Diabetes

Diabetes mellitus encompasses a group of disorders characterized by high levels of blood glucose (hyperglycemia; Gondivkar et al., 2019). Diabetes has several classifications:

• Type 1 diabetes is due to autoimmune beta‐cell destruction, usually leading to absolute insulin deficiency.
• Type 2 diabetes is due to a progressive loss of adequate beta‐cell insulin secretion, frequently against a background of insulin resistance.
• Gestational diabetes mellitus is diabetes diagnosed in the second or third trimester of pregnancy that was not overt diabetes prior to gestation (American Diabetes Association, 2021).

Diabetes is diagnosed at a glycated hemoglobin (HbA1c) equal to or more than 6.5%. The global diabetes prevalence in 2019 is estimated to be 9.3% (463 million people), rising to 10.2% (578 million) by 2030 and 10.9% (700 million) by 2045 (Saeedi et al., 2019). The goal for those with diabetes is to always maintain close to normal blood glucose levels and reduce spikes in blood glucose primarily through diet, exercise, and in severe cases medication.

Uncontrolled diabetes can lead to retinopathy, nephropathy, neuropathy, and periodontal disease. The reverse is also true: periodontitis may affect blood glucose control, and people who have diabetes may be more susceptible to bacterial infection, leading to gum disease. Nearly 1 in 5 people with severe gum disease had type 2 diabetes and did not know it (Teeuw et al., 2019). The connection between periodontal disease and diabetes is so closely linked that oral health providers must treat periodontal disease while managing diabetes and vice versa.

Heart disease

Although the connection is not as conclusive, there is also a lot of research that shows a connection between periodontal disease and heart disease. According to the World Health Organization, cardiovascular disease is the leading cause of death globally. It is estimated that 17.9 million people died from cardiovascular disease in 2019, representing 32% of all global deaths (World Health Organization, 2021). Cardiovascular disease is a group of disorders of the heart and blood vessels. However, most cardiovascular diseases can be prevented by modifying lifestyle choices like tobacco cessation, losing excess weight, increasing physical activity, moderate alcohol use, and implementing a healthy diet (Leishman et al., 2010). If these lifestyle choices are not addressed, increased systemic inflammation in the body can ultimately enter the bloodstream and lead to inflamed gingivae and vice versa (Leishman et al., 2010). Even though a direct correlation cannot be proved, it is imperative that treatment of cardiovascular disease includes treatment of oral diseases.

Obesity

One of the fastest‐growing chronic conditions is obesity both in adults and in children (Flegal et al., 2012). Overweight and obesity are defined by abnormal or excessive fat accumulation that may impair health. Body mass index (BMI) is calculated by a person’s weight in kilograms divided by the square of their height in meters (kg/m²). BMI is the most widely accepted tool for defining obesity; however, there have been concerns over the accuracy of this calculation (Stanford et al., 2019). Worldwide obesity has tripled since 1975 (Wright and Aronne, 2012). In 2016, 1.9 billion adults (39%) were overweight and 650 million (13%) were obese, as well as over 340 million children and adolescents (5–19 years old) being overweight or obese. While environmental (access to healthy food, health insurance) and genetic risk factors are not easily modifiable, obesity can be managed through diet and exercise. Just like cardiovascular disease, there is no direct correlation between obesity and oral health; however, diets consisting of high‐calorie, non‐nutrient‐dense foods (fermentable carbohydrates) and inactivity can increase a patient’s risk for obesity, dental caries, and periodontal disease.

Management of chronic diseases depends on the individual, his or her comorbidities, and the onset of the diagnosis, and includes modifying risk factors like diet and physical activity. Diet can be modified based on chronic conditions or the current stage of the life cycle. If lifestyle modification proves to be ineffective, more invasive interventions are required. This is where medication prescriptions are introduced as part of the treatment plan. It should be noted that many medications, including common over‐the‐counter ones such as antihistamines, can cause decreased salivary flow or xerostomia. As important as it is for dental professionals to understand the connections between diet/nutrition, oral health, and overall health, when nutrition issues are beyond the orthodontic scope of practice, referral can be made to a physician or a registered dietitian.

Children

On average, 19.4% (14.4 million) American children are defined as obese. Childhood obesity has more than tripled in the past 30 years. It is widely understood that obese children are more likely to become obese adults and are more likely to have risk factors for adult‐onset chronic diseases such as cardiovascular disease and type 2 diabetes (Estrada et al., 2014). Obese children are also more likely to have low self‐esteem, which may contribute to poor socialization and poor academic performance (Wu et al., 2016; Gong et al., 2022).

The method of presenting the dietary guidelines to the general population has evolved over time, from the 1940s and the Basic Seven to the Food Pyramid in 1992 and MyPyramid in 2005 (Figures 6.3–6.5). The most current adaptation, known as MyPlate, was created with the 2010 dietary guidelines and not only provides general dietary guidelines for health, but also offers specific recommendations based on age, sex, weight, and exercise level (Figure 6.6). This can be a useful tool for both orthodontists and patients alike. While these nutritional recommendations and guidelines apply to the general population, it is important to understand that there are recommendations for those with specific chronic conditions.

The etiology of obesity is multifactorial and includes genetic and lifestyle components such as diet and physical activity. Other factors contributing to childhood obesity are the home/school environments, the larger community, and the societal environment. However, there is a current consensus among the scientific community that diet and nutrition play a significant role in the prevention and treatment of childhood obesity. Worsening dietary habits such as eating larger portions, snacking frequently, overconsumption of processed food, and consuming sugar‐laden beverages are postulated to contribute to childhood obesity. These dietary patterns are also associated with increased risk of dental caries and therefore can and should be addressed in the orthodontic office. The entire healthcare team must be willing to address nutrition issues to improve the general and oral health of our youth in the current childhood obesity epidemic.

Teens/Adolescents

Adolescence encompasses major changes in physical, emotional, psychosocial, and cognitive development. Many studies show a high prevalence of weight‐control behaviors among adolescents, especially girls. One study, Eating Among Teens (Project EAT, https://www.sph.umn.edu/research/projects/project‐eat), found that 45% of adolescent girls were trying to lose weight. Oftentimes, they choose unhealthful weight‐loss techniques such as use of diet pills, laxatives, diuretics, or vomiting. Project EAT found that 12% of girls report these extreme weight‐loss behaviors. Evidence of such behaviors could indicate more serious psychological conditions such as bulimia or anorexia nervosa. Signs of eating disorders frequently appear first in the oral cavity. Manifestations of eating disorders in the oral cavity include tooth sensitivity, inflamed gums, and tooth erosion (Hasan et al., 2020; Lin et al., 2021). When evidence of these behaviors is found, patients should be referred for medical evaluation. Many hospitals now have eating disorder clinics that provide important multidisciplinary approach to care.

In adolescent boys, major physical growth continues and calorie requirements increase significantly. Appetite usually increases dramatically, resulting in consumption of large amounts of food. Although more common among girls, dieting and extreme weight‐loss behaviors also occur among adolescent boys. Project EAT reports that 21% of boys were currently trying to lose weight, while 5% reported using extreme behaviors to achieve weight loss. Males make up 25% of people with anorexia. Boys and men are likely underdiagnosed with eating disorders because clinical assessment tools emphasize a desire to lose weight as opposed to building muscle. Delayed diagnosed puts this population at higher risk of dying compared to their female counterparts.

The patient’s stage of life is an important nutritional consideration during orthodontic treatment. Orthodontic patients are often treated during the adolescent growth spurt. This growth period is a time of increased nutritional requirements, making dietary choices even more important (Bhutta et al., 2017; Ibrahim et al., 2017). The role of the orthodontist is crucial to help these patients to make healthy dietary food choices and learn healthy eating habits early.

Typical eating patterns

Among both male and female adolescents, dietary patterns are generally poor. Starting in adolescence, more food is consumed away from the home and teens begin to make their own food choices. Food may be used to establish an independent identity separate from the family unit. As adolescents begin to exert their independence from family life, peer influence becomes more significant and may influence food choices. Characteristic patterns include:

• Irregular meals.
• Meal skipping.
• Frequent snacking.
• Vending machine use.
• Fast food purchases.
• Meals on the go.
• High sugar‐sweetened, carbonated, and/or caffeinated beverage intake.
• Mindless eating.
• Eating late at night.

These patterns do not align with generally healthful eating recommendations for adolescents and significantly affect oral health. For example, poor calcium intake is common in girls, precisely during this most important period of bone density accretion. Frequent use of sugar‐sweetened beverages and frequent snacking can be associated with increased caries risk in teens. It is important to understand the factors that influence teens’ eating behaviors to be able to be effective in helping them make dietary improvements. Orthodontic discharge instructions should always include healthy age appropriate dietary recommendations.

Adults

The demography of orthodontics is changing rapidly. According to the American Association of Orthodontists (AAO), 27% of US and Canadian orthodontic patients are adults. This percentage means that there are 1,441,000 orthodontic patients who are 18 and older.

Adult patients can come with their own challenges. Typically, adult patients have a lengthier medical history. Many adults have chronic diseases that may influence treatment. Practitioners should understand these diseases and their impact on the oral cavity and orthodontic treatment, and refer patients for further care if it appears that these health conditions are not well controlled. For example, type 2 diabetes mellitus is common and often results from adult obesity. If a patient’s diabetes is not well controlled, they may have episodes of hypoglycemia in the dental office and may even require medical attention. Quickly absorbed sugar such as fruit juice should be kept on hand for the hypoglycemia that can occur if a patient has not eaten before their appointment. Those with poorly controlled diabetes may carry hard candies with them to use to overcome hypoglycemia, but if these are used too frequently, dental caries could result. Many adults also take one or more medications with side effects like xerostomia, which increases the risk of root caries and recurrent caries around existing dental restorations.

The caries process

Dental caries results from the demineralization of tooth enamel and dentin by organic acids formed by bacterial metabolism of dietary sugars, specifically fermentable carbohydrates. The only cariogenic foods are those that are composed of one or more of the simple sugars. For the general public, the term sugar that is associated with dental caries is often synonymous with the disaccharide sucrose, or table sugar. However, all monosaccharides (glucose, fructose, galactose) and disaccharides (sucrose, maltose, lactose) have cariogenic potential. These include sugars added during manufacturing (formerly sucrose, now primarily high‐fructose corn syrup) as well as table sugar added in cooking and naturally occurring sugar found in fruit, juice, honey, and molasses (Moynihan and Petersen, 2004).

An alarming dietary trend in recent years is the increased consumption of sugars in the diet of younger adults and children. Dentists need to be aware of these trends, including common and hidden sources of sugars. This will allow them to give better‐informed dietary counseling to their patients and suggest healthier alternatives (Bailey et al., 2018). In the realm of dental health, the term fermentable carbohydrates is often used to refer to those carbohydrates that can be metabolized by oral bacteria to produce acid and, as a result, increase caries risk (Kandelman, 1997). These are primarily mono‐ and disaccharides, but starches can also be cariogenic when held in the mouth long enough for salivary amylase to hydrolyze them to simple sugars. It is important to remember that the total amount of sugars consumed does not seem to be the most important factor in the cariogenic potential of the diet. Dietary patterns that include frequent snacking/sipping on foods or beverages that contain simple sugars are more conducive to caries development than infrequent snacking (Moynihan and Petersen, 2004).

When making recommendations to patients, sometimes offering simple modifications can increase compliance. It is therefore important to communicate that protein, fats, and food fibers are not cariogenic. The development of dental caries is influenced primarily by the total amount of time fermentable carbohydrates (simple sugars: mono‐ and disaccharides) are in contact with dental plaque. Thus, the following dietary habits can increase the risk of caries development:

• The frequency of consumption.
• The form of sugar (indicating retention of sugar in the mouth).
• The timing of consumption (at or between meals).

Protective role of diet/nutrition against dental caries

Fluoride is commonly accepted to be the most effective way to protect against dental caries. Topical fluoride increases the resistance of enamel to demineralization by organic acids following sugar consumption. Frequent exposure to fluoride helps protect enamel against the detrimental effects of acid, but it does not eliminate the risk of developing caries. Overly frequent consumption of cariogenic sugars can overwhelm the benefits of fluoride. The primary source of fluoride is fluoridated community drinking water. Fluoride is also found in tea, but is not present in appreciable amounts in most other foods. Most bottled waters are not good sources of fluoride. The most reliable sources are fluoridated drinking water and fluoridated dentifrice. Topical fluoride is also a good source of fluoride and can be protective against caries, for example using fluoridated toothpaste or mouth rinse.

Another protective measure against caries is saliva. Saliva plays a major role in preventing dental caries by promoting enamel remineralization, cleansing the mouth, and helping neutralize acids. The act of chewing facilitates salivary flow. Many medications, including common over‐the‐counter medications, can cause decreased salivary flow or cause xerostomia (Marcott et al., 2020). Xerostomia increases the caries risk associated with the diet, due to the loss of the acid‐mitigating effects. Thus, hydration to maintain salivary flow is vital for caries prevention (Moynihan and Petersen, 2004).

Foods high in calcium and phosphorus (dairy products: cheese, milk, and hight protein foods such as nuts and grains etc.) can also be protective against the formation of caries, by reducing bacterial adhesion to teeth, inhibiting biofilm formation, and enhancing enamel remineralization while reducing demineralization. Studies have shown that cheese, when provided after a cariogenic challenge such as a cookie, immediately facilitates plaque return to neutral (Tanaka et al., 2012). Although the etiological mechanism is not clear, it has been postulated that the salivary‐stimulating effect of chewing these foods, the remineralizing effect of the calcium from the cheese, or the plaque‐coating effect of the fat from the cheese or nuts may be contributing factors. Chewing gum (artificially sweetened) has the same beneficial effect. Gum containing xylitol has a heightened effect as the xylitol itself is cariostatic (Cocco et al., 2017). Unfortunately, sugar‐free chewing gum and nuts may not be appropriate suggestions for orthodontic patients treated with fixed appliances. Protein alternatives for orthodontic patients include soft cheese, yogurt, and milk. Patients should be advised to focus on “good” fats such as those found in plants, for example olive oil, avocado, and coconut oil (Box 6.1).