Epidermoid cyst in a temporomandibular joint dermal graft: report of a case and review of the literature

Epidermoid Cyst Mimicking a Cystic Parotid Tumor: A Diagnostic Dilemma Deciphered Intraoperatively

Cystic lesions in the preauricular may have various histological origins, ranging from the skin to the acinar and non-acinar lesions from the parotid. Though advanced radiological investigations provide a good insight into the diagnosis of these lesions, diagnostic dilemmas may still prevail and warrant good clinical and surgical acumen to provide optimal treatment. The aim of the current report is to describe a case of an epidermoid cyst that mimicked a parotid cyst and discuss in detail the probable differential diagnosis and their management strategies.

Histological evaluation of full thickness skin as an interpositional graft in the rabbit craniomandibular joint

PURPOSE

The purpose of this study is to determine the histological fate of the full thickness skin graft when placed into the temporomandibular joint using a rabbit model.

MATERIALS AND METHODS

Fourteen New Zealand white rabbits were used and divided into 3 groups. Two rabbits were used as controls (Group A) whereby a sham operation was undertaken with an incision made and immediately repaired without breaching the joint space of the left craniomandibular joint (CMJ). In 6 rabbits (Group B), the joint capsule of the left CMJ was surgically breached but the articular disc was preserved and the wound was repaired. The remaining 6 rabbits (Group C) also had the left CMJ surgically exposed with preservation of the articular disc and the interpositional placement of a full thickness skin graft that was taken from the skin of their necks. All grafts were placed above the articular disc and head of condyle in the superior joint space and firmly secured to the surrounding tissues with nonresorbable sutures. The rabbits were sacrificed at 1, 3, and 5 months after surgery and the left CMJs were histologically prepared and examined under light microscopy.

RESULTS

The condylar head in the regions where the disc was present appeared to closely resemble that of the control rabbits. However, where the disc was breached by inadvertent surgical trauma (Group B), the underlying condyle showed an irregular outline with increased fibrosis and a marked reduction in mature cartilage. In the subarticular bone there was increased osteoblast and osteoclast activity reflecting high bone activity indicative of a remodeling rather than a degenerative process. The interpositional skin grafts in all experimental animals (Group C) were found adjacent to the condyle on the lateral aspect rather than above the condylar head where it was originally sutured in place. Significant atrophy and reduction in the number and size of the skin appendages such as sweat glands and hair follicles was found within the grafted skin of all experimental animals (Group C) compared with normal skin. All the grafts showed evidence of epidermoid inclusion cysts.

CONCLUSIONS

The full thickness skin graft is not a suitable interpositional material for the TMJ because of the high risk of epidermoid cyst formation and the propensity for lateral displacement of the graft even when sutured into the appropriate intra-articular position.

The use of dermis grafts after discectomy for internal derangement of the temporomandibular joint

PURPOSE

The aim of this retrospective clinical study was to review the outcomes of temporomandibular joint (TMJ) discectomy with autogenous dermis used as an immediate interpositional graft in patients with advanced internal derangement of the TMJ.

PATIENTS AND METHODS

Thirty-five joints in 29 patients who presented with advanced internal derangement of the TMJ with degenerate and irreparable discs were identified and included in the study. All patients underwent a TMJ arthrotomy (including 6 bilateral TMJ procedures) that involved removal of the disc (discectomy) and immediate replacement with autogenous dermis graft. Patients were followed up for an average of 2 years.

RESULTS

There was a mean +6.7-mm improvement in maximum interincisal opening, a 66% mean improvement in pain ( P < .001), and a 42% mean improvement in function ( P < .05) after TMJ discectomy with immediate dermis graft replacement. After an average follow-up period of 24.6 months, patients reported good to excellent improvement in their TMJ symptoms in 30 of the 35 joints (85.7%). All patients showed radiologic evidence of varying degrees of condylar remodeling at 6 months or later after surgery. Of the 7 patients who had magnetic resonance imaging (MRI) performed at 6 months or later after surgery, none showed any radiologic evidence of the dermis graft. No clinical evidence of joint sounds such as crepitus was found in 33 of the 35 operated joints.

CONCLUSIONS

This study found that TMJ discectomy can have a significant positive effect on the management of patients with advanced internal derangement of the TMJ who fail to respond to less invasive measures such as splint therapy and TMJ arthroscopy. However, the only advantage of dermis grafts over no grafts seems to be that it can minimize or eliminate joint sounds such as crepitus in the discectomized TMJ. In this study, the dermis grafts did not prevent regressive remodeling of the mandibular condyles.

A unique case of an epidermoid cyst of the pterygopalatine fossa and its management

Epidermoid cysts are rare benign tumors that are derived from the development of abnormally situated ectodermal tissue. Although they may originate from any part of the body head and neck region is occasionally affected. Epidermoid cyst originating from pterygopalatine fossa has not been reported previously in the literature. We report the first case of epidermoid cyst of pterygomaxillary fossa in this study.