2026 Poster Presentations
P054: END STAGE ODONTOGENIC SINUSITIS
Manasa K Melachuri, MD; Dana Crosby, MD; Kody Bolk, MD; Southern Illinois University School of Medicine
Osteomyelitis of the skull base from an odontogenic source is rare. It most commonly originates from otogenic infections with the temporal bone, clivus, occipital bone, and mandible most frequently involved. But atypical osteomyelitis of the skull base can be caused by bacterial or fungal spread from the sphenoid, ethmoid or frontal sinus and very rarely the maxillary sinus. Spread to the skull base from the maxilla would require an infection to move backwards through the infratemporal and pterygopalatine fossa moving through multiple tissue and bone layers. Similarly, odontogenic infections can lead to osteomyelitis of the mandible with very rare involvement of the maxilla.
We report a case of skull base osteomyelitis secondary to a non-healing oroantral fistula in an elderly patient. The patient presented with left sided facial pain, drainage into her mouth, and diplopia with history of dental work several months prior. Physical exam demonstrated a 3cm left sided oroantral fistula with purulent drainage. CT and MRI demonstrated osteomyelitis of the left maxilla extending into the pterygopalatine fossa, infratemporal fossa, orbit, and skull base of the middle cranial fossa. Endoscopic resection of devitalized maxilla and pterygoids demonstrated acute osteomyelitis on pathology. Tissue cultures demonstrated beta Streptococcus group F, diphtheroid and Prevotella species. All bacterial and fungal blood cultures were negative. After debridement, the patient responded well to a course of long-term antibiotics with complete resolution of symptoms.
Risk factors including malnutrition with recent twenty-pound weight loss, long term bisphosphonate use for osteoporosis, history of Chemotherapy for breast cancer, prior dental extractions, multiple decades of denture utilization, severe iron deficiency anemia requiring multiple blood transfusion during admission, as well as elderly age may have predisposed the patient to this disease. We highlight presentation and management related to osteomyelitis of the skull base secondary to odontogenic sinusitis.
Figure 1: CT Sinus coronal plane preoperatively demonstrating opacification of left sphenoid with osteitis and erosion of the left skull base of the middle fossa and pterygoids.
Figure 2: MRI Brain and face with contrast in the axial plane preoperatively demonstrating extensive left maxillary sinus inflammation extending into the pterygopalatine and infratemporal fossa with enhancement.
Figure 3: Endoscopic visualization on the left following medial maxillectomy and posterior maxillary wall removal with removal of devitalized pterygoid bone.
Figure 4: 3 month post operative endoscopy demonstrating the healing left medial maxillectomy cavity with re-mucosalization over the exposed pterygopalatine and infratemporal fossa.