Osteotomi Le Fort I:s inverkan på röstens nasalitet hos individer med gomspalt

Abstract Objective: The purpose of this study was to see if it is possible to predict the outcome of an osteotomy Le Fort I on voice resonance by individuals with cleft lip and palate using only a nasometer as the assessing method. The aim was also to see if sex or the type of cleft had an impact on the outcome, and if the point of time for the postoperative assessment had an impact on the nasalance scores. Previous studies have shown that osteotomy Le Fort I can have an impact on velopharyngeal function, leading to velopharyngeal insufficiency (VPI) in some cases. Previous research of outcomes of osteotomy Le Fort I have been criticized for too small samples and methodological differences. The preoperational nasalance scores could contribute to be useful tool to objectively predict possible risks for VPI after an osteotomy Le Fort I surgery. In this study the nasalance scores before and after surgery are compared. Method: The material used in this study consisted of nasometry scores from 100 individuals who were a part of an investigation of osteotomy Le Fort I’s impact on the velopharyngeal function, collected at the centre for cleft lip and palate in Helsinki (HUSUKE) 2006-2016. Nasalance scores were collected from 7 sentences with non-nasal speech sounds. The material was worked on statistically by parametric methods, using the SPSS program for statistics, version 25. Results and conclusion: This study could notice an increase of the nasalance scores after the surgery. The mean of the increase in nasalance scores for all the sentences was 6% (SD=10). There was no correlation to be found on either sex or type of cleft on nasalance scores, which means that there is no predictability depending on sex or type of cleft for the outcome of osteotomy Le Fort I on voice resonance after the surgery. There was no connection between the point of time of post-assessment and the nasalance scores. This was unexpected but can probably be explained by the big variation in the point of time when the postoperational assessment was done. The number of individuals that according to the preoperational scores were at risk to have a postoperational VPI did not correspond with the statistical analysis in this study. The number of persons that had an elevated risk for a postoperational VPI were more than the statistical prediction according to the preoperational scores (an increase of 7%). According to this study it is not possible to use the instrumental assessment by a nasometer as the only method to predict the outcome of an osteotomy Le Fort I- surgery on VPI. However, an increase in the nasalance scores is to be expected.