A new anatomical landmark to simplify temporomandibular joint arthrocentesis.

rthrocentesis of the temporomandibular joint (TMJ) was rst described by Nitzan et al.1 and is an accepted treatment or various disorders of the TMJ. Their technique includes nsertion of two needles along the canthal-tragal line, the first f which is placed into the upper joint compartment of the MJ, and the second anterior to the first to allow effective avage of the joint (Fig. 1). However, in some cases it is diffiult to insert the second needle, which means that lavage fails, he operation takes longer, the patient is uncomfortable, and here may be increased postoperative morbidity and possible amage to the facial nerve.2 For this reason single needle rthrocentesis has been proposed, in which inflow and outow go through the same cannula.2 The joint is lavaged with a ingle needle used for injection and ejection resulting 40 ml f irrigation. However, with a single needle the amount of uid may be inadequate and the pressure too low. Previously, we have used a single cannula with two ports nd two lumens that allow irrigation and lavage of the joint ith the same device and permit sufficient irrigation under the esired pressure.3 Rehman and Hall4 used a similar device alled a Shepard cannula that holds two needles together. evertheless the device that keeps two needles together eems to be relatively thick, which has the potential to damge the nerve. Repetitive use of the device may cause the tips f the needles to blunt, and increase the risk of infection. We propose a new technique, by which the patients are sked to open and close the mouth several times so that the