Facial muscle innervation in Cebid (New World) and Macaque (Old World) monkeys via a ramus communicating with the trigeminal nerve.

Direct motor and reflex EMG responses were recorded from facial muscles in monkeys subjected to stimulation of the communicating ramus of the auriculo-temporal nerve. Transection of the ramus distal to the stimulus site eliminated the direct motor response. Transection of the ramus proximal to the stimulus site eliminated the reflex component. The results suggest that the trigeminal nerve carries motor fibres serving facial muscles.     

A morphometric study of submandibular salivary gland changes in streptozotocin-induced diabetic rats

The morphology of the glands in 9 male rats was studied after 3 months of streptozotocin-induced diabetes mellitus and compared with that of 9 control rats and 6 streptozotocin-treated, non-diabetic rats which served as controls for any effect of streptozotocin not due to diabetes mellitus. In the diabetic group, mean salivary-gland weight and volume was reduced. There was an increase in the ratio of mean volume to total gland volume for seromucous acini (p less than 0.01), intra-lobular striated ducts (p less than 0.001), fat (p less than 0.001) and blood vessels (p less than 0.01), and a decrease in both granular duct (p less than 0.001) and intercalated duct (p less than 0.01) volume ratios. There was a marked reduction in the total length of granular ducts (p less than 0.001) and an increase in the length of striated ducts (p less than 0.001). Measurements from the streptozotocin-treated, non-diabetic group did not differ significantly from those of controls. These effects may be attributable to failure of growth and chronic sodium depletion.     

Temporomandibular joint sounds and condyle/disk relations on magnetic resonance images.

This study compared the condyle/disk relationships on magnetic resonance images (MRIs) in a group of subjects with completely silent temporomandibular joints (TMJ) when tested clinically with those in subjects with readily discernible TMJ sounds. The sounds were recorded with an accelerometer as the transducer. Selected degrees of jaw separation were electronically determined and recorded with interocclusal wafers for use with the imaging process. Of the "silent joints" 89% were found to have sounds when tested with the accelerometer. These "subclinical" sounds tended to be of shorter duration and occurred at a greater degree of vertical opening than the clinically discernable sounds. The MRIs of the group with clinically discernable sounds tended to show a change in the relationship between the head of the condyle and the intermediate zone of the disk, at the degree of jaw separation of the sound occurrence, whereas no condyle/disk change occurred in the group with "clinically silent joints." It is likely that all joints create sound during function. The different characteristics of the subclinical sounds versus the clinical sounds may indicate differing sound origins.