Orthodontic treatment for prominent upper front teeth in children

Background

Prominent upper front teeth are an important and potentially harmful type of orthodontic problem. 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. 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. When treatment is provided during adolescence the orthodontist may provide treatment with various orthodontic braces, but there is currently little evidence of the relative effectiveness of the different braces that can be used.

Objectives

To assess the effectiveness of orthodontic treatment for prominent upper front teeth, when this treatment is provided when the child is 7 to 9 years old or when they are in early adolescence or with different dental braces or both.

Search strategy

The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. The handsearching of the key international orthodontic journals was updated to December 2006. There were no restrictions in respect to language or status of publication.
Date of most recent searches: February 2007.

Selection criteria

Trials were selected if they met the following criteria:
design - randomised and controlled clinical trials;
participants - children or adolescents (age < 16 years) or both receiving orthodontic treatment to correct prominent upper front teeth;
interventions - active: any orthodontic brace or head-brace, control: no or delayed treatment or another active intervention;
primary outcomes - prominence of the upper front teeth, relationship between upper and lower jaws;
secondary outcomes: self esteem, any injury to the upper front teeth, jaw joint problems, patient satisfaction, number of attendances required to complete treatment.

Data collection and analysis

Information regarding methods, participants, interventions, outcome measures and results were extracted independently and in duplicate by two review authors.
The Cochrane Oral Health Group's statistical guidelines were followed and mean differences were calculated using random-effects models. Potential sources of heterogeneity were examined.

Main results

The search strategy identified 185 titles and abstracts. From this we obtained 105 full reports for the review. Eight trials, based on data from 592 patients who presented with Class II Division 1 malocclusion, were included in the review.

Early treatment comparisons: Three trials, involving 432 participants, compared early treatment with a functional appliance with no treatment. There was a significant difference in final overjet of the treatment group compared with the control group of -4.04 mm (95% CI -7.47 to -0.6, Chi² 117.02, 2 df, P < 0.00001, I² = 98.3%). There was a significant difference in ANB (-1.35 mm; 95% CI -2.57 to -0.14, Chi² 9.17, 2 df, P = 0.01, I² = 78.2%) and change in ANB (-0.55; 95% CI -0.92 to -0.18, Chi² 5.71, 1 df, P = 0.06, I² = 65.0%) between the treatment and control groups.
The comparison of the effect of treatment with headgear versus untreated control revealed that there was a small but significant effect of headgear treatment on overjet of -1.07 (95% CI -1.63 to -0.51, Chi² 0.05, 1 df, P = 0.82, I² = 0%). Similarly, headgear resulted in a significant reduction in final ANB of -0.72 (95% CI -1.18 to -0.27, Chi² 0.34, 1 df, P = 0.56, I² = 0%).
No significant differences, with respect to final overjet, ANB, or ANB change, were found between the effects of early treatment with headgear and the functional appliances.

Adolescent treatment (Phase II): At the end of all treatment we found that there were no significant differences in overjet, final ANB or PAR score between the children who had a course of early treatment, with headgear or a functional appliance, and those who had not received early treatment. Similarly, there were no significant differences in overjet, final ANB or PAR score between children who had received a course of early treatment with headgear or a functional appliance.
One trial found a significant reduction in overjet (-5.22 mm; 95% CI -6.51 to -3.93) and ANB (-2.27 degrees; 95% CI -3.22 to -1.31, Chi² 1.9, 1 df, P = 0.17, I² = 47.3%) for adolescents receiving one-phase treatment with a functional appliance versus an untreated control.
A statistically significant reduction of ANB (-0.68 degrees; 95% CI -1.32 to -0.04, Chi² 0.56, 1 df, P = 0.46, I² = 0%) with the Twin Block appliance when compared to other functional appliances. However, there was no significant effect of the type of appliance on the final overjet.

Authors' conclusions

The evidence suggests that providing early orthodontic treatment for children with prominent upper front teeth is no more effective than providing one course of orthodontic treatment when the child is in early adolescence.