Three-dimensional surgical guide approach to correcting skeletal Class II malocclusion with idiopathic condylar resorption

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders: A case report and review of literature

BACKGROUND

The relation between orthodontic treatment and temporomandibular disorders (TMDs) is under debate; the management of TMD during orthodontic treatment has always been a challenge. If TMD symptoms occur during orthodontic treatment, an immediate pause of orthodontic adjustments is recommended; the treatment can resume when the symptoms are managed and stabilized.

CASE SUMMARY

This case report presents a patient (26-year-old, female) with angle class I, skeletal class II and TMDs. The treatment was a hybrid of clear aligners, fixed appliances and temporary anchorage devices (TADs). After 3 mo resting and treatment on her TMD, the patient's TMD symptom alleviated, but her anterior occlusion displayed deep overbite. Therefore, the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves. After the levelling, the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion. After careful examination of temporomandibular joints (TMJ) position, the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion. Eventually, the improved facial appearance and relatively stable occlusion were achieved. The 1-year follow-up records showed there was no obvious change in TMJ morphology, and her occlusion was stable.

CONCLUSION

TMD screening and monitoring is of great clinical importance in the TMD susceptible patients. Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

Mandibular stability and condylar changes following orthognathic surgery in mandibular hypoplasia patients associated with preoperative condylar resorption

OBJECTIVES

To evaluate postoperative mandibular stability and condylar changes in patients with mandibular hypoplasia and preoperative condylar resorption (CR) undergoing orthognathic surgery.

MATERIALS AND METHODS

Fifty-four patients were included in this retrospective study. Computed tomography (CT) scans were acquired preoperatively (T0), 2-7 days immediate postoperatively (T1), and at least 1 year postoperatively (T2). Three-dimensional (3D) cephalometric analysis and measurements of condylar angle, volume, and position (joint spaces) were performed. A 2-mm mandibular relapse was deemed clinically acceptable. We also analyzed the correlations between relapse and postoperative CR and susceptible factors using a multivariate logistic regression model.

RESULTS

The results showed one year after the surgery, the average mandibular relapse was 1.0 mm (p < 0.05), and the average reduction of condylar volume was 152.4 mm³ (12.7%). Condyle-fossa relationships were improved immediately after the surgery, with a tendency of returning to their original state in the follow-up (p < 0.05). Anteroposterior advancement at point B (B-CP advancement) at T1 and superior joint space (SJS) at T0 were significantly correlated with mandibular relapse, and postoperative CR was mainly associated with vertical increasement at point B (B-AP increasement) at T1. The optimal cut-off values were as follows: 1.6 mm for SJS, 4.2 mm for B-CP advancement, and 1.8 mm for B-AP increasement. Concomitant advancement Genioplasty showed no significant correlation with relapse and postoperative CR.

CONCLUSIONS

While patients with mandibular hypoplasia and preoperative CR were vulnerable to further condylar resorption after mandibular advancement, the treatment outcomes were generally clinically acceptable. Postoperative relapse was associated with a larger than 4.2 mm of mandibular advancement measured at B-CP and a larger than 1.6 mm of superior joint space measured at SJS, and postoperative CR was associated with a larger than 1.8 mm of mandibular vertical increasement measured at B-AP.

CLINICAL RELEVANCE

The findings of this study suggested that the mandibular advancement might be limited to 5 mm for patients with preoperative CR. A concomitant advancement genioplasty might also be considered to achieve a better facial profile in these patients.