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Biomedical subjects

A I Chasens

Publications and source records attributed to A I Chasens.

18 recordsLinked to original sources

Controversies in occlusion.

The tissues and structures of the stomatognathic system adapt in different ways but in a coordinated manner to functional forces. This adaptive capacity differs from individual to individual and tends to cloud the picture as to how these mechanisms function. This leads to many areas of disagreement as to the role of occlusal trauma in the etiology of periodontal disease; the importance of centric, bite collapse versus arch collapse; the role of incisal guidance in maintaining occlusal stability; canine protected-guided occlusion versus group function; the use of appliances in occlusal therapy; prophylactic versus interceptive occlusal adjustment; and the role of bruxism and other parafunctional habits in occlusal trauma. An attempt is made in this article to clarify these issues.

Animals

Rapid loss of alveolar bone associated with nonprecious alloy crowns in two patients with nickel hypersensitivity.

In recent years there has been a dramatic increase in the use of nonprecious alloy and porcelain crowns in clinical dentistry. The alloy in these restorations frequently contains a high percentage (greater than 70%) of nickel. Most cases of metal hypersensitivity are related to nickel, and clinical manifestations of the hypersensitivity are the result of a cellular (T lymphocyte) immune response. In this report, we review the cases of two women who demonstrated significant loss of alveolar bone about nickel-rich nonprecious alloy and porcelain crowns. The loss of alveolar bone occurred within 18 months after placement of the restorations. Both individuals displayed a positive patch test to a nickel preparation. These findings suggest that a Type IV hypersensitivity reaction may have accounted for the rapid loss of alveolar bone. Though the majority of individuals treated with nonprecious alloy and porcelain crowns apparently tolerate these restorations quite well, greater care is urged in case selection.

Adult

The relationship between the mobility of human teeth and their supracrestal fiber support.

A method to study the relationship between the mobility of human teeth and their supracrestal fiber support was developed. The results of this study would indicate that: (1) The supracrestal fibers do not contribute significantly to the support of a normal premolar tooth. (2) As a human premolar tooth develops moderate to severe loss of osseous support, the relative contribution of the supracrestal fibers to the support of the tooth increases significantly.

Adolescent

Preserved scleral allografts in periodontal defects in man. I. Preparation, preservation and use.

A method has been presented for the preparation, preservation and surgical adaptability of sclera as implant material. As a result of the knowledge gained from the use of this material in reconstructive surgery and limited reports in the dental literature, there appears to be a justification for further research on the utilization of this very available material in periodontal and other oral surgical procedures.

History of Medicine

Preserved scleral allografts in periodontal defects in man. II. Histological evaluation.

1. The scleral grafts appeared to be well accepted as there were no signs of antigenicity or untoward reactions. 2. The gingival connective tissue, periodontal ligament and the periosteum were observed intertwined with sclera at the interface. 3. Sclera was invaded by host fibroblasts, capillaries, and appeared in some areas to be raplaced by a dense connective tissue. 4. Areas of cementogenesis could be observed in all specimens. 5. There were no signs of osteogenesis within the scleral grafts. 6. The alveolar crest appeared relatively nonreactive to sclera. 7. There were no signs of external root resorption or ankylosis. 8. Sclera may be able to be used to fill in osseous craters, other periodontal defects and as a scaffolding in conjunction with osseous grafts. This requires further investigation. 9. Sclera may possibly be used in areas where there was loss of gingival contour or need for ridge augmentation.

Alveolar Process

Plaque, gingivitis and dental aptitude test scores of dental students.

In general, plaque and gingivitis scores were correlated negatively with the manual parameters and positively with the academic and mental parameters studied. Plaque showed significant negative correlations with the manual average and the carving test. Gingivitis also demonstrated a negative correlation, just short of significance, with the manual average, but virtually no correlation existed between gingivitis and the carving test. Gingivitis displayed a significant positive correlation with the academic average, and plaque exhibited a nonsignificant positive correlation with the academic average. Relationships between these parameters may help determine what segments of the population are more susceptible to plaque accumulation and gingivitis and may suggest possible new approaches to the adoption of preventive measures. Finally, in view of the statistically significant but relatively low correlation found between manual dexterity and oral health, further investigations are indicated to establish the validity of the relationship.

Adult

Low HL-A2 frequency and periodontitis.

The frequency of HL-A2 was significantly low (21%) in patients with periodontitis when compared to controls who were free of periodontal disease (61%). The effect was most pronounced in females in whom HL-A2 was present in 12.5% (2 out of 16). This finding suggests that genes controlling susceptibility to microbial agents may be linked to the HL-A LOCUS.

Epitopes