Puncture sites in and around the peak height of the glenoid fossa carry greater risk of GF perforation.
The angulation and direction of the trocar upon puncture through the capsule of the TMJ should be directed carefully with a slight upward direction to avoid the disc, but it should NOT be directed toward the GF. The position of the patient’s head is again important and should be as described earlier. Again, poor head position can result in misdirected punctures due to disorientation of the surgeon.
Maintaining the depth of initial puncture at 20-25 mm will not avoid perforation of the GF if the trocar is directed toward it.
The puncture force must also be controlled and appropriate. The tenacious lateral capsular ligament creates the most resistance to the trocar puncture. Once the joint space is entered, manipulation should be with delicate and gentle force, and the sharp trocar should be removed. The surgeon must again be aware of the resistance to trocar advancement and also when the trocar tip is on the bone.