This study discusses the effects of infrared thermography in dentistry. Infrared thermography allows the quantification of infrared rays and provides useful data for dental care and research. It has been used for the diagnosis of temporomandibular dysfunction (TMD) and proposed as an objective measure of myofascial pain. It is closely related to temperature and produces beneficial objective data. A study of the heat emissions from facial structures has the potential to benefit dental diagnosis of TMD, postoperative inferior alveolar damage, and endodontic and conservative treatments. In this paper, we assessed infrared thermography in dentistry and consider future developments of infrared thermography.