Transoral approach to the upper cervical spine.

The transoral approach to pathology of the upper cervical spine is logical, but it is seldom used due to concerns about exposure and infection. The authors report on 16 consecutive patients requiring exposure from clivus through C3 for pathology, including spinal cord compression by rheumatoid pannus, craniovertebral anomalies, and tumor. Exposure was obtained using a Dingman mouth gag and soft palate retraction with silicone rubber sheeting.

Comparison of biomaterials for facial bone augmentation.

We compared the gross behavior of and microscopic response to implant materials currently in clinical use for facial bone augmentation at different sites in dogs. Materials evaluated include porous polytetrafluoroethylene carbon (Proplast), large-pore high-density polyethylene (Medpor), solid medical-grade silicone rubber (Silastic), polyamide mesh (Supramid), and autogenous rib bone. The subjects were 12 mixed-breed dogs and the materials were implanted directly on bone with periosteum removed at one of three sites in the dog's face (malar eminence, nasal dorsum, and chin).

Lack of effect of carbonic anhydrase inhibition on direct measurements of endolymph bicarbonate.

In the past, sodium, potassium, and chloride have been measured in endolymph directly, but bicarbonate has been measured only indirectly. We sampled endolymph directly while monitoring endocochlear potentials in normal and methazolamide-treated guinea pigs. Bicarbonate was determined in samples by use of a method that depends on reduction of NADH to NAD linked to malate formation from oxaloacetate.

Margins of safety with transantral orbital decompression.

This study involves evaluation of the surgical limits of transantral orbital apex decompression (as described by Ogura) by performing the operation on 17 cadaveric half-heads. Measurements were then made of the proximity of bone removal to several vital structures including the optic nerve, carotid artery siphon, cavernous sinus, and frontal lobe dura. Entrance into the sphenoid sinus was found to be routine.