Critical Reviews in Oral Biology & Medicine

The Official Publication of the American Association of Oral Biologists

A Publication of the International/American Associations for Dental Research
Table of Contents for Volume 1, 1990

Volume 1, Issue 1
Volume 1, Issue 2
Volume 1, Issue 3
Volume 1, Issue 4

Volume 1, Issue 1

• Slavkin H
• School of Dentistry Biochemistry, University of Southern California, Los Angeles.
• Pages 1-16.

• Graves DT; Cochran DL
• Boston University School of Graduate Dentistry, Massachusetts.
• Pages 17-36.

• Michalek SM; Childers NK
• Department of Microbiology, University of Alabama, Birmingham.
• Pages 37-54.

• Fleiss JL; Kingman A
• Columbia University, School of Public Health, New York.
• Pages 55-66.

• Martinez JR
• Lovelace Medical Foundation, Albuquerque, New Mexico.
• Pages 67-78.

Volume 1, Issue 2

• Mina M; Kollar EJ; Bishop JA; Rohrbach DH
• Department of Pediatric Dentistry, University of Connecticut Health Center School of Dental Medicine, Farmington.
• Pages 79-87.

• Boughman JA; Astemborski JA; Blitzer MG
• Department of OB/GYN, University of Maryland School of Medicine, Baltimore.
• Pages 89-99.

• Aukhil I; Nishimura K; Fernyhough W
• Department of Periodontics, University of North Carolina School of Dentistry, Chapel Hill.
• Pages 101-115.

• Van Dyke TE; Hoop GA
• Department of Periodontology at Emory University School of Postgraduate Dentistry in Atlanta, Georgia.
• Pages 117-133.

The pathological sequela of reduced neutrophil function in the oral cavity and the mechanisms behind dysfunction have added to our understanding of infectious diseases. Numerous examples have been given, and the overriding conclusion must be that any impairment of neutrophil function will lead to some degree of increased susceptibility to infection. Perhaps the tissue most sensitive to pathological changes in the oral cavity is the periodontium. In cases of severe neutrophil dysfunction, there is severe periodontal breakdown, but also in cases of "mild" neutrophil dysfunction, where there is no other infection, such as in individuals with LJP, there is severe periodontal breakdown. The molecular basis of neutrophil dysfunction is beginning to be understood in individuals with LJP, LAD, CGD, and AIDS. It is our hope that further research in this area will help to delineate the pathogenesis of these and other oral diseases.

• Suddick RP; Harris NO
• Pages 135-151.

From antiquity, individuals, tribes, and cultures have sought the abilities of singular individuals to try to heal them or to help them to endure the onslaughts of disease. For thousands of years before recorded history, these services were provided by the medicine man or shaman of the tribe, whose secret treatments were passed from generation to generation by the apprenticeship methods of teaching. For the most part, their therapies were at best palliative and their effects were placebo and psychological in nature. Reliable written records of healing practices began with the ancient Greek civilization about 400 years before Christ. The written recording of rational therapies and practices established the "physician" as one of the premier occupations (or "professions") of ancient Greek society. About 160 years after Christ, the Greek physician Galen began the practice of examining the post-mortem anatomy of various animals and extrapolating his findings in an attempt to understand the structure of the human body. This was the first well-recorded and documented effort in what we, today, would term "biomedical research". While Galen's efforts and written production were massive, his impact on medical practices beyond Greece was minimal due, at least partially, to the lack of mass printing and distribution methods. Ironically, at almost the same time that Galen's complete works were published, Andreas Vesalius of Brussels published the most startling and exquisite book in the history of medicine. Vesalius' De Humani Corporporis Fabrica (1543)2 was a lavish and beautiful exposition of human anatomy. This event, for all intents and purposes, formalized the separation of the science of medicine from its art. We suggest that this event established the division of medicine into two historical streams—the "healers" and the "scientists" (or Streams "H" and "S"). However, even to the present, the biomedical scientists remain dependent on the established institutions of the healers for their very existence and continuity. Very early the dental healers developed as a distinctly separate branch of the H Stream, due to the efficacy and directness of the therapy of tooth extraction and the need for mechanical aptitude for its execution. This was exemplified in the long and successful history of the barber-surgeons, or their earlier equivalents, as therapists in every society on Earth, including the U.S., up to nearly the turn of the 20th century.

Volume 1, Issue 3

• Gerson SJ
• Department of Oral Medicine and Diagnostic Sciences, University of Illinois, Chicago 60680.
• Pages 153-166.

In the U.S. oral cancer accounts for 2.1% of all cancers and 1% of cancer deaths. Two to three times as many males as females are affected. Blacks have more intra-oral cancer than whites, and their incidence and mortality rates have increased in recent years. The etiologic process very likely involves several factors. The major etiologic agents are tobacco (all types) and alcoholic beverages. Herpes simplex virus, human papilloma virus, and Candida have been implicated. Host factors include poor state of dentition, nutritional aberrations, cirrhosis of liver, lichen planus, and immunologic impairmant. Cellular changes include amplification of some oncogenes, alterations in antigen expression, production of gamma-glutamyl transpeptidase, and disturbance of keratin and involucrin production. Experimentally, cancer is readily produced on the hamster cheek pouch and rat oral mucosa. Unlike oral cancer in humans, most experimental lesions are exophytic, and they rarely metastasize.

• Dale BA; Salonen J; Jones AH
• Department of Oral Biology, University of Washington, Seattle 98195.
• Pages 167-190.

Epithelial structural proteins, the keratins and keratin-associated proteins, are useful as markers of differentiation because their expression is both region-specific and differentiation-specific. In general, basal cells in all stratified oral epithelia express similar keratins, while the suprabasal cells express a specific set of markers indicating commitment to a distinct program of differentiation. Critical factors in the regulation of epithelial protein expression are now under investigation. The promoter regions of keratin genes are being characterized to determine what sequences within the genes are responsible for differential expression. One important extracellular factor that influences epithelial protein expression is retinol (vitamin A), which exerts its effects via a group of nuclear receptor proteins that may also be expressed in a region-specific manner. These molecular biological approaches enhance our understanding of the mechanisms regulating differentiation of oral epithelia and its regional complexity.

• Russell MW; Wu HY
• Department of Microbiology, University of Alabama, Birmingham 35294.
• Pages 191-205.

Investigations of immune responses to Streptococcus mutans have fostered consideration of vaccination as a possible preventive measure against dental caries. However, the finding that hyperimmune rabbit antisera to S. mutans sometimes give immunofluorescent reactions on human heart raised concerns over safety, especially as most individuals display circulating antibodies to this common oral organism. Recent progress in elucidating the molecular mechanisms of the well-established immunological cross-reactivity between group A streptococci and human heart tissue and the structure of S. mutans antigens permits a re-evaluation of this problem. This review examines the evidence for heart cross-reactivity induced by S. mutans in relation to studies on group A streptococci and current understanding of autoimmunity. Although the mechanisms involved in this phenomenon need further clarification, it now appears that it cannot be ascribed to antigenic similarity between heart tissue and a high-molecular-weight surface protein antigen of S. mutans.

• Macrina FL; Dertzbaugh MT; Halula MC; Krah ER 3d; Jones KR
• Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond 23298-0678.
• Pages 207-227.

As the study of oral microorganisms intensified almost 2 decades ago, the application of genetic techniques resulted in important contributions to the understanding of this clinically and ecologically important group of bacteria. The isolation and characterization of mutants of cariogenic streptococci helped to focus attention on traits that were important in colonization and virulence. Such classic genetic approaches gave way to molecular genetic techniques, including recombinant DNA methodology in the late 1970s. Gene cloning systems and methods to move DNA into cells have been developed for oral streptococci. Many streptococcal genes thought to be important in colonization and virulence have since been cloned and their nucleotide sequence determined. Mutant strains have been constructed using defective copies of cloned genes in order to create specific genetic lesions on the bacterial chromosome. By testing such mutants in animal models, a picture of the cellular and molecular basis of dental caries is beginning to emerge. These modern genetic methodologies also are being employed to develop novel and efficacious cell-free or whole cell vaccines against this infection. Genetic approaches and analyses are now being used to dissect microorganisms important in periodontal disease as well. Such systems should be able to exploit advances made in genetically manipulating related anaerobes, such as the intestinal Bacteroides. Gene cloning techniques in oral anaerobes, Actinomyces and Actinobacillus, are already beginning to pay dividends in helping understand gene structure and expression. Additional effort is needed to develop facile systems for genetic manipulation of these important groups of microorganisms.

Volume 1, Issue 4

• Tabak LA
• Department of Dental Research, School of Medicine and Dentistry, University of Rochester, New York 14642.
• Pages 229-234.

• Sauk JJ
• Department of Pathology, Dental School, University of Maryland, Baltimore 21201.
• Pages 235-245.

• Kleinberg I; Westbay G
• School of Dental Medicine, State University of New York, Stony Brook 11794-8702.
• Pages 247-259.

• Kaminsky LS; Mahoney MC; Leach J; Melius J; Miller MJ
• Wadsworth Center for Labs and Research, New York State Department of Health, Albany 12201-0509.
• Pages 261-281.

This summarizes current knowledge of the benefits and risks of fluoride ingestion. The preponderance of evidence indicates that fluoride can reduce the incidence of dental caries and that fluoridation of drinking water can provide such protection. Due to the ubiquitous nature of exposures to fluoride sources other than drinking water, it is currently impossible to draw firm conclusions regarding the independent effect of fluoride in drinking water on caries prevalence using an ecologic study design. Moderate dental fluorosis occurs in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water and in about 10% of the population at 2 mg/l; moderate/severe fluorosis occurs in variable percentages ranging up to 33% of the population exposed to fluoride at 2.4 to 4.1 mg/l in drinking water. The issue of whether moderate or severe dental fluorosis represents an adverse health effect is still controversial. There is no evidence of skeletal fluorosis among the general U.S. population exposed to drinking water fluoride concentrations lower than 4 mg/l. Radiographically detected osteosclerosis after chronic exposure to fluoride in drinking water at 8 mg/l was not associated with clinical symptoms. Reports of crippling skeletal fluorosis associated with low concentrations of fluoride in drinking water in tropical countries have been attributed to other dietary factors. The available data suggest that some individuals may experience hypersensitivity to fluoride-containing agents. Further studies on hypersensitivity are required. There is no evidence of increased incidence of renal disease or renal dysfunction in humans exposed to up to 8 mg fluoride per liter in drinking water. Structural changes in kidneys of experimental animals have been detected at doses exceeding 1 to 5 mg fluoride per kilogram per day. Based on four case reports, individuals with renal insufficiency who consume large volumes of naturally fluoridated water at 2 to 8 mg/l are possibly at increased risk of developing skeletal fluorosis. Studies on the effects of fluoride in individuals with renal insufficiency are needed. There is no evidence that chronic exposure to concentrations of fluoride reported to be greater than 2 mg/l in drinking water increases human cancer mortality or incidence. A study of lifetime exposure to fluoride on cancer incidence in rats and mice has been completed, but assessment for cancer has not been completed. There is no evidence that fluoride is genotoxic except in some in vitro assays at cytotoxic concentrations. There is no in vivo evidence that fluoride affects human cellular enzyme activities.

• Ebersole JL
• Department of Periodontics, University of Texas Health Science Center, San Antonio 78284-7894.
• Pages 283-331.