To review the phenomenon and implications of temporal bone and craniofacial bone staining in the context of prolonged exposure to tetracycline antibiotic.

Case report and literature review.

A 52-year-old male with a 5-year history of tetracycline use presented to undergo tympanomastoidectomy and was found to have an unusual rusty green pigmentation of the entire aspect of the exposed temporal bone. A literature review revealed more than 20 cases of tetracycline-induced pigmentation of intraoral maxillary and mandibular bone, and 2 prior cases involving the cranial bones.

Tissue and organ pigmentation is an unexpected and unfavourable consequence of the use of tetracyclines, particularly minocycline. Tetracycline is contraindicated in children because of the risk for dysosteogenesis and enamel hypoplasia. In adults, although the unusual staining may present as an unexpected dilemma upon surgical exposure, current research shows no significant clinical consequences for this type of pigmentation.

Osteonecrosis is a benign condition characterised by necrotic exposed bone, and is associated with bisphosphonate use. Osteonecrosis of the external auditory canal is rare, with only a few reported cases.

Two case reports of temporal bone osteonecrosis are presented.

A 64-year-old man with a history of immunoglobulin G kappa multiple myeloma developed a right external auditory canal ulcer 6 years after commencement on clodronate. A 72-year-old woman taking alendronate for osteoporosis, initially diagnosed and treated for right-sided otitis externa, was found to have underlying exposed bone in the right external auditory canal, with a computed tomography scan confirming destruction of the temporal bone.

With increasing use of both oral and intravenous bisphosphonates in the community for benign conditions such as osteoporosis and for malignant conditions such as breast cancer and multiple myeloma, the diagnosis of bisphosphonate-associated osteonecrosis should always be considered in patients with a temporal bone lesion, and a relevant drug history taken.