Effects of twin-block appliance on the anatomy of pharyngeal airway passage (PAP) in class II XXXX subjects.

@entity1 @entity7551 @entity27 @entity3232
BACKGROUND: The use of functional appliances for the correction of retrognathic mandible is very common in orthodontics. Similar appliances known as oral appliances are also frequently used in adults for the treatment of mild to moderate @entity27 ( @entity27 ). Many studies have reported improvement of pharyngeal airway passage (PAP) dimensions following functional appliance therapy in @entity1 and oral appliance therapy in adults. There is only one study in the literature that discussed the effect of oral appliance therapy on @entity7551 ( @entity7551 ) among subjects with @entity27 . The effect of functional appliance therapy on @entity7551 has never been investigated. Thus the present study was conducted to evaluate the effects of twin-block appliance on pharyngeal airway passage (PAP) dimensions and @entity7551 ( @entity7551 ) in class II @entity3232 subjects with retrognathic mandibles. METHODS: Thirty-eight class II @entity3232 subjects in the age range of 8 to 14 years with mandibular retrusion were divided into a treatment (n   =   20) and control (n   =   18) group. Mandibular retrusion in the treatment group subjects was corrected by twin-block appliance. The effect of twin-block appliance on PAP and @entity7551 dimensions were evaluated from lateral cephalograms recorded prior-to and after 6 months of appliance therapy in the treatment group subjects and the changes were compared with the changes in the control group subjects. Student's t-test was used for statistical analysis; P-value of 0.05 was considered a statistically significant level. RESULTS: The depth of the oropharynx was increased significantly in the treatment group subjects (P   <   0.001) as compared to the control group subjects (P   <   0.05). The depth of the hypopharynx increased significantly in treatment group subjects (P   <   0.01). The @entity7551 at the level of the nasopharynx, oropharynx, and hypopharynx were maintained in the treatment group subjects; whereas in control group subjects, the @entity7551 was further reduced although the changes were not statistically significant. CONCLUSIONS: Correction of mandibular retrusion by twin-block appliance in class II @entity3232 subjects increased the PAP dimensions and maintained the pre-treatment thickness of posterior pharyngeal wall.
