ANATOMY

It is helpful when discussing the manifestations and treatment of odontogenic infections to have an understanding of the fascial spaces surrounding maxillomandibular dentition (Figure 8.1). Although both maxillary and mandibular teeth can become infected, infections of mandibular dentition are more common. Anatomic spaces involved by maxillary infections include the canine and buccal spaces, with the orbit and cavernous sinus less commonly affected. If untreated, odontogenic infections tend to erode through the thinnest, closest cortical plate. The thinner bone in the maxilla is on the labial-buccal side, the palatal cortex being thicker. The canine space is that region between the anterior surface of the maxilla and the levator labii superioris (Figure 8.2). Infection of this fascial space usually results from maxillary canine tooth infection. The buccal space is located between the buccinator muscle and the skin and superficial fascia. Infections of this space usually result from maxillary molar processes with the premolars as the rare culprits. Orbital cellulitis or cavernous sinus thrombosis are unusual but serious manifestations of maxillary infection. Under such circumstances, the infection most likely spreads both by direct extension as well as hematogenously.

In the mandible, the thinnest region is on the lingual aspect around the molars and the buccal aspect anteriorly. The primary mandibular spaces include the submental, sublingual, and submandibular fascial spaces. The submental space is that area between the anterior belly of the digastric muscle, the mylohyoid muscle, and the skin.