Orthodontics Objective Grading System Research Articles

Assessing treatment outcomes for a graduate orthodontics program: Follow-up study for the classes of 2001-2003

Based on an initial 3-year study (1998-2000) of clinical outcomes, specific changes were made in the clinical protocol in the orthodontic clinic at Indiana University, Indianapolis, Ind. To evaluate these adjustments, a follow-up study with the same methods assessed the clinical outcomes for the next 3 years (2001-2003). The 3 changes introduced in 2000 were assessment of prefinish records, education of residents about previous outcomes, and more frequent practice evaluations by the program director. The American Board of Orthodontics (ABO) objective grading system (OGS) and a supplemental comprehensive clinical assessment (CCA) were used to evaluate the results for all patients completed by the classes of 2001 through 2003 (n = 437). The mean ABO OGS, CCA, and combined scores were 25.19 +/- 11.16, 4.38 +/- 2.74, and 29.57 +/- 13.01, respectively. A progressive improvement was noted from 2001 to 2003. The ABO OGS and the combined scores were significantly (P <.001) improved in 2001 through 2003 compared with 1998 through 2000. The CCA score tended to improve, but it was not significantly different. Significant improvements were seen for maxillary and mandibular first order, mandibular second order, mandibular third order, overjet, occlusal contacts, occlusal relationships, and root angulations (P <.001). As with the previous study, excessive treatment times correlated with worse clinical outcomes. Changes implemented by the graduate program were effective for improving treatment outcomes. Cast scores were more amenable to improvement than other more comprehensive outcomes.

Evaluation of the accuracy of digital model analysis for the American Board of Orthodontics objective grading system for dental casts

In 1999, after 3 years of field testing, the American Board of Orthodontics (ABO) implemented a grading system for posttreatment orthodontic models and panoramic radiographs, to make the phase III examination both fair and objective. In the ABO's objective grading system, 7 occlusal criteria (tooth alignment, vertical positioning of marginal ridges, buccolingual inclination of posterior teeth, occlusal relationship, occlusal contacts, overjet, and interproximal contacts) are measured on plaster models to assess a patient's final occlusion. To date, no study has evaluated the ABO grading system for use on digital models. The purpose of this study was to determine whether digital models can be used with reasonable accuracy and reliability for assessing patients' final occlusions. Plaster and digital (OrthoCAD, Cadent Inc, Carlstadt, NJ) posttreatment models of 24 patients were gathered from the postgraduate orthodontic clinic at Columbia University School of Dental and Oral Surgery. The plaster models were scored by using the ABO measuring gauge and the 7 criteria of the ABO grading system. A second analysis was done on the digital models. To determine interexaminer error, a fourth-year dental student at Columbia University served as a second examiner and repeated all the analyses. The means of the total score and those for marginal ridges, occlusal contacts, occlusal relationships, overjet, and interproximal contacts were not significantly different between plaster and digital models. However, the means for alignment and buccolingual inclination were significantly different. In addition, the scorings of 2 examiners differed for the 2 methods. This finding suggests that alignment and buccolingual inclination should be reevaluated with both methods, and adequate calibration of the examiners is essential to achieve repeatability in both methods. Digital models might be acceptable for use in the ABO model examination.

Outcome assessment of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system

This treatment-outcome assessment objectively compares Invisalign (Align Technology, Santa Clara, Calif) treatment with braces. This study, a retrospective cohort analysis, was conducted in New York, NY, in 2004. Records from 2 groups of 48 patients (Invisalign and braces groups) were evaluated by using methods from the American Board of Orthodontics Phase III examination. The discrepancy index was used to analyze pretreatment records to control for initial severity of malocclusion. The objective grading system (OGS) was used to systematically grade posttreatment records. Statistical analyses evaluated treatment outcome, duration, and strengths and weaknesses of Invisalign compared with braces. The Invisalign group lost 13 OGS points more than the braces group on average, and the OGS passing rate for Invisalign was 27% lower than that for braces. Invisalign scores were consistently lower than braces scores for buccolingual inclination, occlusal contacts, occlusal relationships, and overjet. Invisalign's OGS scores were negatively correlated to initial overjet, occlusion, and buccal posterior crossibite. Invisalign patients finished 4 months sooner than those with fixed appliances on average. P < .05 was used to determine statistically significant differences. According to the OGS, Invisalign did not treat malocclusions as well as braces in this sample. Invisalign was especially deficient in its ability to correct large anteroposterior discrepancies and occlusal contacts. The strengths of Invisalign were its ability to close spaces and correct anterior rotations and marginal ridge heights. This study might help clinicians to determine which patients are best suited for Invisalign treatment.

Comparison of university and private-practice orthodontic treatment outcomes with the American Board of Orthodontics objective grading system

Treatment outcomes and duration of treatment for patients treated in university graduate orthodontic programs and private orthodontic practices were assessed and compared with the ABO objective grading system. The treatment records of 139 randomly selected adolescents who had received comprehensive orthodontic treatment were examined. Seventy-seven subjects had been treated in 3 postgraduate orthodontic clinics, and 62 had been treated in 3 private orthodontic practices. Pretreatment, all subjects had Class II Division 1 malocclusions and ANB angles equal to or greater than 4 degrees . All patients were treated with premolar extractions. Posttreatment dental casts were measured and scored with the ABO objective grading system. No significant differences were found between the groups in the alignment, buccolingual inclination, and overjet components. Patients treated in private practice had significantly lower scores for marginal ridge height and occlusal relationship. Patients treated in the university programs had significantly lower scores for occlusal contact and interproximal contact components. There was no significant difference in the overall score, thus no significant difference in the overall quality of orthodontic treatment outcome between patients treated in university programs and private practices. However, the university group had a significantly larger sample variance for the overall score. There was no significant difference in the duration of the treatment between patients treated in a university setting and in a private practice.

Visual application of the American Board of Orthodontics grading system

Abstract Background: Assessment of treatment outcomes has traditionally been accomplished using the subjective opinion of experienced clinicians. Reduced subjectivity in the assessment of orthodontic treatment can be achieved with the use of an occlusal index. To implement an index for quality assurance purposes is time-consuming and subject to the inherent error of the index. Quality assessment of orthodontic treatment on a routine basis has been difficult to implement in private practice. Objectives: To investigate whether a clinician can accurately apply the American Board of Orthodontics Objective Grading System by direct visual inspection instead of measuring individual traits. Methods: A random sample of 30 cases was selected, including pretreatment and post-treatment upper and lower study casts and panoramic radiographs. The cases were examined and scored with the standardized measuring gauge according to the protocol provided by the American Board of Orthodontics (ABO). The records were re-examined 6 weeks later and the individual traits scored by visual inspection (VI). Results: There were no significant differences between the pre- and post-treatment ABO gauge and VI scores. Conclusions: This study suggests that occlusal traits defined by the ABO Objective Grading System can be accurately assessed by visual inspection. The VI score provides a simple and convenient method for critical evaluation of treatment outcome by a clinician.

Long-term posttreatment changes measured by the American Board of Orthodontics objective grading system

The American Board of Orthodontics (ABO) developed the objective grading system (OGS) to evaluate cases submitted as part of the phase III examination for board certification. This study examines the long-term changes in 6 of the 8 criteria measured by the board, with an emphasis on the relationship between posttreatment results and subsequent improvement or worsening. One hundred subjects were randomly chosen from the postretention archives of the Department of Orthodontics at the University of Washington. Pretreatment peer assessment rating (PAR) scores and posttreatment and postretention OGS scores were measured on study casts. The ABO criteria studied were alignment, marginal ridges, buccolingual inclinations, occlusal contacts, occlusal relationships, and overjet. Interproximal contacts and root angulations were not scored. The mean overall OGS score at posttreatment was 21.5 points. At postretention, this score had improved significantly, by approximately 4 points. When comparing posttreatment scores and long-term changes, similar patterns were seen for all criteria, except alignment; increased posttreatment scores were associated with increased long-term improvement. Well-treated cases tended to deteriorate, and poorly finished cases tended to improve, illustrating a regression to the mean. Alignment was the only criterion associated with a mean long-term worsening, as well as a less predictable pattern of change. The results of this study indicate that settling occurs after orthodontic treatment, and that the attainment of perfect occlusal results does not ensure stability.

Evaluation of Invisalign treatment utilizing the American Board of Orthodontics Objective Grading System for dental casts

For orthodontic treatment of certain malocclusions, Invisalign (Align Technology, Santa Clara, Calif) offers an alternative to fixed appliances. The purpose of this study was to evaluate the treatment outcome of patients treated with Invisalign aligners by using the American Board of Orthodontics Objective Grading System (OGS) for dental casts. The dental cast component of the OGS scores 7 categories for discrepancies from ideal related to tooth alignment and occlusion. Depending on the magnitude of the discrepancy, up to 2 points can be scored in each category; thus the fewer the points scored, the more ideal the result.

Comprehensive clinical evaluation as an outcome assessment for a graduate orthodontics program

To supplement the American Board of Orthodontics (ABO) objective grading system (OGS) for posttreatment dental casts and panoramic radiographs, a comprehensive clinical assessment (CCA) method was developed to assess facial form, dental esthetics, vertical dimension, arch form, periodontium preservation, root resorption, and treatment efficiency. The sum of the CCA and the ABO OGS scores was defined as the clinical outcome. To determine a 3-year baseline for treatment outcomes in a graduate orthodontic program, the posttreatment records of 521 consecutive patients were evaluated. The mean ABO OGS score for the entire sample was 34.4 points: 32.4, 33.1, and 37.8 points for 1998, 1999, and 2000, respectively. The mean CCA score for the entire sample was 4.67 points: 2.96, 5.13, and 6.15 points for 1998, 1999, and 2000, respectively. Corresponding ABO OGS and CCA scores showed a progressive decrease in the quality of finished cases that was associated with a treatment time increase from 28.9 to 39.3 months. Overall, longer active treatment times resulted in a diminished clinical outcome, primarily due to "patient burn-out." Scoring of all finished cases is an effective means for determining clinical outcomes. However, the data suggest that, in initiating a clinical grading program, it is important to establish a multiyear baseline. Patients who are progressing well in treatment tend to be finished by the time the current class graduates, and the problem patients are transferred. Because long treatment times are associated with diminished clinical outcomes, it is often in the best interest of the uncooperative patient to terminate treatment rather than extend active mechanics in an attempt to achieve a better result.

Comparing orthodontic treatment outcome between orthodontists and general dentists with the ABO index

This study used the American Board of Orthodontics (ABO) Objective Grading System (ABO index) (ABOI) to compare treatment outcome between patients treated by orthodontic specialists (OS) and patients treated by general dentists (GP). The sample (n = 196) consisted of 126 dental casts of patients treated by OS and 70 treated by GPs. All casts were collected in 1997 and 1998 from 10th grade students attending high schools in Cuyahoga County, Ohio, and were scored by 1 operator (Y.A.) calibrated in the use of the ABOI. The mean ABOI score for the OS group was 26.0 +/- 11.4 compared with 29.6 +/- 12.8 for the GP group. This difference was significant at the P < or = .05 level. Of the 7 components used in the ABOI, alignment of teeth was found to be the most significant between groups (OS mean = 5.39 +/- 4.37 versus GP mean = 7.8 +/- 5.21, P < or = .0007). In this sample, a significantly lower ABOI score was found for patients treated by OS compared with patients treated by GP.

TMJ: Clinical and practice management: Errol Lader, New York, 1981, Vadare, Inc. 200 pages, illustrated, appendix

The aim of this study was to compare the virtual and manual tooth setups with digital and plaster models in extraction cases by measuring various occlusal parameters and applying the American Board of Orthodontics objective grading system.Linear intra-arch and interarch dimensions (arch width and length, perimeter, overjet, and overbite), angular variables (tip, torque, and rotation), and American Board of Orthodontics objective grading system scores obtained from a digital virtual setup model were compared with those from a plaster model setup.The digital virtual setup model resulted in smaller arch perimeters than did the plaster setup model by 2.20 mm in the maxillary arch (P <0.01) and 1.30 mm in the mandibular arch (P <0.05). The digital virtual setup also exhibited significantly lower values for overbite and overjet (P <0.01). The digital virtual setup had tendencies toward mesial angulation of the anterior teeth, labial inclination of the maxillary anterior teeth (P <0.05), and distal in-rotation of the mandibular teeth (P <0.05). The resulting American Board of Orthodontics objective grading system evaluation showed that larger deductions for overjet, occlusal contact, and total score (P <0.01) were required for the digital than for the manual setup model.Digital and manual setups lead to similar measurements for intra-arch and interarch occlusal variables. However, because of the possibility of collision on proximal and occlusal contact, delicate adjustments in proximal and occlusal contacts are required.