This report describes a Yorkshire terrier that suffered progressive neurologic signs 2 days after dental extractions. Signs included: circling to the left, occasionally falling to the right, right-sided blindness and hemiparesis, and proprioceptive ataxia. After clinical signs progressed, MRI revealed a small skull fracture in the frontal bone and a linear tract extending from the caudal oropharynx through the left retrobulbar space and frontal lobe into the left parietal lobe. This was consistent with the observed neurolocalization to the left forebrain. Although iatrogenic periorbital injury has been reported subsequent to tooth extraction, TBI is rarely reported. In this case, the dental elevator slipped during extraction of tooth 210; the referring veterinarian thought the elevator had entered the left retrobulbar space.
Treatment included mannitol and clindamycin. After 1 month, MRI showed continued presence of the linear tract but significant decrease in cerebral edema. Neurologic examination results improved, but right-sided blindness and absent postural reactions persisted. At 4-month and 1-year rechecks, gait and vision were normal, but right-sided postural reactions were still delayed. The tract was present but smaller. The dog maintained a good quality of life.
Penetration of the orbital floor may occur as a result of regionally thin bony structures, periodontal pathology leading to weakening of the bone, and improper extraction techniques. Techniques to reduce risk for iatrogenic trauma include using dental radiographs to assess proximity of roots to the orbit; sectioning of multiple rooted teeth; gentle, slow elevation; and use of a finger as a stop to prevent elevator slippage.
During dental cleanings and extractions, it is possible for an instrument to slip accidentally and, rarely, cause ocular and neurologic injuries. In cases in which periorbital or skull injuries are suspected following a dental procedure, referral for brain/head CT or MRI should be offered, particularly if the patient is exhibiting neurologic signs. The dental elevator should always be held with a finger near the tip of the instrument to minimize deep-tissue penetration in the event of accidental slippage. With extraction, a twisting rather than a pushing motion may help minimize instrument slippage. Most important, this case demonstrates that recovery and good quality of life are possible after traumatic brain injury.—Erin Y. Akin, DVM, DACVIM