A novel diagnostic tool for sagittal jaw relationship: The P angle

Abstract

Aim: To introduce a new cephalometric measurement called P-angle using three skeletal landmarks&#s8212;point S, point Gn, and point A, to evaluate the sagittal relationship between the maxilla and mandible. Materials and Methods: A total of 130 pretreatment lateral cephalograms were selected and segregated into skeletal Class I, II, and III groups based on W-angle and ANB angle. It included 50 Class I (25 males and 25 females), 50 Class II (25 males and 25 females), and 30 Class III (13 males and 17 females) skeletal pattern patients. The P angle was formed between the line from point A perpendicular to the S-Gn line and line A-Gn. The P-angle and W-angle were measured in each patient. Data was entered in MS Excel sheet and analyzed by using SPSS software 24.0 version IBM USA. The mean and standard deviation of P-angle and W-angle was calculated and were compared using an unpaired t-test. Results: The unpaired t-test results showed that there is no significant difference between P-angle and W-angle in Class I, Class II, and Class III skeletal pattern. Conclusion: P-angle can be used as an adjunct for W-angle during pretreatment cephalometric tracing.