Selected classes of chemotherapy, including the vinca alkaloids, vincristine, and vinblastine, can cause direct neurotoxicity. Additionally, drugs such as thalidomide and lenalidomide are associated with peripheral neuropathies that can affect the face and jaw. Deep-seated, throbbing mandibular pain can occur. Because this symptom is also consistent with acute dental pulpal disease, it is important that a thorough history and oral physical examination be performed when oral pain is present; radiographs and vitality testing of the dental pulp are typically necessary. After neurotoxicity is appropriately diagnosed, management includes pain support and patient counseling. The symptom generally resolves within a week of discontinuing the causative chemotherapy.
Dental hypersensitivity may occasionally arise in patients weeks or months after they discontinue chemotherapy. Additionally, it has been observed that patients being treated with cyclosporine for treatment of graft-versus-host disease will report increased thermal sensitivity. The mechanisms of this response are not known. Fortunately, thermal stimuli are self-resolving after discontinuation or withdrawal of therapy, though they can persist for several months. Topical application of fluorides and/or desensitizing toothpaste may ameliorate the discomfort.
Patients may experience temporomandibular dysfunction pain involving muscles of mastication, temporomandibular joints, or teeth. This condition is not unique to cancer patients, and it correlates with stress and dysfunctional habits including bruxism and clenching of the jaws. Stress and sleep dysfunction appear to be the most frequent etiologic factors. Judicious use of muscle relaxants or anxiety-reducing agents plus physical therapy (moist heat applications, massage, and gentle stretching) are standard approaches for management. For patients with a propensity for clenching or bruxism during sleep, customized occlusal splints for use while sleeping may be of value.