Discrepancy Index Scores Research Articles

Accuracy of digital American Board of Orthodontics Discrepancy Index measurements.

A digital analysis that is shown to be accurate will ease the demonstration of initial case complexity. To date, no literature exists on the accuracy of the digital American Board of Orthodontics Discrepancy Index (DI) calculations when applied to pretreatment digital models. Plaster models were obtained from 45 previous patients with varying degrees of malocclusion. Total DI scores and the target disorders were computed manually with a periodontal probe on the original plaster casts (gold standard) and digitally using Ortho Insight 3D (Motion View Software, Hixson, Tenn) and OrthoCAD (Cadent, Carlstadt, NJ). Intrarater and interrater reliabilities were assessed for 15 subjects using the Spearman rho correlation test. Accuracies of the DI scores and target disorders were assessed for all 45 subjects using Wilcoxon signed ranks tests. Intrarater and interrater reliabilities were high for total DI scores and most target disorders (r>0.8). No significant difference was found between total DI score when measured with OrthoCAD compared with manual calculations. The total DI scores calculated by Ortho Insight 3D were found to be significantly greater than those by manual calculation by 2.71 points. The findings indicate that a DI calculated by Ortho Insight 3D may lead the clinician to overestimate case complexity. OrthoCAD's DI module was demonstrated to be a clinically acceptable alternative to manual calculation of the total scores.

Relationship between pretreatment case complexity and orthodontic clinical outcomes determined by the American Board of Orthodontics criteria

To evaluate the relationship between pretreatment case complexity and orthodontic treatment outcomes. The total sample contained 1693 cases (853 females and 840 males, mean age = 16.3 years) from the archives of postgraduate orthodontic clinics. The complexity of each case was evaluated using the American Board of Orthodontics (ABO) Discrepancy Index (DI), and orthodontic clinical outcomes were evaluated using the ABO Objective Grading System (OGS). Only one investigator evaluated all cases. Multivariate analysis of variance, correlation analysis, and multiple variable regression analysis were used for statistical evaluation (P < .05 as significant). The mean total DI score was 16.2, and the mean total OGS score was 18. No significant correlation was found between the total DI and the total OGS scores. However, pretreatment overbite, lateral open bite, crowding, buccal posterior crossbite, and other components affected the total OGS score significantly. The highest percentage of passing OGS values was found for cases of medium-level complexity. This retrospective study of university clinical records showed that the posttreatment clinical outcomes were significantly affected from pretreatment case complexity. Posttreatment alignment was affected significantly from pretreatment buccal posterior crossbite and cephalometric values. Similarly, posttreatment buccolingual inclination was affected from pretreatment anterior open bite, occlusion, and other factors. Occlusal contacts were affected significantly from pretreatment lingual posterior crossbite and other factors. In addition, we determined that posttreatment root angulations were affected significantly from pretreatment crowding values.

Evaluation of 3 retention protocols using the American Board of Orthodontics cast and radiograph evaluation

The purpose of this study was to quantify tooth movement among different retention protocols after the orthodontic appliances were removed. A total of 90 patients were evaluated using the American Board of Orthodontics discrepancy index and the cast and radiograph evaluation at debond and the 1-year recall. These patients were equally divided into 3 retention protocols: upper Hawley/lower Hawley, upper Hawley/lower bonded, and upper Essix/lower bonded. The patients were then equally grouped by extraction or nonextraction treatment and case complexity. Paired t tests were used to compare the paired sample means. Analysis of variance tests were used to compare the means for more than 2 groups. A 2-sided 0.05 alpha level was used to define statistical significance. The upper Hawley/lower bonded showed the greatest amount of settling, and the upper Essix/lower bonded had the least settling, but these differences were statistically insignificant. The differences between the extraction and nonextraction treatments were not significant. The group with low discrepancy index scores showed significantly more settling than did the group with high discrepancy index scores. The cast and radiograph evaluation variables that improved overall were marginal ridges, overjet, occlusal contacts, interproximal contacts, root angulation, and total cast and radiograph score. The cast and radiograph evaluation variables that worsened were alignment/rotation, buccolingual inclination, and occlusal relationship. Extraction or nonextraction treatment led to no real difference in settling. The discrepancy index, or initial case complexity, was the greatest factor in determining the improvement of occlusion or settling during the retention phase.

Evaluation of the severity of malocclusions in children affected by osteogenesis imperfecta with the peer assessment rating and discrepancy indexes

Osteogenesis imperfecta is a heritable disorder affecting bone and tooth development. Malocclusion is frequent in those affected by osteogenesis imperfecta, but this has not been studied in detail. The purpose of this study was to describe and quantify the severity of malocclusions in patients with osteogenesis imperfecta. Articulated dental casts were obtained from 49 patients diagnosed with osteogenesis imperfecta (ages 5-19 years; 28 female) and 49 age- and sex-matched control subjects who did not have osteogenesis imperfecta. Both groups were seeking orthodontic treatment. Malocclusions were scored by using the peer assessment rating (PAR) and the discrepancy index (DI). The average United Kingdom weighted PAR scores were 31.1 (SD, 14.5) for the osteogenesis imperfecta group and 22.7 (SD, 10.7) for the control group (P<0.05). The mean United States weighted PAR scores were 32.2 (SD, 15.0) for patients with osteogenesis imperfecta and 21.6 (SD, 9.6) for the controls (P<0.05). The average modified DI scores were 29.8 (SD, 20.2) for the osteogenesis imperfecta group and 12.4 (SD, 6.8) for the control group (P<0.05). Group differences were greatest for lateral open bite (osteogenesis imperfecta group, 7.1; control group, 0.3) for the DI parameters and anterior crossbite (osteogenesis imperfecta group, 13.0; control group, 3.8 [United Kingdom]) for the PAR. Both the PAR and the DI showed that malocclusions were significantly more severe in patients with osteogenesis imperfecta than in the control group. There was a higher incidence of Class III malocclusion associated with anterior and lateral open bites in patients affected by osteogenesis imperfecta.

Clinical outcomes assessment of consecutively finished patients in a 24-month orthodontic residency: A 5-year perspective

The purpose of this study was to report on the clinical outcomes of a 24-month orthodontic residency. One examiner scored 1019 consecutive pretreatment records and 714 consecutive posttreatment records annually over 5 years, using the American Board of Orthodontics discrepancy index and objective grading system. The mean discrepancy index scores were 19.63, 14.84, 12.30, 15.72, and 15.39 for years 1 through 5, respectively. The mean objective grading system scores were 31.16, 34.79, 28.55, 26.28, and 22.11 for years 1 through 5, respectively. The residents' completion rates for all cases were 58.9%, 60.5%, 82.7%, 74.4%, 78.2%, and 72.2% for years 1 through 5, respectively. The establishment of an annual objective outcomes assessment benefited patients by improving objective grading system scores and reduced the number of transfers between residents (increased case completion rate), thus reducing faculty time for managing many transfer patients.

The quality of treatment in the adult orthodontic patient as judged by orthodontists and measured by the Objective Grading System

The increase in adult orthodontic patients in the last 20 years makes it more likely that a clinician will have adult cases to present to the American Board of Orthodontics (ABO) for board certification. The applicability of the Objective Grading System (OGS) to adult dentitions, however, has not been reported. Therefore, the purpose of this study was to determine if well-treated adult cases, as designated by orthodontists, could pass the ABO clinical examination using the OGS. Posttreatment casts of 35 adult patients from Temple University, Department of Orthodontics were ranked by 4 examiners based on visual examination of the quality of case finish using the Q-sort method. Data on each examiner's personal selection criteria to classify a well-treated case were gathered. Discrepancy index (DI) and OGS scores were measured, and the number of missing teeth was recorded. There was a moderate correlation between the rankings of the 4 examiners and their rankings to the OGS score. A 63% overall ABO pass rate was found. The pass rate for the well-treated cases and failure rate in the lower ranked group were both 100%. The DI scores of 97% of the cases were high enough to qualify as a board case, and 77% had 1 or more missing teeth after treatment. Examiners largely used the factors of the OGS in deciding if a case was well treated, with intercuspation being the most important factor. This study demonstrates that well-treated adult cases can pass the ABO clinical examination using the OGS. In addition, it illustrates that missing teeth automatically inflate the DI score and improve the OGS score.

The relationship between the ABO discrepancy index and treatment duration in a graduate orthodontic clinic

To test the hypothesis that there is no relationship between the components of the American Board of Orthodontics (ABO) discrepancy index (DI) and duration of orthodontic treatment. A retrospective review of 732 patient records with permanent dentition was performed. Pretreatment radiographs and casts were used to determine the DI score. Other data collected were total treatment duration, age, sex, ethnicity, and the date fixed appliances were removed. Reliability tests showed substantial agreement between examiners (Cohen's kappa 0.68-0.94). Pearson and Spearman correlation coefficients were used to assess the association between the DI scores and length of treatment. A multiple variable regression analysis was used to determine which variables predict treatment duration (P < .05 significant). There was a significant association between the DI and treatment duration. There was a significant multivariate association for DI components (occlusions, crowding, overjet, cephalometrics, overbite, lateral open bite, and tooth transposition) and treatment duration. The hypothesis was rejected. This retrospective study of university clinical records showed that the average increase in treatment duration was about 11 days for each point increase in total DI score. Treatment duration was differentially increased by various components of the DI: approximately 6.5 months for tooth transposition; approximately 1 month for crowding, overjet, or overbite; approximately 3 weeks for occlusion discrepancies; approximately 2 weeks for lateral open bite; and approximately 5 days for cephalometric discrepancies.

Clinical outcomes for patients finished with the SureSmile™ method compared with conventional fixed orthodontic therapy

Utilize American Board of Orthodontics (ABO) cast/radiographic evaluation (CRE) to compare a series of 63 consecutive patients, finished with manual wire bending (conventional) treatment, vs a subsequent series of 69 consecutive patients, finished by the same orthodontist using the SureSmile™ (SS) method. Records of 132 nonextraction patients were scored by a calibrated examiner blinded to treatment mode. Age and discrepancy index (DI) between groups were compared by t-tests. A chi-square test was used to compare for differences in sex and whether the patient was treated using braces only (no orthopedic correction). Analysis of covariance tested for differences in CRE outcomes and treatment times, with sex and DI included as covariates. A logarithmic transformation of CRE outcomes and treatment times was used because their distributions were skewed. Significance was defined as P < .05. Compared with conventional finishing, SS patients had significantly lower DI scores, less treatment time (∼7 months), and better CRE scores for first-order alignment-rotation and interproximal space closure; however, second-order root angulation (RA) was inferior. SS patients were treated in less time to better CRE scores for first-order rotation (AR) and interproximal space closure (IC) but on the average, malocclusions were less complex and second order root alignment was inferior, compared with patients finished with manual wire bending.

Discrepancy index relative to age, sex, and the probability of completing treatment by one resident in a 2-year graduate orthodontics program

The American Board of Orthodontics' discrepancy index (DI) was designed to objectively quantify the complexity of a malocclusion before orthodontic treatment. In this study, we assessed the influence of age and sex on the DI distribution of a large mixed sample of patients. An additional objective was to ascertain the effectiveness of the DI for predicting the probability that 1 resident can complete the treatment of the malocclusion in a 24-month residency. A group of 6 calibrated investigators independently determined the DI scores for 716 consecutive patients in the permanent dentition from the patient pool of Indiana University's graduate orthodontics program over 7 years. The DI was scored and compared with the patient's sex and age, and it was noted whether the patient was transferred to a second resident when the first one graduated. The DI is not significantly related to sex or age, but it was a significant predictor for patients who required transfer to a second resident for completion of treatment. The DI was a relatively stable index for measuring malocclusion complexity. It is independent of sex or age but is a consistent indicator of the greater time and effort required to complete treatment, because of the significant correlation to the necessity to transfer patient care to a second resident.

The Association of Malocclusion Complexity and Orthodontic Treatment Outcomes

To determine the relationship of the ABO Discrepancy Index (DI) to outcomes for routine malocclusions, and to ascertain whether significant trends in DI scores could be noted among annual samples of patients taken from 1998 to 2004. A total of 716 consecutive patients with permanent dentition from a large urban graduate orthodontics program were sampled over the 7-year span. A group of six researchers with a dental background were trained and calibrated in the various components of the DI method to ensure reproducible criteria and accurate recording of clinical and radiographic data across researchers. Data management and analyses were undertaken by two other investigators who were not involved in data coding. Only a weak positive association was seen between the DI and Objective Grading System (OGS) and Comprehensive Clinical Assessment (CCA) scores. The DI was not significantly related to a general time trend. The DI was found to be a reliable and relatively stable index for measuring malocclusion complexity in annual samples of patients. Although the DI is significantly related to outcomes for the most severe malocclusions, it was not a good predictor of outcome for more routine malocclusions. If the minimal acceptable outcome is defined as 30 OGS points, the mean DI (15.7) and the average OGS score (28.2) indicate that many of the malocclusions in patients in the present sample were of potential board quality.

Treatment complexity index for assessing the relationship of treatment duration and outcomes in a graduate orthodontics clinic

Clinical cases completed by the Indiana University School of Dentistry (IUSD) graduating orthodontic classes of 2004, 2005, and 2006 were assessed to determine factors that affect orthodontic treatment duration. The sample consisted of 455 consecutively finished patients who received comprehensive treatment in the full permanent dentition. They included optimally finished and prematurely terminated (early debond) patients. The American Board of Orthodontics (ABO) discrepancy index (DI) was used to evaluate the severity of the pretreatment malocclusion. A specifically designed treatment complexity index (TCI) was used to evaluate complexity based on treatment modalities. The ABO objective grading system (OGS) and the IUSD comprehensive clinical assessment (CCA) were used to evaluate the clinical outcome for all patients. The average treatment duration was 29 months. The mean DI, OGS, and CCA scores were 15.30, 23.34, and 4.48, respectively. Increased treatment length was associated with 0.022-in slot size brackets, percent of treatment spent in nickel-titanium wires, Class II malocclusion, increased DI score, and increased TCI score. In evaluating outcomes for 2004 through 2006, there was no significant relationship between treatment duration and clinical outcome as measured by the OGS and CCA scores. The DI and TCI are sensitive prospective indicators of treatment duration. After the introduction of a rigorous clinical protocol for controlling poor outcomes, because of patients exceeding predicted treatment times, the clinical results for this sample are independent of treatment duration.

Treatment outcomes in a graduate orthodontic clinic for cases defined by the American Board of Orthodontics malocclusion categories

The American Board of Orthodontics (ABO) discrepancy index (DI) quantifies the severity of a malocclusion. The ABO objective grading system (OGS) assesses the quality of orthodontic finishing. Indiana University's comprehensive clinical assessment (CCA) supplements the OGS to provide an instrument to determine clinical outcomes. The purposes of this article were to (1) determine whether treatment outcome is related to the type of malocclusion as defined by the ABO classification, (2) determine the fraction of finished orthodontic cases in the graduate orthodontics clinic that are within the ABO standards for passing the phase III clinical examination, (3) evaluate the contribution of each component of the OGS and the CCA to the total OGS and CCA scores, (4) determine the percentage of finished cases that meet the ABO case category specifications, and (5) identify problem areas to improve the quality of treatment for challenging malocclusions. Three hundred eighty-two cases that satisfied requirements for 8 of the ABO's malocclusion categories were selected from 989 consecutively finished cases from 1998 through 2003. They were evaluated by using the OGS, the CCA, and the DI. The average OGS score was 32.64, the average CCA score was 5.62, and the average DI score was 20.94. There was no significant difference in the OGS and the CCA scores among the categories. Categories 2, 5, 7, and 8 had a DI score that was significantly higher than the average for the entire sample. The OGS and CCA scores were positively correlated with the DI score, meaning that complex malocclusions are challenging to finish well. The most points lost for the OGS and the CCA were for occlusal contacts and treatment efficiency (length of treatment relative to the result), respectively. The fewest points lost were for interproximal contacts and vertical control, respectively. Furthermore, prematurely terminated cases (early debonds) had longer treatment times and higher (worse) OGS and CCA scores. This study demonstrates problems in treating complex malocclusions in a graduate orthodontics program and suggests methods for increasing the quality of clinical outcomes.

Clinical assessment of orthodontic outcomes with the peer assessment rating, discrepancy index, objective grading system, and comprehensive clinical assessment

The purpose of this study was to quantitatively assess orthodontic treatment outcomes in postgraduate orthodontic clinics at Okayama University (OU) and Indiana University (IU). Using the peer assessment rating (PAR) index, the discrepancy index (DI), the American Board of Orthodontist's objective grading system (OGS), and the comprehensive clinical assessment (CCA), we evaluated pretreatment and posttreatment records of 72 patients from OU and 54 patients from IU. The average pretreatment PAR score with United Kingdom weighting was 32 for OU subjects and 28 for IU subjects. Differences in maxillary and mandibular buccal alignment between schools were statistically significant ( P < .01). The posttreatment PAR scores were 7 for OU and 4 for IU. The difference in overjet between schools was statistically significant ( P < .05). The mean DI scores were 19 for OU and 17 for IU. OU patients scored significantly more DI points for crowding and mandibular plane angle compared with IU patients ( P < .05). On the other hand, they lost significantly fewer DI points for overbite and occlusion compared with IU patients ( P < .05). The mean OGS scores were 34 for OU and 33 for IU. Buccolingual inclination and overjet scores were significantly higher in OU patients compared with IU ( P < .05). The mean CCA score was approximately 4 points for both OU and IU. These data suggest that these indexes are useful for comparing treatment outcomes between clinics. They were able to identify specific problems in treating Asian patients.

Relationships between Weight-Height Ratios, other Body Measurements, and Self-Perception of Body Contours

Abstract A battery of test instruments was devised and utilized in an attempt to determine relationships existing between indicators of gross body size and configuration and the ability to perceive and delineate body contour lines and proportional dimensions. The scores obtained were compared with selected body measurements, the ponderal index, the number of pounds over or under the “desirable” weight-height ratio, and responses made to direct questions concerning contour line satisfaction. Subjects were 102 undergraduate female students from selected classes of the basic physical education program. From the initial group of students, 77 retest sets of data were obtained. Analysis of first and second test results indicated a correlation coefficient of .73 between the Total Front and Total Side Discrepancy Index scores on both the first (102 students) and the second (77 students) test administrations. Further, comparisons between first and second drawing-task scores indicated that the amount of change betw...