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India-ink-imaged blood-vessel networks in cleared tympanic membranes and adnexa from ten neonatal dogs were examined microscopically and photographed. The major significance of the study lies in documentation of a dual source of arterial supply, a bilaminar relationship of arterial and venous plexuses intrinsic to the tympanic membrane, and a consistent major venous pathway relative to a definite locus (pars flaccida of the membrane). Illustration of all three types of blood pathways (arteries, veins, and capillaries) provides new vasculoanatomic data that are essential to ear surgery, specifically--to myringotomies and myringoplasties. A comparison was made between dog and human tympanic membrane structures and their arterial supplies. Close similarities suggested that dog tympanic membrane might serve as a suitable model for development of innovative surgical procedures and as a model for rehearsal of difficult techniques. The results of this investigation provide a valuable caveat to otologists.

Arterial networks in 50 pairs of human fetal hands, made visible by perfusion with radiopaque media, were compared between right and left hands. The imaged primary arterial networks in the fetal hands were also compared with those in adult human and rhesus monkey hands. It was found that superficial arch configurations and their primary ramifications are bilaterally similar in human fetal hands. The configurations of the primary arterial networks are established very early in prenatal growth and may be maintained into adulthood. The similarities in the arterial network arrangements between fetal human and rhesus monkey hands suggest that the rhesus monkey hand could provide an appropriate model for studies of surgical neurovascular anastomosis.

Many edentate human mandibles obtained at random from cadaveric subjects of different ages were cleansed of their soft tissue coverings (macerated) and then divided into groups based upon alveolar process resorption differences. Each mandible was transected at five locations corresponding to prior sites of the molar and premolar teeth. The medial surface area of each section and its cortical and medullary components were accurately measured by computerized digital morphometry. Skeletomorphologic details were examined by gross, microscopic, and radiographic methods. Images made visible by the three methods were compared. Comparison clearly indicated that images of cortical thickness peripherally, trabecular bone density centrally, and the differences in density of canal borders and their locations in many edentate mandibles are very often inadequately portrayed by conventional oral radiographic methods. These inadequacies present a strong caveat to the unwary oral implantologist.

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