Some odontogenic infections erode into fascial spaces directly and spread toward lymphatic tissues and blood streams. The principal maxillary primary spaces are the canine, buccal, and infratemporal space, the next secondary spaces are the masseteric, temporal and pharygeal space. As a result of the infection, trismus and orocutaneous fistula may be occurred. Trismus is owing to conditions not associated with temporomandibular joint itself and may be of myogenic, neurogenic, or psychogenic nature. Muscular trismus is due to infection adjacent to the elevator muscles of the jaw. The four principles of treatment of infection are as follows: (1) removal of the cause, (2) establishment of drainage, (3) institution of antibiotic therapy, and (4) provision of supportive care, including rest, nutrition and physiotherapy. Jaw physiotherapy is necessary to increase the amount of mouth opening and regain normal muscle tone. If proper care of odontogenic infection could be attained, the orocutaneous fistula will heal and close spontaneously by wound contraction mechanism of natural homeostatic response. This is a case report of the care of trismus and orocutaneous fistula due to fascial space abscess by advanced odontogenic infection in a physically disabled patient.