Maxillary Expansion Treatment of Pediatric Obstructive Sleep Apnea

Background Literature Review Obstructive sleep apnea syndrome (OSAS) is a sleep disorder characterized by recurrent, partial or complete episodes of upper airway obstruction, commonly associated with intermittent hypoxemia and sleep fragmentation.1 The best data available from international studies reports a prevalence rate of 1.2-5.7% in children.2-4 The potential consequences of OSAS in children are serious and include failure to thrive5, attention deficit and hyperactivity disorder6, excessive daytime sleepiness7, and poor learning6. There is also significant concern about long-term cardio-pulmonary risks in these patients8. Not surprisingly, along with higher morbidity, children with OSAS also have higher use of health care services starting from the first year of life9.

OSAS is a multifactorial disease, with the primary cause in children thought to be hypertrophic tonsils and adenoids. However the persistence of OSAS following surgery to remove the tonsils and adenoids is not uncommon. Recent studies using a moderate cut-off apnoea-hyponea index (AHI) of greater than 5 events per hour in relatively low-risk populations, have demonstrated that 13%10 to 29%11 of children have residual OSAS following adenotonsillectomy (AT). Craniofacial form also clearly plays a role in pediatric OSAS as skeletal discrepancies such as transverse maxillary deficiency have been strongly associated with the disease12,13, and skeletal malocclusion has been found to be predictive of a higher AT failure rate14. While the precise nature of the contribution of craniofacial proportions to OSAS remains to be characterized, there is early evidence in the literature to support maxillary expansion (ME) as an alternative treatment to surgery. Results of OSAS treatment with ME have suggested that it may be effective in reducing sleep respiratory disturbances in patients with15 and without16 tonsillar hypertrophy. However, limitations existing in the study designs have left unanswered questions as to the role of ME in the treatment of children suffering from OSAS. Furthermore the studies have been limited to patient populations in Rome, Italy, and while anatomical factors are key determinants of the predisposition to airway collapse, their relative importance for OSAS risk likely varies between ethnicities.17 For this reason, further studies examining these effects on a diverse multicultural population such as that found in North America and in particular urban centers such as Vancouver, Canada are warranted to realize the potential of this novel form of OSAS treatment.

Study Purpose The purpose of this study is to explore the efficacy of maxillary expansion in the treatment of OSAS in children with tonsil and adenoid hypertrophy.

3. Hypothesis The null hypothesis is there is no significant difference in improvement between maxillary expansion and adenotonsillectomy in the objective and subjective outcome measures in children with mild to moderate obstructive sleep apnea.

4. Objectives 4.1: Aim 1- To validate the methodology. The methodology will be validated through conducting this pilot study and analyzing the preliminary data that are generated - if required, improvements in methodology design can be identified during this pilot study to assist in design modification before a larger multi-site study.