Orthodontic maxillary expansion and its effect on nocturnal enuresis.

A previous retrospective study of 10 children with varying degrees of nocturnal enuresis has shown that one side effect of rapid maxillary expansion (RME) is spontaneous reduction in bed-wetting at night. The aim of this prospective study was to analyze the effect of RME treatment (mean 2 weeks) in cases of chronic, long-standing nocturnal enuresis. Ten children, 8 to 13 years old, who had not responded to conventional medical treatment for bed-wetting, were referred from the pediatric department. Within 1 month of RME of 3 to 5 mm, 4 children were completely dry and 3 showed notable improvement. The results are encouraging, especially given the spontaneous recovery rate of about 15% per year. A reduction in nocturnal enuresis in children has also been reported after tonsillectomy. However, in this pilot study, no significant associations could be found between improvement in nocturnal enuresis and improvement in the nasal airway, age, amount of expansion, or nasopharyngeal dimension (measured on cephalograms).