RESUMEN
OBJECTIVE: To compare the occlusal characteristics of persistent digit suckers with those of a group of individuals who reported never to have sucked their thumb or finger. SETTING: School children and regular attenders to four general dental practices in Kettering, UK. DESIGN: Cross-sectional, observational. OUTCOME MEASURES: Prevalence of anterior open bite, posterior crossbite, size of overjet, overbite and buccal segment relationship. SUBJECTS AND METHODS: The exposed group consisted of 7-13-year-old children with a persistent digit sucking habit or those who had given up the habit less than 2 years previously, compared with an unexposed group of children who had never reported a history of the habit. Upper and lower alginate impressions were taken and the resultant study models were used to measure occlusal differences between the two groups. RESULTS: Following exclusions, 39 digit suckers were compared to 36 non-suckers. The odds of a reduced overbite being present were significantly higher in the digit sucking group compared to the non-suckers (OR: 5.6, 95% CI: 1.6-20.8). The prevalence of anterior open bites was higher in the digit suckers (P<0.001). Although the overjet was slightly increased in the digit suckers compared with the non-suckers (mean difference: 1 mm, P = 0.036), this result needs to be interpreted with caution. No significant differences were seen in the presence of posterior crossbites or buccal segment relationships between the two groups. CONCLUSIONS: This study has shown that reduced overbite and anterior open bites were significantly more prevalent in digit suckers. The orthodontic management of anterior open bites can involve complex and prolonged treatment. Early intervention to eliminate digit sucking habits is therefore recommended on both oral health and health economic grounds.