Abscess of the orbit arising 48 h after root canal treatment of a maxillary first molar

Aim To discuss a rare, but severe complication arising following routine root canal treatment. Summary An orbital abscess is reported that occurred following routine root canal treatment. A young, healthy female patient, with no history of chronic paranasal infection had undergone root canal treatment of the right maxillary first molar. On hospital admission, she presented with extensive periorbital swelling and discreet diplopia. Computed tomography imaging identified massive purulent sinusitis and subsequent involvement of the orbit via the inferior and medial orbital wall within 48 h after completion of root canal treatment. Immediate surgical drainage of the maxillary sinus and the orbit was established and a high dose of perioperative antibiotics (Amoxicillin/Clavulanic acid, Gentamycin, Metronidazole) were administered. Vision remained undisturbed and mobility of the globe recovered within 10 days. Key learning points Rapid exacerbation of a periapical inflammation may occur following root canal treatment and may even involve the orbit. A typical speed of disease progression or ophthalmic symptoms should alert the clinician to at least consider unusual early orbital spread of odontogenic infection. When extra-alveolar spread and especially orbital spread is suspected, immediate referral to a maxillofacial or other specialized unit is mandatory.