Randomised cross-over study of oral appliances for snoring.

OBJECTIVES: To compare a mandibular advancement splint to a control bite raising appliance in the treatment of snoring with or without mild obstructive sleep apnoea syndrome.

DESIGN: A prospective two-treatment randomised cross-over clinical trial.

SETTING: Single centre secondary care Dental Hospital.

PARTICIPANTS: Fifty-two subjects (36 men, 16 women) diagnosed with non-apnoeic snoring or mild obstructive sleep apnoea syndrome (apnoea/hypopnoea index < or =15 events/h), were recruited from Departments of Respiratory Medicine and ENT surgery, Newcastle upon Tyne Hospitals NHS Foundation Trust.

MAIN OUTCOME MEASURES: The Snoring Symptoms Inventory questionnaire (SSI) and the Epworth Sleepiness Score (ESS) were used to evaluate changes in symptoms. Patient reported outcomes (compliance, adverse events, splint preference) were recorded by questionnaire. Subjects attended for five study visits and used a mandibular advancement splint and a bite raising appliance at home each for 4 weeks, with a 3-week washout period between devices.

RESULTS AND CONCLUSIONS: Thirty-eight subjects completed the study. Both the mandibular advancement splint and bite raising appliance significantly reduced the SSI compared to the baseline scores: mandibular advancement splint 5.5, P = 0.013; bite raising appliance 3.1, P = 0.005. No statistically significant difference between the two treatment periods was detected (P > 0.05). The reduction in the Epworth Sleepiness Score was: mandibular advancement splint 1.0, P = 0.02; bite raising appliance 0.3, P = 0.4. The change in the Epworth Sleepiness Score was not statistically significantly different between the mandibular advancement splint and bite raising appliance treatment periods (P > 0.05).

CONCLUSIONS: In this cohort of patients diagnosed with snoring +/- mild OSA: 1 both the mandibular advancement splint and bite raising appliance designs of splint appeared to reduce the symptoms of snoring; 2 no difference in the magnitude of this effect was detected in favour of one design of splint.