Prominent upper front teeth are a common problem that affect approximately one in four 12-year-old children in the UK. Children with this type of malocclusion may be a target for teasing and bullying and the teeth are 2 to 3 times more likely to be damaged. A number of different treatment approaches are used and there is a need to understand the relative effectiveness all of the available grace types..
The aim of this review was to assess the effects of orthodontic treatment for prominent upper front teeth initiated when children are seven to 11 years old (’early treatment’ in two phases) compared to in adolescence when they are around 12 to 16 years old (’late treatment’ in one phase); to assess the effects of late treatment compared to no treatment; and to assess the effects of different types of orthodontic braces.
Searches were conducted in the Cochrane Oral Health’s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) Medline, Embase, the US National Institutes of Health Ongoing Trials Register and the World Health Organization International Clinical Trials Registry Platform. There were no date or language restrictions. All randomised controlled trials (RCTs) of orthodontic treatments to correct class II Division I malocclusions were considered. Trials involving participants with cleft lip /palate, other craniofacial deformities/ syndromes all of those receiving surgical treatment for malocclusion were excluded.
Two reviewers independently selected studies, abstracted data and assessed risk of bias using the Cochrane tool. The quality of evidence was assessed using the GRADE approach. Odds ratios (ORs) and 95% confidence intervals (CIs) were are used for dichotomous outcomes, and mean differences (MDs) and 95% CIs for continuous outcomes. Fixed-effect meta-analysis was used with 2 to 3 studies and random effects model for more than 3 studies.
- 27 RCTs involving a total of 1251 patients were included.
- 15 studies were considered to be at high risk of bias, 10 at unclear risk and 2 at low risk. Hello
- 23 studies contributed to the meta-analysis.
- 3 trials compared early functional appliance treatment with late treatment for overjet, ANB and incisal trauma. when both groups had completed treatment, there was:-
- no difference between groups in final overjet (MD= 0.21, 95% CI −0.10 to 0.51, 343 participants) (low-quality evidence) or
- ANB (MD = −0.02, 95% CI −0.47 to 0.43; 347 participants) (moderate-quality evidence).
- Early treatment with functional appliances reduced the incidence of incisal trauma compared to late treatment (OR 0.56, 95% CI 0.33 to 0.95; 332 participants) (moderate-quality evidence). This was clinically important with 30% (51/171) of participants reporting new trauma in the late treatment group compared to only 19% (31/161) of participants who had received early treatment.
- 2 trials compared early treatment using headgear versus late treatment.
- After phase one of early treatment, headgear had reduced overjet and ANB; however, when both groups had completed treatment, there was no evidence of a difference between groups in overjet) or ANB. Early (two-phase) treatment with headgear reduced the incidence of incisal trauma (OR= 0.45, 95% CI 0.25 to 0.80; 237 participants) (low-quality evidence), with almost half the incidence of new incisal trauma (24/117) compared to the late treatment group (44/120).
- 7 trials compared late treatment with functional appliances versus no treatment.
- There was a reduction in final overjet with both fixed functional appliances (MD= −5.46 mm, 95% CI −6.63 to −4.28; 2 trials, 61 participants) and removable functional appliances (MD −4.62, 95% CI -5.33 to -3.92; 3 trials, 122 participants) (low-quality evidence).
- There was no evidence of a difference in final ANB between fixed functional appliances and no treatment but removable functional appliances seemed to reduce ANB compared to no treatment (MD= −2.37°, 95% CI -3.01 to -1.74; 2 trials, 99 participants) (low-quality evidence).
- 6 trials compared orthodontic treatment for adolescents with Twin Block versus other appliances finding no difference in overjet. The reduction in ANB favoured treatment with a Twin Block (−0.56°, 95% CI −0.96 to −0.16; 6 trials, 320 participants) (low-quality evidence).
- 3 trials compared orthodontic treatment for adolescents with removable functional appliances versus fixed functional appliances and found a reduction in overjet in favour of fixed appliances (0.74, 95% CI 0.15 to 1.33; two trials, 154 participants) (low-quality evidence), and a reduction in ANB in favour of removable appliances (−1.04°, 95% CI −1.60 to −0.49; 3 trials, 185 participants) (low-quality evidence).
The authors concluded: –
Evidence of low to moderate quality suggests that providing early orthodontic treatment for children with prominent upper front teeth is more effective for reducing the incidence of incisal trauma than providing one course of orthodontic treatment in adolescence. There appear to be no other advantages of providing early treatment when compared to late treatment. Low-quality evidence suggests that, compared to no treatment, late treatment in adolescence with functional appliances, is effective for reducing the prominence of upper front teeth.
This review updates the earlier Cochrane review on this topic (Dental Elf – 4th Jan 2014) with 10 more trials available. Despite the fact that many of these trials have been published in recent years when reporting guidelines for trials (CONSORT) and greater clarity regarding trial methodology have been available the overall quality of the evidence available to answer questions related to treatment of class II Division I malocclusion is still low. Overall the main findings of this update are similar to previous version of the review in that the only advantage of providing two-phased treatment compare to one phase treatments is that there may be a reduction in the incidence of incisal trauma with the two phase approach.
Batista KBSL, Thiruvenkatachari B, Harrison JE, O’Brien KD. Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children and adolescents. Cochrane Database of Systematic Reviews 2018, Issue 3. Art. No.: CD003452. DOI: 10.1002/14651858.CD003452.pub4.
Cochrane oral Health Group Blog – Early-phase treatment of prominent upper front teeth in children may have benefits
Dental Elf – 16th Oct 2017
Orthodontic treatment for Class II division 2 malocclusion: No randomised trial evidence
Dental Elf – 9th Dec 2015
Class II malocclusion- fixed or removable functional appliances?
Dental Elf – 4th Jan 2014
Early orthodontic treatment may reduce incisal trauma in children with class II malocclusions