Study design and populations
Nine patients with moderate to severe periodontal attachment loss were selected from the patient population of the Advanced Education Program in Periodontics at the Ashman Department of Periodontology and Implant Dentistry at the New York University College of Dentistry (NYUCD) between 2010 and 2014. Exclusion criteria were; periodontitis as a result of systemic disease, patients with diabetes mellitus, patients with mixed dentition, patients with implants, and patients with extensive restorative work. Patients with mixed dentitions, extensive restorations, or implants were excluded as the appearance of these in a clinical exam could provide clues to a patient’s age. Case reports were prepared based on the comprehensive periodontal evaluations preformed by the graduate students enrolled in the Advanced Education Program in Periodontics. These case reports included a full set of radiographs and periodontal charting with the following clinical periodontal measures; pocket depth, bleeding on probing, clinical attachment loss, mobility, and furcation involvements. Measurements of pocket depth, clinical attachment loss, and bleeding on probing were recorded for six surfaces of all teeth; mesiobucal, the direct buccal, distobuccal, mesiolingual, direct lingual, and distolingual [11]. The Hamp classification was used when assessing furcation involvement and the Miller classification was used to record tooth mobility [12, 13]. The patients’ chief complaint, medical history and dental history were included in the case report and care was taken to remove all personal identifiers. A sample of radiographs and intraoral photos from case report 8 is available as Fig. 1. Case reports were de-identified and protected health information was not used in accordance with the Health Portability and Accountability Act privacy rule. Patients gave written informed consent for the use of their de-identified information for research purposes. This study protocol was evaluated by the International Review Board Human Research Protection Program, NYU School of Medicine, NYU Langone Medical Center, using the approved Self-Certification Form, on file with NYUCD Advanced Education Program in Periodontics, and was deemed exempt from IRB review.
The board certified periodontal faculty at NYUCD were asked to participate as examiners for this pilot study and sixteen members agreed. The faculty included both full and part time members, and each was a Diplomat of the American Board of Periodontology. The board certified periodontists who participated in this study were informed of the nature of the study, and all gave written informed consent and were provided the ability to opt out without consequence.
Data collection and analysis
The cases were presented twice to the sixteen examining periodontists via electronic format. The case reports consisted of a complete periodontal chart, a case narrative, intraoral photos, and a complete radiographic series. The examining periodontists were asked to evaluate each case independently, without consultation, and provide a diagnosis. For each case, based only on the information provided, the periodontist was prompted to choose either a diagnosis of chronic or aggressive periodontitis. The examining periodontists were first presented with the case reports without the patient’s age. The second time the same cases were presented with the patient’s age included. The examining peridontisits were not permitted to see or change their diagnostic selections from the first set of case presentations while reviewing the cases the second time. None of the examiners were directly involved in supervising the graduate students during data collection for these cases. The diagnostic agreement among the examiners was compared for each round using Fleiss’ Kappa statistic and the Landis and Koch’s 1977 interpretation of Kappa Values [14, 15].