Cephalometric analysis of the middle part of the face in patients with mandibular prognathism
Authors: Cutovic Tatjana , Jovic Nebojsa , Kozomara Ruzica , Radojcic Julija , Janosevic Mirjana , Mladenovic Irena , Matijevic Stevo 
Published: October 2014

Background/Aim. The middle part of the face, that is the maxilla, has always
been mentioned as a possible etiologic factor of skeletal Class III. However,
the importance of the relationship of maxillary retroposition towards the
cranial base is still unclear, although it has been examined many times. The
aim of this study was to conduct cephalometric analysis of the morphology of
maxilla, including the whole middle part of the face in patients with
divergent and convergent facial types of mandibular prognathism, as well as
to determine differences betweeen them. Methods. Lateral cephalometric
teleradiograph images of 90 patients were analyzed at the Dental Clinic of
the Military Medical Academy, Belgrade, Serbia. All the patients were male,
aged 18-35 years, not previously treated orthodontically. On the basis of
dentalskeletal relations of jaws and teeth, the patients were divided into
three groups: the group P1 (patients with divergent facial type of mandibular
prognathism), P2 (patients with convergent facial type of mandibular
pragmathism) and the group E (control group or eugnathic patients). A total
of 9 cephalometric parameters related to the middle face were measured and
analyzed: the length of the hard palate - SnaSnp, the length of the maxillary
corpus - AptmPP, the length of the soft palate, the angle between the hard
and soft palate - SnaSnpUt, the angle of inclination of the maxillary
alveolar process, the angle of inclination of the upper front teeth, the
effective maxillary length - CoA, the posterior maxillary alveolar
hyperplasia - U6PP and the angle of maxillary prognathism. Results. The
obtained results showed that the CoA, AptmPP and SnaSnp were significally
shorter in patients with divergent facial type of mandibular prognathism
compared to patients with convergent facial type of the mandibular
prognathism and also in both experimental groups of patients compared to the
control group. SnaSnp was significantly shorter in patients with divergent
facial type of mandibular prognathism compared to the control group, whereas
SnaSnp was significantly smaller in patients with convergent facial type of
mandibular prognathism compared to the control group. Additionally, there was
a pronounced incisor dentoalveolar compensation of skeletal discrepancy in
both groups of patients with mandibular prognathism manifested in the form of
a significant upper front teeth protrusion, but without significant
differences among the groups, while the maxillary retrognathism was present
in most patients of both experimental groups. A pronounced UGPP was found
only in the patients with divergent type of mandibular prognathism.
Conclusion. The maxilla is certainly one of the key factors which contributes
to making the diagnosis, but primarily to making a plan for mandibular
prognathism treatment. Accurate assessment of the manifestation of
abnormality, localization of skeletal problems and understanding of the
biological potential are key factors of the stability of the results of
surgical-orthodontic treatment of this abnormality.