Background: Prominent upper front teeth are a common problem affecting about a quarter of 12-year old children in the UK. The correction of this condition is one of the most common treatments performed by orthodontists. This condition develops when the child's permanent teeth erupt and children are often referred to an orthodontist for treatment with dental braces to reduce the prominence of the teeth. These teeth are more likely to be injured and their appearance can cause significant distress.If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait until the child is older and provide treatment in early adolescence.
Objectives: To assess the effects of orthodontic treatment for prominent upper front teeth when this treatment is initiated when the child is seven to 11 years old compared to when they are in early adolescence, or when treatment uses different types of orthodontic braces.
Search methods: We searched the following databases: Cochrane Oral Health Group's Trials Register (to 17 April 2013), CENTRAL (The Cochrane Library 2013, Issue 3), MEDLINE (OVID) (1946 to 17 April 2013) and EMBASE (OVID) (1980 to 17 April 2013). There were no restrictions regarding language or publication date.
Selection criteria: Randomised controlled trials of children and/or adolescents (age < 16 years) on early treatment (either one or two-phase) with any type of orthodontic braces (removable, fixed, functional) or head-braces compared with late treatment with any type of orthodontic braces or head-braces; or, on any type of orthodontic braces or head-braces compared with no treatment or another type of orthodontic brace or appliance (with treatment starting in children of similar ages in both groups) to correct prominent upper front teeth.
Data collection and analysis: Review authors screened the search results, extracted data and assessed risk of bias independently, used odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous outcomes, mean differences (MDs) and 95% CIs for continuous outcomes and a fixed-effect model for meta-analyses as there were fewer than four studies.
Main results: We included 17 studies based on data from 721 participants.Three trials (n = 343) compared early (two-phase) treatment (7-11 years of age) with a functional appliance, with adolescent (one-phase) treatment. Statistically significant differences in overjet, ANB and PAR scores were found in favour of functional appliance when the first phase of early treatment was compared with observation in the children due to receive treatment in adolescence. However, at the end of treatment in both groups, there was no evidence of a difference in the overjet (MD 0.21, 95% CI -0.10 to 0.51, P = 0.18) (low quality evidence), final ANB (MD -0.02, 95% CI -0.47 to 0.43, P = 0.92), PAR score (MD 0.62, 95% CI -0.66 to 1.91, P = 0.34) or self concept score (MD 0.83, CI -2.31 to 3.97, P = 0.60). However, two-phase treatment with functional appliance showed a statistically significant reduction in the incidence of incisal trauma (OR 0.59, 95% CI 0.35 to 0.99, P = 0.04) (moderate quality evidence). The incidence of incisal trauma was clinically significant with 29% (54/185) of patients reporting new trauma incidence in the adolescent (one-phase) treatment group compared to only 20% (34/172) of patients receiving early (two-phase) treatment.Two trials (n = 285), compared early (two-phase) treatment using headgear, with adolescent (one-phase) treatment. Statistically significant differences in overjet and ANB were found in favour of headgear when the first phase of early treatment was compared with observation in the children due to receive treatment in adolescence. However, at the end of treatment in both groups, there was no evidence of a difference in the overjet (MD 0.22, 95% CI -0.56 to 0.12, P = 0.20) (low quality evidence), final ANB (MD -0.27, 95% CI -0.80 to 0.26, P = 0.32) or PAR score (MD -1.55, 95% CI -3.70 to 0.60, P = 0.16). The incidence of incisal trauma was, however, statistically significantly reduced in the two-phase treatment group (OR 0.47, 95% CI 0.27 to 0.83, P = 0.009) (low quality evidence). The adolescent treatment group showed twice the incidence of incisal trauma (47/120) compared to the young children group (27/117).Two trials (n = 282) compared different types of appliances (headgear and functional appliance) for early (two-phase) treatment. At the end of the first phase of treatment statistically significant differences, in favour of functional appliances, were shown with respect to final overjet only. At the end of phase two, there was no evidence of a difference between appliances with regard to overjet (MD -0.21, 95% CI -0.57 to 0.15, P = 0.26), final ANB (MD -0.17, 95% CI -0.67 to 0.34, P= 0.52), PAR score (MD -0.81, 95% CI -2.21 to 0.58, P = 0.25) or the incidence of incisal trauma (OR 0.79, 95% CI 0.43 to 1.44, P = 0.44).Late orthodontic treatment for adolescents with functional appliances showed a statistically significant reduction in overjet of -5.22 mm (95% CI -6.51 to -3.93, P < 0.00001) and ANB of -2.37° (95% CI -3.01 to -1.74, P < 0.00001) when compared to no treatment (very low quality evidence).There was no evidence of a difference in overjet when Twin Block was compared to other appliances (MD 0.01, 95% CI -0.45 to 0.48, P = 0.95). However, a statistically significant reduction in ANB (-0.63°, 95% CI -1.17 to -0.08, P = 0.02) was shown in favour of Twin Block. There was no evidence of a difference in any reported outcome when Twin Block was compared with modifications of Twin Block.There was insufficient evidence to determine the effects of Activator, FORSUS FRD EZ appliances, R-appliance or AIBP.
Authors' conclusions: The evidence suggests that providing early orthodontic treatment for children with prominent upper front teeth is more effective in reducing the incidence of incisal trauma than providing one course of orthodontic treatment when the child is in early adolescence. There appears to be no other advantages for providing treatment early when compared to treatment in adolescence.