Relapse following maxillary expansion. A study of twenty-five consecutive cases.

Twenty-five patients consecutively treated with maxillary expansion were studied. Both successful and unsuccessful cases were included, but five were excluded for other reasons. The expansion was measured 2 or 3 months out of retention to allow the overexpansion to settle. Measurements were made again 21/2 years out of retention. The net expansion had been 3.5 mm., and this had subsequently not relapsed. Possible reasons for this are discussed. The associated improvement in dental alignment was measured by an index which is also discussed.