Prevention of Neuropathic Pain in Temporomandibular Joint Surgery
A discussion of the prevention of neuropathic pain in temporomandibular joint surgery is made difficult by the paucity of quality evidence surrounding its exact incidence, comorbid, and causative factors. However, we can draw several corollaries from the general evidence on neuropathic and postsurgical pain.
Prevention of neuropathic pain complications should start with the identification of risk factors in the presumptive surgical patient. Genetic polymorphisms in the COMT line can affect sensitivity to pain, and the susceptibility to neuropathic pain has been determined to have a significant genetic component though no specific gene products have been identified [12]. Psychosocial factors such as anxiety, depression, catastrophizing behavior, and perceived social support have also been linked to the postoperative experience of pain. There is a significant correlation between the severity of immediate postoperative pain and the risk of the development of chronic postsurgical pain [13-15], which has led to the development of preoperative pain grading schema in several surgical specialties [16, 17]. It is currently equivocal as to whether or not aggressive pain control or neural blockade in these patients provides any long-term benefit with regard to chronic postsurgical pain [18]. The most likely significant predictor for neuropathic pain after surgery is the presence of preexisting neuropathic pain [19]. Unfortunately, as many of these factors are also correlated with the evolution of temporomandibular joint disease, circumvention of these issues in a surgical patient may be unavoidable.
Other than these factors, based on the epidemiology of neuropathic pain in TMJ surgery, some conclusions can be drawn. Open surgical techniques have been shown to have a significantly higher rate of nerve damage than arthroscopic techniques, so in a susceptible patient, minimally invasive surgery should be considered whenever possible [20, 21]. Nerve injuries in arthroscopy are thought to evolve secondary to extravasation of irrigation solution, so tight control of flow rate intraoperatively may help prevent these complications [22].
