a RCT was started

Myofunctional therapy has been shown to be effectively reduce symptoms of paediatric sleep apnea. As the effectiveness of reeducation relies on parental involvement and child's compliance, the investigator's research question was to evaluate two methods of myofunctional therapy (daily oral exercices versus a flexible oral appliance, both in combination with nasal hygiene), compared to nasal hygiene alone (control group).

Introduction: Paediatric Obstructive Sleep Apnea (OSA) is a multifactorial condition, associated with significant comorbidities, affecting cardiovascular health, cognitive development and quality of life. Its main cause is adenotonsillar hypertrophy, but some co-factors such as obesity, orofacial dysfunctions and craniofacial abnormalities contribute to the severity of symptoms or their persistance after adeno-tonsillectomy.

Aim : Myofunctional therapy has been shown to reduce Apnea-Hyponea indexes (AHI) of children, and can serve as an adjunct to other therapies, but the level of compliance is a limiting factor. The investigator's aim is to evaluate two methods of oral reeducation in a group a children scheduled for adeno-tonsillectomy (in association with nasal hygiene) and to compare them with nasal hygiene alone (control group).

Methods : The design of the study is a randomized Controlled Trial, enrolling 60 children with significant obstructive sleep apnea and divided into 3 groups : Group 1 following daily oral exercises (+nasal hygiene), Group 2 using of a flexible oral appliance during quiet activities and sleep (+nasal hygiene), and Group 3 using nasal hygiene alone (control group). The objective assessment of sleep parameters is performed at home using an ambulatory device (AHI, desaturation index, minimal oxygen saturation, flow limitation, snoring), before and after therapy, in a 3 months interval. An orthodontic and craniofacial assessment, the examination of orofacial functions and tongue/lip strength measurements (IOPI system), as well as quality of life questionnaires (OSA-18) are also performed on participants, before and after therapy.

Inclusion Criteria: participants must:

• present signs of obstructive sleep apnea: snoring, apnea / respiratory pauses audible by the entourage (objectivized by a score, to the hierarchical questionnaire of severity of Spruyt and Gozal, greater than or equal to 2,72- This questionnaire comprises six Questions and has a good sensitivity (60%) and specificity (82%) in screening for pediatric sleep apnea.
• be programmed for adenoidectomy, tonsillectomy or adeno-tonsillectomy within 3 months (or more).

Exclusion Criteria: participants should not:

• present with a craniofacial syndrome nor a severe medical condition with complex medical management,
• present with an abnormality of the neuromuscular tone (such as Duchenne myopathy or cerebral palsy)
• receive orthodontic therapy during the study
• have a class III malocclusion (mandibular prognathy type), for which a propulsion oral appliance is contraindicated because it may aggravate mandibular prominence. Maxillary deficiency is not a exclusion criterion.
• A non-nutritive oral habit such as digital sucking (or pacifier) that persists because it interferes with oral reeducation, and is a contraindication to orthodontic treatments. Children who have recently stopped such a habit may be included in the study.