Evaluation of The Relation Between Vertical Growth Pattern And Pharyngeal dimensions in CL II/ DIV I Patients

Considering the prevalence of skeletal open bite and existing controversies around the relation between pharyngeal dimensions and dentofacial as well as craniofacial structures, the aim of this study was to investigate the pharyngeal dimensions in CLII division I subjects with and without skeletal open bite malocclusion. This case control, double blind study was based on paraclinical data obtained through close analysis of files, cepholograms and study models. A total of 40 subjects, including 19 male and 21 females (mean age: 65.14± 1.53 yrs) were selected based on the maxillary-mandibular plan angle, SN-Mandibular plan angle, Y-Axis and Tarabak Index. The study group was divided into two groups. The case group included 20 subjects with skeletal open bite and the control group consisted of 20 subjects without skeletal open bite. The pharyngeal dimensions including nasopharyngeal, oropharyngeal and Hypopharyngel, depths were measured. The length of the airway and the distance between the hyoid bone and the mandibular plane were also recorded. Data was analyzed by T-test. There was no significant difference between the two groups in terms of Nasopharyngeal, Oropharyngeal and Hypopharyngeal dimensions. Significant statistical difference was found between the length of the airway in the case group (62.4± 3.78) and the control group (15.75± 3.76) (p<0.03). There was also statistically significant difference between the distance of Hyoid bone to mandibular plane in the case group (15.75± 3.76) and the control group (12.1± 3.64) (p<0.003). There was an increase in both variables in the case group. The Nosopharyngeal, Oropharyngeal and Hypopharyngeal depths are not associated with skeletal open bite The length of the airway and the Hyoidbone- Mandibular plane distance could affect the growth pattern. Pharyngeal dimensions or respiration patterns have no effect on the growth pattern.