Snoring Remediation with Oral Appliance Therapy Potentially Reverses Cognitive Impairment: An Intervention Controlled Pilot Study

Abstract

Respiration rate (RR) dynamics entrains brain neural networks. RR differences between mild cognitive impairment (MCI) and Alzheimer’s disease (AD) in response to oral appliance therapy (OAT) are unknown. This pilot study investigated if RR during stable sleep shows a relationship to pathological severity in subjects with MCI and AD who snore and if RR is influenced following stabilization of the upper airway using OAT. The study cohort was as follows: cognitively normal (CN; n = 14), MCI (n = 14) and AD (n = 9); and a sub-population receiving intervention, CN (n = 5), MCI (n = 7), AD (n = 6) subjects. The intervention used was an oral appliance plus a mouth shield (Tx). RR maximum (max) rate (breaths/minute) and RR fluctuation during 2116 stable sleep periods were measured. The Montreal cognitive assessment (MoCA) was administered before and after 4 weeks with Tx. Baseline data showed significantly higher RR fluctuation in CN vs. AD (p < 0.001) but not between CN vs. MCI (p = 0.668). Linear mixed model analysis indicated Tx effect (p = 0.008) for RR max. Tx after 4 weeks lowered the RR-max in MCI (p = 0.022) and AD (p < 0.001). Compared with AD RR max, CN (p < 0.001) and MCI (p < 0.001) were higher with Tx after 4 weeks. Some MCI and AD subjects improved executive and memory function after 4 weeks of Tx.

Obstructive sleep apnea mouth breathing phenotype response to combination oral appliance therapy

“…These results complement the report by Edwards and colleagues, who found that oral appliances improved passive anatomical collapsibility and ventilation (Edwards et al, 2016). Enabling nasal breathing using the added mouth shield likely improved ventilation efficiency (Teschler et al, 1999), while both oral appliance plus mouth shield and oral appliance only reduced snoring (Rappai et al, 2003;Norrhem and Marklund, 2016;Schramm et al, 2021) and upper from baseline T1 −0.6 (−0.8 to 0.3) 2.5 (0.5 to 3.7) 0.003 T2 0.5 (−0.3 to 0.6) 3.5 (0.9 to 3.5) 0.017 T3 −0.3 (−0.8 to 0.3) 2.9 (−1.7 to −0.1) 0.019…”

“…Studies using custom-fitted oral appliances (Byun et al, 2020;Schneiderman et al, 2021;Labarca et al, 2022) or temporary oral appliances (Schramm et al, 2021;Segù et al, 2021) confirm significant AHI or respiratory event index and snoring reduction, regardless of oral appliance brand or design. However, these investigations included heterogeneous OSA patients, making the interpretation of oral appliance efficacy among the OSA mouth breathing phenotype difficult.…”

“…Arousals from sleep cause blood pressure surges (Carrington and Trinder, 2008) and increase heart function from concomitant increases in sympatho-excitatory activity responses. Measuring respiratory effort changes in response to increased or decreased airway resistance should not only reflect pathological states (Boas et al, 2013;Edwards et al, 2016) but also identify effective therapy (Schramm et al, 2021).…”

“…Oral appliances are also recommended as the first-line treatment for mild to moderate OSA and second-line therapy for severe OSA (Trzepizur et al, 2021) or in those who refuse CPAP (ADA Delegates, 2017). Mouth shields have been used to address malocclusions (Tallgreen et al, 1998) and as comfort devices with oral appliances (Schramm et al, 2021). Buccal soft tissues, the tongue, and teeth comprise a barrier unit between atmospheric extra-oral environmental and intra-oral functional space that even maintains a specific pressure when closed (Moss and Salentijn, 1969).…”