Angular and dimensional linear analysis were performed on 100 patients with mandibular prognathism. The results were classified to show the relationship between maxilla and mandibule. Details are given below:
Sanborn's classification was followed for angular classification.
Group A: Maxilla within the normal range, mandibule beyond the normal range.
Group B: Mandibule within the normal range, maxilla below the normal range.
Group C: Maxilla and mandibule within the normal range.
Group D: Maxilla below the normal range, mandibule beyond the normal range.
Group E: Maxilla and mandibule beyond the normal range.
The linearly measured classification was performed according to the distance from a line perpendicular to SN plane through S to Point A and Pogonion.
typea-type e has the same relationship as Group A-Group E.
type f: Maxilla and mandibule below the normal range.
There were considerable differences between the angular and the linearly measured analyses. Which seems to have a close relationship to the distance of S-N.
It seems to be useful to display both classifications together in order to grasp precisely the form of mandibular prognathism and also to be useful clinically.
