Skeletal Class III Deformity Patients

Hamide Ghaemi1

, Sahand Samieirad *5

1- 1. Department of Speech Therapy, School of Paramedical Sciences, Mashhad University of Medical Sci-ences, Mashhad, Iran.
2- Student Research Committee, Facul-ty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
3- 3. Department of Oral and Maxillofa-cial Surgery, Mashhad Dental School, Mashhad University of Med-ical Science, Mashhad, Iran.
4- Department of Orthodontics, Tehran Dental School, Tehran University of Medical Science, Tehran, Iran
5- Oral and maxillofacial diseases re-search center, Mashhad University of Medical Sciences, Mashhad, Iran

Abstract: (4803 Views)

BACKGROUND
We aimed to detect the changes in nasalance, articulation errors, and speech intelligibility after bimaxillary orthognathic surgery in skeletal class III pa-tients.
METHODS
This double-blinded before and after quasi-experimental study was conducted in the Department of Maxillofacial Surgery, Qaem Hospital, Mashhad, Iran from Mar 2019 to Apr 2020. The main intervention was maxillary advance-ment with LeFort I osteotomy and mandibular setback surgery with bilateral sagittal split osteotomy (BSSO). The nasalance score, speech intelligibility, and articulation errors were evaluated one week preoperatively (T0), 1 and 6 months (T1, T2) postoperatively by a speech therapist. The significance level was set at 0.05 using SPSS 21.
RESULTS
Eleven women (55%) and 9 men (45%) with a mean age of 31.95 ± 4.72 yr were enrolled. The mean maxillomandibular discrepancy was 6.15 ± 1.53 mm. The mean scores of nasalance for the oral, nasal, and oral-nasal sentences were significantly improved postoperatively (P<0.001). Pre-operative articulation errors of consonants /r/, /z/, /s/ and /sh/ were corrected following the surgery. The percentage of speech intelligibility was significantly increased over time (P<0.001).
CONCLUSION
The patients might show a normal articulation pattern and a modified nasalance feature, following maxillary advancement plus mandibular setback surgery.