Thyroid Disease and Chronic Periodontitis

This is a retrospective, cross-sectional patient records review study. Only records with
subjects that were 35 years or older and have been active patients of the School of Dental
Medicine, University at Buffalo will be included. Three individual searches with three
distinct patient criteria will be conducted to obtain records from subjects in three
populations with different degrees of periodontal disease. All subjects that qualify the
eligibility criteria will be selected. The IT Department has access to select the subjects
according to the eligibility criteria without requiring access to the physical patient
record. The three subject groups are:

1. Periodontally healthy patients: Patients with a D1110 or D1111 (adult prophylaxis
including those with 6 or fewer teeth) treatment code, seen by a 3rd or 4th year
pre-doctoral dental student. Excludes all charts that have ever had a U4990 (Perio case)
treatment code. Patient is 35 years or older relative to 1/1/2016.

2. Patients with a history of advanced periodontal treatment, group 1: All patients treated
in the Postgraduate Periodontics department by a periodontics resident between 1/1/2000
- 12/31/2017. Patients presenting for treatment of chronic periodontitis will be
included while those patients presenting to the clinic for other reasons, such as crown
lengthening procedures, will be labeled as such. All patients selected will be 35 years
or older at time of initial exam.

3. Patients with history of advanced periodontal treatment, group 2: All patients ever
treated in the private faculty practice of one periodontist, that were still active
patients during between 1/1/16 - 12/31/16. Only those 35 years and older were included.
Patients presenting for treatment of chronic periodontitis will be included while those
patients presenting to the clinic for other reasons, such as crown lengthening
procedures, will be labeled as such.

All duplicates within a group will be excluded (e.g. patients may have had a D1110 code more
than once per year). These 3 subject search criteria should yield a sufficient number of
patient records for statistical analysis.

All patient records will be reviewed and data will be collected and recorded in an electronic
Microsoft Excel database file that is saved on an encrypted flash drive. The only patient
identifier recorded will be the patient records number. Once data collection is complete, or
at a maximum of 3 years from the start of the study, all identifying information will be
deleted and only de-identified data saved on a separate electronic file will be analyzed. No
code key will be required.

Data will be analyzed using ANOVA (F-test). If multiple variables are used, analysis will be
by using generalized estimating equations (GEE).

Inclusion Criteria:

- Active patient of the School of Dental Medicine, University at Buffalo.

- The remaining eligibility criteria varies between the three distinct subject
populations, which are noted below. All eligibility criteria is selected for by an
electronic search of patient records performed by the IT Department at the School of
Dental Medicine, University at Buffalo.

1. Periodontally healthy patients:

1. A treatment code of D1110 or D111 was processed at least once but excluding
patients that were ever assigned a treatment code of U4990

2. A 3rd or 4th year pre-doctoral dental student provider

3. 35 years or older as of 1/1/2016

4. Patient presented to clinic between 1/1/2016-12/31/2016

2. Patients with history of advanced periodontal treatment, group 1:

1. All patients presenting to the Postgraduate Periodontics Department at UB
and being seen by a periodontics resident

2. Time period between 1/1/2000-12/31/2017

3. Patients will be 35 years or older at time of initial exam

4. Patients presenting for reasons other than chronic periodontitis treatment
(e.g. crown lengthening) will be labeled as such.

3. Patients with history of advanced periodontal treatment, group 2:

1. All patients treated in the faculty practice of one periodontist that
remained active patients during the time period 1/1/2016-12/31-2016

2. All patients were 35 years or older at time of initial exam

Duplicates within groups are eliminated.

Exclusion Criteria:

- inadequate data from records

Note: the majority of patient records selected by the search criteria done electronically
by the IT department will be included in the study, since the search criteria very closely
overlaps the overall study criteria