Prevention of overbite and overjet development in the 3 to 8 year old by controlled nighttime guidance of incisal eruption: a study of 43 individuals.

The purpose of this study conducted at Tufts University School of Dental Medicine is to investigate the possibility of limiting the development of an excessive vertical overbite and horizontal overjet during sleeping hours in young children prior to and during the eruption of the permanent incisors. A sample of 43 individuals, whose mean age was 6.17 years, wore a Preventive Eruption Guidance Appliance passively only while sleeping at night for 13 months (mean) to control the development of the overbite as the permanent incisors erupted and to correct the excessive overjet. The mean initial overbite of the sample was 3.4 mm and was reduced to 1.4 mm. The mean initial overjet was 3.0 mm and was reduced to 1.4 mm. Fourteen percent (6 cases) of the sample had an open bite of 1.84 mm (mean), which was reduced to a mean open-bite of 0.81 mm. As a result of the statistical comparison between the treatment sample to the control sample of 50 non-treated individuals, it was shown that the reduction of the overbite and overjet was accomplished solely by altering the problematic dentition without affecting the normal growth pattern or facial morphology as measured from nine lineal dimensions. It was also shown that the change in overbite and overjet was a significant improvement over what would have occurred if no intervention had been instituted, and that the overbite was corrected by restricting continued excessive eruption of the maxillary incisors with only nighttime passive use of the appliance.