Maine Smiles Matter PC 1

Lesson 1: Prenatal Care

Overview: The health care provider gains an understanding of how pregnancy- related events are associated with tooth development.

Goals: The health care provider will be able to describe:

¬ Why expectant mothers need to maintain healthy teeth and gumsduring their entire pregnancy to help reduce the risks of prematurebirths and low birth weight babies

¬ The link between pregnant women’s nutrient intake and their oralhealth

¬ The effects of nutrient deficiencies of a pregnant woman on her child’stooth development

¬ The transmission of mutans streptococci from caregiver to child

¬ Orofacial growth and development

Key Terms:

Ameloblasts enamel forming cells

Early Childhood Caries infectious disease that initially affects the teethof infants and young children; rapidlydeveloping type of decay that primarily affectsthe 4 upper front teeth, although lower teethand molars may also be affected

Enamel Hypoplasia defective or incomplete development of enamel

Mutans Streptococci cariogenic bacteria

Odontoblasts dentin and pulp forming cells

Periodontal Disease infection of the supporting structures of theteeth (gums, bones, and ligaments) which, ifleft untreated, can lead to tooth loss

Permanent Teeth second set of teeth that erupt into a

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person’s mouth; also known as secondary oradult teeth

Primary Teeth first set of teeth that erupt into a person’smouth; also known as baby or deciduous teeth

Prenatal Counseling

It is important to provide prenatal counseling that includes information regarding:• pre and postnatal parental oral health• prevention of Early Childhood Caries (ECC), formerly known as Baby

Bottle Tooth Decay (BBTD)

Studies show that the transmission of mutans streptococci to a child’s mouthusually occurs from a child’s primary caretaker. Therefore, this informationshould be shared with caregivers so they will see how important it is for them toimprove their oral health, which would decrease the bacterial burden and,potentially decrease the child’s risk for dental decay. Expectant couples shouldbe encouraged to gain, and maintain, good personal oral health during theprenatal period and beyond.

Decreasing the primary caretakers’ mutans streptococci levels maydecrease the child’s risk of developing early childhood caries.

Coordination is needed between dental care and obstetrical care providers toenhance the oral health of pregnant women. Obstetricians are stronglyencouraged to recommend an oral health evaluation early in pregnancy,given the possible association between maternal periodontal disease anddelivery of pre-term babies. Pregnancy is a period when proper maternalhealth care and patient education can have a profound effect on the oral healthof both the mother and child.

• Pregnant women with gum disease are seven and a half times more likelyto have a premature, low birth weight baby.

• Alcohol and smoking are also risk factors.

The enzyme produced by infected gums, cytokines, is the same enzyme thatpregnant women produce to induce labor when it is time to give birth. When thisenzyme enters the blood stream from the gums before the baby is due, it mayinduce premature delivery.

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Periodontal disease is also linked to low birth weight babies (those born weighingless than five pounds, eight ounces). Low birth weight babies are prone tosevere physical problems. As young children, they may continue to haveproblems and are more likely to develop early childhood caries.

Prevention of early childhood caries begins with intervention in the perinatal andprenatal periods. Women should be advised to optimize their own nutritionduring the third trimester and their infant’s nutrition during the first year, when theenamel of the child’s teeth is undergoing maturation.

Nutrition and oral health are closely linked. Diet and its nutritional consequencescan have a profound impact on tooth development and good oral health, and onthe development and progression of diseases of the oral environment.

Gestational Development

At two months of gestation, primary tooth development begins. Permanent teethbegin to form several months before birth. A pregnant woman’s nutrient intakemust therefore supply the pre-eruptive teeth with the appropriate buildingmaterials. Teeth are formed by mineralization of a protein matrix. Themineralization process begins as early as four months of gestation and continuesinto late adolescence as the root structures are completed. The calcium,phosphorus, and other minerals that are needed to form a baby’s developingteeth are taken from the mother’s bloodstream, and unless she is actuallyundernourished, there is little that will interfere with the ability of the baby’s tooth-forming cells to turn these basic minerals into normal dentin and enamel cells.

About five to six months before birth, some parts of all the twenty primary teethbegin to develop in the baby’s jaws. If they are in their proper place, they act asfoundations for the dental arch and help keep all the other teeth in their properpositions. For a full term infant (37-40 weeks gestation), a part of the firstpermanent molar begins to form before birth. The rest of the permanent teethbegin to form right after birth.

Between four and twelve months after birth, the first teeth usually appear in aninfant’s mouth. A normal set of teeth includes eight incisors in the front of themouth, four canine teeth in the corners of the mouth, and eight molars in theback. All twenty primary teeth are generally in position by three to four years ofage.

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Why talk about this now? Because now - before birth - is when the molar teethare beginning to form. How resistant these caries-sensitive teeth will be dependson how well they mineralize. The mother, by balancing the necessary calcium,phosphorus, and vitamins in her bloodstream, contributes to successful toothdevelopment. However, an imbalance in these minerals occurs most often froma high fever or a viral infection, not from a nutritional lack.

Enamel hypoplasia results when the enamel matrix formation is disturbed. Theresult may be an irregularity of tooth form, color, or surface. Factors that maycontribute to enamel hypoplasia include:

1. severe nutritional deficiency, particularly rickets2. fever producing diseases, such as measles, chickenpox, and scarlet fever3. congenital syphilis4. hypoparathyroidism5. birth injury6. prematurity7. Rh hemolytic disease8. infection

Hypoplasia is common in children with low birth weight or systemic illness in theneonatal period. There is considerable evidence that malnutrition orundernutrition during the prenatal period is a cause of hypoplasia. A consistentassociation exists between clinical hypoplasia and early childhood caries.

Hypoplastic enamel of primary teeth is usually a manifestation of the mother’sgeneral health during pregnancy. However, hypoplastic permanent first molarsand anterior teeth could be a result of an infection or intervention (such aspharmaceutical) prior to age three. Children born prematurely or at very lowbirth weight may have hypoplastic enamel in both primary and permanentdentitions due to disturbances during enamel formation and maturation.

Examples of developmental defects

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Embryonic Development

The orofacial complex is developed through a series of events that aregenetically controlled. It is important for all health providers to havedevelopmental and growth information to better understand this section of thebody.

Third and fourth weeks Germ cell layers (ectoderm, mesoderm, andendoderm) - essential in developing parts ofthe face and mouth.

Third to sixth week Lips, parts of the nose and jawsDevelopment of the palate

Sixth week Teeth begin to develop from a band of oralepithelium on the upper and lower jaws. Fromthis tissue tooth buds form and eventually atooth germ develops with ameloblasts andodontoblasts. With the dentin mineralizing andenclosing the pulp, the ameloblasts will beginto form enamel.

Any time during these developmental stages, alterations in the enamel contentcan affect not only the clinical appearance of the teeth but also its risk for dentalcaries.

CHRONOLOGY OF THE HUMAN DENTITION

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Tooth RootTooth Formation Begins Tooth Eruption Completed Exfoliation

Primary Dentition - Maxillary

Central Incisor 4 mo in utero 8-12 mos 1 _ yrs 6-7 yrs

Lateral Incisor 4 _ mo in utero 9-13 mos 2 yrs 7-8 yrs

Cuspid 5 mo in utero 16-22 mos 3 _ yrs 10-12 yrs

First molar 5 mo in utero 13-19 mos 2 _ yrs 9-11 yrs

Second molar 6 mo in utero 25-33 mos 3 yrs 10-12 yrs

Primary Dentition - Mandibular

Central Incisor 4 _ mo in utero 6-10 mos 1 _ yrs 6-7 yrs

Lateral Incisor 4 _ mo in utero 10-16 mos 1 _ yrs 7-8 yrs

Cuspid 5 mo in utero 17-23 mos 3 _ yrs 9-12 yrs

First molar 5 mo in utero 14-18 mos 2 _ yrs 9-11 yrs

Second molar 6 mo in utero 22-31 mos 3 yrs 10-12 yrs

Permanent Dentition - Maxillary

Central Incisor 3-4 mos 7-8 yrs 10 yrs

Lateral Incisor 10-12 mos 8-9 yrs 11 yrs

Cuspid 4-5 mos 11-12 yrs 13-15 yrs

First bicuspid 1 _ -1 _ yrs 10-11 yrs 12-13 yrs

Second bicuspid 2-2 _ yrs 10-12 yrs 12-14 yrs

First molar at birth 6-7 yrs 9-10 yrs

Second molar 2 _ -3 yrs 12-13 yrs 14-16 yrs

Permanent Dentition - Mandibular

Central Incisor 3-4 mos 6-7 yrs 9 yrs

Lateral Incisor 3-4 mos 7-8 yrs 10 yrs

Cuspid 4-5 mos 9-10 yrs 12-14 yrs

First bicuspid 1 _ - 2 yrs 10-12 yrs 12-13 yrs

Second bicuspid _ - 2 _ yrs 11-12 yrs 13-14 yrs

First molar at birth 6-7 yrs 9-10 yrs

Second molar 2 _ - 3 yrs 11-13 yrs 14-15 yrs

Other Concerns

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Three things that may happen to the expectant mother that could directly affecther baby’s teeth:

1. If the mother gets a fever from a virus or some other infection (a commonoccurrence between the fifth and ninth months of pregnancy), the delicatebalance of calcium and phosphorous in her bloodstream could be upset.This affects the quality and quantity of tooth structure that is forming in thefetus. This disruption in tooth structure formation will continue for as longas it takes the mother’s system to regain its balance.

2. If the mother’s physician gives her an antibiotic containing tetracycline, thedeveloping teeth might become stained. Later, when the teeth come intothe mouth, they will be discolored. The color may range from dark greythrough yellow to bright orange, depending on how much tetracycline themother got, how long she took it, and at what time during pregnancy it wasconsumed. Most physicians don’t prescribe tetracycline for pregnantmothers; its use is becoming rare. Nevertheless, a woman who ispregnant but doesn’t “show” should tell or be asked by any healthcareprovider - general physician, dentist, chiropractor - whether she’sexpecting.

3. If the expectant mother gives birth before term, it is possible that thechild’s teeth will be affected. There is some evidence today that full termchildren have fewer cavities. This is because those areas of the teeth thatare mineralizing just around the time of birth are the ones mostsusceptible to decay.