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412 Part 4 The Transitional Years: Six to Twelve Yearsof the anterior teeth should be carefully and easily observed by the practitioner for developmental and esthetic reasons.Except for third molars, all of the permanent teeth usually have erupted by the end of the 12th year. Permanent tooth enamel formation is complete by age 8 years. In the mandibular arch (except for the rst permanent molar), molars erupt in immediate succession, that is, centrals, laterals, canines, rst and second premolars, and second permanent molars from 6 to 7 years through 11 to 13 years of age. e same sequence takes place in the maxillary arch except for the maxillary canine, which usually erupts after one or both premolars and at about the same time as or before the eruption of the second permanent molars (Fig. 30.4).e mandibular central incisor roots are complete by age 9 or 10 years. e roots of the four rst permanent molars, the maxillary central incisors, and the mandibular lateral incisors are usually complete by age 10 years. e roots of the maxillary lateral incisors are complete by age 11 years.4Because the position of the dental lamina of the permanent teeth is located to the lingual side of all of the primary teeth (except for the dental lamina coming o the second primary molars for the three permanent molars), the anterior teeth develop in their vault or crypt lingual to and near the apex of the primary incisors. When the roots begin to form on the permanent teeth, the per-manent teeth start to migrate to the oral cavity. Generally, they follow a pattern such that they come across the primary root, resorbing it and erupting slightly lingual to the location sustained by the primary tooth (Fig. 30.5). Ultimately the permanent teeth are usually angulated more buccally compared with their primary predecessors (Fig. 30.6). e developing premolars develop between the roots of the primary molars and continue to erupt in a slightly buccal position.Dental ChangesEarly during this period most children experience the eruption of all four rst permanent molars and the exfoliation of the mandibular and maxillary primary central and lateral incisors. e permanent incisors erupt between the ages of 6 and 7 years (see Table 13.5). However, it is not unusual for the maxillary permanent lateral incisors to erupt later than age 7 years in some children. Eruption Growth IncrementsSN = 1NeuralgrowthcurveA = 2B = 3YEARS 0–5185% oftotal growthcompleted96% oftotal growthcompletedRemaining 4%completed245% oftotal growthcompleted65% oftotal growthcompletedRemaining 35%completed340% oftotal growthcompleted65% oftotal growthcompletedRemaining 35%completed5–10 10–20Bodily orgeneralgrowth curve• Figure 30.1 Differential growth center rates of craniofacial compo-nents. (From Behrents RG. Growth in the Aging Craniofacial Skeleton. Ann Arbor, MI: Center for Human Growth and Development, University of Michigan; 1985.)• Figure 30.2 This anterior cranial base superimposition of the Bolton standard for 6- and 12-year-olds (solid line and dashed line, respectively) demonstrates the magnitude of anteroposterior and vertical skeletal growth during this period as well as the soft tissue change. (Redrawn from Broadbent BH Sr, Broadbent BH Jr, Golden WH. Bolton Standards of Developmental Growth. St Louis: Mosby; 1975.)• Figure 30.3 This anterior cranial base superimposition of the Bolton standard for 6- and 12-year-olds (solid line and dashed line, respectively) demonstrates the magnitude of transverse and vertical skeletal growth during this period. (Redrawn from Broadbent BH Sr, Broadbent BH Jr, Golden WH. Bolton Standards of Developmental Growth. St Louis: Mosby; 1975.) CHAPTER 30 The Dynamics of Change 413 eruption of permanent rst molars, ectopic eruption of lateral incisors due to positioning or crowding, ectopic canine eruption, and transpositions all can be traced to this period of development. Obviously monitoring and intervention in these conditions are crucial to a normally developing dentition. e clinician should consider whether early and sustained crowding requires extraction of primary or permanent teeth or whether space maintenance should be considered to treat nonextraction. By the end of this period, most of the residual space resulting from either idiopathic spacing or leeway spacing has closed. Further eruption and drift occur in response to continued growth.It is normal to nd diastemas between the primary incisors. is helps provide space for the larger permanent incisors. e permanent canine in the maxillary arch is usually the last permanent tooth to erupt mesial to the rst permanent molar. As the permanent canine begins to erupt, it migrates down the distal root surface of the maxillary lateral incisor and ultimately moves the crowns of the incisors mesially and will close moderate to small diastemas. is period of development has been called the “ugly duckling stage” (Fig. 30.7).5Most of the eruption problems occur during this time period and the clinician should be checking for these at each exam. Ectopic • Figure 30.4 These two panoramic radiographs show the transition from the beginning of the perma-nent dentition to its completion with the exception of the third molars. Note that an upper left lateral supernumerary tooth was removed. 414 Part 4 The Transitional Years: Six to Twelve YearsDeciduousincisorRoot resorptionEnamel ofpermanentincisorDentin• Figure 30.5 Resorption of the root of a primary incisor owing to pres-sure from the erupting successor. (From Bhaskar SN, ed. Orban’s Oral Histology and Embryology. 11th ed. St Louis: Mosby; 1990.)• Figure 30.6 Angulation of permanent and primary incisors. (Redrawn from Moyers RE. Handbook of Orthodontics. 3rd ed. Chicago: Year Book; 1973.)AB• Figure 30.7 (A and B) The “ugly duckling” stage is typied by spacing between the permanent maxil-lary incisors. The roots of the incisors are tipped mesially by the erupting crowns of the permanent maxillary canines. As the canines erupt, they push the incisors together and close modest diastemas but not extensive ones. CHAPTER 30 The Dynamics of Change 415 boredom. Previously, the preschooler immersed his mind in an activity until all his energy and attention were spent. en, at the point of burnout, he looked to his parents or other attendants to nd something else for him to do. Between ages 6 and 12 years, however, the need for adults to direct the child’s attention rapidly recedes, and by age 12 years a child usually has a ledger of wants and desires, a sense of the time that should be spent in their pursuit, and an ability to set priorities for which wants and desires should come rst or last.In this age range, body image starts to become an emotional feature of the child’s life. Unquestionably, for the majority of children, the importance of body image becomes most dramatic during adolescence, but its emergence certainly occurs during these years. Whereas the 6-year-old usually cares little about having ketchup on his face or mud on his pants, the 12-year-old may agonize over a blemish or wearing clothes that are not stylish. In summary, body appearance becomes a subject of emotional awareness and emphasis during these years. Unquestionably this has dental ramications. A 6-year-old may be indierent to the appearance of hypomineralized incisors or a malocclusion. By age 12 years, such conditions may account for a lack of smiling, social withdrawal, and a loss of self-esteem. Teasing and bullying may exacerbate the problem.Although there certainly are exceptions, the majority of children from ages 6 to 12 years nd overall emotional satisfaction only when they are accepted socially by their peers. Lack of acceptance, outright ostracism, teasing, and bullying can certainly be very damaging emotionally. During these years—with the help of parents, teachers, role models, and other signicant individuals—it is important for the child to become emotionally resilient. e abilities to handle and recover from humiliation, frustration, loss, and disappointment should at least begin to emerge during these years. If they do not, then adolescence may become tumultuous years.Social Changese period between ages 6 and 12 years is often called middle childhood. ese years are clearly more complicated socially than the earlier years because of the demands of school, the increasing importance of peers, and the enormous expansion of the child’s social environment. ese years see the child intensifying his or her focus on and pursuance of existing interests and competencies while minimizing or eliminating others.School is extremely important for this age group and represents an extrafamilial world that may reinforce social responses learned at home, provide new ones, and even discourage others. In school, children are expected to control themselves, cultivate good work habits, sit quietly for long periods of time, and comply with rules and expectations for personal conduct set by adults.7Perhaps surprisingly, most children anticipate school positively and remain enthusiastic about their experiences there. It has also been noted that children’s self-importance, self-control, and ability to be independent (e.g., getting their own breakfast) increase quickly during the rst few months of school.8 Unfortunately, self-condence and motivation tend to decline later in the elementary school years, and this trend continues through adolescence. is may result in students avoiding certain courses or dropping out of school completely. Children may shy away from activities in which they are initially unlikely to succeed. However, if they are able to see that they can become competent with practice and development, supportive adults are able to help children manage their frustrations.7Cognitive ChangesA book could easily be written describing the great cognitive acquisitions, adjustments, and sophisticated changes occurring in a child from age 6 to 12 years. Mental capacity alone grows extensively. Unquestionably the attention span of the child older than 7 years is substantially greater than that of the child younger than 5 years.e school-age years of 6 to 12 are when a child becomes literate. Before age 6 years, few children can do much more than print their names. After age 12 years, most children have accomplished an appropriate approach to grammar and syntax and have the ability to produce increasingly sophisticated oral and written communications. In some parts of the world, it is not uncommon for a child to be uent in a second language by age 12 years.According to Piaget,6 the ages between 6 and 12 years roughly approximate the third major developmental stage of cognition—that is, the phase of concrete operations. Piaget proposed the following four major periods of intellectual development:1. Sensorimotor: birth to 18 months2. Preoperational: 18 months to 7 years3. Concrete operations: 7 to 12 years4. Formal operations: 12 years and onwardSo far we have presented a study of the child through the sensorimotor and preoperational stages. In the concrete operations stage, Piaget describes numerous sophisticated changes in the child’s mental abilities. For instance, the 5-year-old may be able to walk “two blocks down, one block right to the second white house” to get to his or her aunt’s residence, but the same 5-year-old could not draw this route on a piece of paper. However, by age 7 or 8 years, the child could portray the route on a self-drawn map. In other words, mental representations of actions become a part of the cognitive abilities of the child during these years. For the dentist who communicates with children, it will be helpful to design discussions based on the child’s mental representation ability.During the years from 6 to 12 (7 to 12 according to Piaget), children acquire the ability to understand the constancies between length, mass, number, and weight despite external dierences. Relativity also emerges in the child’s evaluation system. To the 4-year-old, the word dark means black. e 10-year-old can talk about a “dark” green car. In summary, the child between the ages of 6 to 12 years grows cognitively. By the age of 12 years, mind and mental prowess have matured, and real as well as theoretical or abstract information can be assimilated.Emotional Changese period from 6 to 12 years is one of advancement toward the acceptance by the child of societal norms of behavior. Crying, tantrums, and other rages will, in normal children, be relinquished as possible modes to express frustration. Whereas the preschooler needs and perhaps demands immediate rewards and satisfaction, the child in the transitional years masters the emotional ability to delay gratication. is awareness of delay is reinforced by the child’s schooling, and increasingly the child is guided toward the appropriate investment of his or her time in worthwhile activities. Homework, household chores, caring for pets, and extracurricular activities such as scouting, team sports, dance, and music lessons are some of the behaviors expected of this age group, which were almost impossible during the preschool years.Another emotional renement that is developed from age 6 to 12 years is the ability to use life’s tasks to eectively stave o 416 Part 4 The Transitional Years: Six to Twelve Yearsgroup ingested 300 g of sucrose per day and 40% of it was consumed between meals. Although there were aws in the design of this study, the magnitude of the dierences in caries development are impressive. e questions regarding the ethics of this type of study ensure it will probably never be repeated.Another study corroborating the role of sucrose was conducted with 3- to 14-year-olds who resided at Hopewood House in Bowral, New South Wales, Australia.15,16 Almost all of these institutionalized children had lived there since infancy and were fed an almost pure vegetarian diet supplemented with milk and an occasional egg yolk. e vegetables were generally served raw, and rened carbo-hydrates were rigidly restricted. In spite of poor oral hygiene, the caries prevalence among the children was very low. Primary dentition involvement was almost nonexistent, whereas the caries prevalence of the permanent teeth was about one-tenth that of the mean score for other Australian children. Almost one-third of the children remained caries-free throughout the 5-year study. Children who left Hopewood House at an older age experienced a signicant increase in dental caries.Some still question the primary role of sucrose and other sugars in the etiologic development of caries.17 Burt and Pai18 concluded in their systematic review that the relationship between sugar consumption and caries is weaker but not eliminated in the modern era of uoridation. Marshall and colleagues19 conclude that the cariogenicity of a food is less dependent on the nature of the sugar than on the characteristics of the food and the nature of the exposure, primarily frequency. However, others remain convinced that free sugars (which include all mono- and disaccharides added to food and sugars naturally present in honey, syrup, fruit juices, and concentrates) are the primary factors facilitating the develop-ment of dental caries.10,20Other Food Factorsere is evidence to show that both the frequency of intake of sugar-rich foods and drinks and the total amount consumed are related to dental caries. In addition, these two factors are closely related.10 In a study of 5-year-old children in Iceland, Holbrook et al. found a threshold eect for the frequency of sugar consump-tion on caries development to be up to four times a day. Children reporting four or more episodes of sugar intake per day or three or more between-meal snacks per day had much higher caries rates. In 5-year-old children who developed three or more lesions, the sugar intake averaged 5.1 times per day compared with 2.1 times a day for children who developed less than three carious lesions.21 e Vipeholm study also showed that caries development was low when sugars were consumed up to four times a day at mealtimes.14 More frequent contact with sugars at mealtime and frequent between-meal snacks result in prolonged or multiple pH challenges to the teeth and possibly to longer oral clearance times. Yet several longitudinal studies have shown the amount of sugar intake to be more important than frequency.10 Ismail et al. found a very high correlation between the frequency of consumption of sugary drinks between meals and the amount consumed. In addition, both the frequency and the amounts consumed were associated with higher caries risk.22e multiplicity of food factors requires that estimations of the relative cariogenicity of foods be approached with caution. ese factors include carbohydrate-sucrose concentration, retentiveness, oral clearance rate, detergent quality, texture, eect of mixing foods, sequence of ingestion, frequency of ingestion, and pH of the food itself. For example, most fruits will depress plaque pH by virtue of their own low pH. is occurs even though the low pH of the e peer group that a child joins also can be a powerful social-izing force. Sometimes the values of the peer group are antithetical to those of the teacher and parents. is presents a conict for the child in that he or she may risk reprimand from authoritative adults or ridicule or rejection from his or her peers if he or she conforms to one or the other’s expectations. It is important for parents to understand these conicts and how socially inuential peer pressure can be for children in this age group. It is also important to note that the child who eagerly accepts a peer value that disappoints her or his parents may in fact be doing so to gain the feelings of acceptance and nurturing that were not provided suciently at home.One last factor marks the middle childhood years. is is the advent of increasingly stronger, more stable, and more meaningful friendships. Generally friendships are made with children of the same gender. Friends at this age level as a rule also share similar socioeconomic status, intelligence, maturity, and interests. At the same time, it is important to recognize that as closer bonds and friendships are dened, social cruelty and bullying also increase.Dental Caries and Dietary FactorsDental caries is the most common chronic disease of childhood. Even though caries prevalence in permanent teeth has remained relatively stable since the 1980s and some 60% of adolescents have dental caries, this disease still aects a majority of school-aged children in the United States.9 See Chapter 12 for a discussion on the epidemiology of caries in the transitional dentition.Why Dietary Factors Are Important to the Transitional Dentitionere is ample evidence linking dietary sugars to the etiology of dental caries.10 As mentioned in Chapter 12, sugars (sucrose, fructose, glucose, and others) are among the major etiologic factors in dental caries. Sucrose has been labeled the “arch criminal of dental caries,”11 but animal studies have shown that other sugars, notably glucose and fructose, are as cariogenic as sucrose.12,13SucroseOne of the rst controlled studies to document sucrose as an etio-logic factor was the Vipeholm study14 near Lund, Sweden. A total of 436 inmates in a mental institution were given sugar in various forms to supplement the relatively sugar-free institutional diets. e sugar was oered as sucrose in solution or in retentive forms, such as sweetened bread and toee. e sucrose in solution and the bread were introduced with meals, whereas the other forms were given between meals. e study showed that an increase in sucrose intake was associated with an increase in caries activity. Furthermore, this caries activity decreased when the sucrose-rich foods were discontinued. e cariogenic potential of the sucrose was enhanced when it was given between meals and in a more retentive form (caramels and toees). e time required for the sugar to clear the oral cavity was closely related to the caries activity. e study also pointed out that caries formation varied among individuals and that caries formation continued in some individuals even after a return to low-sucrose diets. e subjects who received only 30 g of sucrose per day, all at mealtimes, developed an average of 0.27 new carious lesions per year. ose who ingested 330 g of sucrose per day (300 g in solution) developed 0.43 new carious surfaces per year. Lastly, subjects in the group who received 24 sticky toees per day developed 4.02 new lesions per year. is CHAPTER 30 The Dynamics of Change 417 Dietary CounselingStookey32 has enumerated the attributes of the ideal snack as one that should (1) stimulate salivary ow by its physical form; (2) be minimally retentive; (3) be relatively high in protein and low in fat, have minimal fermentable carbohydrate, and have a moderate mineral content (especially calcium, phosphate, and uoride); and (4) have a pH above 5.5 so as not to decrease oral pH, with a large acid-buering capacity and a low sodium content. Certain foods, such as raw vegetables, meet most or all of these requirements. Present-day food technology should make it possible to create snacks that are nutritious and noncar-iogenic, but this will not happen until the food industry nds a reliable cariogenicity test and the incentives to invest in such production.Based on evidence showing positive associations between sugars and caries, the World Health Organization (WHO) in 2015 issued guidelines calling for restricted sugar intake. e WHO guidelines include (1) a strong recommendation to reduce free sugar intake over the course of a lifetime, (2) a strong recommendation to limit free sugar intake to less than 10% of total energy (calories) con-sumed, and (3) a conditional recommendation to reduce the free sugar intake to less than 5% of total energy intake. e term free sugar refers to all mono- and disaccharides added to foods by the manufacturer, cook, or consumer plus sugars naturally present in honey, fruit juices, and syrups. e term “fermentable carbohydrates” refers to free sugars, glucose polymers, fermentable oligosaccharides, and highly rened starches. Less than 10% energy equates to less than 15 to 20 kg/person per year of sugar intake or less than 40 to 55 g/day.33 Added sugar labeling and education are also included in the guidelines. What remains to be seen is how the ndings will translate into public policies to induce positive behavior changes limiting the intake of sugars.34In the meantime, we are left with the dicult but important task of working with families to improve the dietary habits of caries-susceptible children. e dental profession has an obligation to make dietary information available to them. Although it is neither feasible nor desirable to eliminate sugar completely from the diet, counseling and coaching should be provided to patients and families to lower the daily intake of free sugars, reduce the frequency of between-meal snacks, and limit sugars and processed cooked starches to mealtimes when salivary ow is higher. Lowering the frequency of fermentable carbohydrate ingestion is more important than reducing the total carbohydrate intake. Utilizing a risk-based chronic disease management approach35,36 to addressing dental caries in clinical dental practice can be eective in assisting patients and their families to make sustainable changes in their dietary and oral hygiene practices and, in doing so, improving their caries risk (see the case study).Summarye period from ages 6 through 12 years is probably the most dynamic period for craniofacial, dental, emotional, and social changes in a child’s growth. Growth modication and intervention related to dental eruption and space problems can be critical. All interventions are undertaken on a rapidly changing social and emotional substructure that can make success or failure precarious.Eective counseling and coaching to establish and maintain healthy dietary habits as well as good oral hygiene are important to reduce the child’s risk of developing dental caries.food inhibits natural fermentation of its sugar content. Low-pH fruits can also demineralize enamel by the direct action of their acids. At the same time, low-pH fruits stimulate a ow of saliva that buers plaque pH drops; other foods, such as vegetables, stimulate salivary ow through the chewing reex. On balance, however, there is not a strong case for a caries-protective eect from fruits and vegetables.23 On the other hand, Moynihan and Petersen argued that dried fruits may potentially be more cariogenic, since the drying process breaks down the cellular structure of the fruit, thus releasing free sugars, and that dried fruits tend to have a longer oral clearance.10In fact, stickiness or retentiveness is another food factor that has received much attention. Foods high in cooked processed starch content (e.g., breads, cereals, potato chips), judged by lay individuals to be relatively nonsticky, were much slower to clear the oral cavity, whereas those foods that were high in sucrose (e.g., caramels and jelly beans), judged as among the stickiest foods, exhibited a rapid clearance from the mouth.24,25 However, epidemiologic studies have shown that in general starch is of low risk for dental caries. Consumers of high-starch/low sugar diets generally demonstrate low caries experience whereas consumers of low-starch/high sugar diets demonstrate high level of caries.10 In the Hopewood House study, children consumed a high starch/low sugar diet and had low levels of caries.15,16 Rugg-Gunn concluded that the cariogenicity of uncooked starch and cooked staple starchy foods such as rice, potatoes, and bread is low. On the other hand, nely ground and heat-treated starch can induce caries, but less so than sugars. Furthermore, the addition of sugar increases the cariogenicity of cooked starchy foods.26Clearly no one cariogenicity test can account for all these factors except possibly trials in humans. Even in human trials, individual variations exist in plaque composition and amount, salivary buering capacity, and enamel resistance to dissolution with or without the ability to remineralize.Certain food components and factors may have cariostatic or caries-inhibiting eects. Phosphates, principally sodium metaphos-phate, have been shown to reduce caries in animal studies.27 e eect is probably local, related to buering capacity, a reduction of enamel solubility, and other bacterial and biochemical properties. Unfortunately, clinical trials with phosphate supplements in human diets have not proved as eective.28 Other animal studies29 have shown that foods high in fat, protein, uoride, or calcium may protect against caries. Such foods include cheese, yogurt, bologna, chocolate, and peanuts. Fats may protect by coating the teeth and reducing the retention of sugar and even plaque by changing the enamel’s surface activity. Fats also may have toxic eects on oral bacteria and may decrease sugar solubility. Protein elevates the urea level in saliva and increases the buering capacity of the saliva. Protein may also have an enamel-coating eect. Protein and fat in combination may raise plaque pH after exposure to carbohydrates. Tannins and other components of cocoa have been shown to suppress caries activity. e addition of uoride to dietary sucrose in concentrations as low as 2 ppm has also been found to signi-cantly reduce decay in rats.30 Similar studies in humans have yet to be undertaken.It has been proposed that the brous quality of some foods, such as celery or apples, may have a detergent effect on the teeth.31 Such foods may remove gross debris during mastication, but they are ineective at plaque removal. By requiring vigor-ous chewing, these foods may stimulate salivary ow, which in turn buers plaque acid and promotes the remineralization of enamel.