Relation between incisal overjet and traumatic injury: a case control study.

Most previous studies have shown the prevalence of traumatic dental injuries in anterior teeth to increase with increasing overjet. This study identified 36 Singapore schoolchildren, age 7-18 years, from a clinic population of 11,179, who had suffered dental trauma while playing contact or collision sports. A case control group of 36 children, matched for age, sex, race and sporting activities, but who had not suffered dental trauma, was selected from the same clinic population. Both groups were examined and the nature of injuries received, together with overjet measured to the nearest 0.5 mm were determined. The mean overjet for the trauma group was 3.42 +/- 1.45 mm and for the injured group 3.42 +/- 1.33 mm. These means were not statistically different (p = 1.00), neither did the distribution of overjet between the groups differ. These data were not in accord with the majority of studies correlating incisal overjet and dental trauma, and they suggested that overjet was not a positive correlate with traumatic dental injury in Singapore schoolchildren.