The authors present a case of combined preseptal and postseptal cellulitis of odontogenic origin. The infection started as a dental abscess associated with a first maxillary molar. The infection spread into the paranasal sinus, developed into a pansinusitis, and then spread into the preseptal and postseptal tissues. In addition to extraction of the infected tooth, the patient underwent bilateral nasal endoscopy, maxillary antrostomy, total ethmoidectomy, sphenoidotomy, and frontal sinusotomy with balloon dilation. Sinus cultures were positive for 2+ microaerophilic streptococci.