Of note, the most common cause for this abscess is the teeth. The mylohyoid line on the inner aspect of the body of the mandible descends in a slanting nature such that the tips of the roots of the second and third molars are behind and below this line. Therefore, if these teeth are abscessed, the pus will go into the submandibular space and may spread to the parapharyngeal space. These patients present with swelling, redness, pain and fever. Usually, the infected tooth is not painful.
Treatment is once again incision and drainage.
Antibiotic coverage should include oral cavity anaerobes. If, however, the tooth roots are above the mylohyoid line as they are from the first molar and forward, the abscess that breaks through the mandibular cortex will enter the sublingual space. This is above and in front of the mylohyoid and will cause the tongue to be pushed up and back as previously noted. These patients require tracheotomy as the infection can progress quite rapidly, producing airway obstruction. A good rule of thumb about a tracheotomy is if you think about it, you probably should do it.