Which of the following is a common cause of orbital cellulitis?

Orbital cellulitis is an inflammatory condition of the tissues surrounding the eye, often resulting from an infection that spreads from nearby structures. Dental infections are a well-known contributing factor to the development of orbital cellulitis. This typically occurs when bacteria from an infected tooth or tissue surrounding the teeth invade the orbit, particularly when there is an extension of infection from the maxillary sinus, which is closely situated to the dental roots. The proximity of the dental structures to the orbit allows for such bacterial spread, leading to serious complications if left untreated.

While fungal, allergic, and viral infections can affect the eye or surrounding structures, they are not as commonly associated with orbital cellulitis. Fungal infections tend to occur in immunocompromised individuals and are less frequent compared to bacterial causes. Allergic reactions usually manifest as conjunctivitis or other conditions but do not lead to the infectious process seen in orbital cellulitis. Viral infections, such as those causing viral conjunctivitis, can also occur but typically do not result in the significant inflammation and infection of the orbital tissues that is characteristic of orbital cellulitis.