Sensory endings of chorda tympani and lingual (trigeminal) nerve fibers were identified by selective denervation and localized within specific regions of fungiform pipillae in the hamster. The chorda tympani was resected from the middle ear and the peripheral fibers were allowed to degenerate for 1, 3, or 8 days prior to perfusion-fixation and electron-microscopic examination of the anterior tongue. Taste buds were virtually devoid of intact nerves by 3 days following chorda tympani denervation. Remnants of the fibers were restricted to taste buds. Lingual fibers, on the other hand, persist in normal numbers after chorda tympani resection and populate perigemmal areas of connective tissue and extragemmal areas located apically in the squamous, nontaste epithelium surrounding the taste bud. This study provides evidence of a segregation of chorda tympani fibers in the taste bud and lingual nerve fibers in the apical fungiform papilla. The lingual nerve-epithelial arrangement and superficial location, near the least cornified area of the tongue, may be well suited for relatively sensitive somatosensation, possibly mechanoreception. Thus, the apical fungiform papilla appears to be a site where both taste and tactile oral stimuli interact with receptors.

Increasing penetration depth of TADs results in greater retention. Increased abutment head distance from cortical plate leads to decreased retention. Placement of TADs at 90 degrees to the cortical plate is the most retentive insertion angle. Insertion at an oblique angle from the line of force reduces retention of TADs.

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In the Institute of Medicine's report Dental Education at the Crossroads, it was suggested that dental schools across the country move toward integrated basic science education for dental and medical students in their curricula. To do so, dental school admission requirements and recommendations must be closely reviewed to ensure that students are adequately prepared for this coursework. The purpose of our study was twofold: 1) to identify student dentists' perceptions of their predental preparation as it relates to course content, and 2) to track student dentists' undergraduate basic science course preparation and relate that to DAT performance, basic science course performance in dental school, and Part I and Part II National Board performance. In the first part of the research, a total of ninety student dentists (forty-five from each class) from the entering classes of 1996 and 1997 were asked to respond to a survey. The survey instrument was distributed to each class of students after each completed the largest basic science class given in their second-year curriculum. The survey investigated the area of undergraduate major, a checklist of courses completed in their undergraduate preparation, the relevance of the undergraduate classes to the block basic science courses, and the strength of requiring or recommending the listed undergraduate courses as a part of admission to dental school. Results of the survey, using frequency analysis, indicate that students felt that the following classes should be required, not recommended, for admission to dental school: Microbiology 70 percent, Biochemistry 54.4 percent, Immunology 57.78 percent, Anatomy 50 percent, Physiology 58.89 percent, and Cell Biology 50 percent. The second part of the research involved anonymously tracking undergraduate basic science preparation of the same students with DAT scores, the grade received in a representative large basic science course, and Part I and Part II National Board performance. Using T-test analysis correlations, results indicate that having completed multiple undergraduate basic science courses (as reported by AADSAS BCP hours) did not significantly (p<.05) enhance student performance in any of these parameters. Based on these results, we conclude that student dentists with undergraduate preparation in science and nonscience majors can successfully negotiate the dental school curriculum, even though the students themselves would increase admission requirements to include more basic science courses than commonly required. Basically, the students' recommendations for required undergraduate basic science courses would replicate the standard basic science coursework found in most dental schools: anatomy, histology, biochemistry, microbiology, physiology, and immunology plus the universal foundation course of biology.