Establishing a new anatomical indicator for antero-posterior jaw discrepancy

الملخص EN

To overcome the deficiencies, at least geometric drawbacks, associated with the most commonly available sagittal indicators (ANB, Wits), efforts were done to develop another an accurate and valuable mean for skeletal prediction.To establish the mean value of a new sagittal approach (μ angle) for the assessment of skeletal relationship in its different patterns and whether or not there is a correlation with the other cephalometric indexes.Depending on a predetermined criteria, the total study sample consist of ninety-four pretreatment lateral cephalometric radiograph of Iraqi subjects with a mean age (13.5± 2).

Again it have been subdivided into three skeletal relations (I, II, III) according to the combined criteria of both (ANB and Wits appraisal) for each relevant class.

μangle measured from A-B line and a perpendicular on Mandibular plane from point A.The mean values of μ angle were (22.16 ± 3.04; 13.56 ± 3.04; 28.84 ± 3.52) for class I; II; III, respectively and no significant gender differences were detected.Regardless sample subgroups, a strong negative significant correlation (P<0.001) was found between μangle and both ANB and Wits indexes.

It was concluded that the new μ angle can accurately be utilized in clinical assessment of sagittal jaw relationship where the other skeletal measures such as ANB angle and Wits appraisal fail to accurately assess some of jaw relations due to anatomical and occlusal factors.