Weighted Peer Assessment Rating Research Articles

Evaluation of effectiveness and efficiency of fixed orthodontic treatment comparing standard and computer-aided design and manufacturing conventional bracket systems using indirect bonding for both: A retrospective study

To compare the effectiveness and efficiency of orthodontic treatment (OT) with standard versus computer-aided design and computer-aided manufacturing (CAD/CAM) indirect bonding of conventional brackets. This retrospective study examined two groups: standard indirect bonding group (12 males, 13 females; mean age 12.21 ± 0.52 years), and digital indirect bonding group (11 males, 14 females; mean age 12.76 ± 1.32 years), treated via a CAD/CAM indirect bonding system. Conventional brackets were used in both groups. Pretreatment and post-treatment records were acquired for all subjects. Weighted Peer Assessment Rating (W-PAR) index was used to assess the effectiveness of OT, in conjunction with five angular cephalometric measurements (ANB°, Sn-GoGn°, U1-PP°, IMPA° and FMA°) and comparatively analyzed using generalized mixed-effects models and post hoc test. Treatment efficiency was assessed in terms of the numbers of bracket repositionings, archwire bends, accidental bracket debondings, appointments and treatment months. Comparative analysis of efficiency was performed using the asymptotic Wilcoxon-Mann-Witney test. Statistical significance was set at 5%. Total W-PAR and W-PAR component scores decreased significantly during treatment for both groups and in a similar way. Cephalometric measures ANB° and IMPA° significantly decreased and increased, respectively. Significantly fewer bracket repositionings, number of appointments and treatment months were recorded in group digital indirect bonding. Although both methods investigated were effective to achieve good outcomes, CAD/CAM indirect bonding method increased the efficiency of OT, when conventional brackets are used.

Cancer survivors present significantly lower long-term stability of orthodontic treatment: a prospective case-control study.

SummaryBackground/ObjectivesThe aim of the study was to compare the stability of orthodontic treatment in cancer survivors who had been treated with cytotoxic drugs with a generally healthy control group.Materials/MethodsThe study included 52 cancer survivors treated orthodontically and 52 healthy control subjects matched for age, gender, and malocclusion. The weighted Peer Assessment Rating (w-PAR) index, the Index of Complexity, Outcome and Need (ICON) were assessed before treatment, after the treatment, and at the 3-year follow-up. Patients Satisfaction Score was assessed after the treatment and at the 3-year follow-up. A repeated analysis of variance test was used to check the statistical significance between the scores.ResultsIdeal occlusion was achieved in all patients. The mean w-PAR and ICON values were significantly reduced in both groups after the end of the orthodontic treatment with no significant differences between the groups regarding the obtained results. However, after the 3-year follow-up, only the cancer survivors’ group presented statistically significant (P < 0.001) increase of the w-PAR and ICON values comparing to the values obtained at the end of the treatment. There was no significant change in Patients’ Satisfaction Score within 3 years after treatment.LimitationsThe limited size of the study sample as well as different types of oncological diagnoses could have had an impact on the final results of the study.Conclusions/ImplicationsPrevious cytotoxic drug treatment significantly decreases the stability of orthodontic treatment among the cancer survivors, particularly within first 12 months after the end of the treatment.

Class II Division 1 malocclusion treatment with extraction of maxillary first molars: Evaluation of treatment and post-treatment changes by the PAR Index.

ObjectiveTo investigate occlusal result and post‐treatment changes after orthodontic extraction of maxillary first permanent molars in patients with a Class II division 1 malocclusion.Setting and SampleRetrospective longitudinal study in a private practice, with outcome evaluation by an independent academic hospital. Ninety‐six patients (53 males, 43 females) consecutively treated by one orthodontist with maxillary first permanent molar extraction were studied, divided into three facial types, based on pre‐treatment cephalometric values: hypodivergent (n = 18), normodivergent (n = 21) and hyperdivergent (n = 57).MethodsOcclusal outcome was scored on dental casts at T1 (pre‐treatment), T2 (post‐treatment) and T3 (mean follow‐up 2.5 ± 0.9 years) using the weighted Peer Assessment Rating (PAR) Index. The paired sample t test and one‐way ANOVA followed by Tukey's post hoc test were used for statistical analysis.ResultsPAR was reduced by 95.7% and 89.9% at T2 and T3, respectively, compared with the start of treatment. The largest post‐treatment changes were found for overjet and buccal occlusion. Linear regression analysis did not reveal a clear effect (R‐Square 0.074) of age, sex, PAR score at T1, incremental PAR score T2‐T1, overjet and overbite at T1, and facial type on the changes after treatment (incremental PAR score T3‐T2).ConclusionsThe occlusal outcome achieved after Class II division 1 treatment with maxillary first permanent molar extractions was maintained to a large extent over a mean post‐treatment follow‐up of 2.5 years. Limited changes after treatment were found, for which no risk factors could be discerned.

Changes in orthodontic occlusal indices after semi-rapid maxillary expansion

ObjectivesTo quantify malocclusion complexity changes after semi-rapid maxillary expansion. Materials and methodThe study sample consisted of pre- and postexpansion dental models and frontal intraoral photographs of 195 consecutive patients treated for maxillary expansion using a removable plate and a semi-rapid screw activation protocol. Differences between the pre- and posttreatment scores of the weighted Peer Assessment Rating Index (PAR), dental health component (DHC), aesthetic component (AC) of Index of Orthodontic Treatment Need (IOTN), and Discrepancy Index (DI) were analyzed. ResultsThe intraclass correlation coefficient test to assess the intraobserver error in PAR index and DI was performed and the value was found to be more than 0.80. The kappa score of 0.923 and 0.926 was observed in DHC and AC indices of IOTN, respectively, suggesting a good intraobserver agreement of scores. The pre- and postexpansion mean values in all the indices showed a significant reduction (P < 0.001). The IOTN-DHC, PAR, IOTN-AC, and DI scores showed improvements in 87.2%, 81.6%, 80.5%, and 72.8% of the subjects, respectively. The percentage change in the scores was maximum for IOTN-DHC (−27.8%) followed by PAR (−23.3%). IOTN-AC and DI showed approximately 20% improvement each. More than 25% improvement in scores was seen in 47% to 82% of the subjects. ConclusionThe study suggests that there is a significant decrease in orthodontic treatment need and treatment complexity after semi-rapid maxillary expansion treatment.

Dental compensation for skeletal Class III malocclusion by isolated extraction of mandibular teeth. Part 1: Occlusal situation 12 years after completion of active treatment.

The purpose of this work was to statistically evaluate the outcomes achieved by isolated extraction of mandibular teeth (second premolars or first molars) for Class III compensation. Part A of the study dealt with the quality of outcomes at the end of active treatment, using weighted Peer Assessment Rating (PAR) scores determined on the basis of casts for 25 (14 female and 11 male) consecutive patients aged 16 ± 1.7 years at the time of debonding. These results were compared to the scores in a randomly selected control group of 25 (14 female and 11 male) patients who were 14.7 ± 1.9 years old at debonding. Part B evaluated the long-term stability of the outcomes based on 12 (all of them female) patients available for examination after a mean of 11.8 years. The mean weighted PAR scores obtained in both study parts were analyzed for statistical differences using a two-tailed paired Student's t-test at a significance level of p ≤ 0.05. Mean weighted PAR scores of 4.76 ± 3.94 and 3.92 ± 3.44 were obtained in the Class III extraction group and the control group, respectively, at the end of active treatment. This difference was not significant (p = 0.49). Among the 12 longitudinal patients, the mean score increased from 4 ± 3.46 at debonding to 6.25 ± 3.67 by the end of the 11.8-year follow-up period. This difference was significant (p = 0.0008). Treatment of Class III anomalies by isolated extraction of lower premolars or molars can yield PAR scores similar to those achieved by standard therapies. These scores, while increasing significantly, remained at a clinically acceptable level over 11.8 years. Hence this treatment modality--intended for cases that border on requiring orthognathic surgery--may also be recommended from a long-term point of view.

Correction of Class II, Division 2 malocclusions using a completely customized lingual appliance and the Herbst device

The purpose of the present study was to examine the efficiency of correcting a ClassII, Division2 malocclusion using a completely customized lingual appliance. In 18 consecutively completed, ClassII, Division2 malocclusion patients, the correction of the upper incisor inclination, deep and distal bite were assessed by means of plaster casts, digital lateral cephalograms, and intraoral photographs taken at the time of debond. Furthermore, two independent calibrated examiners determined the weighted Peer Assessment Rating index (PAR Index) of the initial and end models. All ClassII, Division2 patients were treated successfully: upper incisor inclination using the palatal plane as a reference improved on average from 95.4° to 111.2°. The deep bite was reduced on average from 3.6mm to 1.7mm. Neutral occlusion was achieved in all patients who had undergone correction of an initially pronounced distal occlusion (4.5mm on average). An 86.2% marked improvement was observed in the weighted PAR index score from an average of 24.7 at the beginning of treatment to 2.9 at the end of treatment, with no patient classified as "worse or no different." ClassII, Division2 malocclusions can be efficiently and reliably treated by a combination of a completely customized lingual appliance and the Herbst device.

Mixed longitudinal evaluation of masticatory performance in children 6 to 17 years of age

The purposes of this study were to determine (1) how masticatory performance changes with age, (2) whether masticatory performance differs between the sexes, and (3) whether patterns of masticatory performance differ among subjects with various types of malocclusion. A total of 450 children and adolescents (244 boys, 206 girls) were assigned to 4 age cohorts (ages 6, 9, 12, and 15 years) and followed for 3 consecutive years. The subjects were selected based on having about equal numbers of boys and girls, and about equal numbers of subjects with normal occlusion and Class I and Class II malocclusions. Masticatory performance was assessed by using the artificial food CutterSil (Heraeus Kulze, South Bend, Ind). The peer assessment rating index was used to quantify the severity of the malocclusions. Median particle size (MPS) decreased significantly from 6 to 17 years of age. There were no statistically significant differences in MPS between the 3 occlusal groups, but there were significant sex differences, with girls having smaller MPS than boys. Multilevel analysis showed greater decreases in MPS between 6 and 9 years, and after 12 years of age, than between 9 and 12 years of age. There were no significant correlations between MPS and the weighted peer assessment rating index. MPS showed significant intercorrelations between measures of MPS obtained at years 1, 2, and 3, with correlations tending to be highest for the oldest age cohort. Masticatory performance improves with age, and the changes appear to be influenced by the loss of the deciduous teeth during the late mixed dentition phase of dental development. Although there are limited sex differences in masticatory performance among subjects 6 to 17 years of age, mild forms of Class I and Class II malocclusions have little or no effect on masticatory performance.

The long-term benefits of orthodontic treatment

Objective This study aimed to evaluate post-treatment changes at least five years out of retention in a cohort of 100 consecutively started patients treated by a postgraduate student in a UK orthodontic department. Design Analysis of study models using recognised occlusal indices. Setting Patients initially treated at Newcastle Dental Hospital were recalled for record collection. Materials and methods Study models and clinical photographs were taken for each patient attending for post-retention records. Weighted Peer Assessment Rating (PAR) Index and Index of Orthodontic Treatment Need (IOTN) scores were recorded for cases at the beginning, end and at least 5 years post-retention. Main outcome measures Post-treatment changes were evaluated using PAR Index and IOTN to evaluate extent and likelihood of change and to compare treatment modalities. Results Seventy-eight patients attended for post-retention records. Overall PAR reduction immediately post-treatment was 68.6% and at a mean of 6.5 years post-retention was 55.5%. Dual arch fixed appliance treatments achieved the greatest reduction in PAR score, and maintained the reduction beyond the retention period better than other treatment modalities. Eighty-four per cent of the cohort still had some demonstrable improvement after a mean of 6.5 years post-retention. There was a residual need for treatment in 8% of cases on aesthetic grounds and in 24% of cases on dental health grounds. Conclusions Occlusal deterioration after orthodontic treatment is almost universal. Dual arch fixed appliance treatment provides the best post-treatment and post-retention result.

How long does orthodontic treatment last?

Objective This study aimed to evaluate post-treatment changes at least five years out of retention in a cohort of 100 consecutively started patients treated by a postgraduate student in a UK orthodontic department. Design Analysis of study models using recognised occlusal indices. Setting Patients initially treated at Newcastle Dental Hospital were recalled for record collection. Materials and methods Study models and clinical photographs were taken for each patient attending for post-retention records. Weighted Peer Assessment Rating (PAR) Index and Index of Orthodontic Treatment Need (IOTN) scores were recorded for cases at the beginning, end and at least 5 years post-retention. Main outcome measures Post-treatment changes were evaluated using PAR Index and IOTN to evaluate extent and likelihood of change and to compare treatment modalities. Results Seventy-eight patients attended for post-retention records. Overall PAR reduction immediately post-treatment was 68.6% and at a mean of 6.5 years post-retention was 55.5%. Dual arch fixed appliance treatments achieved the greatest reduction in PAR score, and maintained the reduction beyond the retention period better than other treatment modalities. Eighty-four per cent of the cohort still had some demonstrable improvement after a mean of 6.5 years post-retention. There was a residual need for treatment in 8% of cases on aesthetic grounds and in 24% of cases on dental health grounds. Conclusions Occlusal deterioration after orthodontic treatment is almost universal. Dual arch fixed appliance treatment provides the best post-treatment and post-retention result.

Orthodontic treatment outcome in a First Nations population in Alberta, Canada: A comparative study

The primary objective of this study was to determine whether there was a significant difference in the degree of improvement after orthodontic treatment between a sample of First Nations orthodontic patients and a control sample of non-First Nations orthodontic patients. The secondary objective was to determine whether there was a difference in the severity of malocclusions being treated in a sample of the First Nations patients compared with a control sample of the non-First Nations patients. Several factors that might affect treatment outcome, such as missed appointments, treatment duration, oral hygiene, extractions, dental classification, and geographic location, were also studied. A sample of 60 First Nations patients and a control group of 60 non-First Nations patients between the 11 and 18 years of age who had been treated with full fixed orthodontic appliances were evaluated. The weighted peer assessment rating (PAR) index was applied to pretreatment and posttreatment study models to address the study's main objectives. The results showed that the First Nations group had greater PAR scores pretreatment than did the controls, and their weighted PAR scores improved more with treatment. Posttreatment PAR scores were similar between the 2 groups. In addition to First Nations status, only extractions and geographic location affected PAR improvement scores. (Am J Orthod Dentofacial Orthop 2002;121:396-402)

Occlusal outcome in patients undergoing orthognathic surgery with internal fixation

Fifty consecutive patients undergoing orthognathic surgery with internal fixation (IF) were studied retrospectively with a weighted Peer Assessment Rating (PAR) Index to assess occlusal outcome at the end of all active treatment, and compared with 50 patients who had undergone treatment for malocclusion by orthodontic means alone. In the surgically treated patients, the mean percentage reduction in the weighted PAR Index was 83% and 31 out of 38 patients (82%) were ‘greatly improved’. This implies a high standard of treatment in terms of the occlusal outcome. There was no difference in the proportion of patients having a final weighted PAR Index of less than 10 and no significant difference in the final weighted PAR Index between the two groups. This suggests that the occlusal outcome is no different whether patients undergo orthognathic surgery or orthodontic treatment alone, and that excellent occlusal results can be achieved in patients undergoing orthognathic surgery with internal fixation.

Assessment of biological changes in a nonorthodontic sample using the PAR index

The aim of the present study was to assess the effect of normal growth and development on the Peer Assessment Rating index between 12 and 22 years of age. The sample consisted of 49 nonorthodontic subjects (24 male and 25 females) from the Nijmegen Growth Study. The mean age at the first observation was 12.2 ± 0.7 years and at the second observation 22.1 ± 0.6 years. The dental casts at these ages were scored with the Peer Assessment Rating index. The influence of the Angle classification and the treatment need on changes over time in the Peer Assessment Rating score were evaluated. The mean changes in the PAR scores over time between cases that have more than 30% improvement to those that have less than 30% improvement were calculated. The results indicate that there were no significant differences between the mean Peer Assessment Rating score at 12 years of age (12.20 ± 0.91) and at 22 years of age (12.45 ± 1.28), but there were relevant differences in individual cases. The changes were irrespective of the Angle classification or the treatment need. Changes over time in the weighted Peer Assessment Rating score were mainly correlated to changes in the anterior crossbite and the overjet. This correlation may be influenced, however, by the applied weighting factor for those occlusal traits. (Am J Orthod Dentofacial Orthop 1998;114:224-228)

Associations between changes in selected facial dimensions and the outcome of orthodontic treatment

The purpose of this study was to determine, in children with Class II, Division I malocclusion who were treated with functional appliances, the strength of the associations between the changes over 18 months in selected facial dimensions and the success of orthodontic treatment as determined by the weighted Peer Assessment Rating (PAR). Forty-two children, between 10 and 13 years of age (mean age 11.6 years), were randomly assigned to either an untreated group (control) or a group treated with either a Fränkel function regulator or Harvold activator (treatment). The outcome of treatment was assessed on study models and the craniofacial changes were measured on lateral cephalometric radiographs. Correlation coefficients were then calculated between the differences in the cephalometric variables over 18 months and the differences in the PAR scores. In the treatment group, the effects of normal growth were held constant by partial correlation. The partial used was the change in both stature and weight. Significant positive partial correlations were found between the increases in total anterior face height, posterior face height, S-Pg, and treatment success. Significant negative partial correlations were found between downward movement of the maxilla and mandibular body and lower anterior face height and treatment success. It is postulated that these associations occurred mainly in response to the bite opening by the appliances. Treatment success was also significantly associated with maxillary restriction, an increase in the SNB angle and a reduction in the ANB angle. Changes in B point due to proclination of the mandibular incisors were considered to be responsible for the two latter significant associations. Although mandibular length increased significantly in the treatment group, as compared with the control group, it was not significantly associated with treatment success. (Am J Orthod Dentofac Orthop 1996;110:46-53.)

Specialist orthodontics in the General Dental Service.

This study investigated treatment times and treatment standards produced by 10 specialist orthodontic practitioners working in the General Dental Service (GDS) in England. Twenty cases from each practitioner, consecutively completed with two-arch fixed appliance therapy, were selected and assessed to evaluate treatment times and treatment standards. Observer-generated timings were recorded to provide values for the time taken by these practitioners to perform the various component activities associated with fixed appliance orthodontic therapy. These timings were then pooled to produce an 'average' value for each procedure. Treatment time was assessed retrospectively by applying these average times to the appropriate appointments, as documented on the patient's record card. The treatment duration, number of visits, appliance type and extraction regime were also recorded. Treatment standards were assessed by applying the weighted Peer Assessment Rating Index (PAR Index) to pre- and post-treatment study casts. Relationships between each of these variables were investigated using multiple regression analysis. No relationship was found between treatment time and PAR score change. Predictors of treatment time were the number of visits, and more interestingly, the use of extra-oral forces. However, no useful predictors of the treatment standard were found. On the basis of this sample, it appears that when specialist orthodontic practitioners in the GDS provide two-arch fixed appliance therapy: treatment is completed, on average, in 3-5 hours of chairside time, in 20 visits, spread over 22 months; they provide a high standard of treatment, as assessed by the PAR Index, to a caseload of patients in need to treatment.