Identifying Predictors of Acquired Velopharyngeal Insufficiency in Cleft Lip and Palate Following Maxillary Osteotomy Using Multiple Regression Analyses.

BACKGROUND: Maxillary osteotomy is typically undertaken to correct abnormal facial growth in cleft lip and palate. The surgery can cause velopharyngeal insufficiency resulting in hypernasality. This study aims to identify valid predictors of acquired velopharyngeal insufficiency following maxillary osteotomy by using a range of perceptual and instrumental speech investigations and multiple regression. METHODS: A prospective study was undertaken consisting of a consecutive series of patients with cleft lip and palate (N = 20) undergoing maxillary osteotomy by a single surgeon. Participants were seen at: 0 to 3 months pre-surgery (T1), 3-months (T2), and 12-months (T3) post-surgery. Hypernasality was rated using the cleft audit protocol for speech-augmented (CAPS-A) and visual analog scales, and nasalance was measured on the Nasometer II 6400. For lateral videofluorosopic and nasendoscopic images, visual perceptual ratings and quantitative ratiometric measurements were undertaken. Multiple regression analyses were undertaken to identify predictors. RESULTS: T3 models with hypernasality as the dependent variable were found to be a good fit and significant (eg, CAPS-A: R2 = 0.920, F(11,7) = 7.303, P = 0.007). Closure ratio (a quantitative ratiometric measurement) and proportion of palate contacting the posterior pharyngeal wall (a visual perceptual rating) were identified as significant predictors for the CAPS-A model (P = 0.030, P = 0.002).

Effect of Maxillary Osteotomy on Speech in Cleft Lip and Palate: Instrumental Outcomes of Velopharyngeal Function.

OBJECTIVE: To investigate the effect of maxillary osteotomy on velopharyngeal function in cleft lip and palate (CLP) using instrumental measures. DESIGN: A prospective study. PARTICIPANTS: A consecutive series of 20 patients with CLP undergoing maxillary osteotomy by a single surgeon were seen at 0 to 3 months presurgery (T1), 3 months (T2), and 12 months (T3) post-surgery. INTERVENTIONS: Nasalance was measured on the Nasometer II 6400. For videofluoroscopy and nasendoscopy data, visual perceptual ratings, for example, palatal lift angle (PLAn), and quantitative ratiometric measurements, for example, closure ratio (CRa), were made using a validated methodology and computer software. Reliability studies were undertaken for all instrumental measures. MAIN OUTCOME MEASURES: Repeated measures analysis of variance (with time at 3 levels) for nasalance and each velar parameter. Planned comparisons across pairs of time points (T1-T2, T1-T3, and T2-T3) including effect sizes. RESULTS: A significant difference over time was found for nasalance (P = .001) and planned comparisons across pairs of time points were significant between T1 and T2 (P = .008), T1 and T3 (P = .002), but not between T2 and T3 (P = .459) providing evidence that maxillary osteotomy can impact on nasalance adversely and that the changes seen are permanent and stable. There were also significant differences over time for PLAn (P = .012) and CRa (P = -.059) and planned comparisons for both velar parameters reflected similar findings to those of nasalance. CONCLUSIONS: Maxillary osteotomy can adversely affect velopharyngeal function in patients with CLP. The study provides evidence for a much earlier post-surgery review even as early as 3 months after surgery.

Myosin proteins identified from masseter muscle using quantitative reverse transcriptase-polymerase chain reaction--a pilot study of the relevance to orthodontics.

There is a clearly established relationship between masticatory muscle structure and facial form. Human studies in this area, however, have been limited, especially in consideration of the myosin heavy chain (MyHC) family of contractile proteins. The aim of this pilot study was to assess if differences were detectable between genotype with respect to MyHC isoforms and the vertical facial phenotype in a sample of nine Caucasian female patients, age range 18-49 years, using a novel rapid technique. Masseter muscle biopsies were taken from patients with a range of vertical facial form. The levels of expression of the MyHC isoform genes MYH 1, 2, 3, 6, 7, and 8 were compared with the expression in a female calibrator patient aged 23 years with normal vertical facial form, using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Statistical analysis was undertaken using Pearson correlation coefficient. The results showed that there were distinct differences in gene expression between patients with a wide range of variation although changes in MYH1 were consistent with one cephalometric variable, the maxillo-mandibular angle. The full procedure, from start to finish, can be completed within half a day. Rapid genotyping of patients in this way could reveal important information of relevance to treatment. This technology has potential as a diagnostic and prognostic aid when considering correction of certain malocclusions.