|3124 Longitudinal Stability of Divergent Growth Patterns|
P. GARCIA-MORALES, and P.H. BUSCHANG, Baylor College of Dentistry, Dallas, TX, USA|
Objectives: The purpose of this study was to determine whether individuals maintain or change divergent growth patterns during childhood and adolescence. Methods: Standard lateral cephalograms of 73 untreated growing children (51% female) were taken every year from 6 to 15 years of age. Four standard morphological measurements were evaluated, including 1) mandibular plane angle; 2) Y-axis; 3) lower to total facial height ratio; and 4) anterior to posterior facial height ratio. For each measure, the sample was categorized as hyperdivergent (³ 1 SD), normal (± 1 SD), and hypodivergent (£ 1 SD). Results: On average, individuals became slightly (≈ 5%) less divergent between 6-15 years of age; changes occurred regularly throughout the age span. Approximately 60-72% of hyperdivergent 6 years olds were also hyperdivergent at 16 years. Z-scores for approximately 1/3 of individuals classified as hyperdivergent at 6 years increased between 6-15 years; the remaining 2/3's showed Z-scores decreased. Hypodivergent subjects showed similar patterns of instability. Measures of divergence at 6 years of age were moderately related with divergence at 15 years. While the changes in divergence between 6-15 were unrelated to divergence at 6 years, they explained approximately 50% of the variation at 15 years of age. Conclusions: We conclude that hyper- and hypodivergent patterns are not stable during growth. While the six-year of phenotype predicts approximately 50% of the variation in the 15-year-olds phenotype, it does not predict growth changes between 6-15.
|Seq #286 - Post-natal Craniofacial Growth|
9:00 AM-11:00 AM, Saturday, 9 March 2002 San Diego Convention Center Room 17A (Mezzanine Level)