The position of glenoid fossa in different skeletal patterns and its relation to the functional occlusal plane

Abstract

ABSTRACT
Background: Glenoid fossa position plays an important role in the establishment of different craniofacial patterns. The
purposes of this study were to verify the position of the glenoid fossa in subjects with different sagittal and vertical
skeletal patterns, to assess the correlation between the position of glenoid Fossa and skeletal patterns (sagittal and
vertical), and to assess the correlation between the position of the glenoid fossa and the functional occlusal plane.
Materials and method: A lateral cephalometric study was carried out on 124 subjects aged 18-30 years who were
classified according to skeletal sagittal relationships using ANB angle into three groups (Cl. І =48, Cl. ІІ =41, Cl. ІІІ =35
subjects), and according to skeletal vertical relationships using MP-SN angle into three groups (normal angle=67, high
angle=23, low angle=34 subjects). Cephalometric analysis comprised both sagittal and vertical measurements for the
assessment of the position of the glenoid fossa in relation to surrounding skeletal structures. The assessment was
achieved by measuring three angular and seven linear variables using the AutoCAD computer program 2008.
Results: The results revealed that in sagittal skeletal relation, the glenoid fossa position was more posterior in skeletal
Class II when compared with skeletal Class III, while in the vertical plane; the position of the glenoid fossa relative to
Basicranial structures was more caudal in low angle subjects when compared with subjects with normal or high angle
vertical relationships. On the other hand, there was no correlation between the position of the glenoid fossa and the
functional occlusal plane.
Conclusions: Class II skeletal relation is associated with a more posterior position of the glenoid fossa when compared
to Class III skeletal relation regarding the Anteroposterior plane. Subjects presenting with high angle vertical
relationships show a more cranial position of the glenoid fossa in relation to the cranial base when compared to
subjects with either normal or low angle vertical relationships regarding the vertical plane. This study did not reveal a
strong relationship between the glenoid fossa position and the functional occlusal plane in anteroposterior and
vertical relationships.
Key words: Glenoid fossa, functional occlusal plane, skeletal relation. (J Bagh Coll Dentistry 2010;22(2):81-86).