Supplementary Material for: Odontogenic orbital cellulitis due to an oroantral fistula following dental extraction: a case report

Introduction
Orbital cellulitis is a serious infection involving the soft tissues of the orbit. Odontogenic orbital cellulitis (OOC) is an important subtype and typically results from the contiguous spread of a dental infection. One uncommon route for this spread is the development of an oroantral fistula (OAF), a communication between the oral cavity and maxillary sinus which typically arises after extraction of a maxillary molar.

Case presentation
A 47-year-old female presented to the emergency department with a 1-day history of right sided periorbital edema and pain on extraocular movements. She had a history of a right maxillary dental infection which required tooth extraction 2 months prior to presentation. Her ocular exam revealed right periorbital edema and erythema that extended down to the midface with mild tenderness to palpation. Computed tomography scan showed pre-septal cellulitis, post-septal fat stranding, and a right-sided OAF. The patient had a complete resolution of infection and spontaneous closure of the OAF after 1 month of meropenem 1g IV daily.

Conclusion
In conclusion, this case highlights a rare presentation of OOC due to an OAF occurring months after dental extraction. Immediate imaging due to atypical history, including lack of dental pain, allowed for prompt identification of the OAF and subsequent use of appropriate broad-spectrum antibiotics resulting in a favourable outcome compared to previously published cases. It is critical to recognize odontogenic infections as treatment differs from other etiologies of orbital cellulitis.