Evaluation of the Tolerance and Benefits of Mandibular Advanced Device for Snoring and Sleep Apnea in Patients With Oropharyngeal Cancer: Mixed Design Study.

The department of stomatology of the CHUM (Centre Hospitalier Université de Montreal) mandate is to ensure oral management of patients with oropharyngeal cancers (OPC), including papillomavirus (HPV), treated with radiotherapy (RTH), surgery and chemotherapy. At CHUM clinic, several patients who have had RTH treatments (with or without surgery or/and chemotherapy) complain of snoring and respiratory arrest during sleep. HPV-associated OPC, squamous cell carcinoma, has had a net increasing incidence for more than 20 years in North America (4.6/100,000) and male mortality has increased by 3.1% per year since 2001. In Quebec, the incidence is almost 26 cases per million. Worldwide, it is ranked to be the 13 most common cancer in male aged 25-39 years; the male/female ratio is 2.5 (female have more HPV cervix related cancer) - Global oral health status report: towards universal health coverage for oral health by 2030- (Geneva: World Health Organization; 2022).

Snoring occurs in nearly 40% of the general population, increases with age and can be one of the telltale signs of sleep apnea (brief and repetitive breathing stops at risk of mortality if left untreated). Snoring can be associated with poor sleep quality and produces a loud disturbing noise for the sleeping partner. Obstructive sleep apnea (OSA) is reported by 2-4% of the general population and by almost 30% of the elderly mainly related to obesity and heart disorders. The risk factors associated with these conditions are lost of airway muscle tone during sleep, retrognathia, deep/narrow palate, obesity and age. Fatigue and drowsiness are markers of OSA. Following RTH, there may be oropharyngeal tissue fibrosis that may contribute to snoring and sleep apnea.

Sleep disordered breathing are known in individuals with OPC. Our first results of the ongoing survey seem to indicate that severe snoring, causing drowsiness or fatigue, would be present in 47% of patients with OPC. A recently published literature review, from our team, also found a snoring self-reports prevalence from 33% to 82%. A polygraphic sleep recording study found that 65% of individuals with head and neck cancer (including OPC) have snoring, a value that increases to 92% when OSA is concomitant. On the other hand, OSA seem to be present in over 70% of OPC patients, before and after treatment. However, causality remains to be demonstrated; these sleep disorders are often pre-existing and can worsen as a result of RTH.

In adults, snoring is mainly controlled by devices correcting the dorsal position of sleep as well as with mandibular advanced device (MAD). Regarding apnea, positive pressure vessels (PPC or CPAP) are the most effective. The MAD is indicated for mild to moderate OSA or for low CPAP tolerance. To date, following RTH, there are no studies conducted under strict conditions. Some 'suggestions' in favour of standard treatments, PPC or MAD, were made. In addition, no studies have estimated the nasal discomfort and dryness associated with these treatments in the OPC population. Intuitively, nylon MAD, thin and with little contact on the mucous membranes, could be indicated in the presence of OPC. To date, only one study, based on 2 cases, suggests the use of MAD in the presence of OPC. There is therefore a gap of evidences in the literature as to whether patients treated for OPC presenting snoring and OSA would be able to tolerate and benefit from MAD.

Objectives: Conduct a pilot study, with a mixed quantitative and qualitative design, to reduce snoring or sleep apnea using an MAD, and improve the quality of life and sleep.