Julian O'Neill

Early treatment for Class II Division 1 malocclusion with the Twin-block appliance: a multi-center, randomized, controlled trial.

INTRODUCTION The aim of this study was to evaluate the effectiveness of early orthodontic treatment with the Twin-block appliance for the treatment of Class II Division 1 malocclusion. This was a multi-center, randomized, controlled trial with subjects from 14 orthodontic clinics in the United Kingdom. METHODS The study included 174 children aged 8 to 10 years with Class II Division 1 malocclusion; they were randomly allocated to receive treatment with a Twin-block appliance or to an initially untreated control group. The subjects were then followed until all orthodontic treatment was completed. Final skeletal pattern, number of attendances, duration of orthodontic treatment, extraction rate, cost of treatment, and the childs self-concept were considered. RESULTS At the end of the 10-year study, 141 patients either completed treatment or accepted their occlusion. Data analysis showed that there was no differences between those who received early Twin-block treatment and those who had 1 course of treatment in adolescence with respect to skeletal pattern, extraction rate, and self-esteem. Those who had early treatment had more attendances, received treatment for longer times, and incurred more costs than the adolescent treatment group. They also had significantly poorer final dental occlusion. CONCLUSIONS Twin-block treatment when a child is 8 to 9 years old has no advantages over treatment started at an average age of 12.4 years. However, the cost of early treatment to the patient in terms of attendances and length of appliance wear is increased.

Early treatment for Class II malocclusion and perceived improvements in facial profile

INTRODUCTION The aims of this study were to assess whether early Twin-block appliance treatment improves the attractiveness of Class II profiles and to determine the orofacial features of a profile that most influence the perception of attractiveness. METHODS Silhouetted profiles of 20 treated patients and 20 untreated controls randomly selected from 174 subjects (ages, 8-10 years) of a randomized, controlled trial into the effectiveness of early Class II treatment were assessed by 30 children (ages, 10-11 years) and 24 teaching staff using a 5-point Likert scale. Independent samples t tests were used to compare attractiveness ratings between the treated and untreated groups. Linear regression was used to determine the features defining attractiveness. RESULTS Early orthodontic treatment resulted in improved perceptions of facial profile attractiveness. Profiles were likely to be rated as attractive if the overjet was smaller (P = 0.001) and no teeth showed (P <0.05). CONCLUSIONS Profile silhouettes of children who had received early orthodontic treatment for Class II malocclusion were perceived to be more attractive by peers than those of children who did not receive treatment.

Do folic acid supplements reduce facial clefts

DesignThis was a national population-based case-control study in Norway.Case and control selectionCases consisted of all newborn infants born from 1996–2001 who had been referred for surgical treatment of a cleft [either cleft lip with or without cleft palate (377 children) or cleft palate only (196 children)]. Controls (763) were a randomly selected at an average of four per 1000 live births (identified through the medical birth registry of Norway).Data analysisData were collected using questionnaires. Crude odds ratios (OR) were calculated and adjustments for potential confounders (diet and multivitamins, mothers education, mothers employment during early pregnancy, smoking, alcohol consumption, and year of babys birth) were made.ResultsFolic acid supplementation during early pregnancy (400 μg/day) was associated with a reduced risk of isolated cleft lip with or without cleft palate after adjustment for multivitamins, smoking, and other potential confounding factors [adjusted OR, 0.61; 95% confidence interval (CI), 0.39–0.96]. Independent of supplements, diets rich in fruits, vegetables and other high-folate-containing foods reduced the risk somewhat (adjusted OR, 0.75; 95% CI, 0.50–1.11). The lowest risk of cleft lip was among women who ate folate-rich diets who also took folic acid supplements and multivitamins (adjusted OR, 0.36; 95% CI, 0.17–0.77). Folic acid provided no protection against cleft palate alone (adjusted OR, 1.07; 95% CI, 0.56–2.03).ConclusionsFolic acid supplements during early pregnancy seem to reduce the risk of isolated cleft lip (with or without cleft palate) by about a third. Other vitamins and dietary factors may provide additional benefit.

Maxillary expansion as an interceptive treatment for impacted canines

DesignThis was a randomised controlled trial.InterventionPatients in the control group received no treatment, whereas the patient treatment group had a rapid maxillary expander soldered to bands placed on the second deciduous molars or the first permanent molars. Activation of the screw was continued until the palatal cusps of the maxillary posterior teeth were in contact with the buccal cusps of the mandibular posterior teeth. Once the required expansion was achieved, the expansion screw was locked in position. After expansion, all patients were retained with the expander in place for 6 months after which the patients wore a retention plate at night for 1 year.Outcome measureThe main outcome was successful or unsuccessful eruption of the maxillary permanent canines.ResultsThe sample comprised 54 patients (32 in the treatment group and 22 in the control). No statistically significant differences were found for any variable at baseline. The prevalence rates of successful eruption of the maxillary canines were 65.7% (21 subjects) in the treatment group and 13.6% (three subjects) in the control. The comparison was statistically significant (chi-square, 12.382; P >0.001).ConclusionsThe use of rapid maxillary expansion (RME) in the early mixed dentition appears to be an effective procedure to increase the rate of eruption of palatally displaced maxillary canines (PDC) compared with an untreated control group.

Little evidence exists about optimal caries-prevention strategies during orthodontic treatment.

Data sources Medline, PubMed and hand searches were used to source studies.Study selection Publications were screened independently by two observers. Only randomised controlled trials (RCT) of orthodontic fixed appliance treatment with bonded brackets that addressed prevention of white spot lesions which were published in English were included. Studies also had to provide enough data to calculate the preventive fraction (PF).Data extraction and synthesis The studies were divided into four groups based on comparable preventive measures (fluoride, chlorhexidine, sealants and bonding materials) and then the PF was calculated.Results The overall PF of the fluoride-releasing bonding materials was 20% (standard error, 0.09). This effect, however, was not statistically significant. It was impossible to calculate an overall PF for the other preventive measures, but the tendency of their caries-inhibiting effect was described. The use of toothpaste and gel with a high fluoride concentration of 1500–5000 ppm or of complementary chlorhexidine during orthodontic treatment showed a demineralisation-inhibiting tendency. The use of a polymeric tooth coating on the tooth surface around the brackets showed almost no demineralisation-inhibiting effect.Conclusions Many publications had to be excluded from this systematic review because of inadequate research designs. Future clinical trials are needed to give evidence-based advice on the optimal caries-prevention strategy.

Functional appliances and mandibular growth — is there an effect?

Data sources A MEDLINE search strategy for the years 1966 to 1999 was developed. The search was limited to randomised controlled trials (RCT) and meta-analyses, which were performed on humans and written in English.Study selection Articles retrieved were critically appraised for their validity. For inclusion, an article had to meet four of seven validity standards and also the following criteria: it pertained to functional appliance use in the early treatment of Class II malocclusions; it was an RCT; and it included measurable mandibular cephalometric values.Data extraction and synthesis Cephalometric values were used to assess mandibular growth in the horizontal and the vertical dimensions. The following linear measures were assessed: condylion–pogonion (Co–Pg), articulare–pogonion (Ar–Pg), condylion–gnathion (Co–Gn), articulare–gnathion (Ar–Gn), sella–gonion (S–Go), articulare–gonion (Ar–Go), and condylion–gonion (Co–Go). Two angular parameters, sella-nasion-B point (SNB) and lower incisal angle (LIA), were also measured. Three horizontal measurements were also used in some of the studies examined, namely: gonion–menton (Go–Me), pogonion–N (Pg–N), and gonion–pogonion (Go–Pg). Annualised changes (linear or angular) in specific cephalometric data were pooled from the selected articles and then compared and plotted. Statistical significance was tested through analysis of variance, the Student’s t-test for paired data and 95% confidence intervals.Results The search identified 17 articles of which six met the inclusion and validity criteria. There was a significant difference between the control and the treated groups for Ar–Pg and Ar–Gn. No other horizontal or vertical cephalometric measurements were statistically significant.Conclusions It is currently difficult to obtain definitive answers about efficacy of functional appliances on mandibular growth because of many inconsistencies in measuring the treatment outcome variables. There is still a need to conduct more RCT to reduce the methodological limitations.

Quad-helix appliances may be more successful than removable expansion plates at correcting posterior crossbites.

Data sourcesThe Cochrane Oral Health Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) Medline, Embase, the US National Institutes of Health Trials Register and the World Health Organisation (WHO) Clinical Trials Registry Platform were searched with no restrictions.Study selectionRandomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults were considered.Data extraction and synthesisStudy selection, data abstraction and risk of bias assessment were carried out independently by two reviewers. Dichotomous data were summarised with risk ratios (RR) and 95% confidence intervals (CIs) and continuous data with mean differences (MD) with 95% CIs. Meta-analyses were conducted when comparisons and outcomes were sufficiently similar.ResultsFifteen studies were included; seven were at high risk of bias, two at low risk and six at unclear risk. Nine studies compared fixed appliances with mid-palatal expansion but no difference between appliances was reported. Low quality evidence from two studies with 96 participants found that fixed quad-helix appliances may be 20% more likely to correct crossbites than removable expansion plates (RR 1.20; 95% CI 1.04 to 1.37), and quad-helix appliances may achieve 1.15 mm more molar expansion than expansion plates (MD 1.15 mm; 95% CI 0.40 to 1.90;). Very limited evidence showed that both fixed quad-helix appliances and removable expansion plates were superior to composite onlays in terms of crossbite correction, molar and canine expansion.ConclusionsThere is a very small body of low to moderate quality evidence to suggest that the quad-helix appliance may be more successful than removable expansion plates at correcting posterior crossbites and expanding the inter-molar width for children with early mixed dentition (aged eight to 10 years). The remaining evidence we found was of very low quality and was insufficient to allow the conclusion that any one intervention is better than another for any of the outcomes in this review.

Do lip bumpers work

Data sourcesSearches were made using PubMed, Embase, the Cochrane Central Register of Controlled Trials and the Cochrane database of systematic reviews, along with searches by hand of the following journals: Angle Orthodontist, American Journal of Orthodontics and Dentofacial Orthopedics, Journal of Orthodontics and European Journal of Orthodontics.Study selectionThe first step was to identify eligible reports based on their titles and abstracts: 52 articles were found. Inclusion and exclusion criteria were then applied. Studies were included if subjects were human; they were randomised controlled trials and prospective or retrospective studies; they discussed the effect of the lip bumper on the arch and teeth; and they were reported in the English language. Articles excluded were mainly animal studies, case reports, case series, review articles, abstracts, in-vitro studies, discussions and interviews; were published in a language other than English; or did not follow the objective of this review. The selection was made by two researchers. Their results were compared to identify discrepancies and reach mutual agreement.Data extraction and synthesisIf two or more studies had evaluated the same technique, a meta-analysis was planned.ResultsA total of 16 RCT were identified of which 13 underwent detailed evaluation; of these, only one study was considered to have usable outcome information. The others were excluded because of control group, sex, age, study casts and cephalometric analysis, and measurement error. This single small study showed that lip bumper can increase arch dimensions and contribute to crowding relief in mixed dentition.ConclusionsThe results showed increases in arch dimensions, including a greater arch length. This was attributed to incisor proclination, distalisation, and distal tipping of the molars. There were also increases in arch width and intercanine and deciduous intermolar or premolar distances. The long-term stability of the effects of the lip bumper need to be elucidated.

Long-term stability after orthodontic treatment remains inconclusive

Data sourcesPubMed and Cochrane Library electronic databases were searched from 1966 to January 2005. Reference lists of the relevant studies were searched by hand.Study selectionFor inclusion, articles had to satisfy the following criteria: have a follow-up period of at least 5 years post-retention; report on randomised clinical trials (RCT), prospective or retrospective clinical controlled studies or on cohort studies; and investigate orthodontic treatment including fixed or removable appliances, selective grinding or extractions.Data extraction and synthesisScreening of eligible studies, data extraction and assessment of methodological quality was conducted independently and in duplicate. The level of evidence of the included studies was graded as high, moderate or low according to predetermined criteria.ResultsThe search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment but the mandibular arch length and intercanine width gradually decreased, and crowding of the lower anterior teeth reoccurred post-retention. This condition was unpredictable at the individual level. Treatment of Angle class-II division-1 malocclusion with a Herbst appliance normalised the occlusion. Relapse occurred but could not be predicted at the individual level. The scientific evidence was insufficient to draw conclusions about treatment of cross-bite, angle class III, open-bite and various other malocclusions, or about long-term patient satisfaction.ConclusionsDespite a large number of studies on long-term stability after orthodontic treatment, this systematic review shows that evidence-based conclusions are few. This is mostly because of inherent problems with retrospective and inferior study design. There is a great need for well-designed prospective studies with untreated control groups; sufficient sample sizes; and sample selection according to type of malocclusion, age and growth pattern.

No randomised trials of interventions to manage relapse of lower incisors after orthodontic treatment

Data sourcesThe Cochrane Oral Health Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched with no language or date restrictions. Handsearching of a number of orthodontic journals was undertaken.Study selectionRandomised controlled trials (RCTs) comparing fixed and removable treatment options for the management of relapsed lower front teeth after orthodontic treatment were to be considered. RCTs involving patients with craniofacial deformities/syndromes or serious skeletal deformities were excluded.Data extraction and synthesisTwo review authors, independently and in duplicate, assessed the results of the searches to identify studies for inclusion. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis.ResultsNo trials were identified.ConclusionsThis review has revealed that there was no evidence from RCTs to show that one intervention was superior to another to manage the relapse of the alignment of lower front teeth using any method or index, aesthetic assessment by participants and practitioners, treatment time, patient discomfort, quality of life, cost-benefit considerations, stability of the correction, and side effects including pain, gingivitis, enamel decalcification and root resorption. There is an urgent need for RCTs in this area to identify the most effective and safe method for managing the relapse of alignment of the lower front teeth.