No abstract

Background: In the scientific literature, there is no consistency of results regarding the effectiveness of mandibular advancement devices (MADs) for sleep apnoea treatment. We have considered facial growth as an important predictor of treatment. In this study we analysed that how facial biotype can influence the therapeutic effect of MADs according to polysomnographic records in SAHS patients.Methods: The study enrolled 46 patients with mild to moderate SAHS diagnosed by a polysomnographic test. Using cephalometry, we classified all the patients according their facial biotype (mesofacial, brachyfacial or dolichofacial). Shapiro-Wilk test was used to choose the parametric or non-parametric tests. The quantitative variables were described with the arithmetic mean with its standard deviation or the median with its interquartile range. The hypothesis tests used were Pearson’s chi-squared test, paired sample Student's t test, the Wilcoxon test, one-way ANOVA, Kruskal-Wallis test and Mann-Whitney U test. A p < 0.05 was considered statistically significant.Results: The respiratory disturbance index (RDI) results were: brachyfacial patients had a reduction to 15 events/hour (p < 0.001), the mesofacial patients had a reduction to 14 events/hour (p < 0.001) and the dolichofacial patients did not show a significant reduction in the RDI. The oxygen desaturation index (ODI) results were as follows: brachyfacial patients had a reduction in ODI episodes to 45 episodes/hour (p = 0.001), mesofacial patients had a reduction to 18 episodes/hour (p = 0.001). The dolichofacial patients did not show a reduction in this index. As far as the number of arousals, in the brachyfacial group, the number of awakenings with MAD therapy was reduced to 23 events/hour (p = 0.003), while in the mesofacial group, it was reduced to 37 episodes/hour (p = 0.012). The same behaviour was observed in the dolichofacial group, did not have a reduction in the number of awakenings during sleep after MAD therapy.Conclusions: The facial biotype influences the effectiveness of MAD therapy and is considered a good predictive factor. Dolichofacial patients failed to obtain a significant result in the polysomnographic records using a MAD for sleep apnoea treatment.