Immediate and six-month space changes after premature loss of a primary maxillary first molar.

Background. Premature loss of primary maxillary first molars has been associated with a number of consequences (such as tipping of the first permanent molar). The aim of the authors' study was to investigated dental-arch space problems arising as a result of premature lass of a primary maxillary first molar. Methods. The study was composed of 19 children who experienced unilateral premature loss of a primary maxillary first molar. The authors used each patient's intact contralateral arch segment as a control. The authors obtained maxillary dental study casts two or three days after the tooth was extracted, as well as six months later. Results. The D + E space from the extraction side six months after removal: of the tooth (mean +/- standard deviation, 15.62 +/- 1.13 millimeters) was significantly smaller than the space on the control side (16.88 +/- 1.12 mm) and the initial-D + E space (16.70 +/- 0.6 mm).'The authors found a significantly shorter arch length (25.47 +/- 1.58 mm) and'larger interdaniewidth(31.29 +/- 2.49 mm) six months after the tooth was extracted compared with the initial arch length (25.86 +/- 1.64 mm) and intercanine width (30.42 +/- 2.64 mm). Conclusions. The early space changes,to the maxillary arch subsequent to premature loss, of a primary maxillary first molar are primarily distal drift of the primary canines toward the. extraction space and palatal migration of the maxillary incisors. Although 1 mm of space was lost, which is statistically significant, this is not likely to be of sufficient clinical significance to warrant use of a space, maintainer. If palatal-movement appears:to be needed, the dentist should consider use of a palatal, arch rather than a band-and-loop maintainer. Clinical Implications. he effects of space maintainers need to be re-evaluated in cases of-unilateral premature loss of a primary maxillary first molar.