Maxillo-Facial Surgical Considerations in the Management of Obstructive Sleep Apnoea
thesisposted on 09.08.2016, 10:59 by Shofiq Islam
Obstructive sleep apnoea (OSA) represents an important public health issue affecting approximately 4% of the UK population. Maxillo-mandibular advancement (MMA) can be considered the most successful surgical procedure for the treatment of OSA. Despite the evidence of the efficacy of MMA, there have been no previously published studies from the UK in this area. This research was designed to investigate several key aspects relevant to the application of MMA in OSA. The results from these studies shed light on both the effectiveness and role of maxillofacial orthognathic procedures in the treatment of selected patients with OSA who require alternative treatment options to first-line therapies. The potential applications of technical modifications to maxillofacial procedures in order to improve outcome is also discussed. The research addresses the important consideration of optimising patient selection for MMA procedures through the utilisation of clinical tools, as well as considering important individual patient factors. In particular, these studies have demonstrated that the Malampatti airway classification does not have a predictive role in outcome following MMA, in contrast to other surgical modalities used to treat OSA. The Kushida morphometric model which incorporates cranio-facial dysmorphism, does not appear to correlate with surgical outcomes, but in spite of this, it retains a diagnostic value to maxillofacial surgeons treating OSA patients. These research findings have shown that baseline OSA severity as well as duration of continuous positive airway pressure (CPAP) use prior to MMA surgery, would appear to significantly correlate with a reduction in subjective outcome measures, however, this association was not seen with objective outcome measures. The lack of consistent correlation between these outcome variables perhaps highlights a complexity that has not been reflected in previously published surgical literature. The important surgical consideration of patient acceptance of a permanently altered facial profile was investigated, with the findings demonstrating that the majority of patients subjectively rated their postoperative facial appearance positively following MMA. This was found to be independent of overall surgical outcome. Additionally, we examined cardiovascular risk factor modification after MMA demonstrating that this surgery has a potent beneficial effect on blood pressure reduction, particularly in those with established hypertension. This body of research significantly contributes to the evidence base in support of this branch of maxillofacial surgery which is currently not widely practiced in the UK. The research demonstrates that surgery can be safely and efficaciously applied to treat selected patients with MMA procedures as an alternative treatment modality in OSA, when other first-line treatments are not tolerated or successful.