CARIES DUE TO BREASTFEEDING
Breastfeeding is best for mother and baby in many ways. From the dental and speech therapy perspective, breastfeeding is the best form of myofunctional and hence orthodontic prophylaxis. It strengthens the entire oral and perioral musculature, trains lip closure, encourages the sensitivity of the oral cavity, reinforces nasal breathing, prepares the tongue and lips for eventual articulation, strengthens the mother-baby bond, and promotes the baby’s socioemotional development. The latter also has a beneficial effect on later speech development.5 Therefore, pediatric dentists should definitely encourage their pregnant patients to breastfeed their children when asked for their opinion. Of course it is the individual decision of a mother if and how long she wants to breastfeed her child according to her own circumstances in life. It is your responsibility to address the scientific basis of why breastfeeding is recommended, but it is always best to approach this conversation with sensitivity.
In the dental context, prolonged and high-frequency breastfeeding at night has been viewed critically. While breast milk on its own does not increase the risk for early childhood caries (ECC), together with other carbohydrates, it has been classified as highly cariogenic in in vitro studies.18 Studies further prove that breastfeeding beyond 2 years markedly increases the risk of caries.19 However, several studies have reported that it is not the duration of breastfeeding that increases the risk of caries but instead the way in which breastfeeding is performed, specifically in frequent, short nighttime feeds.20,21 A meta-analysis from 2015 concluded that children who are breastfed beyond 12 months have a higher risk of caries and that the risk was also increased in this group if they were breastfed more frequently at night.22 As such, parents must be made aware that very frequent, short, nonnutritive nighttime breastfeeding episodes when primary teeth are present are indisputably a major risk factor and can be a contributory cause of ECC. But why is that?
Caries is a multifactorial disease that can be influenced by many factors. One cannot say definitively that breastfeeding will certainly cause caries if a baby is breastfed beyond 12 months of life. Many other factors play a role here. We pediatric dentists often see children in our practice who are breastfed far beyond that age and show no lesions whatsoever. But it is also an undisputed fact that very common, short, nonnutritive nocturnal breastfeeding episodes with existing primary teeth can be a major risk factor contributing to caries. We also see these patients again and again. The following factors are responsible for the increased caries risk:
• Oral hygiene is not possible at night.
• Salivation is strongly reduced, therefore only an insufficient buffering of the decreasing pH value is taking place.
• Breast milk contains approximately 7.2% lactose (for comparison, cow’s milk contains approximately 4.5%).
• Because it contains only small amounts of caries-inhibiting components such as calcium and phosphate, breast milk can reduce the intraoral pH below 5.5, which leads to a demineralization of the primary tooth enamel.20
Short and frequent nightly breastfeeding episodes beyond the first birthday of the child are usually more of a sleeping or calming aid that can be viewed independently of food intake. This nonnutritive sucking pattern is entirely different from a normal, nutritive breastfeeding sucking mechanism. It is characterized by a high sucking frequency but a low sucking activity, which means that only so-called “foremilk” (ie, the milk produced in the first nursing phase) is produced. In this milk, the lactose content is in aqueous solution, and thus available for bacteria to be metabolized, and rinses around the maxillary incisors.20 During nutritive breastfeeding, children suck much more vigorously, which leads to the production of so-called “hindmilk.” While this hindmilk contains the same amount of lactose as the foremilk, in hindmilk this lactose content is bound to fat molecules, so the harmful effect in the mouth is directly avoided because there is no enzyme in the mouth that is able to split fat components. The lactose content is only split off once it is in the stomach. In addition, during a nutritive sucking pattern the milk does not touch the teeth but is expressed at the palate and swallowed. With all these factors, comfort nocturnal breastfeeding can indeed be a caries risk factor. Furtenbach also wrote that “the breast is not to be used as a pacifier” because the physiologic oral flora needs rest.5 This is exactly the crucial point.
When highly frequent and prolonged breastfeeding is identified as a caries risk factor in a patient, we should encourage parents to reduce nighttime nursing, to quench baby’s thirst with water if possible, and to find ways to make it easier for baby to fall asleep without breastfeeding, primarily by establishing a different bedtime ritual that does not involve breastfeeding. Infants who are used to only falling asleep at the breast obviously find it harder to settle down again without the breast in occurring waking phases. Therefore, mothers are advised not to let their babies fall asleep at their breast from the age of about 6 months but rather to breastfeed, then brush the teeth before continuing to the rest of the bedtime ritual (singing, looking at books, etc). Moreover, we should check for lip and tongue-ties that might be an influencing factor as well. The question of caries risk is less about “how long” and more about “what form” breastfeeding takes.
It is important to discuss this highly sensitive subject with parents calmly and nonjudgmentally. Pediatric dentists, in particular, are often reproached for advising against breastfeeding. Especially in view of the multifactorial etiologic model of caries and the many advantages that breastfeeding affords mother and child, it is extremely important for our profession to encourage breastfeeding when appropriate. After all, socioeconomic status is more important as a caries risk factor than the source of a baby’s nutrition.23
While the decision about the duration of breastfeeding lies with each mother herself, all nursing mothers should be made aware of the subject and should be instructed on how to ensure good oral hygiene in their infant. We dentists should and indeed must contribute to this part of the parents’ education.
Bottle caries
Bottle-fed or formula-fed babies are just as susceptible to ECC from nighttime feedings or too-frequent “snacking” on the bottle during the day. A baby should never be sent to bed with a bottle of milk for nighttime soothing, and a bottle should not be used as a pacifier during the day. While these practices may seem convenient for parents to avoid nighttime wakings or fussy babies, it’s the frequency of feeding that can become a major risk factor for ECC.
The same is true for solid foods. Children do not have to eat or chew something throughout the whole day. It should be made clear to parents that eating and drinking should be offered numerous times throughout the day but should not be something that is carried out constantly. The oral flora needs rest for the saliva to buffer the decreasing intraoral pH and therefore to stop demineralization of the primary teeth.
DIETARY AND DRINKING HABITS
What children drink
The most important thing about dietary and drinking advice in relation to ECC is certainly educating parents about drinks and the frequency of consumption. Parents are sometimes concerned about how much liquid intake their child should have every day. As a result, they often give their children juice just to make sure they get enough to drink. But a glass of apple juice contains more sugar than the same amount of Coke; bearing that in mind, it is definitely not a good alternative.
In terms of whether or not children are drinking enough liquid, dentists can reassure parents that no child will voluntarily die of thirst!