Virtual Surgical Planning for Temporomandibular Joint Reconstruction with Stock TMJ Prostheses: Pilot Study

The temporomandibular joint (TMJ) is one of the most complex joints in the human anatomy. In advanced degenerative stages, conservative or minimally invasive surgical therapies have failed to restore joint function, and joint replacement with prostheses has been required. Stock prostheses, compared to custom-made prostheses, are much less expensive and require less pre-operative preparation time. Four patients followed for years for temporomandibular dysfunction and previously operated on by arthroscopy or open joint surgery that have been reconstructed with stock TMJ prostheses (STMJP) through virtual surgical planning (VSP) and an STL model with surgical and positioning guides were included. The median follow-up was 15 months; the median number of previous TMJ surgeries was 2. The mean preoperative MIO was 24.6 mm and at longest follow-up was 36.4 mm. The median preoperative TMJ pain score was 8, and the median postoperative TMJ pain was 3. All patients have improved their mandibular function with a clear improvement of their initial situation. In conclusion, we believe that stock TMJ prostheses with virtual surgical planning and surgical guides are a good alternative for TMJ reconstruction at the present time. Nonetheless, prospective and randomized trials are required with long-term follow up to assess their performance and safety.

Trans-mastoid anchorage as a novelty in glenoid fossa reconstruction for hemifacial microsomia with agenesis of zygomatic arch and external acoustic meatus-Technical note with a case illustration

Total joint reconstruction (TJR) has become the most preferred method of reconstruction in recent years for hemifacial microsomia (HFM). This requires meticulous planning for the glenoid fossa and ramus prosthesis along with the arch in certain indications. TJR in a type V HFM is extremely challenging due to agenesis/hypolasia of the zygoma and arch which compromises anchorage of the glenoid prosthesis. Conventional options used for such indications incorporate extended designs for the fossa. However, the two designs used commonly are associated with limitations; (i) the temporal extension is overtly large and cannot be anchored in patients with thin temporal bone and (ii) the glenoid fossa incorporated into the arch prosthesis, where the fossa is not positioned on stable bone and occlusal loading is non-physiological; transmitted onto the arch prosthesis rather than the skull base. The authors propose the use of the mastoid process as an alternative for anchorage of fossa prosthesis. This technique offers stable anchorage while facilitating ideal positioning on the skull base for optimal masticatory load transmission. The case illustration depicts reconstruction of the TMJ, zygoma and the zygomatic arch in a 31-year-old man with type V HFM, with a three-year follow-up, with good clinical outcomes sans complications.

Surgical management and final outcomes of chondrosarcoma of the temporomandibular joint: case series and comprehensive literature review

BACKGROUND

Surgical management for chondrosarcoma of the temporomandibular joint (TMJ) is challenging due to the anatomical location involving the facial nerve and the functional joint. The purpose of this case series was to analyze the largest number of TMJ chondrosarcoma cases reported from a single institution and to review the literature about chondrosarcoma involving the TMJ.

METHODS

Ten TMJ chondrosarcoma patients at Seoul National University Dental Hospital were included in this study. Radiographic features, surgical approaches, histopathologic subtypes, and treatment modalities were evaluated. All case reports of TMJ chondrosarcoma published in English from 1954 to 2021 were collected under PRISMA guidelines and comprehensively reviewed.

RESULTS

The lesions were surgically resected in all 10 patients with efforts to preserve facial nerve function. Wide excision including margins of normal tissue was performed to ensure adequate resection margins. All TMJs were reconstructed with a metal condyle except one, which was reconstructed with vascularized costal bone. At last follow-up, all patients were still alive, and there had been no recurrence. Among 47 cases (patients from the literature and our cases), recurrence was specified in 43 and occurred in four (9.5%).

CONCLUSIONS

For surgical management of TMJ chondrosarcoma, wide excision must consider preservation of the facial nerve. Reconstruction using a metal condyle prosthesis and a vascularized free flap is reliable. A more conservative surgical approach correlates with a favorable prognosis for facial nerve recovery. Nevertheless, wide excision is imperative to prevent tumor recurrence. In cases in which the glenoid fossa is unaffected by the tumor, it is deemed unnecessary to reconstruct the glenoid fossa within an oncological setting.

Analysis of maximum bite force and chewing efficiency in unilateral temporomandibular joint ankylosis cases treated with buccal fat pad interpositional arthroplasty

There is limited knowledge about masticatory function after the release of temporomandibular joint (TMJ) ankylosis. In this study, masticatory function was evaluated by measuring maximum voluntary bite force (MVBF) and chewing efficiency in 30 unilateral TMJ ankylosis patients who were treated with buccal fat pad (BFP) interpositional arthroplasty. Eighteen subjects over 12 years of age were included in study Group A and 12 subjects below 12 years of age in study Group B. Patients in the study groups had completed a minimum follow up of one year after surgery. Control groups C (over 12 years of age, n = 18) and D (under 12 years of age, n = 12) consisted of age, sex, and weight-matched normal subjects. The mean MVBF was measured between occluding molar teeth with a strain gauge transducer. Chewing efficiency was measured with two different coloured chewing gum strips. These were chewed for 5, 10, 20, 30, and 50 strokes. Compared with normal subjects, the study groups (A and B) could generate 64.7% (p = 0.004*) and 89.8% (p = 0.121) of MVBF, respectively. Overall chewing efficiency was 88.7% in Group A and 92.9% in Group B (p = 0.014* and p = 0.138, respectively) when compared with normal subjects. The study has shown that BFP interpositional arthroplasty effectively restores masticatory function.

Ankylosis management with autogenous grafts: A systematic review

A systematic review was performed to assess the clinical outcomes of the reconstructive methods using autogenous grafts for the management of temporomandibular joint (TMJ) ankylosis A comprehensive electronic and manual search of the literature without date or language restriction was performed in January 2021 to identify randomized controlled trials, prospective, and retrospective studies with the aim of comparing the various surgical modalities for TMJ ankylosis. Twenty-six publications were included: prospective (n ​= ​17), retrospective (n ​= ​7), randomised control trial (n ​= ​1) and ambispective study (n ​= ​1). Costochondral graft was the most common graft used followed by Coronoid process graft. Meta-analysis was not possible as most of studies were non-controlled in nature. Based on the available data, there was a strong evidence that autogenous grafts especially Costochondral grafts and coronoid grafts have remained one of the most favoured methods of reconstruction. Prospective and randomized control studies are recommended for the best stratification for the use of autogenous grafts for the management of TMJ ankylosis.

Temporomandibular Joint Reconstruction in the Growing Child

Indications and considerations for reconstruction of the temporomandibular joint (TMJ) differ between growing and skeletally mature patients. Osteoarthritis, which is the most common cause of TMJ destruction in adults, is comparatively rare in children. The most common indications in young patients are congenital deformities, pathology, ankylosis and progressive resorptive processes. Options for reconstruction include distraction osteogenesis, autologous reconstruction (ie, costochondral graft, free fibula flap), and total alloplastic joint replacement. The choice of the ideal reconstruction is based on multiple factors, which include extent and laterality of the deformity, patient age, jaw growth pattern, and potential for progressive destruction.

Transport Distraction Osteogenesis in Reconstruction of Condyle: Use of a 3D Model for Vector Planning

Introduction

The temporomandibular joint (TMJ) is a complex joint, and it allows bilateral synchronous rotatory and translatory movements. TMJ reconstruction has evolved as an important step in the management of conditions affecting the TMJ like ankylosis, traumatic injuries and congenital deformities. Distraction osteogenesis (DO) is a biological process of forming new bone and adjacent soft tissues by gradual and controlled traction applied on osteotomized bone segments.

Case report

Here is a case report of bilateral TMJ ankylosis which was managed effectively by resection of ankylotic mass and reconstruction of TMJ by transport distraction osteogenesis with preoperative vector planning using a 3D printed model.

Conclusion

Distraction osteogenesis can be considered as an effective means of condylar reconstruction for an anatomical and functional TMJ with minimal complications. Use of 3D models can help making such complex TMJ reconstruction procedures simpler.

Novel technique for harvesting the sternoclavicular graft

PURPOSE

Originally introduced for mandibular reconstruction more than 40 years ago, the sternoclavicular graft (SCG) has gained widespread popularity for the reconstruction of the ramus-condyle unit (RCU) owing to its anatomic and histological likeness to the normal mandibular condyle. Conventional longitudinal osteotomy design for its harvest has been fraught with considerable complications at the donor site including fracture clavicle and major neurovascular injury. In an attempt to alleviate these ill effects, a new technique for procuring the sternoclavicular graft is presented.

MATERIAL AND METHODS

A split-thickness cortico-cancellous graft was harvested form the sternal end of the clavicle along with the articular disk with the osteotomy cut oriented parallel to the coronal plane, with limited soft tissue dissection. Donor site complications were assessed in terms of incidence of clavicle fracture, neurovascular injury, pleural tear and radiographic healing as seen in the six-month postoperative chest radiograph.

RESULTS

17 patients suffering from unilateral temporomandibular joint ankylosis underwent SCG harvesting for RCU reconstruction following osteoarthrectomy. No adverse events were seen in the intra- and post-operative period in any patient and satisfactory radiographic osseous healing was observed after six months.

CONCLUSION

The proposed harvest technique for SCG results in reduced donor site morbidity and favourable healing and greater patient comfort.

Bilateral alloplastic prostheses for temporomandibular joint reconstruction in a patient with ankylosing spondylitis

Ankylosing spondylitis (AS) or Bechterew disease is a chronic, usually progressive, systemic inflammatory joint disease, which predominantly affects the spine and sacroiliac joints. In these joints, early inflammatory changes are followed by lumbosacral pain and progressive restriction of spinal movement associated with radiologically visible intervertebral ossification. Peripheral joint involvement occurs in 10 to 30% of patients and shows a predilection for the shoulders, knees, ankles, feet, and wrists. Temporomandibular joint (TMJ) involvement has been described, and its reported frequency varies from 11 to 35%. However, ankylosis is uncommon with a single documented case utilizing an alloplastic prosthesis for total joint replacement. A case report of bilateral ankylosis of the jaw treated with alloplastic prostheses for total TMJ replacement using a Brazilian system in a patient with AS is presented.