Advances in diagnosis and detection of oral diseases

And the next 50 years? The future of recombinant DNA technology in oral medicine

As we celebrate this spectacular 50th anniversary, fluoridation continues to be the most effective public health strategy to reduce the disease burden of dental caries. Curiously, while H. Trendley Dean and his colleagues at the National Institutes of Health were investigating the effects of fluoride on tooth enamel in the mid-1930s, two young boys, one in London and the other in Chicago, were growing up to become the catalysts for another "biological revolution." These two very talented individuals, James Watson and Francis Crick, would later meet by accident at Cambridge and produce their seminal discovery published in April 1953 as a letter in Nature, a one-page article provoking an international scientific adventure to understand living organisms in terms of the structure and function of deoxyribonucleic acid (DNA), a universal genetic code and a rationale for the applications of recombinant DNA technology (rDNA) in fields as diverse as agriculture, energy, industry, and health. As we now reflect upon the triumphs from fluoridation and ponder the next 50 years and the complexities of craniofacial, oral, and dental diseases, it becomes increasingly evident that recombinant DNA technology coupled with health promotion, disease prevention, and public education offers the promise for remarkable advances in prevention, diagnosis, and therapeutics in oral medicine.

Growth, development, and aging of orofacial tissues: neural aspects

Neural factors influence post-natal growth, development, and aging throughout the body. This influence may be mediated through sensory or motor effects interacting with endocrine and immunological factors. Growth effects may be expressed directly by sensory or motor nerves on the tissue or indirectly by motor function. Direct neutrotrophic effects have been well-documented in the development of striated muscle, the taste bud, and the amphibian limb. Evidence for a trigeminal neurotrophic effect on tooth development and facial development is lacking. Growth disturbances of the jaws consequent to lesioning of the trigeminal nerve are due most likely to functional disturbances rather than neutrotrophism. Examples of function impact on orofacial growth are abundant. Oral and facial target tissues, like those elsewhere in the body, determine the nature of the target tissue innervation and its central organization. Central effects consequent to tooth loss or dental pulp entirpation are well-documented. Inflammation and pain may exert growth effects through release of "wound hormones" or secondarily to somatic and autonomic effects. There is evidence that vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) elaborated from sympathetic and parasympathetic neurons may have a modulatory role in growth. While the effects of longstanding motor pathologies on skeletal growth are well-known, concomitant sensory deficits and soft tissue disturbances have not been examined. However, the pathological models beg the question of normal regulation. While muscle develops in the absence of innervation, neurotrophic effects are clearly identified. Little is known about the interaction of simple and complex motor behavior on growth. Regulation of growth is frequently visualized within a form-function paradigm. For example, anterior open bites have been seen as the consequence of tongue thrusting or tongue thrusting as a consequence of open bites. Low tonic forces in posture are thought to be more important in the development of both the face and the dental alveolar complex than the higher intermittent forces in mastication and swallowing. The need for an active (reflex) contribution to growth at the TMJ is in dispute.(ABSTRACT TRUNCATED AT 400 WORDS)