Evaluation of the change in the tongue posture and in the hyoid bone position after Twin Block appliance therapy in skeletal class II subjects

Evaluation of head and cervical spine posture after functional therapy with Twin‑Block and Bionator appliances: A pilot randomized controlled trial

OBJECTIVE

Evaluation of head and cervical spine posture and estimation of sample size.

METHODS

Thirty eligible participants who required functional therapy were randomly assigned to the Control group (C), Twin Block group (TB), or the Bionator group (B). Randomization was accomplished by means of blocks of fixed size stratified by sex and age, with the allocations concealed in opaque and sealed envelopes.

RESULTS

Significant differences were identified between the pre -and post-functional SNB (p = 0.024) and ANB (p = 0.034) angles in the Twin Block group and SNA (p = 0. 019) and ANB (p = 0. 028) angles in the Bionator group. No statistically significant changes were seen in the head or cervical variables in the three groups.

CONCLUSION

The functional appliance did not cause any statistical change in head posture or cervical spinal column in comparison with the non-treatment group.

Three-dimensional evaluation of upper pharyngeal airway, hyoid bone, and craniocervical changes following stabilization splint therapy in adult patients with temporomandibular joint disorders and mandibular deviation: A retrospective study

OBJECTIVE

This study aimed primarily to analyze the three-dimensional (3D) changes in the pharyngeal airway (PA), and secondarily, the hyoid bone (HB) and the craniocervical (CC) following stabilization splint (SS) therapy in adult patients with temporomandibular joint disorders (TMD) and mandibular deviation (MD).

METHODS

Thirty-five adult patients with TMD and MD, who were treated using SS with a mean age of 25.14 ± 6.11 years, were enrolled in this retrospective clinical study. Pre- and post-therapeutic cone-beam computed tomography (CBCT) scans were analyzed. PA dimension,nasopharyngeal, oropharyngeal, hypopharyngeal, sub-hypopharyngeal, and total pharyngeal airway spaces were measured in surface area, volume, minimum constricted area (MCA) and width, HB position, and CC posture were analyzed three-dimensionally using InVivo 6.0.3 and Dolphin 11.95 software. Wilcoxon rank-sum or Paired t-test was conducted, and P < 0.05 was considered significant.

RESULTS

SS therapy was administered for a period of 9.49 ± 4.02 months. The oropharyngeal airway space showed a significant decrease in sagittal width. The hypopharyngeal surface area, volume, MCA, and sagittal width decreased significantly. In terms of HB, hyoid-mandibular plane (H-MP), retrognathia-third vertebra's most inferior-anterior (RGN-C3ia), and retrognathia-Sella (RGN-S) distances significantly decreased. The Nasion-Sella line and the line that passes through C2ip to the odontoid process posterior tangent (NSL-OPT) angle in CC posture also decreased significantly.

CONCLUSION

SS therapy in TMD patients with MD mainly results in narrowing of the hypopharyngeal region, no change in HB position and improvement in head posture. These results undoubtedly assist in diagnosis and treatment of clinical conditions.

Effects of Elastodontic Appliance on the Pharyngeal Airway Space in Class II Malocclusion

BACKGROUND

The present study analyzed the changes obtained on the upper airway and hyoid bone dimensions in a group of patients with skeletal Class II malocclusion treated with functional elastodontic devices compared to an untreated control group.

METHODS

A group of 33 patients (19 females and 14 males) with Class II malocclusion treated with AMCOP^® SC elastodontic device was compared with a control group of 35 subjects (17 females and 18 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start (T0) and end of treatment/period of observation (T1). Cephalometric analysis was performed and linear measurements to evaluate airway space and hyoid bone position were also obtained. A multivariate analysis of variance for repeated measures (MANOVA) was performed to determine the effects of interactions for the groups for time.

RESULTS

Statistically significant differences were found in the study group from T0 and T1 with an improvement of superior upper airway (SPAS p < 0.0001), while in the control group it did not change in a statistically significant way from T0 to T1. The MANOVA test showed statistically significant differences between the two groups for the changes of SPAS (p = 0.003), IAS (p = 0.049), and H-C3 vertical (p = 0.038) values.

CONCLUSIONS

Functional elastodontic therapy produced significant favorable airway changes in skeletal class II subjects.