(1333) Olfactory Changes after Maxillomandibular Advancement

Introduction: Obstructive sleep apnea (OSA) has been shown to impair olfactory function; however, limited research has examined the effects of maxillomandibular advancement (MMA) on olfactory function.

Methods: A prospective study was conducted to analyze patients who underwent MMA with sinonasal modifications. The SNOT-22 was collected preoperatively and at 1, 3, 6, and 12 months postoperatively to assess subjective olfaction (question 12, Q12). Scores were subdivided into previously published subdomains. Nasal blockage was used to represent the conductive mechanism, and nasal subdomain scores without nasal blockage were used to represent non-conductive mechanisms. Patients were grouped according to improvement or worsening of subjective olfactory function. Paired t-tests and one-way ANOVA with repeated measures with Bonferroni correction were used for analyses.

Results: Fifty-six patients were included. The median age was 53.0 years (range, 21.0-68.0), and 26.8% were female. AHI significantly decreased from 54.9±28.2 to 14.1±12.1 (p < 0.001). Success rate was 92.1%. Cure rate (AHI4%) was 47.4%. There was a significant improvement in subjective olfaction after MMA F(2.5, 40.7) = 3.1, p=0.046, ηp² = 0.16; 0.9 ± 1.2 vs. 0.2 ± 0.5. Fifty (89.3%) patients had either improved olfactory function or no dysfunction before and after MMA. Patients with improvement in Q21 exhibited significant improvement in their nasal subdomain without blockage scores (7.3±5.2 vs. 1.0±3.8, p=0.011), but did not show significant changes in nasal blockage scores (2.4±1.6 vs. 1.2±1.3, p=0.113).

Conclusions: MMA shows early evidence of improving or maintaining olfactory function, with results suggesting that changes in non-conductive mechanisms play a larger role than those in conductive mechanisms. Further long-term research is needed to support these findings.