An analysis of the variation of the ANB angle
: a statistical appraisal.
Skeletal bi-max- illary protrusion or prognathic jaws is usually associ- ated with increased skeletal lower facial height, accen- tuated ANB angle
, short posterior cranial base, ante- rior positioned glenoid fossa and divergent facial planes.2
Cephalometric analysis of distracted mandible revealed decreased ANB angle
, decreased overjet and increased mandibular body and ramus length.6 In this study on an average for all the cases it was observed ANB angle
, overjet decreased mandibular body and ramus length was increased as per cephalometric analysis.
Lateral Cephalogram was then traced and sagital pattern of the patient was established from ANB angle
(ANB>40)13,14 and or wits value (1.5 mm).
For all the 40 samples AnB angle
was measured to confirm class I skeletal base with the SnA angle between 80-
Skeletal bi-maxillary protrusion or prognathic jaws is usually associated with prominent everted lips, convex facial profile, accentuated ANB angle
, short posterior cranial base, anterior positioned glenoid fossa and divergent facial planes.2
Skeletal type was determined based upon the ANB angle
and Wits, which indicates the positional relationship of the maxilla and mandible.
All the participants were divided in Class I or Class II skeletal patterns, according to the ANB angle
and WITS appraisal.
Similar results were found in a study by Jabbar et al3 they observed weak correlation between OJ and ANB angle
in all three malocclusion groups but found that it is statistically significant only in class III malocclusion.3
The lateral cephalometric films of all patients were traced and the anterior-posterior skeletal relationship of the maxilla and mandible was classified as skeletal Class I (ANB angle
between 0 and 4), Class II (ANB angle
5 or more), and Class III (ANB angle
less than 0) using the measurements of the Witz and ANB angle
The skeletal discrepancy between maxilla and mandible improved as reflected by the improved ANB angle
The study performed by Forster CM, Sunga E, Chung CH5 included only skeletal Class I (as determined by ANB angle
) subjects, contrary to our study which included all malocclusion groups.