Numeric Code Identifies Tooth Pattern, Jaw Symmetry in Ectodermal Dysplasia

Missing teeth found in various genetic forms of Ectodermal Dysplasias (ED) is well know but is there a pattern to this agenesis? Objective: During three annual conferences of the National Foundation for Ectodermal Dysplasias (NFED) a visual observation of dental condition and presence of teeth are recorded of the ED subjects. This record of missing teeth could show a pattern/genetic relationship. Methods: Data was collected during three annual conferences, 2005-2007, by calibrated dental pattern specialists. Subjects, self report dental condition and type of ED if known. Attending dentists chart observed teeth. Results: 88 subjects, ages 2 - 48 were seen demonstrating various types of dysplasia. Using a numeric code published by Arjen J. van Wijk a Tooth Agenesis Code (TAC) value is given to each quadrant per subject charted. TAC values assign a single number that represents a pattern of missing teeth. TAC value = 0, there are no missing teeth, TAC value = 255 all teeth are missing. Using the provided web-based script and entering subject's missing teeth, TAC values demonstrate the dominate pattern of each quadrant per three age groups. Group A, ages 2-5.9, Group B, ages 6-12 and Group C, ages 12-48. Group B's dominate pattern for q1-q2 is TAC value 250, 20.0%, 13.3% respectively. Dominate pattern for q3-q4 is TAC value 255, 30.0%, 33.3% respectively. TAC value 250 equates to teeth #6, 8, 9, 11 are present but percentages show no symmetry. TAC value 255 equates to all teeth missing in the mandible, q3=30.0%, q4=33.3%. Symmetry of the whole group can also be demonstrate, example Group B n=29, mandible 80%, maxillary 66.7%, right 30.0 %, left 23.3%. Conclusion: TAC values allow data analysis, in demonstrating single value for any given quadrant for data examination of pattern and symmetry. Supported by the National Foundation for Ectodermal Dysplasias.