Relationship and inter observer agreement of tooth and face forms in a Saudi subpopulation.

OBJECTIVE To determine the relationship of tooth form with the face form by different observers and further investigate the inter observer agreement on tooth forms, face forms, their relationship among male Saudis. STUDY DESIGN A comparative cross-sectional study. PLACE AND DURATION OF STUDY Department of Prosthodontics, College of Dentistry, King Saud University, Riyadh, KSA, from February till August 2013. METHODOLOGY Ninety four male participants aged 18 - 35 years were randomly recruited for the study. Full-face and anterior teeth (intraoral) digital photographs in the frontal plane were recorded. The outline tracings of the face and the tooth were obtained using Autocad (version 2010) software. The outline of the tooth was enlarged proportionately, without altering the length to width ratio to fit the face outline. The outlines were then evaluated visually by 6 prosthodontists and results were tabulated. RESULTS The most common type of face form (49.65%) and tooth form (56.38%) was square tapering. Using the visual method, a good relationship (31.41%), moderate relationship (35.31%), weak relationship (19.68%) and no relationship (13.65%) between the tooth form and face form was found by the observers. Overall kappa for inter observer agreement on face form, tooth form and their relationship was 0.24, 0.17 and 0.26 respectively. The kappa values showed a fair agreement between the observers. CONCLUSION The study results indicated that there was no highly defined relationship between the tooth form and face form in the studied Saudi subpopulation. A fair agreement was found between the observers for classifying the tooth forms, face froms and their relationship.