An intraoral phototherapy device for directing light from an associated light source into an oral cavity of a patient is disclosed. The device comprises a main body portion shaped to conform to contours of the oral cavity when inserted therein to direct the light to targeted regions of the oral cavity, wherein the main body portion comprises a pair of laterally spaced side wings sized and shaped to be received between a patient's teeth and cheeks on opposite sides of the oral cavity for transmitting and directing the light to the targeted regions of the oral cavity； and the targeted regions of the oral cavity include the mandibular and maxillary buccal surfaces of the oral cavity.
