Controversies about Midpalatal Suture and Maxillary Expansion: Literature Review

Introduction: Which is the composition of the midpalatal suture (MPS)? Which are its functions? At which moment of life does its obliteration occur? In addition to these questions, disagreement is frequently found in the literature about several details associated with the treatment of transverse maxillary deficiency using orthopedic expansion. The results of recent studies have helped understanding the physiology and behavior of MPS during and after maxillary expansion, in the prepubertal and post-pubertal periods, leading, in some cases, to an absolutely diverse interpretation of aspects presented in previously published relevant studies. New knowledge of MPS contrasts in several points with old concepts. Objective: To analyze, by means of a literature review, actual data and assumptions to elucidate the possibility of total obliteration of MPS after puberty, the influence of mineral density in the MPS region during maxillary expansion, and how patient's age affects it. Conclusion: The hypothesis that total obliteration of MPS occurs in a certain phase of life could probably be abandoned because it is not supported by the recent data and the physiological behavior of the suture. The mineral density of MPS, which varies according to the person's age, could affect the physiological capacity of bone repair and the elasticity of suture. The high density mineral of MPS, which has been described as normal in middle-aged individuals, could be responsible by the contraindication of maxillary expansion in adult life.