Validation of the complexity and treatment outcome components of the index of complexity, outcome, and need (ICON).

Occlusal indexes objectively quantify malocclusions. The index of complexity, outcome and treatment need (ICON) is a new index developed to measure several aspects of occlusion and treatment outcome. The purpose of this study was to test the validity of the ICON in measuring orthodontic complexity, outcome, and degree of improvement. Fifteen orthodontists evaluated 100 pairs of pretreatment and posttreatment study models for complexity, outcome, and degree of improvement. A calibrated examiner used ICON to score the casts. One month later, a random subset of 40 study casts was rescored by raters and the examiner for reliability testing. A simple kappa statistic was used to assess agreement between the scores from the expert panel and from the ICON examiner. Interrater agreement was moderate for complexity (kappa =.50), slight for outcome (kappa =.18), and poor for degree of improvement (kappa =.04). Reliability of the calibrated examiner was kappa =.90 for pretreatment and kappa =.83 for posttreatment casts. Agreement between the raters and the ICON scores was moderate for complexity (kappa =.52) and outcome (kappa =.50) and fair for degree of improvement (kappa =.27). ICON is valid for assessing cases for complexity and outcome. However, lack of agreement among the raters for degree of improvement and between the ICON-based evaluations and the orthodontists' evaluation of degree of improvement suggests that this component should be reexamined.     

Effectiveness of training dental students in two occlusal indices

The purpose of this study was to evaluate the ability of students in a U.S. dental school to learn and apply two indices of orthodontic need: the Index of Orthodontic Treatment Need (IOTN) and the Index of Complexity, Outcome, and Need (ICON). Dental students were randomly selected and separated into three groups: control, IOTN, and ICON. Each evaluated thirty casts that had previously been evaluated by a panel of thirteen orthodontists to develop a gold standard of orthodontic treatment need for these casts. Students re-evaluated the same thirty casts after IOTN and ICON training for their own group, while the control group did not receive any training. Logistic regression of pre- and post-training agreement with the gold standard was calculated for each group to create a clear quadratic relationship. Significant differences were not found between pre- and post-training evaluation for either the IOTN or the ICON groups as compared to the control. However, the IOTN group did show more improvement when compared with the ICON group. This study demonstrates that the use of the IOTN index improved assessment in predoctoral dental students to determine orthodontic treatment need.     

The reliability and validity of the Index of Complexity, Outcome and Need for determining treatment need in Dutch orthodontic practice

The Index of Complexity, Outcome and Need (ICON), based on international opinion, has been proposed as a multipurpose occlusal index. The aim of this study was to validate the ICON for treatment need in the Netherlands by relating it to Dutch orthodontic opinion. Furthermore, the reliability of this index was explored, for both a calibrated orthodontist and non-calibrated orthodontists. A sample of 102 patients was chosen which represented the actual distribution of severity of malocclusion experienced by orthodontists in every day practice. The ICON was scored, based on complete patients records of those 102 patients, by an examiner calibrated in the use of this index. The results were compared with the opinion about treatment need of seven Dutch orthodontists - the 'gold standard'. Nine non-calibrated orthodontists also scored the ICON for 49 patients. The intra-examiner agreement of both the non-calibrated and the calibrated orthodontists was moderate to high [0.52-0.86 and 0.89, respectively, measured with the Intraclass Correlation Coefficient (ICC)]. The inter-examiner agreement of the ICON score of the nine orthodontists was moderate measured with the single estimate of the ICC (0.60), and high measured with the average estimate (0.93). Spearman's correlation coefficient between the ICON score (calibrated) and the gold standard was sufficient: 0.78. The sensitivity and specificity were 1 and 0.36, respectively. The best compromise between sensitivity and specificity was at a cut-off point of 52, instead of the international ICON cut-off point of 43. There was a significant difference in ICON score between the non-calibrated orthodontists and the calibrated orthodontist, mainly based on the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). It can be concluded that the ICON needs to be adjusted when used to determine treatment need in the Dutch orthodontic population.     

A comparison of the reliability and validity of 3 occlusal indexes of orthodontic treatment need.

Several occlusal indexes are currently used to ascertain eligibility for orthodontic treatment. A comparison of 3 indexes of orthodontic treatment need was made with the consensus opinion of a panel of 15 experienced orthodontists. Sets of study casts (170) representing the full spectrum of malocclusions were selected. An examiner, calibrated in the Dental Aesthetic Index, the Handicapping Labiolingual Deviation with the California Modification, and the Index of Orthodontic Treatment Need, scored the casts. The panel of orthodontists individually rated the same casts for their degree of orthodontic treatment need. The mean rating of the panel on the need for treatment was used as the gold standard for evaluating the validity of the indexes. Intrarater and interrater reliability was high (kappa > 0.8). Overall accuracy of the indexes, as reflected in area under receiver-operating characteristic curves, was also high: Dental Aesthetic Index, 95%; Handicapping Labiolingual Deviation with the California Modification, 94%; and Index of Orthodontic Treatment Need, 98%. Cutoff points for the indexes that resulted in the closest agreement with the gold standard differed from the published cutoff points for the indexes. The indexes appear to be valid measures of treatment need as perceived by orthodontists. The published cutoff points for the indexes were more conservative in assigning patients for treatment than a panel of orthodontists. However, adjusting the cutoff points moved all 3 indexes into close agreement with the experts.     

A validation study of three indexes of orthodontic treatment need in the United States

Abstract The purpose of this study was to compare the reliability and validity of three occlusal indexes of orthodontic treatment need in predicting the opinion of treatment need of a panel of 18 orthodontists. A set of 160 study casts representing all types of malocclusion was used. The casts were scored with the following occlusal indexes: the Index of Orthodontic Treatment Need (IOTN), the Handicapping Labio-Lingual Deviations index (HLD), and the Handicapping Malocclusion Assessment Record (HMAR modified). The diagnostic accuracy or validity of each index was calculated using the mean opinion of the orthodontic raters as a “gold standard”. Receiver Operating Characteristic curves were plotted for each index. The overall diagnostic accuracy, as determined by percent area under the curve, was similar for each index: IOTN 98.6%; HLD 96.1%; HMAR 96.6%. The score optimizing the sensitivity and specificity relationship for each index was as follows: IOTN (dental health component) 4; HLD 13; HMAR 12. These results indicate that the three occlusal indexes provided valuable information for determining orthodontic treatment need.     

Efficacy of training dental students in the index of orthodontic treatment need.

Orthodontic studies over several decades have found generally inconsistent opinions among dentists when evaluating orthodontic treatment need. There has also been recent concern that dental school education does not sufficiently prepare dentists to diagnose malocclusion and make appropriate referrals of potential orthodontic patients. The purpose of this study was to investigate the efficacy of using the index of orthodontic treatment need (IOTN) as a tool to improve dental students' ability to assess orthodontic treatment need. Fourth-year dental students were randomly divided into control, sham-control, and experimental groups stratified for mean grade point average. On 2 occasions, the subjects evaluated 30 orthodontic study models with a gold standard previously established by an expert panel of 15 orthodontists for orthodontic treatment need. The experimental group reevaluated the models after IOTN instruction. Kappa statistics, sensitivity, and specificity were calculated for each subject. Analysis of covariance (ANCOVA) showed that the experimental group had significantly higher agreement with the expert panel after IOTN training than did either control group. IOTN is a promising teaching aid for improving educational outcomes for orthodontic referral.     

Commentary

Abstract

Objective: To design a new index categorizing the functional need for orthognathic treatment. Design: Laboratory-based study. Setting: Records were obtained from two UK hospital-based orthodontic departments. Participants: A panel of four consultant orthodontists, experienced in providing orthognathic care, devised a new index of Orthognathic Functional Treatment Need (IOFTN) with the aid of the membership of the British Orthodontic Society Consultant Orthodontists Group (COG). Twenty-three consultants and post-CCST level specialists took part in the study as raters to test the validity and reliability of the new index. Methods: A total of 163 start study models of patients who had previously undergone orthognathic treatment were assessed by the panel of four consultant orthodontists using the new index (IOFTN) and the agreed category was set as the ‘gold standard’. Twenty-one consultants and post-CCST level specialists then scored the models on one occasion and two scored 50 sets of models twice to determine the test–re-test reliability. Results: Kappa scores for inter-rater agreement with the expert panel for the major categories (1–5) demonstrated good to very good agreement (kappa: 0·64–0·89) for all raters. The percentage agreement ranged from 68·1 to 92% in all cases. Intra-rater agreement for the major categories was moderate to good (kappa: 0·53–0·80). Conclusions: A new index, the IOFTN, has been developed to help in the prioritization of severe malocclusions not amenable to orthodontic treatment alone. It demonstrates good content validity and good inter-rater and moderate to good intra-rater reliability. As a result of being an evolution of the IOTN, the familiar format should make it easy to determine functional treatment need within daily orthognathic practice.     

Evaluation of the peer assessment rating (PAR) index as an index of orthodontic treatment need.

The need for orthodontic treatment has an objective component based on occlusal traits and a subjective component based on the esthetic impact of the occlusion. An occlusal index that measures the objective deviation from normal or ideal occlusion might be sufficient to mirror the subjective opinion of orthodontists about treatment need. The objective of this study was to determine whether the American (US) and United Kingdom (UK) weightings of the peer assessment rating (PAR) index are valid instruments with which to determine treatment need. Fifteen orthodontists rated the need for orthodontic treatment of 170 casts. Their collective decision was compared with the PAR value for the cast determined by a calibrated examiner. A range of suggested treatment cutoff points from the literature was used to generate receiver operating characteristic (ROC) curves and optimized cutoff points. The cutoff points were 17 for both the US PAR and the UK PAR, and sensitivity, specificity, and kappa were 92%, 86%, and 0.77 for the US PAR and 92%, 89%, and 0.80 for the UK PAR. The area under the ROC curve was 97% for the US PAR and the UK PAR. Both the US PAR and the UK PAR scores were excellent predictors of orthodontic treatment need as determined by a panel of orthodontists. An occlusal index used to measure deviation from normal or ideal occlusion might perform as well as indexes of treatment need in predicting orthodontists' evaluations of treatment need.     

Evaluating the cost-effectiveness of orthodontic provision

The assessment of orthodontic provision is important to determine if treatment was necessary and undertaken appropriately. The ICON objectively quantifies orthodontic treatment need, complexity and outcome and is a valuable occlusal index in the assessment effectiveness of orthodontic care. It is possible to develop cost-effectiveness models by analysing the costs and effectiveness of orthodontic treatment. Several methods are illustrated to compare the orthodontic provision of specialist orthodontists.     

Inter-examiner variability in orthodontic treatment decisions for Danish children with 'borderline' treatment need

This study explored the variation between examiners in the orthodontic treatment need assessments of fifth-grade children with a borderline orthodontic treatment need. Each of three groups of children with borderline treatment need (n = 18, 19, and 19, respectively) were examined by one of three groups of orthodontists (33 in each group), whereby each of 56 children had 33 orthodontic treatment need assessments based on a clinical examination. This treatment need determination exercise was subsequently repeated with treatment need determined based on study casts and extraoral photographs. The proportion of positive treatment decisions based on the clinical examination was 49.3, 49.6, and 52.5 per cent, respectively, and 45.7, 46.3, and 50.5 per cent, based on the model assessments. There was a considerable disagreement between examiners in the treatment need assessments, whether assessments were based on a clinical examination or on a model-based case presentation. The average percentage agreement between two orthodontists for the treatment need based on clinical examination was 69, 66, and 61, respectively, corresponding to mean kappa values of 0.38, 0.32, and 0.22. When the model-based assessments were considered, the average percentage agreement between two orthodontists was 62, 58, and 69, respectively, corresponding to mean kappa values of 0.25, 0.16, and 0.37. Linear regression analysis of the orthodontists' treatment propensity as a function of their gender, place of education, years of orthodontic treatment experience, type of workplace, and place of work showed that only the orthodontic experience was influential for the model-based treatment propensity [β = 0.34 per cent/year (95 per cent confidence interval = 0.01-0.66)].     

正畸治疗难度、结果、需要指数的相关研究

正畸治疗难度、结果、需要指数(ICON)是由9个国家的97位正畸学者共同研究制定的指数,并于2001年正式提出,旨在通过对患者及其模型进行评价,评价患者的治疗需要、治疗难度、治疗的改善程度及治疗结果的可接受度等。近年来ICON在欧美国家得到了广泛的采用,然而国内尚无相关研究报道。本文就近年来对ICON的研究进展作一综述,并探讨该指数在国内应用的研究方向。     

The influence of cephalometrics on orthodontic treatment planning

Since its introduction, cephalometrics, i.e. cephalometric radiography and analysis, has been used for orthodontic treatment planning. However, the effectiveness of this diagnostic method remains questionable. A randomized crossover study was designed to assess the influence of cephalometrics in orthodontic treatment planning of individual patients. Diagnostic records of 48 subjects (24 males and 24 females aged 11-14 years) were divided in two stratified groups and assigned to one of two combinations: A, dental casts only, and B, dental casts, cephalometric radiographs, and analysis. The records were presented to 10 orthodontic postgraduates and four orthodontists for formulation of orthodontic treatment plans containing a dichotomous decision regarding the use of a functional appliance (FUNC), rapid maxillary expansion (RME), and extraction (EXTR). The combination of FUNC + RME + EXTR was used as the basis of the outcome measure. Agreement on orthodontic treatment planning using all possible comparisons of diagnostic records of individual patients (AB, AA, and BB) was assessed and overall proportions of agreement (OPA) were calculated for orthodontic postgraduates and orthodontists separately. Median OPA were 0.60 (AB), 0.65 (AA), and 0.60 (BB) for orthodontic postgraduates and 0.50 (AB), 0.75 (AA), and 0.50 (BB) for orthodontists. Irrespective of the level of experience, neither consistency of orthodontic treatment planning between both combinations of diagnostic records showed a statistically significant difference (P > 0.05) using Wilcoxon signed rank test nor did consistencies and agreement of orthodontic treatment planning after the addition of cephalometrics. It appears that cephalometrics are not required for orthodontic treatment planning, as they did not influence treatment decisions.     

Assessment of orthodontic treatment need: a comparison of study models and facial photographs

Abstract – Objectives: The current study aims to examine how orthodontic treatment need is prioritized depending upon whether dental study models or facial photographs are used as the means of assessment. Methods: A group of three orthodontists and three postgraduate orthodontic students assessed: (i) dental attractiveness; and (ii) need for orthodontic treatment in 40 subjects (19 males, 21 females). The 40 subjects displayed a range of malocclusions. Separate assessments were made from study models and facial photographs. Results: There was a bias towards higher scores for dental attractiveness from facial photographs compared with assessment of study casts, for all examiners. This was statistically significant for five of the six examiners (P = 0.001–0.101). The need for orthodontic treatment was rated as 20% higher from study models compared with facial photographs (P < 0.001); overall the level of need for orthodontic treatment was rated as 18.9% higher from study models compared with facial photographs (P < 0.001). Reproducibility analyses showed that there was a considerable variation in the intra‐ and inter‐examiner agreement. Conclusions: This study shows that a group of three orthodontists and three postgraduate students in orthodontics: (i) rated orthodontic treatment need higher from study models compared with facial photographs and; (ii) rated dental attractiveness higher from facial photographs compared with study models. It is suggested that the variable intra‐examiner agreement may result from the assessment of orthodontic treatment need and dental attractiveness in the absence of any specific assessment criteria. The poor reproducibility of assessment of orthodontic treatment need and dental attractiveness in the absence of strict criteria may suggest the need to use an appropriate index.     

Occlusal traits,orthodontic treatment need and treatment complexity among untreated 17–21-year-olds in Estonia

Objective: To analyze data on occlusal traits, orthodontic treatment need and treatment complexity in orthodontically untreated 17–21-year-old Estonians.

Materials and methods: Clinical records and plaster casts of 390 untreated young adults (219 females and 171 males, mean age 18.5 years, range 17–21 years) were analyzed. Assessed occlusal traits included first molar and canine sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite and scissor bite. The Index of Complexity, Outcome and Need (ICON) was used to assess orthodontic treatment need and complexity. Participants’ opinions regarding their teeth were determined with a questionnaire.

Results: The most prevalent occlusal traits were Class I sagittal relationship in canines (76%) and molars (70%), crowding (51%), overbite ≥3.5?mm (48%), the end-to-end sagittal relationship in canines (48%) and overjet ≥3.5?mm (47%). Antero-posterior asymmetry was common both in canines (39%) and molars (37%). According to ICON, 36% of participants had orthodontic treatment need.

Conclusions: Desire for orthodontic treatment was associated with crowding and increased overjet, and with no gender difference, participants’ main expectation of treatment was an improvement in dentofacial aesthetics. Treatment needs determined with ICON was moderate and in line with the participants’ desire for orthodontic treatment.     

Conference Report

Abstract

The criteria that dentists use to judge the need for orthodontic treatment are not clear. This study investigates variation in dentists' perception of orthodontic treatment need. Seventy-four dentists were asked to assess 320 dental casts in relation to aesthetic and dental health need. The results of this investigation revealed that the panel was divided as what constituted a need for orthodontic treatment on dental health grounds. It is suggested that one method of achieving a more uniform evaluation of orthodontic treatment need is the use of an occlusal index. Until an occlusal index is accepted and used by the profession, the distortion of need and demand for orthodontic treatment by dentists' unequal perceptions will continue.     

The effectiveness of phase I orthodontic treatment in a Medicaid population.

BACKGROUND: The effectiveness of early orthodontic treatment for Medicaid-enrolled children in the mixed dentition was assessed and compared with results in a population of private-pay patients. MATERIAL: Pre- and posttreatment casts from 196 subjects treated with interceptive orthodontics in the mixed dentition were evaluated by using the peer assessment rating (PAR) index and the index of complexity, outcome, and need (ICON). Ninety-six of the patients were treated at Odessa Brown Community Clinic in Seattle; their treatment was paid by Medicaid. One hundred private-pay patients were treated at the University of Washington graduate orthodontic clinic. The Medicaid and private-pay populations were comparable with respect to initial severity of malocclusion, as assessed by both indexes. RESULTS: PAR and ICON scores fell by similar amounts in the Medicaid (44.1% and 37.5%, respectively) and private-pay (46.8% and 37.3%, respectively) populations. Thus, the groups exhibited similar degrees of improvement with interceptive orthodontic treatment. According to the PAR and ICON, midline discrepancy, overjet, and esthetics exhibited the greatest improvement. The Medicaid population missed significantly more appointments and had poorer oral hygiene than the private-pay group, but these factors did not appear to worsen the outcomes, as measured by the 2 indexes. An appliance with 2 bands and 4 brackets was the most commonly used, and it produced the most significant treatment effect. CONCLUSIONS: Phase I orthodontic treatment significantly reduces malocclusion severity in Medicaid and private-pay populations. There was no difference in initial severity or final outcome, as assessed by the PAR and ICON, between Medicaid and private-pay populations. The degree of improvement in PAR scores did not appear to be associated with compliance.     

正畸治疗指数间的一致性研究

目的:观察不同的正畸治疗指数评价正畸治疗需要的一致性。方法:随机选取220副正畸记存模型,采用常用的4种指数评估这些模型是否需要正畸治疗,并对结果的一致性进行分析。结果:不同的指数鉴定出有不同数量的模型需要正畸治疗(31.6%~85.9%),各指数间的判断结果有显著但弱的相关性,各指数间的一致性较低。结论:采用不同的指数会有不完全相同的结果。     

Eligibility for publicly funded orthodontic treatment determined by the handicapping labiolingual deviation index

INTRODUCTION: Access to orthodontic care for Medicaid patients has been limited, in part because of orthodontists' reluctance to treat severe malocclusions for low reimbursements. Limited orthodontic treatment in the mixed dentition (phase 1 treatment) has been proposed to address this issue, because the intent of phase 1 treatment is to improve or prevent severe malocclusions. Orthodontists might be more willing to provide shorter, simpler treatment. The purpose of this study was to determine whether phase 1 treatment would reduce malocclusion severity to the extent that eligibility for subsequent Medicaid-funded treatment was significantly reduced. METHODS: Eligibility was determined by the handicapping labiolingual deviation (HLD) index, which is used by several states for this purpose. Eligibility was also determined with the index of complexity, outcome, and need (ICON). This allowed us to compare these 2 indexes. Pre-phase 1 and post-phase 1 index scores were calculated by using study casts from 193 patients treated at the University of Washington orthodontic clinic and the Odessa Brown Children's Dental Clinic, both in Seattle. RESULTS: Using the HLD index, we found that eligibility for orthodontic treatment decreased by 62% after phase 1 treatment. This change was statistically significant at P < .0001. The ICON found significantly more treatment need before phase 1 (90%) than did the HLD index (35%) (P < .0001). CONCLUSIONS: Early interceptive treatment significantly reduces eligibility for comprehensive Medicaid-funded orthodontic treatment. The HLD index is a useful tool for determining Medicaid eligibility.     

Measuring failure of orthodontic treatment: a comparison of outcome indicators

OBJECTIVE: To compare treatment failure rates on a sample of completed and discontinued orthodontic treatment cases as measured by PAR, IOTN and ICON to determine whether the use of a sole index would suffice. SUBJECTS AND METHOD: All patients completing or discontinuing orthodontic treatment in the hospital orthodontic departments in the Northern Region during two calendar months were identified and pre and post-treatment models were analysed. PAR scores, IOTN (DHC and AC) and ICON were recorded. RESULTS: One-hundred-and-forty-five cases were identified and 15 had incomplete records on the day of analysis. The final sample was therefore 130. The overall treatment discontinuation rate of these 130 patients was 24.6%. The treatment failure rate with respect to occlusal improvement varied from 3.1% when measured by PAR and 10.0% using ICON. With respect to residual need it varied from 0.77 to 20.1% with respect to IOTN depending on the criteria examined. The residual treatment need with respect to ICON was 17.2%. CONCLUSIONS: Different occlusal indices give differing failure rates when used on the same patients with ICON being the most critical index. We felt that ICON was the most valid with respect to identifying treatment failure. Its use would enable international comparison of results.