Abstract
Objective: Long time observation of the pharyngeal airway and hyoid bone position changes of class II division I cases following bionator treatment.
Materials and Methods: There were 86 (51 males and 35 females) Angle Class II division I patients diagnosed with mandibular deficiency collected in this study. All of them were treated by the modified bionator with lower incisor resin capping and expansion screw. Lateral cephalometric radiographs were taken before and after bionator treatment. Average treatment time was 1.75 years for males and 2.02 years for females. Five linear items of pharyngeal depths and seven linear items of hyoid bone position were measured. ANOVA was used to compare the four stages (before treatment, after treatment, 2 years follow up, and 4 years follow up) in both gender. The level of significance was set at p＜0.05.
Result: Pharyngeal depths were not changed significantly before and after treatment expect nasopharynx (D1) in both gender and hypopharynx(D5) in male. Hyoid bone position was maintain in the vertical position relate to the mandible (H5 and H6 changed not significantly) in male and female. Horizontally, hyoid bone moved forward immediately after bionator treatment but returned to posterior position later.
Conclusion: Through mandible advancement by bionator for class II treatment in growing patients, the pharyngeal airway depths were not change significantly at sagittal direction. However, after bionator treatment, hyoid bone was maintained in the vertical position related to mandible during growth.
Materials and Methods: There were 86 (51 males and 35 females) Angle Class II division I patients diagnosed with mandibular deficiency collected in this study. All of them were treated by the modified bionator with lower incisor resin capping and expansion screw. Lateral cephalometric radiographs were taken before and after bionator treatment. Average treatment time was 1.75 years for males and 2.02 years for females. Five linear items of pharyngeal depths and seven linear items of hyoid bone position were measured. ANOVA was used to compare the four stages (before treatment, after treatment, 2 years follow up, and 4 years follow up) in both gender. The level of significance was set at p＜0.05.
Result: Pharyngeal depths were not changed significantly before and after treatment expect nasopharynx (D1) in both gender and hypopharynx(D5) in male. Hyoid bone position was maintain in the vertical position relate to the mandible (H5 and H6 changed not significantly) in male and female. Horizontally, hyoid bone moved forward immediately after bionator treatment but returned to posterior position later.
Conclusion: Through mandible advancement by bionator for class II treatment in growing patients, the pharyngeal airway depths were not change significantly at sagittal direction. However, after bionator treatment, hyoid bone was maintained in the vertical position related to mandible during growth.
| Translated title of the contribution | Treatment Effects of the Modified Bionator on Pharyngeal Airway Depth, Hyoid Bone Position, and Craniofacial Change of Skeletal Class II Patients |
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| Original language | Chinese (Traditional) |
| Title of host publication | 中華牙醫學會第三十二次學術研討會 |
| Publication status | Published - 2009 |