Quantifying plaque during orthodontic treatment:.

OBJECTIVE: To evaluate the literature on different methods of scoring plaque in patients with fixed orthodontic appliances. MATERIALS AND METHODS: A systematic electronic and hand search using MEDLINE and PubMed was conducted. RESULTS: Most orthodontic trials have used the original Silness and Löe plaque index. Indices vary in several potentially important aspects. Only two papers have reported reproducibility of methods of plaque scoring in orthodontic patients. CONCLUSION: Some plaque indices are inappropriate for orthodontic patients. Newer digital planimetric methods are promising if more complex. There is a need to further assess the reproducibility and practicability of the advocated methods.

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.

Which way forward? Fixed or removable lower retainers.

OBJECTIVE: To determine whether lower lingual, canine to canine, bonded multistrand retainers prevent relapse of lower labial segment alignment following fixed appliance therapy and to compare this with lower Hawley-type removable retainers. MATERIALS AND METHODS: Two groups of 29 patients were identified. Group 1 had bonded lower canine to canine multistrand retainers placed following debonding, whereas Group 2 had lower Hawley-type retainers (with acrylic labial to the incisors) fitted following debonding. Study models were taken of all patients at debonding (T(1)) and at least 1 year post debonding (T(2)). Changes in Little's index over the study period were recorded using a reflex microscope. RESULTS: Statistically significant changes in Little's index occurred in the lower labial segment of both study groups (P = .001) over the observation period. There was no statistically significant difference in the amount of change in Little's index between the bonded and removable retainer groups (P = .13). Bonded retainers tended to be placed in older patients (P = .02). CONCLUSIONS: Relapse can occur in the lower labial segment with both fixed and removable retainers. The amount of relapse seen with both types of retainer is not statistically significantly different.

Tooth size discrepancies in an orthodontic population.

OBJECTIVE: To explore how many millimeters of tooth size discrepancy (TSD) are clinically significant, to determine what percentage of a representative orthodontic population has such a tooth size discrepancy, and to determine the ability of simple visual inspection to detect such a discrepancy. MATERIALS AND METHODS: The sample comprised 150 pretreatment study casts with fully erupted and complete permanent dentitions from first molar to first molar, which were selected randomly from 1100 consecutively treated white orthodontic patients. The mesiodistal diameter tooth sizes were measured using digital calipers, and the Bolton analysis and the tooth size corrections were calculated by the Hamilton Arch Tooth System (HATS) software. Simple visual estimation of Bolton discrepancy was also performed. RESULTS: In the sample group 17.4% had anterior tooth-width ratios and 5.4% had total arch ratios greater than 2 of Bolton's standard deviations from Bolton's mean. For the anterior analysis, correction greater than +/- 2 mm was required for 16% of patients in the upper arch or 9% in the lower arch. For the total arch analysis, the corresponding figures are 28% and 24%. CONCLUSIONS: It is recommended that 2 mm of required tooth size correction is an appropriate threshold for clinical significance. A significant percentage of patients have a TSD of this size. Visual estimation of TSD has low sensitivity and specificity. Careful measurement is more frequently required in clinical practice than visual estimation would suggest.

A cephalometric study of Class II malocclusions treated with mandibular surgery.

INTRODUCTION: Class II malocclusion is often associated with retrognathic mandible. Some of these problems require surgical correction. The purposes of this study were to investigate treatment outcomes in patients with Class II malocclusions whose treatment included mandibular advancement surgery and to identify predictors of good outcomes. METHODS: Pretreatment and posttreatment cephalometric radiographs of 90 patients treated with mandibular advancement surgery by 57 consultant orthodontists in the United Kingdom before September 1998 were digitized, and cephalometric landmarks were identified. Paired samples t tests were used to compare the pretreatment and posttreatment cephalometric values for each patient. For each cephalometric variable, the proportion of patients falling within the ideal range was identified. Multiple logistic regression analysis was performed to identify predictors of achieving ideal range outcomes for the key skeletal (ANB and SNB angles), dental (overjet and overbite), and soft-tissue (Holdaway angle) measurements. RESULTS: An overjet within the ideal range of 1 to 4 mm was achieved in 72% of patients and was more likely with larger initial ANB angles. Horizontal correction of the incisor relationship was achieved by a combination of 75% skeletal movement and 25% dentoalveolar change. An ideal posttreatment ANB angle was achieved in 42% of patients and was more likely in females and those with larger pretreatment ANB angles. Ideal soft-tissue Holdaway angles (7 degrees to 14 degrees ) were achieved in 49% of patients and were more likely in females and those with smaller initial SNA angles. Mandibular incisor decompensation was incomplete in 28% of patients and was more likely in females and patients with greater pretreatment mandibular incisor proclination. Correction of increased overbite was generally successful, although anterior open bites were found in 16% of patients at the end of treatment. These patients were more likely to have had initial open bites. CONCLUSIONS: Mandibular surgery had a good success rate in normalizing the main dental and skeletal relationships. Less ideal soft-tissue profile outcomes were associated with larger pretreatment SNA-angle values, larger final mandibular incisor inclinations, and smaller final maxillary incisor inclinations. The use of mandibular surgery to correct anterior open bite was associated with poor outcomes.

Class III surgical-orthodontic treatment: a cephalometric study.

INTRODUCTION: In this retrospective study, we investigated treatment outcomes in Class III surgical-orthodontic patients. METHODS: Records of 151 consecutively completed Class III surgical-orthodontic patients (overjet, 0 mm or less) were obtained from 87 consultant orthodontists in the United Kingdom. Pretreatment and posttreatment cephalometric radiographs were analyzed. RESULTS: Bimaxillary surgical patients (75%) had more negative initial ANB-angle values and smaller initial SNA-angle values than those treated with single-jaw mandibular surgery. Mandibular surgery patients (15%) had greater pretreatment mandibular prominence (SNB angle) than maxillary patients. Maxilla-only patients (10%) had lower negative initial overjet values than bimaxillary patients. An overjet within the ideal range of 1 to 4 mm was achieved in 83% of the patients. Logistic regression identified no predictors of ideal overjet outcome. SNB angle was corrected to within the ideal range of 75 degrees to 81 degrees in 44% of the patients. This was less likely in those treated with maxillary surgery only and larger initial SNB-angle values. An ideal posttreatment ANB angle (1 degrees to 5 degrees) was achieved in 40% of the patients and was more likely in those with bimaxillary surgery, lower negative pretreatment ANB angles, and presurgical orthodontic extractions in the maxillary arch. Ideal posttreatment unadjusted Holdaway angles (7 degrees to 14 degrees) were achieved in 59% of the patients and were more likely when single-jaw mandibular surgery was used. Incisor decompensation was incomplete in 46% of the patients and was associated with mandibular arch extractions. CONCLUSIONS: Surgical-orthodontic treatment had a high success rate in normalizing the overjet and soft-tissue profile to within ideal ranges in Class III patients. Bimaxillary surgery was the most frequently used procedure and was associated with an increased likelihood of an ideal correction of the anteroposterior skeletal discrepancy.

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.

Effectiveness of early orthodontic treatment with the Twin-block appliance: a multicenter, randomized, controlled trial. Part 1: Dental and skeletal effects.

This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance 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 reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant.

Effectiveness of treatment for Class II malocclusion with the Herbst or twin-block appliances: a randomized, controlled trial.

The aim of this study was to evaluate the effectiveness of Herbst and Twin-block appliances for established Class II Division I malocclusion. The study was a multicenter, randomized clinical trial carried out in orthodontic departments in the United Kingdom. A total of 215 patients (aged 11-14 years) were randomized to receive treatment with either the Herbst or the Twin-block appliance. Treatment with the Herbst appliance resulted in a lower failure-to-complete rate for the functional appliance phase of treatment (12.9%) than did treatment with Twin-block (33.6%). There were no differences in treatment time between appliances, but significantly more appointments (3) were needed for repair of the Herbst appliance than for the Twin-block. There were no differences in skeletal and dental changes between the appliances; however, the final occlusal result and skeletal discrepancy were better for girls than for boys. Because of the high cooperation rates of patients using it, the Herbst appliance could be the appliance of choice for treating adolescents with Class II Division 1 malocclusion. The trade-off for use of the Herbst is more appointments for appliance repair.