Obstructive Sleep Apnoea (OSA) is a sleep-related breathing disorder that is characterized by the repeated collapse of the upper airway during sleep, resulting in sleep deprivation. Mandibular Advancement Appliances (MAA) or Oral Appliances (OA) is prescribed for the patients with OSA and they have been shown to be effective. However, they rely entirely on the patient's acceptance and use. The aim of this study is to assess whether interventions- additional support approaches, will help patients use their MAA more as compared to those who receive routine care.

The investigators also will try and identify factors that help us to understand why some patients choose to wear the MAA more than others. Adults (≥40 years) with a confirmed diagnosis of OSA (apnoea-hypopnoea index >5) and referred for MAA therapy will be included in this study. It is a multicentre study comprised of recruiting patients from secondary care. Patients will be provided with information in relation to the study and written informed consent obtained at their subsequent appointment for placement of MAA.

Patients will be randomly assigned to Intervention Care (IC) and Standardised care (SC). Patients will also be provided with a sleep diary to subjectively record their hours of sleep and usage of MAA and an objective adherence record from the micro-sensor included in their MAA design. Data indicating adherence will be collected and evaluated, both subjectively at 3- (T2) and 6-months (T3) and objectively by downloading the data stored within a micro-sensor placed in the MAA device. At the end of the follow-up, the investigators also plan to undertake a qualitative one-to-one interview with patients compliant (users) and non-compliant (non-users) to identify their views of what helps and/or prevents their adherence.

The present study aims to assess whether special support approaches i.e. Interventions influence patients with Obstructive sleep apnoea (OSA), to use the Mandibular Advancement Appliance (MAA) or the anti-snoring mouth guard, more as compared to those who receive standard care.

Factors such as mood, anxiety, stress, depression, socioeconomic status, and social support play an important role in the ability of the patients to make decisions about using the appliance. Thus, the investigators also aim to explore the potential role these factors play in the decision-making process to help future patients make most of their treatments.

Patients meeting the selection criteria will be provided with a patient information leaflet, explaining the whole study. Interested patients will be asked to sign the Informed Consent, after which they will be randomly assigned into two groups- Intervention Care group (IC) and Standardized Care group (SCG).

Patients will be provided with a sleep diary to record their hours of sleep and usage of MAA, which will give a subjective record of the adherence (duration of usage of MAA) and an objective record of the adherence will be collected from a sensor present in the MAA.

At Initial Screening, the patient's age, gender, body mass index (BMI) and neck circumference will be recorded. Patients in the IC group will receive a Health Pamphlet about OSA, specially designed for this study. The IC group's knowledge of OSA will be assessed along with their partner's. Patients in the IC group will be shown a 10 min video highlighting the negative impact of OSA. While patients in the SC group will only be provided with a pamphlet about OSA and MAA as per standard routine care.

Patients of both the group will be asked to complete questionnaires regarding their personality, socioeconomic status, social support and quality of sleep and life.

Along the course of the treatment, patients in the IC group will be contacted by telephone at 3, 6, 18, and 21 weeks into the treatment to solve any technical problems with the appliance and for verbal encouragement.

Both IC and SC groups will be called for follow-up at 3 and 6 months into the treatment. Data indicating the hours of usage of the MAA will be collected at 3 and 6 months to assess whether patients in the IC group wore the appliance for more hours as compared to those who are in the SC group. Patients will also be required to complete questionnaires at follow-up appointments. Data from the questionnaires will be analyzed to identify the factors influencing patients adherence to MAA.

At the end of follow-up, one-to-one interviews will be conducted with both (n=5-10) compliant (users) and non-compliant (non-users) patients. It will comprise of questions, which will address the following topics:

• Patient's awareness of risks and benefits of OSA
• Barriers and Facilitators of MAA therapy The interviews will be conducted face-to-face and will be recorded using an audio recorder device and transcribed by a third party, Essential Secretary LTD.

Inclusion Criteria:

• Adult (≥ 40 years old)
• Confirmed diagnosis of OSA (AHI ≥ 5)
• Referred for MAA therapy
• Must be able to understand, read and write English; with the assistance of a translator

Exclusion Criteria:

• Insufficient teeth for MAA fabrication
• Poor dental and/or periodontal health
• Symptomatic Temporomandibular Disorder (TMD)
• Previously used an MAA
• Patients with Epilepsy