A cephalometric comparative study of pharyngeal sagittal dimension in different skeletal patterns


Background: Because of the close relationship between pharynx and the dentofacial structures, this study was
conducted to find whether the pharyngeal sagittal dimension could be affected by the positional relationships
between jaws, and to determine the pharyngeal parameters difference in both genders in different skeletal patterns.
Subjects and method: The study sample consists of 120 digital radiographs of Iraqi subjects (60 males and 60 females)
attending Orthodontic Clinic in the College of Dentistry; University of Baghdad. The 120 radiographs were divided
into three groups (40 radiographs for each group) according to the ANB angles: ANB angle smaller than one degree
(Class III), between two and four degrees (Class I), and larger than four degrees (Class II), each group was further
divided into two subgroups according to gender (20 radiographs for each gender), eleven linear and two area
measurements were used to assess the pharyngeal structures.
Results: Student's t-test showed a significant difference (P<0.05) for t-PPW and Hy-APW2 measurements in all of the
three skeletal groups, with males had shorter t-PPW plane than females, and females had shorter Hy-APW2 plane
than males, on the other hand, Hy-APW4 plane and oropharyngeal area showed highest mean values in skeletal
class III, intermediate values in class I, and lowest mean values in class II in both males and females, F- test analysis of
variance showed highly significant differences (P<0.01) between all skeletal groups for total males and females in
regard t-PPW plane, Hy-APW2 plane, Hy-APW4 plane, and oropharyngeal area.
Conclusions: It can be concluded that the pharyngeal sagittal dimension have not been affected by gender type
except for t-PPW and Hy-APW2 planes, and the larger the ANB angle, the less Hy-APW4 and oropharyngeal area
measurements, and this may be attributed to the different location of the tongue, hyoid bone, and mandible in
skeletal class II malocclusion than other skeletal configurations.
Keywords: Pharyngeal sagittal dimension, skeletal patterns. (J Bagh Coll Dentistry 2011;23(1):100-106).