Nutritional Factors in Tooth Development and Maintenance

At two months of gestation, primary tooth development begins. Permanent teeth begin to form several months before birth. Apregnant woman’s nutrient intake must therefore supply the pre-eruptive teeth with the appropriate building mate-rials. Severe nutrient deficiencies during pregnancy may result in mouth malformations in the child and teeth that are more susceptible to dental caries.2 Likewise, chronically malnourished children may have delayed tooth eruption, compromised tooth integrity, and increased dental caries.3,4 However, the degree of malnutrition known to cause these aberrations is not commonly seen in the United States or other developed countries.

Once the teeth have erupted into the oral cavity, many severe and even moderate nutritional deficiencies or excesses can result in defective tooth development. Table II describes the potential effects of specific nutrient imbalances on tooth development and salivary flow and composition.

Teeth are formed by mineralization of a protein matrix. The mineralization process begins as early as four months of gestation and continues into late adolescence as the root structures are completed. Once teeth have erupted, diet and nutrient intake continue to affect permanent tooth development and mineralization, enamel development and strength, as well as the timing of eruption of the remaining teeth.5 For example, nutrient imbalances during early childhood can interfere with enamel formation, causing hypoplasia or hypocalcification. Additionally, teeth subjected to nutritional insult during critical stages of growth and development show a diminished ability to withstand caries.5

Nutrients essential for tooth development and maintenance include vitamins A, C, and D, as well as calcium, phosphorus, and fluoride. The protein in dentin is collagen, which is dependent on vitamin C for normal synthesis. A tooth’s enamel contains keratin, a type of protein, and requires vitamin A for its formation. Vitamin D is essential to the process by which calcium and phosphorus are deposited into crystals of hydroxyapatite, the structural matrix of bones and teeth.

During tooth development, fluoride is incorporated into the pre-eruptive tooth’s mineralized structure, along with calcium and phosphorus to form fluorapatite, a compound more resistant to erosion than hydroxyapatite. After the tooth erupts, fluoride is no longer involved systemically in tooth formation. However, the topical effects of fluoride continue to impart protection against tooth decay by decreasing demineralization when the tooth is exposed to organic acids and by increasing the rate of remineralization following erosion by plaque acids.6 Fluoride in saliva also inter-feres with acid production in the bacterial cells that cause oral plaque.7,8 Fluoride can be provided topically to teeth in rinses, dentifrices, gels, varnishes, chewable dietary fluoride supplements, or by fluoridated water.

Fluoride supplementation is no longer recommended at birth. Fluoride should not be administered to infants during the first six months after birth, whether they are breast-or formula-fed. During the period from six months to three years of age, infants (both breast-fed and formula- fed) require fluoride supple-mentation only if the water supply is severely deficient in fluoride (< 0.3 ppm).9 (A dietary fluoride supplementation schedule is provided in Table III.) Because of the ingestion of foods with natural fluoride content (e.g., tea) or those reconstituted with fluoridated water (e.g., baby formula, juices) as well as unintentional swallowing of fluoridated oral care products, children are ingesting more fluoride, which may explain the current increase in cases of mild dental fluorosis.9 For this reason, the guidelines for fluoride supplementation reflect more conservative levels at which supplementation is recommended. Parents should be encouraged to monitor the fluoride intake of children younger than six to ensure adequate intake for tooth development, yet prevent overuse.

Once teeth are fully formed, there is little change in their composition throughout life. Unlike bone tissue, teeth do not readily release minerals, such as calcium or phosphorus, when the body’s need for these minerals are not met by the diet.5

Clearly, proper oral tissue development depends on adequate nutri-tion. For expectant mothers, lactating women, infants and young children, dietary advice provided during these critical development times can have profound implications on the health and well being of a growing child’s teeth and oral cavity. Thus, it is important to identify individuals at risk for poor nutrition
and provide nutrition counseling or a referral to a registered dietitian to ensure adequate intakes of essential nutrients that are necessary for optimal oral health.