Longitudinal MRI follow-up of non-reducible posterior disc displacement accompanied by bone marrow oedema in the mandibular condyle

Posterior disc displacement of the temporomandibular joint: A rare case report

BACKGROUND

Posterior disc displacement (PDD) of the temporomandibular joint (TMJ) is quite rare. The normal position of a disc is slightly anterior to the condyle, so the chances of disc displacement to the posterior direction are low.

CASE PRESENTATION

A 71-year-old Japanese female reported with a chief complaint of lack of occlusion on the right-side molar teeth. Clinical examination revealed lack of occlusal contact in the right posterior region, nearly normal range of mouth opening (41.0 mm), masseter muscle tenderness, and deviation to the left on opening. MRI of the right TMJ showed PDD in both the open- and closed-mouth position and joint effusion. Conservative treatment with a non-steroidal anti-inflammatory drug, stretch exercise with fingers, and stabilization splint improved symptoms for 9 months.

CONCLUSION

Conservative treatment was effective in managing the patient. A follow-up for 9 months with a repeat MRI was undertaken to monitor the progress.

Expression of MMP-13 in human temporomandibular joint disc derangement and osteoarthritis

OBJECTIVE

MMP-13 performs digestion of collagen, which is a primary component of the temporomandibular joint (TMJ) articular disc. This study evaluated the expression of MMP-13 in patients with anterior disc displacement with (ADDwR) and without reduction (ADDwoR), and in the presence of TMJ osteoarthrosis.

METHODS

Thirty-nine human temporomandibular joint disc samples were collected and divided in two ways: ADDwR (21 samples), ADDwoR (10 samples), and a control group (8 samples); and with osteoarthrosis (10 samples) and without osteoarthrosis (29 samples). Immunostaining of the TMJ discs was statistically compared between the groups.

RESULTS

There was no statistically significant difference for the area of MMP-13 immunostaining between the control group, ADDwR, and ADDwoR, nor between groups with and without osteoarthrosis.

CONCLUSION

This study suggests MMP-13 is not significantly involved in collagen degradation in human TMJ disc displacement or osteoarthrosis.

Interleukin-6 expression in disc derangement of human temporomandibular joint and association with osteoarthrosis

The inflammatory process is a coordinated response that protects host after infection or trauma, involving several molecular reactions. Once the inflammation is closely linked to the process of destruction of the temporomandibular joint, this study aims to examine, by immunohistochemistry, the expression of interleukin-6 (IL-6), an important inflammatory marker, in temporomandibular articular discs of patients with anterior disc displacement with (ADDwR) and without reduction (ADDwoR) and its association with osteoarthrosis (OA). Thirty-eight (n = 38) articular discs were divided into two cutoffs: 1) analysis 1: 4 control (acute pathology), 17 ADDwR, 17 ADDwoR; and 2) analysis 2: without OA (n = 21) and with OA (n = 17). The area of immunostaining was compared statistically between groups (p < 0.05). In the disc samples, no significant differences were observed between the groups ADDwR and ADDwoR, and with and without OA, in respect to the expression of IL-6 by immunohistochemical examination. Future studies should be conducted with a larger sample size, which could clarify the association of the inflammatory mediator IL-6 with temporomandibular joint dysfunction.

Automobilization intervention and exercise for temporomandibular joint open lock

Temporomandibular joint disorders (TMDs) are common and may cause temporomandibular joint (TMJ) locking, pain, and disability. Evidence supports use of manual therapy and exercise for treatment of TMDs including disk displacement limiting full mouth opening, TMJ 'closed lock'. Only limited case studies describe management of TMJ 'open lock', a condition due to posterior disk displacement (PDD) or TMJ anterior dislocation (TMJ-AD). Reported treatment for open lock includes splinting and intraoral joint manipulation. This case report describes a novel extraoral automobilization using the mandibular elevator muscles to treat TMJ open lock in a 22-year-old male after intraoral joint mobilization failed. The exercise program used to restore neuromuscular control for post-reduction management is described. Short term results of automobilization were excellent with restored ability to swallow, speak normally, and achieve occlusion. Long term results at 14 months were good: the patient was pain-free, could swallow and speak normally, had no recurrence of TMJ locking, and minimal disability. Limited right lateral excursion range and left mandibular deviation during mouth opening indicated possible persistence of PDD. This case suggests that mandibular elevator automobilization and masticatory muscle exercise may be useful to treat TMJ open lock and should be considered to treat PDD and TMJ-AD.

FasL expression in articular discs of human temporomandibular joint and association with osteoarthrosis

BACKGROUND

Apoptosis is a programme of cell death which does not induce an inflammatory response. Recent previous research has suggested a correlation between temporomandibular internal derangement and apoptosis. Fas ligand (FasL) is an apoptosis-inducing factor, known to trigger apoptosis through distinct signal pathways. This study aims to examine, by immunohistochemistry, the expression of FasL in temporomandibular joint (TMJ) articular discs of patients with anterior disc displacement with reduction (ADDwR) and without reduction (ADDwoR) in patients with and without osteoarthrosis (OA).

METHODS

Forty-two (n = 42) TMJ articular discs were divided into two cut-offs: (i) 8 control, 17 ADDwR, 17 ADDwoR, and (ii) without OA (n = 25) and with OA (n = 17). The area of immunostaining was compared statistically between groups (P < 0.05).

RESULTS

Statistically significant differences were found in the expression of FasL in TMJ discs between the three groups (P = 0.001). ADDwR presented significant higher FasL expression when compared with ADDwoR (P < 0.001). Significant higher FasL expression was observed in the group without OA (P = 0.001). All patients without OA presented ADDwR, while all the patients with OA presented ADDwoR.

CONCLUSION

A higher area of in situ immunostaining of FasL was found in temporomandibular discs with reduction, which is the less severe condition. Moreover, a reduced expression of FasL in the discs of patients with osteoarthrosis was found, suggesting that some aspects of apoptosis might underlie the progression of TMJ disorders.

Temporomandibular joint disk fracture: a case report

A case of a patient with a fracture of the temporomandibular joint (TMJ) disk is reported. The patient presented with posterior bilateral open-bite and difficulty to chew due to lack of contact between the posterior teeth. Diagnosis of disk fracture of the right TMJ was made based on magnetic resonance imaging (MRI), with posterior displacement of the posterior fragment of the disk, causing the posterior open-bite, and anterior displacement of the anterior fragment of the disk. TMJ manipulation failed to reposition the posterior fragment of the disk, and the patient refused to undergo TMJ arthroscopy to try to remove it. After four months, the posterior open-bite was reduced, probably because of remodeling of the posterior TMJ capsule and extrusion of the molars and premolars. Contact with the patient was lost after that time.

Internal derangements of the temporomandibular joint

This article discusses several types of internal derangements of the temporomandibular joint. It includes definitions, clinical characteristics, and management options. Nonsurgical and surgical treatment strategies are discussed taking into consideration the latest evidence-based literature.