Vascularized Fibula TMJ Reconstruction: A Report of Five Cases featuring Computerized Patient-specific Surgical Planning

Updates on temporomandibular joint reconstruction following ablative surgery

PURPOSE OF REVIEW

Considerations regarding reconstruction of the temporomandibular junction (TMJ) following ablation have been underreported in head and neck surgery literature. Here, we discuss the complexity of reconstructing this unique joint and highlight the benefits and drawbacks of free tissue transfer. Additionally, we address the growing role of customized alloplastic implants and virtual surgical planning technologies in TMJ reconstruction.

RECENT FINDINGS

Technological advances in computerized manufacturing, 3D printing, and virtual reality have led to a recent burgeoning in patient-specific customization that may become the method of choice in these complex reconstruction cases.

SUMMARY

Since trauma and malignancy rarely compromise the entire TMJ, guidelines currently do not exist regarding how to best reconstruct the region in these unique cases. The methods that work in ankylosis and other intrinsic joint diseases are likely less appropriate in this patient population. Recent literature has reported improved patient outcomes and reduced operative times with virtual surgical planning techniques that may optimize autogenous graft approaches.

Osteo-cutaneous microvascular free-flaps are a viable option for reconstructing the temporomandibular joint

Background

There are multiple reconstructive options after mandibular resection and disarticulation of the condyle. The purpose of this study was to assess the clinical outcomes and functionality of osteocutaneous free flaps in the reconstruction of mandibular defects that involve the Temporo-Mandibular Joint (TMJ).

Methods

Our study is a retrospective cohort study involving subjects who underwent mandibular resection and needed TMJ reconstruction with vascularized bony-free flaps from February 2016 to June 2018. Data gathered included patient demographics, post-operative function, maximum interincisal opening (MIO), occlusion status, deviation on opening, and TMJ symptoms. Data points collected from postoperative CT imaging included the following: position of the flap in relation to the glenoid fossa and articular eminence, and closest point of contact.

Results

Eight out of the nine patients who underwent free flap reconstruction of mandibular defects involving the TMJ qualified for the study. The mean age was 39.7 years old. In all 8 cases, virtual surgical planning (VSP) was used. The mean follow-up time was 18.75 months. The flap success rate was 100%. The mean MIO was 37.37 mm. Six patients resumed their premorbid diet, and one patient developed dysphagia and was peg tube dependent. In seven cases the occlusion was intact and reproducible, one case was without sufficient teeth for occlusion. On imaging, the mean distance from the neo-condyle to the glenoid fossa was 14 mm and to the articular eminence 8.68 mm. The point of closest contact in all cases appeared to be the articular eminence.

Conclusion

Vascularized Osteocutaneous-flaps such as FFFs and DCIA flaps provide a good option for the reconstruction of mandibular defects that involve the TMJ. Ipsilateral deviation on opening does not negatively affect clinical outcomes or function. Placing patients in Maxillomandibular fixation for 4-6 weeks may help to prevent condylar sag and provide stable post-operative occlusion.

[Clinical analysis of denture rehabilitation after mandibular fibula free-flap reconstruction]

OBJECTIVE

To evaluate the postoperative denture restoration and denture function in patients with mandibular defect reconstructed with vascularized free fibula flap.

METHODS

In the study, 154 patients who underwent mandibular segment resection and used vascularized free fibula flap to repair mandibular defects due to inflammation, trauma and tumor from January 2015 to December 2020 were collected. These patients had common inclusion criteria which were stable occlusal relationship before operation, segmental defects of mandibular bone caused by lesions of mandible and adjacent parts (such as floor of mouth, tongue, cheek), free fibula flap used for repair and surviving after operation. Relevant data were reviewed and situation of denture restoration was followed up. A questionnaire related to denture functional evaluation had been proposed for those who had completed the denture rehabilitation. The evaluation index of denture restoration function was assigned by expert authority to obtain the denture function score. SPSS 18.0 software was used for statistical analysis of the basic information of the patients included in the study and the denture restoration of the patients.

RESULTS

The rate of postoperative denture restoration in the patients with mandibular defects repaired by free fibula flap was 17.5%, and the rate of postoperative denture restoration in the patients with benign mandibular tumors was 25.0% (18/72), which was significantly greater than that in the patients with malignant tumors 11.0% (9/82, P < 0.05). There was no significant difference in denture function score between the patients with condylar defect and those without condylar defect in denture repair rate and denture function score (P>0.05). The functional score of implant denture was significantly greater than that of removable denture (P < 0.05). According to Brown classification, the denture function score of the patients with the defect invo-lving the anterior mandibular region was significantly greater than that of the patients without the anterior mandibular region involved (P < 0.05). The poor oral conditions, such as less amount of remaining teeth, insufficient retention strength, large mobility of soft tissue in the surgical area, poor oral vestibular groove condition became the main reason of not receiving denture restoration (37.86%).

CONCLUSION

The denture rehabilitation of mandibular defect reconstructed with vascularized free fibula flap is closely rela-ted to pathological properties and oral conditions. The clinical outcome of implant denture has been confirmed effectively and it is a better choice for future denture restoration after mandibular reconstruction.