With the input of panels of experts in epidemiology and the clinical dental specialties, public health researchers of the National Institute of Dental and Craniofacial Research established the objectives for the oral health components of the NHANES IQ, the content of each component, the examination procedures, and the examination and computer coding systems.
4.10.2 Objectives
The objectives of the oral health component were, with regard to selected oral diseases, disorders, and conditions, to establish their magnitude and relative frequency; describe their distribution among socio-demographic characteristics of the population; describe the association of selected risk factors; and document and investigate reasons for secular trends.
4.10.3 Direct data entry system
The purpose of the direct data entiy system was to provide a means for entering the data collected for the NHANES III into a computer system that would enhance the timeliness and quality of the data. Public health researchers of the NIDGR were in charge of developing the specifications for every component of the direct data entry system and for the establishment of edit checks to enhance data quality.
4.10.4 Examiner training and calibration
The training of the dental examination was conducted by researchers of NIDCR and the surveys standard examiner. I There were three
phases of training and calibration. An instructional phase during which examination team members were familiarized with research examination procedures and criteria for research assessments through lectures and slides. In addition, demonstrations of the examination procedures, techniques and equipment were conducted at this time.
The standardization phase was designed to train the examination team members in the use of standard procedures and to apply standard criteria for the oral health assessments. A demonstration of the examination by the standard examiner and practice sessions with NIDCR staff were conducted at this time until the standard examiner and the NIDCR staff were confident in the trainees ability. The calibration phase was conducted to assure that agreement among the examiners and the standard examiner was achieved. The reliability of the assessments was measured by determining the degree to which examiners could produce uniform and consistent results when performing independent replicate examinations without discussion. Data from the calibration sessions were analyzed to measure agreement between
each examiner and the standard examiner. If the agreement between each of the examiners and the standard examiner were not within acceptable ranges, additional training sessions were scheduled until agreement was obtained.
4.10.5 Equipment and supplies
The equipment and supplies of relevance to this thesis are the standard high intensity, fiber optic light utilized throughout the dental examination and standardized dental mirror heads that were replaced every 15 weeks.
4.10.6 Oral examination components
The oral component of NHANES
in
consisted of a questionnaire and a visual - tactile examination and virtually everyone who participated in the medical, laboratory and anthropometric components also participated in the oral component. The constituents of the oral examination component were medical history, oral mucosal tissue, dental caries assessment, restoration and tooth conditions, traumatic injuries, occlusal and dentofacial characteristics, periodontal disease, denture assessment (Drury et al, 1996). Data for this thesis are derived from the dental caries and denture assessments. The specific procedures of which are described below.4.10.7 Medical history
The medical history queried the sampled person with regard to conditions which would preclude the person from having root caries and periodontal assessments.
4.10.8 Numbers and types of teeth
The data regarding the numbers and types of teeth and the replacement of teeth used in this thesis were derived from the raw data of the dental canes assessment procedure. The dental caries assessment procedure was developed and used by the NIDCR in all of its national surveys beginning in 1970 through NHANES HI (and now for NHANES IV). The examination sequence for teeth was upper left central incisor through second molar, upper light central incisor through second molar, lower left through second molar, and lower right through second molar. Of relevance to this thesis was the examination procedure for identifying missing and replaced teeth which was imbedded in the DMFS examination procedures.
The dental examiner used the code "E" to indicate teeth extracted because of caries or periodontal disease, and a different code “M” for teeth missing due to trauma, orthodontic treatment, or other non-disease related causes. In order to determine whether an “E “ or “M” is called, the sample person was asked about the reason for tooth loss. Unerupted or congenitally missing teeth (code U) were identified. When a missing tooth was replaced by a fixed or removable prosthesis, the E, M or U score was supplemented with the letter R (for replaced), creating the scores ER, UR and MR. A fixed or removable prosthetic replacement was considered to exist when it was visible in the mouth. In the case of removable appliances not being worn at the time of the examination, the replacement was considered to exist when the sample person reported that an appliance existed and that he/she wore it. No differentiation was made in the coding between a fixed or removable prosthetic replacement. When more than one tooth was replaced by a single pontic, each tooth space was scored as replaced.
4.10.9 Denture questionnaire
w hen the dental examiner determined that a sample person was edentulous in either arch or both the sample person was asked if they wore a denture. If the answer was affirmative a denture questionnaire was administered. Of relevance to this thesis was the question “Do you usually wear your (upper/lower) denture(s) (plate) all of the time, only when awake, only occasionally, or don’t wear them?” Appendix A4.10.9