Treatment of Posterior Dislocation of the Mandibular Condyle With the Double Mitek Mini Anchor Technique: A Case Report

Platelet rich fibrin as a bioactive matrix with proosteogenic and proangiogenic properties on human healthy primary cells in vitro

Blood concentrates like platelet rich fibrin (PRF) have been established as a potential autologous source of cells and growth factors with regenerative properties in the field of dentistry and regenerative medicine. To further analyze the effect of PRF on bone tissue regeneration, this study investigated the influence of liquid PRF matrices on human healthy primary osteoblasts (pOB) and co-cultures composed of pOB and human dermal vascular endothelial cells (HDMEC) as in vitro model for bone tissue regeneration. Special attention was paid to the PRF mediated influence on osteoblastic differentiation and angiogenesis. Based on the low-speed centrifugation concept, cells were treated indirectly with PRF prepared with a low (44 g) and high relative centrifugal force (710 g) before the PRF mediated effect on osteoblast proliferation and differentiation was assessed via gene and protein expression analyses and immunofluorescence. The results revealed a PRF-mediated positive effect on osteogenic proliferation and differentiation accompanied by increased concentration of osteogenic growth factors and upregulated expression of osteogenic differentiation factors. Furthermore, it could be shown that PRF treatment resulted in an increased formation of angiogenic structures in a bone tissue mimic co-culture of endothelial cells and osteoblasts induced by the PRF mediated increased release of proangiogenic growth factors. The effects on osteogenic proliferation, differentiation and vascularization were more evident when low RCF PRF was applied to the cells. In conclusion, PRF possess proosteogenic, potentially osteoconductive as well as proangiogenic properties, making it a beneficial tool for bone tissue regeneration.

Prediction of jaw opening function after mandibular reconstruction using subject-specific musculoskeletal modelling

BACKGROUND

Mandibular reconstruction patients often suffer abnormalities in the mandibular kinematics. In silico simulations, such as musculoskeletal modelling, can be used to predict post-operative mandibular kinematics. It is important to validate the mandibular musculoskeletal model and analyse the factors influencing its accuracy.

OBJECTIVES

To investigate the jaw opening-closing movements after mandibular reconstruction, as predicted by the subject-specific musculoskeletal model, and the factors influencing its accuracy.

METHODS

Ten mandibular reconstruction patients were enrolled in this study. Cone-beam computed tomography images, mandibular movements, and surface electromyogram signals were recorded preoperatively. A subject-specific mandibular musculoskeletal model was established to predict surgical outcomes using patient-averaged muscle parameter changes as model inputs. Jaw bone geometry was replaced by surgical planning results, and the muscle insertion sites were registered based on the non-rigid iterative closest point method. The predicted jaw kinematic data were validated based on 6-month post-operative measurements. Correlations between the prediction accuracy and patient characteristics (age, pathology and surgical scope) were further analysed.

RESULTS

The root mean square error (RMSE) for lower incisor displacement was 31.4%, and the error for peak magnitude of jaw opening was 4.9 mm. Age, post-operative infection and radiotherapy influenced the prediction accuracy. The amount of masseter detachment showed little correlation with jaw opening.

CONCLUSION

The mandibular musculoskeletal model successfully predicted short-range jaw opening functions after mandibular reconstruction. It provides a novel surgical planning method to predict the risk of developing trismus.

Evaluation of the effects of prolotherapy on condyles in temporomandibular joint hypermobility using fractal dimension analysis

Objectives

Prolotherapy is a method that has gained popularity in recent years and has been reported to have positive short-term and long-term clinical results in maxillofacial surgery, especially temporomandibular joint (TMJ) hypermobility. This study aimed to evaluate the changes in the trabecular structure of mandibular condyles in patients who underwent prolotherapy due to TMJ hypermobility using the fractal analysis method.

Materials and Methods

Forty-five patients who received dextrose prolotherapy at a concentration of 20% and fifteen control patients were included in the study. All patients had panoramic radiographs just before (T0) and six months after treatment (T1). The patients who received treatment were divided into three groups according to the number of prolotherapy injections. The regions of interest were selected from bone areas close to the articular surfaces of the condyles. The fractal dimension (FD) values were calculated.

Results

The main effect of time on the FD value was significant [F (1, 56)=86.176, P<0.001]. This effect was qualified by a significant time×group interaction effect [F (3, 56)=9.023, P<0.001]. The decreases in FD values in all treatment groups between T0 and T1 times were significant (P=0.004). However, changes in FD values were not significant in the control group (P=0.728).

Conclusion

Dextrose prolotherapy without the effect of the number of injections caused a decrease in FD values in the mandibular condyles over time.

Mini suture anchor: An effective device for reduction and fixation of displaced temporomandibular joint disc with intracapsular condylar fracture

PURPOSE

The main aim is to provide clinical reference for the application of mini suture anchor in the reduction and fixation of displaced temporomandibular joint (TMJ) disc with intracapsular condylar fracture.

METHODS

From October 2018 to October 2019, 21 patients (31 sides) with intracapsular condylar fractures and articular disc displacement from West China Hospital of Stomatology, Sichuan University were included. The selection criteria were: (1) mandibular condylar fractures accompanied by displacement of the TMJ disc, confirmed by clinical examination, CT scan and other auxiliary examinations; (2) indication for surgical treatment; (3) no surgical contraindications; (4) no previous history of surgery in the operative area; (5) no facial nerve injury before the surgery; (6) informed consent to participate in the research program and (7) complete data. Patients without surgical treatment were excluded. The employed patients were followed up at 1, 3, 6 and 12 months after operation. Outcomes were assessed by success rate of operation, TMJ function and radiological examination results at 3 months after operation. Data were expressed as number and percent and analyzed using SPSS 19.0.

RESULTS

All the surgical procedures were completed successfully and all the articular discs were firmly attached to the condyles. The articular disc sufficiently covered the condylar head after the fixation. The fixation remained stable when the mandible was moved in each direction by the surgeons. No complications occurred. The functions of the TMJ were well-recovered postoperatively in most cases. CT scan revealed that the screws were completely embedded in the bone without loosening or displacement.

CONCLUSION

Mini suture anchor can provide satisfactory stabilization for the reduced articular disc and also promote the recovery of TMJ functions.

Bilateral Posterior Dislocation of Mandibular Condyle: A Rare Entity in Maxillofacial Injuries

Background

Dislocation of the mandibular condylar head refers to ectopic positioning of the intact condylar head out of the glenoid fossa. Most commonly reported anterior dislocation results from anteromedial pull of the lateral pterygoid muscle and laxity of the surrounding tissue with advanced age.

Purpose

This case report brings forth a unique case of bilateral posterior condylar dislocation in an edentulous patient who reported after 4 weeks of traumatic injury.

Method

The condition was managed surgically by reduction of the dislocated condyle and placement of mersilene tape on one side and temporalis muscle on the other side as anchorage ligament to stabilize the condyle and prevent any future recurrence.

Results

The patient was maintained on long-term follow-up for up to one year with no reported recurrence or reduction in mouth opening.

Conclusion

This is the first ever case report that highlights bilateral posterior dislocation of intact mandible unlike the previous four reports which have brought forth unilateral dislocation on English literature search. Posterior dislocation of mandibular condyle is encountered in edentulous patients who experience posteriorly directed impact which forces the condylar head behind the postarticular ridge. Unlike anterior dislocation, clinical features include reduced mouth opening and retruded mandible in bilateral dislocation. It has been observed that manual correction by pressing the mandible downwards and forwards yields good results in early cases. Cases that are reported late require surgical exploration for reduction and placement of anchorage ligament to prevent recurrence in unstable condyle.

Mini-Anchors to Surgically Treat the Chronic Mandibular Dislocation

PURPOSE

Evaluate the feasibility of using mini-anchors for the treatment of chronic mandibular dislocation and to identify the variables that affect the success of this approach.

PATIENTS AND METHODS

A retrospective cohort study evaluated 9 patients with bilateral recurrent dislocation of the mandible (18 operated joints), treated by a mandibular translation control system using the mini-anchor technique. Data was collected using a Visual Analog Scale (VAS) for subjective parameters and measurements for objective parameters prior to surgery (T1) and at the longest available follow-up (T2) with a minimum of a 12 months interval. Patients subjectively rated their facial pain/headache, jaw function, disability, temporomandibular joint (TMJ) pain and diet. Objective functional changes were determined by measuring the interincisal opening and lateral excursions at T1 and T2.

RESULTS

Significant subjective improvements in pain and dysfunction (89 to 94%) were observed (P < .01) from T1 to T2 in all parameters. The comfortable and guarded interincisal opening without mandibular dislocation increased by 41%, the maximum interincisal opening reduced 12 mm, and lateral excursions improved by 43%.

CONCLUSIONS

Patients with recurrent mandibular dislocations with or without disc dislocation can be treated effectively by the mini-anchor translation control system.