When performing open surgery for internal derangement of the temporomandibular joint, it is essential to expand the joint spaces to access the lesions and perform various procedures. This paper presents a simple method to achieve this goal.
Regardless of which technique is used to treat internal derangement (ID) of the temporomandibular joint (TMJ), following exposure of the TMJ capsule to visualize the anatomic structures, detect the lesions and perform surgical procedures it is necessary to expand the joint spaces. Several methods can be used, some are used to reduce longstanding dislocation of the condyle, such as traction of the mandible by wire from the mandibular angle or zygomatic hooks from the sigmoid notch . The condyle can be retracted directly with a letter opener or other fabricated instrument . The most useful appliance is the Wilkes spreader , which is fixed by K-wires into the zygoma and the neck of the condyle; to perform the operation, the spreader is expanded to open the joint spaces. The problems with this method are the risk in placing the K-wires accurately to ensure that surrounding vital organs are not damaged, and that it is time consuming. In order to overcome these problems, the author presents a simple method to expand the joint space.
A resin block is made in the clinic before surgery. Mix the ortho-resin powder and liquid and let the mixture set to dough stage. The dough is placed on the occlusal surface of the mandibular first and second molars on the same side as the TMJ operation. Instruct the patient to bite down at 5–6 mm of interincisal distance. Remove the resin dough from the mouth before it sets completely. After setting, remove any sharp edges which might damage the peripheral soft tissues. Pack and sterilize the appliance for use. During surgery, approach the TMJ spaces with a preauricular incision and incise the joint capsule. Insert the appliance in the molar area, and ask the assistant to compress the chin area upward. Using this action, the joint space can be expanded easily ( Figs 1 and 2 ) then select the appropriate surgical method, such as discectomy, discoplasty, eminectomy, or condyle shaving. The shortcoming of this method is that is not suitable for edentulous patients.