A systematic review of the relationship between overjet size and traumaticdental injuries

The aim of this study was to aggregate the risk of traumatic dental injury due to overjet using several published papers and performing a meta-analysi s on the results. The 11 articles involved in this investigation were ident ified by a literature search of Medline (1966-1996) and Exerpta Medica (198 5-1996) databases using predetermined keywords, and inclusion and exclusion criteria. In order to assess the quality of each paper, a methodological checklist fo r observational studies was developed resulting in a score between 0 and 10 0. The relative risk of overjet, compared with a reference, was expressed a s an Odds Ratio (OR), For each study, the OR was computed using the data pr esented and, subsequently, these ORs were pooled across studies. The effect of confounders (i.e, age, gender), which could bias the relationship betwe en overjet and dental injury was taken into account. Furthermore, the influ ence of quality of the study on the pooled OR was addressed. The average methodological score was 41. From the results, it can be conclu ded that children with an overjet larger than 3 mm are approximately twice as much at risk of injury to anterior teeth than children with an overjet s maller than 3 mm. The effect of overjet on the risk of dental injury is les s for boys than for girls in the same overjet group. In addition, risk of i njury of anterior teeth tends to increase with increasing overjet size. Fur thermore, the pooled OR does not seem to be affected by the quality of the studies.