title: Reliability of Beta angle in assessing true anteroposterior apical base discrepancy in different growth patterns.
abstract: BACKGROUND
  Beta angle as a skeletal anteroposterior dysplasia indicator is known to be useful in evaluating normodivergent growth patterns. Hence, we compared and verified the accuracy of Beta angle in predicting sagittal jaw discrepancy among subjects with hyperdivergent, hypodivergent and normodivergent growth patterns.
  
  
  METHODS
  Lateral cephalometric radiographs of 179 patients belonging to skeletal Classes I, II, and III were further divided into normodivergent, hyperdivergent, and hypodivergent groups based on their vertical growth patterns. Sagittal dysplasia indicators - angle ANB, Wits appraisal, and Beta angle values were measured and tabulated. The perpendicular point of intersection on line CB (Condylion-Point B) in Beta angle was designated as 'X' and linear dimension XB was evaluated.
  
  
  RESULTS
  Statistically significant increase was observed in the mean values of Beta angle and XB distance in the vertical growth pattern groups of both skeletal Class I and Class II patients thus pushing them toward Class III and Class I, respectively.
  
  
  CONCLUSIONS
  Beta angle is a reliable indicator of sagittal dysplasia in normal and horizontal patterns of growth. However, vertical growth patterns significantly increased Beta angle values, thus affecting their reliability as a sagittal discrepancy assessment tool. Hence, Beta angle may not be a valid tool for assessment of sagittal jaw discrepancy in patients exhibiting vertical growth patterns with skeletal Class I and Class II malocclusions. Nevertheless, Class III malocclusions having the highest Beta angle values were unaffected.
authors: Department of Orthodontics, Government Dental College, Calicut, Kerala, India.
authors: Shobha
authors: S
authors: Sundareswaran
authors: Department of Orthodontics, Government Dental College, Calicut, Kerala, India.
authors: Vinay
authors: V
authors: Kumar
keywords: Beta angle; sagittal dysplasia; vertical growers