A composite photographic image - could it replace a lateral cephalogram?

INTRODUCTION: Computer software allows a photograph of patient's face and a photograph of their dental casts to be combined into one image, similar to that seen in a lateral cephalogram. The aim of this study was to assess the agreement between the measurements carried out on this novel composite photographic image and those taken from a lateral cephalogram of the same patient. METHODS: The method involved the superimposition of a photograph of a patient's dental casts onto a photograph of their profile thus creating a composite image. The position of teeth in relation to the face was then compared on these images and on lateral cephalograms. The distances between a number of facial reference points to the upper right central incisor and the upper right last molar, were measured on both images. RESULTS: The records of 34 participants showed that there was good or acceptable agreement between measurements carried out on composite images and on lateral cephalograms. This agreement was generally better for measurements carried out from the reference points to the incisor tooth than to the molar. However, standard deviations of the mean differences between measurements were relatively high. CONCLUSIONS: The photographic superimposition method eliminates exposure to ionizing radiation and is relatively inexpensive. However, it is not reliable enough to deliver accurate information on the position of teeth in the face.

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

DATA SOURCES: The Cochrane Oral Health Group's 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 SELECTION: Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults were considered. DATA EXTRACTION AND SYNTHESIS: Study 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. RESULTS: Fifteen 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. CONCLUSIONS: There 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.

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

DATA SOURCES: The Cochrane Oral Health Group's 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 SELECTION: Randomised 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 SYNTHESIS: Two 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. RESULTS: No trials were identified. CONCLUSIONS: This 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.

Limited evidence for interceptive extraction of deciduous teeth to prevent permanent canine impaction.

DATA SOURCES: The Cochrane Oral Health Group's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched with no restrictions regarding language or date of publication. STUDY SELECTION: Randomised controlled trials (RCTs) or quasi-RCTs with at least a 6-month follow-up period after the intervention were included. DATA EXTRACTION AND SYNTHESIS: Data extraction was undertaken independently by two review authors. The primary outcome was the reported prevalence of eruption or non-eruption of the ectopic permanent canine into the mouth following observation or intervention. Results were to be expressed as risk ratios for dichotomous outcomes with 95% confidence intervals and mean differences for continuous outcomes. Heterogeneity was to be investigated, including both clinical and methodological factors. Authors of trials were contacted to request unpublished data. RESULTS: Two trials (involving approximately 128 children, ≥150 palatally displaced canines) excluded from the previous version of this review were included. Both trials had serious deficiencies in their design, conduct and reporting, with the data presented being either incomplete or inconsistent. Both trials are at high risk of bias. Neither trial provides any evidence to guide clinical decision-making. CONCLUSIONS: There is currently no evidence of the effects of extraction of primary canine teeth in 10-13-year-old children with one or two palatally displaced permanent canine teeth.

Digital versus plaster study models: how accurate and reproducible are they?

OBJECTIVE: To compare measurements of occlusal relationships and arch dimensions taken from digital study models with those taken from plaster models. DESIGN: Laboratory study SETTING: The Orthodontic Department, Kettering General Hospital, Kettering, UK Methods and materials: One hundred and twelve sets of study models with a range of malocclusions and various degrees of crowding were selected. Occlusal features were measured manually with digital callipers on the plaster models. The same measurements were performed on digital images of the study models. Each method was carried out twice in order to check for intra-operator variability. The repeatability and reproducibility of the methods was assessed. RESULTS: Statistically significant differences between the two methods were found. In 8 of the 16 occlusal features measured, the plaster measurements were more repeatable. However, those differences were not of sufficient magnitude to have clinical relevance. In addition there were statistically significant systematic differences for 12 of the 16 occlusal features, with the plaster measurements being greater for 11 of these, indicating the digital model scans were not a true 11 representation of the plaster models. CONCLUSIONS: The repeatability of digital models compared with plaster models is satisfactory for clinical applications, although this study demonstrated some systematic differences. Digital study models can therefore be considered for use as an adjunct to clinical assessment of the occlusion, but as yet may not supersede current methods for scientific purposes.

Limited evidence for interceptive extraction of deciduous canines to prevent permanent canine impaction.

DATA SOURCES: PubMed, the Cochrane Library electronic databases and Scopus were searched. STUDY SELECTION: Randomised controlled trials (RCT), prospective and retrospective studies with untreated controls and clinical trials comparing at least two treatment strategies conducted in the mixed dentition with unilateral or bilateral PDC were included. DATA EXTRACTION AND SYNTHESIS: Three reviewers selected and extracted the data independently and evaluated the quality of the studies. Inter-examiner reliability was measured using the intraclass correlation coefficient (ICC). RESULTS: Owing to heterogeneity in the study methods and unequivocal results, the scientific evidence was too weak to evaluate the effect of interceptive treatment on PDC or which treatment modalities are most effective. The quality of the studies is low due to inadequate sample selection and deficient description of sample size, confounding factors, uncertainty of randomisation and no blinding in measurements. CONCLUSIONS: To obtain reliable scientific evidence as to whether interceptive treatment prevents impaction of PDC and which treatment modalities are the most effective, better controlled and well-designed RCTs are needed. Future studies should also include assessment of patient satisfaction and pain experience as well as analysis of the costs and side-effects of treatments.

Maxillary expansion as an interceptive treatment for impacted canines.

DESIGN: This was a randomised controlled trial. INTERVENTION: Patients 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 MEASURE: The main outcome was successful or unsuccessful eruption of the maxillary permanent canines. RESULTS: The 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). CONCLUSIONS: The 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.

The occlusal effects of digit sucking habits amongst school children in Northamptonshire (UK).

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.

Do lip bumpers work?

DATA SOURCES: Searches 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 SELECTION: The 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 SYNTHESIS: If two or more studies had evaluated the same technique, a meta-analysis was planned. RESULTS: A 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. CONCLUSIONS: The 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.

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 child's 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?

DESIGN: This was a national population-based case-control study in Norway. CASE AND CONTROL SELECTION: Cases 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 ANALYSIS: Data were collected using questionnaires. Crude odds ratios (OR) were calculated and adjustments for potential confounders (diet and multivitamins, mother's education, mother's employment during early pregnancy, smoking, alcohol consumption, and year of baby's birth) were made. RESULTS: Folic acid supplementation during early pregnancy (400 microg/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). CONCLUSIONS: Folic 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.

Long-term stability after orthodontic treatment remains inconclusive.

DATA SOURCES: PubMed and Cochrane Library electronic databases were searched from 1966 to January 2005. Reference lists of the relevant studies were searched by hand. STUDY SELECTION: For 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 SYNTHESIS: Screening 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. RESULTS: The 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. CONCLUSIONS: Despite 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.

More evidence required to establish link between premature birth and altered oral development.

DATA SOURCES: PubMed provided the primary data source with references from identified papers being reviewed to find additional studies. STUDY SELECTION: Reports were selected of controlled studies that provided quantitative data on the effects of premature birth on jaws, dentition, dental physiology and tooth anomalies, which were published in the English language. DATA EXTRACTION AND SYNTHESIS: Two independent evaluators extracted data describing the year of publication, definition of prematurity, sample size, material and age, methods and measurements, outcomes and authors' conclusions. Correlation between deformity/alteration and prematurity, intubation and sucking habit were considered. Methodological soundness was assessed and the quality of each article categorised as low, medium or high. RESULTS: A total of 13 articles met the inclusion criteria. Quality was judged to be high for three studies, medium for nine studies and low for a single study. The chosen studies described altered palatal morphology (n=5), altered dental maturation (n=5) and altered tooth-crown dimensions (n=3). The limited evidence suggests there may be a correlation between prematurity and altered palate morphology in the short term, with oral intubation as a contributing factor. If corrected age was considered no delay was found in maturation. CONCLUSIONS: This systematic review revealed contradictory results and a dearth of longitudinal studies in this subject area. Further well-designed controlled and longitudinal studies are required before any conclusions can be made regarding the consequences of premature birth on oral development.

Effectiveness of early orthodontic treatment with the Twin-block appliance: a multicenter, randomized, controlled trial. Part 2: Psychosocial effects.

The aims of this project were to evaluate whether early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion resulted in any psychosocial benefits. This multicenter trial was carried out in the United Kingdom, with 174 children aged 8 to 10 years with Class II Division 1 malocclusions randomly allocated to receive treatment with Twin-block appliances or to an untreated control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in an increase in self-concept and a reduction of negative social experiences. The subjects also reported treatment benefits that could be related to improved self-esteem. Further research is needed to determine the extent to which these effects translate into social behavior and experiences.