Obesity and Dental Decay: Inference on the Role of Dietary Sugar

Objective

To evaluate the relationship of children’s obesity and dental decay.

Methods

We measured parameters related to obesity and dental decay in 8,275 4^th and 5^th grade Kuwaiti children (average age = 11.36 years) in a cross-sectional study. First to determine body weight, height, age for computation of BMI . Second, to determine numbers of teeth, numbers of fillings and numbers of untreated decayed teeth to determine extent and severity of dental disease. From these measurements, we computed measures of dental decay in children from four body weight categories; obese, overweight, normal healthy weight and underweight children.

Results

The percentage of children with decayed or filled teeth varied inversely with the body weight category. The percentage of decayed or filled teeth decreased from 15.61% (n=193) in underweight children, to 13.03% (n=4,094) in normal healthy weight children, to 9.73% (n=1,786) in overweight children to 7.87% (n=2,202) in obese children. Differences between all groups were statistically significant. Male children in this population had more dental decay than female children but the reduction of tooth decay as a function of BMI was greater in male children.

Conclusions

The finding of an inverse obesity-dental decay relationship contradicts the obesity-sugar and the obesity-dental decay relationship hypotheses. Sugar is well recognized as necessary and sufficient for dental decay. Sugar is also hypothesized to be a leading co-factor in obesity. If the later hypothesis is true, one would expect dental decay to increase with obesity. This was not found. The reasons for this inverse relationship are not currently clear.     

昆明市儿童恒牙萌出时间及恒牙萌出与生长发育关系的调查研究

本文报道了昆明市8148例儿童恒牙（第三磨牙除外）萌出时间的横断面调查，对恒牙萌出与年龄、身高、体重和月经初潮的关系进行了探讨。经相关分析，恒牙萌出数与年龄高度相关，与身高和体重低度相关，并建立了由年龄、身高或体重推算萌牙数的回归方程。还发现恒牙萌出与青少年性成熟也有一定的联系。提示恒牙萌出也能反映儿童的生长发育状况，故可作为衡量儿童生长发育的一项指标。     

Genome-wide association study identifies four loci associated with eruption of permanent teeth

The sequence and timing of permanent tooth eruption is thought to be highly heritable and can have important implications for the risk of malocclusion, crowding, and periodontal disease. We conducted a genome-wide association study of number of permanent teeth erupted between age 6 and 14 years, analyzed as age-adjusted standard deviation score averaged over multiple time points, based on childhood records for 5,104 women from the Danish National Birth Cohort. Four loci showed association at P<5×10(-8) and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10(-11). Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9-4.1) fewer permanent teeth than children with 0 or 1 of these alleles.     

Formation of a successional dental lamina in the zebrafish (Danio rerio): support for a local control of replacement tooth initiation

In order to test whether the formation of a replacement tooth bud in a continuously replacing dentition is linked to the functional state of the tooth predecessor, I examined the timing of development of replacement teeth with respect to their functional predecessors in the pharyngeal dentition of the zebrafish. Observations based on serial semithin sections of ten specimens, ranging in age from four week old juveniles to adults, indicate that (i) a replacement tooth germ develops at the distal end of an epithelial structure, called the successional dental lamina, budding off from the crypt epithelium surrounding the erupted part of a functional tooth; (ii) there appears to be a developmental link between the eruption of a tooth and the formation of a successional dental lamina and (iii) there can be a time difference between successional lamina formation and initiation of the new tooth germ, i.e., the successional dental lamina can remain quiescent for some time. The data suggest that the formation of a successional lamina and the differentiation of a replacement tooth germ from this lamina, are two distinct phases of a process and possibly under a different control. The strong spatio-temporal coincidence of eruption of a tooth and development of a successional dental lamina is seen as evidence for a local control over tooth replacement.     

Development of Overweight in Children in Relation to Parental Weight and Socioeconomic Status

The purpose of the study was to test the hypothesis that socioeconomic status (SES) moderates the association between parental weight and changes in BMI from childhood to early adolescence. Participants included 428 twin children from 100 families with obese parents (“obese families”) and 114 sociodemographically matched families with normal‐weight parents (“lean families”) who were assessed in their homes (age = 4.4). Follow‐up study was conducted 7 years later (age = 11.2) on 346 children (81%). Complete data were available for 333 children. Family SES was indexed with maternal education. Children's weights and heights were measured to calculate BMI s.d. scores based on 1990 British norms. Overweight was defined as >91st BMI centile. In children with obese parents, BMI s.d. scores increased from 0.51 at age 4 to 1.06 at age 11. In children with lean parents, BMI s.d. scores decreased from 0.11 to 0.05. Prevalence of overweight remained stable from age 4 to 11 in children with lean parents (8% to 9%), but it more than doubled in children with obese parents (17% to 45%). There was a significant interaction between parental weight and family SES (P < 0.01), so that in children with lean parents there was no SES difference in the BMI status from age 4 to 11; however, in children with obese parents, the increase in adiposity was significantly greater in lower SES families. These results suggest that parental leanness confers significant protection against development of overweight in children regardless of family SES, while parental obesity is an adverse prognostic sign, especially in lower SES families.     

Growth and development in the saddle-back tamarin: The sequence and timing of dental eruption and epiphyseal union

A cross-sectional sample of 121 colony-born saddle-back tamarins, Saguinus fuscicollis, was examined to identify the sequence and timing of dental eruption and epiphyseal union. The state of dental development of the deciduous and permanent dentitions was recorded as erupted or non-erupted on the basis of gingival penetration. Eighteen areas of union of long bone epiphyseal and other secondary centers, the union of the primary elements of the innominate, and the spheno-occipital synchondrosis were examined. The state of union at the areas was recorded on a three-point scale of not united, uniting, and united. The data indicated that deciduous incisors and canines were present at birth and that all deciduous teeth were erupted by 12 weeks. The first permanent tooth, M(1), erupted between weeks 16 and 23; the permanent dentition was fully erupted by 45 weeks. Union of the long bone epiphyses began in the third month at the distal humerus and continued until the first quarter of the second year. The secondary centers at the ischial tuberosity and iliac crest were united slightly later than four and six years of age, respectively. Regression analysis of the data indicate their potential use as parameters for predicting age in feral specimens.     

The timing of eruption of the primary dentition in Nigerian children

The objectives of this study were to clarify the eruption time and sequence for primary teeth in Nigerian children. It also investigated the effect of sex and socioeconomic status on the timing and sequence of eruption. A random sample of 1,657 children from ages of 3-40 months were examined--921 (55.6%) males and 736 (44.4%) females. The age of eruption of the teeth was estimated using probit regression. The results show that there was no effect of sex, socioeconomic status or breastfeeding status on the timing of eruption and pattern of teeth eruption in Nigerian children. Left and right teeth had similar eruption times. Eruption times of the lateral incisor, canine, and molars were similar for upper and lower teeth. Interpopulation studies however showed that though the sequence of eruption of primary teeth in Nigerian population is similar to that of their peers in other compared populations, there are observable sex differences in the timing of tooth eruption.     

Socioeconomic inequality and obesity prevalence trends in luxembourg, 1995¿2007

ABSTRACT: BACKGROUND: Overweight and obesity are becoming increasingly critical problems in most developed countries. Approximately 20% of adults in most European countries are obese. This study examines the prevalence of overweight and obesity in Luxembourg and their association with different demographic, socioeconomic (SES), and behavioural factors. METHODS: The data used in this study were taken from 2 surveys on household income and living conditions conducted in 1995 and 2007. The target population was household residents aged 16 years and older, and body mass index (BMI) data were self-reported. Average BMI, overweight, and obesity prevalence rates were calculated according to each demographic (gender, nationality, marital status), SES (educational level, profession, and place of residence), and behavioural (physical activity and diet) factors. A multivariate logistic regression analysis was conducted to measure the relationship between obesity and demographic, SES, and behavioural factors. All analyses were conducted according to gender, and data used were weighted. RESULTS: Between 1995 and 2007, the average BMI remained nearly constant among men and women in the entire study population. Obesity prevalence increased by 24.5% through the study period (14.3% in 1995 to 17.8% in 2007). Obesity prevalence increased by 18.5% for men (15.1% in 1995 to 17.9% in 2007) and by 30% for women (13.6% in 1995 to 17.7% in 2007). Between 1995 and 2007, obesity increased sharply by 48.2% (from 11% to 16.3%) in Portuguese men, 76.7% (from 13.3% to 23.5%) in Portuguese women, 79.7% (from 17.2% to 30.9%) in widowed men, and 84.3% (from 12.1% to 22.3%) in divorced women. Multivariate logistic regression analysis showed that the relationship between the educational level and obesity was not statistically significant for men, but was significant for women. CONCLUSIONS: The prevalence of overweight and obesity is high in Luxembourg and has changed slightly in recent years. SES inequalities in obesity exist and are most compelling among women. The fight against obesity should focus on education, with emphasis on the socially disadvantaged segment of the population.     

Oral status and its association with obesity in Southern Brazilian older people

Background and objective: The loss of a functional dentition imposes eating difficulties and food avoidance, which may be detrimental in terms of nutritional status and health. The objective of this study was to investigate whether tooth loss and edentulism that were not rehabilitated with dental prostheses were associated with obesity among elderly in Southern Brazil. Materials and methods: A random sample of 872 independently living elderly was evaluated by means of a cross‐sectional study. Socio‐demographic, medical history and behaviour data were assessed using a standardised questionnaire. Two trained dentists assessed the number of teeth and use of prostheses in accordance with the WHO criteria. Height and weight were assessed and used to generate body mass index (BMI = weight (kilos)/height (cm)²) data. Participants were categorised into non‐obese (BMI ≤ 30) or obese (BMI > 30). Multivariate logistic regression was used to model the relationship between number of teeth and use of dental prostheses with obesity adjusting for confounders. Results: Multivariate logistic regression revealed that edentulous persons wearing only upper dentures (OR = 2.34, 95% CI 1.18–4.27) and dentate participants with one to eight teeth wearing 0‐to‐1 prosthesis (OR = 2.96, 95% CI 1.68–5.19) were more likely to be obese. Conclusion: The results show that a poorer oral status, represented by having fewer teeth that were not replaced by dental prostheses, was associated with obesity in Southern Brazil older people, suggesting a close relationship between poor oral status and systemic conditions that may have important clinical implications.     

Schultz's unruly rule: dental developmental sequences and schedules in small-bodied, folivorous lemurs

Schultz's rule (as reconstructed by Smith) states that there is a relationship between the pattern (or relative order) of eruption of molar versus secondary (replacement) teeth and the overall pace (or absolute timing) of growth and maturation. Species with 'fast' life histories (rapid dental development, rapid growth, early sexual maturation, short life spans) are said to exhibit relatively early eruption of the molars and late eruption of the secondary replacement teeth (premolars, canines, incisors), whereas species with 'slow' life histories are said to exhibit relatively late eruption of the molars and early eruption of the secondary dentition. In a recent review, B.H. Smith noted that primates with tooth combs might violate this rule because tooth combs tend to erupt early, regardless of the pace of life history. We show that exceptions to Schultz's rule among lemurs are not limited to the relative timing of eruption of the tooth comb. Rather, among lemurs, some species with extremely accelerated dental development exhibit a pattern of eruption of molars and of secondary teeth in direct opposition to the expectations of Schultz's rule. We focus particularly on the pattern (order) and pace (absolute timing) of dental development and eruption in Avahi and Lepilemur - two relatively small, nocturnal folivores with rapid dental development. These taxa differ markedly in their eruption sequences (the premolars erupt after M2 and M3 in Lepilemur but not Avahi ). We offer an explanation for the failure of Schultz's rule to predict these differences. Schultz's rule presumes that eruption timing is dependent on the size of the jaw and that, therefore, molar crown formation and eruption will be delayed in species with slow-growing jaws. We show that a variety of processes (including developmental imbrication) allows the crowns of permanent teeth to form and to erupt into jaws that might appear to be too small to accommodate them.     

Age estimation from dental eruption in infant and juvenile baboons (Papio sp.)

Two regression methods are proposed for estimating age in nonhuman primates from deciduous dental eruption data. The first method consists of step-wise multiple regression using dental eruption state (present/absent) of each tooth as independent variables. The second method uses the total number of teeth erupted as an independent variable in an exponential model. We applied both methods to a sample of 175 well nourished infant and juvenile baboons (Papio sp.), housed in an outdoor breeding corral, and ranging in age from birth to 763 days. From this sample, 129 animals were used to compute the regression formulae, and 46 animals were used for cross validation. Both models show good overall fits and high predictive accuracy with the independent cross validation sample.     

Effect of current and midlife obesity status on mortality risk in the elderly

The primary purpose of this study was to determine whether current and midlife obesity status provide independent information on mortality risk in elderly persons. Analyses were based on 3,238 participants from the original Framingham Heart Study (FHS) cohort who lived to at least 70 years of age and who had BMI measures from when they were in their 50s. Within this group of 70-year olds, obesity based on current BMI was associated with a 21% increased risk of mortality (P = 0.019) whereas obesity in 70-year olds based on BMI measures obtained at around 50 years of age was associated with a 55% increased risk of mortality (P < 0.0001). Compared to 70-year olds who were nonobese at both 50 and 70 years of age, mortality risk was increased by 47% (P < 0.001) in those who were obese at both 50 and 70 years of age, increased by 56% (P < 0.001) in those who were obese at 50 years of age and nonobese at 70 years of age, and not significantly different (P > 0.9) in those who were nonobese at 50 years of age and obese at 70 years of age. In summary, in this cohort of elderly adults, midlife and current BMI had independent effects on mortality risk. Specifically, although mortality risk was increased in obese older adults who were already obese at midlife, this was not the case for newly obese older adults. Conversely, nonobese older adults who were obese at midlife had an increased mortality risk. These observations imply that it is imperative to consider an elderly adult's BMI in context of their BMI at midlife.     

Masculinization of the eruption pattern of permanent mandibular canines in opposite sex twin girls

The aim of this study is to explore the effect of prenatal androgenization on the clinical eruption of permanent teeth expressing dimorphism and bimaturism. The eruption curves of permanent teeth (except third molars), including those that make up the canine complex (permanent canines, lower first premolars), are compared among opposite sex twins (OS twins) relative to single‐born boys and girls. The comparisons are made with regard to three phases of eruption (pierced mucosa, half‐ erupted, and completely erupted) from a cross‐sectional sample of dental casts, using Kaplan–Meier survival and Cox regression analyzes. The casts were collected from 2159 school children from the US Collaborative Perinatal Project, including 39 pairs of OS‐twins, of which 12 pairs (30.8%) were Euro‐Americans and 27 pairs (69.2%) were of African‐American ancestry. The eruption patterns of the incisors, upper first molars, and lower canines were found to be significantly masculinized (delayed) among OS twin girls. The differences in most other teeth were either not significant, or the number of observations of active eruption phases were too few, such as in the upper first molars and incisors, to yield strong evidence and meaningful results. The masculinization of the tooth eruption pattern in OS twin girls is intriguing because of the lower canine responses during puberty, as well as canine primordial formation during early fetal androgenization of their co‐twin during the 8th to 14th gestational weeks. The present results offer a challenge for future research exploring tooth eruption mechanisms, and may also highlight some cases of delayed or ectopic canines, which are biased toward females. Am J Phys Anthropol 151:566–572, 2013. © 2013 Wiley Periodicals, Inc.     

High childhood obesity in an Australian population

Objective: The objective was to determine the prevalences of overweight and obesity in regional Australian children and to examine the association between BMI and indicators of socioeconomic status (SES). Research Methods and Procedures: Regionally representative cross‐sectional survey of 2184 children, 4 to 12 years of age, was conducted, and the socio‐demographic characteristics of their parents from regional Victoria, Australia, 2003 to 2004, were obtained. Results: The prevalences of overweight and obesity were 19.3 ± 0.8% (proportion ± standard error) and 7.6 ± 0.6%, respectively, using international criteria, and the proportion of overweight/obese girls was significantly higher than that of boys (29.6 ± 1.4% vs. 23.9 ± 1.3%, χ² = 9.01, p = 0.003). Children from households of lower SES had higher odds of being overweight/obese; lower SES was defined by lower paternal education (adjusted odds ratio, 1.18; 95% confidence interval, 1.08 to 1.30) and lower area‐level SES (adjusted odds ratio, 1.13; 95% confidence interval, 1.02 to 1.25), adjusted for age, gender, height, and clustering by school. Discussion: The prevalences of overweight and obesity are increasing in Australian children by about one percentage point per year. This equates to ～40,000 more overweight children each year, placing Australian children among those at highest risk around the world. In addition, girls are more likely to be overweight, and there is a general trend for children of lower SES to be at even greater risk of overweight and obesity.     

Intelligence Test Score and Educational Level in Relation to BMI Changes and Obesity

Objective: To investigate whether intelligence and education are related to subsequent BMI changes and development and persistence of obesity in men from young adulthood through middle‐age. Research Methods and Procedures: Subjects were selected among men (median age, 19 years; examined between 1956 and 1977) appearing at Danish draft boards: a group with juvenile‐onset obesity, including all men with a BMI of ≥31.0 kg/m²; and a nonobese group randomly selected as a 1% sample of the study population. The obese group and 50% of the nonobese group were invited to participate in follow‐up studies between 1982 and 1984 and between 1992 and 1994. Among 907 men with juvenile‐onset obesity and 883 nonobese men, age, examination region, intelligence test score, education, and BMI from baseline to first follow‐up were analyzed by multiple linear and logistic regressions analyses. Results: Education and intelligence, analyzed separately, were inversely related to BMI changes in both groups and to the development of obesity in the nonobese group. When adjusted for education, the association between intelligence score and BMI changes and development of obesity vanished, whereas the inverse relationship for education persisted only for BMI changes. Intelligence score was not associated with the persistence of obesity in the obese group, whereas inverse relationships were found for education. Discussion: Intelligence test score was inversely related to risk of BMI changes and the risk of development of obesity, perhaps with education acting as a mediator or indicator of cognitive ability. Education, but not intelligence, was inversely associated with risk of remaining obese.     

Measured parental weight status and familial socio-economic status correlates with childhood overweight and obesity at age 9

Background

Parental obesity is a predominant risk factor for childhood obesity. Family factors including socio-economic status (SES) play a role in determining parent weight. It is essential to unpick how shared family factors impact on child weight. This study aims to investigate the association between measured parent weight status, familial socio-economic factors and the risk of childhood obesity at age 9.

Methodology/Principal Findings

Cross sectional analysis of the first wave (2008) of the Growing Up in Ireland (GUI) study. GUI is a nationally representative study of 9-year-old children (N = 8,568). Schools were selected from the national total (response rate 82%) and age eligible children (response rate 57%) were invited to participate. Children and their parents had height and weight measurements taken using standard methods. Data were reweighted to account for the sampling design. Childhood overweight and obesity prevalence were calculated using International Obesity Taskforce definitions. Multinomial logistic regression examined the association between parent weight status, indicators of SES and child weight. Overall, 25% of children were either overweight (19.3%) or obese (6.6%). Parental obesity was a significant predictor of child obesity. Of children with normal weight parents, 14.4% were overweight or obese whereas 46.2% of children with obese parents were overweight or obese. Maternal education and household class were more consistently associated with a child being in a higher body mass index category than household income. Adjusted regression indicated that female gender, one parent family type, lower maternal education, lower household class and a heavier parent weight status significantly increased the odds of childhood obesity.

Conclusions/Significance

Parental weight appears to be the most influential factor driving the childhood obesity epidemic in Ireland and is an independent predictor of child obesity across SES groups. Due to the high prevalence of obesity in parents and children, population based interventions are required.     

Plasma Cortisol Levels Increase with Age in Obese Subjects

In order to assess the influence of age, sex, and body mass on plasma cortisol concentrations, we measured the 24-hour Integrated Concentration (IC) of cortisol (F) in 36 obese subjects (16 males, 20 females) aged 5.3–56.4 years, BMI=35.5 ± 7.3 kg/m² and compared with 119 nonobese subjects, body mass indices (BMI) 21.2 ± 2.7 kg/m², aged 8.8–66.2 years (55 males, 64 females). Subjects were nondiabetic, normotensive, without history of psychiatric illness, and otherwise in good health. IC studies were performed using a continuous blood withdrawal methodology, and IC-F was assayed from the 24 hour pooled sample by a protein binding method. The effect of age and gender on IC-F was analyzed by multivariate regression. In the nonobese group there was no effect of age or sex on IC-cortisol levels, the mean IC-F= 173.8 ± 44.1 nmol/L. A statistically significant but weak negative effect of BMI on IC-cortisol (r = -.18, p<0.05) was present. In the obese subjects there was a significant increase in IC-cortisol levels with age IC-F(nmol/L)=2.76 x age(years) + 85.0 (r²=.36, p<0.0001). IC-cortisol levels tended to be lower in obese males than females when controlled for age (p<0.05). We conclude that in nonobese subjects IC-F levels are independent of age and gender. However, there is a significant increase of IC-cortisol levels with age in obese individuals. The observed increase of IC-cortisol with age may contribute to metabolic complications of obesity.     

Observation of Children's Teeth as a Diagnostic Aid: A Review: Part I. Dentition in the Assessment of Development

The accuracy of information obtained from such a simple procedure as looking in the mouth as a measure of child development led to this review. The relationship between dental and physical development has been known for many years. Methods of assessing maturity by counting erupted teeth are described. Measurements taken on two boys illustrated this hypothesis, and from these the close correlation between height and weight, bone age and dental age is shown. It is suggested that physicians and dentists should record the number of erupted teeth on interval examinations, since the pattern of eruption and calcification of teeth may present the first indication of developmental retardation.     

Is Socioeconomic Status of the Rearing Environment Causally Related to Obesity in the Offspring?

We attempt to elucidate whether there might be a causal connection between the socioeconomic status (SES) of the rearing environment and obesity in the offspring using data from two large-scale adoption studies: (1) The Copenhagen Adoption Study of Obesity (CASO), and (2) The Survey of Holt Adoptees and Their Families (HOLT). In CASO, the SES of both biological and adoptive parents was known, but all children were adopted. In HOLT, only the SES of the rearing parents was known, but the children could be either biological or adopted. After controlling for relevant covariates (e.g., adoptee age at measurement, adoptee age at transfer, adoptee sex) the raw (unstandardized) regression coefficients for adoptive and biological paternal SES on adoptee body mass index (BMI: kg/m²) in CASO were -.22 and -.23, respectively, both statistically significant (p = 0.01). Controlling for parental BMI (both adoptive and biological) reduced the coefficient for biological paternal SES by 44% (p = .034) and the coefficient for adoptive paternal SES by 1%. For HOLT, the regression coefficients for rearing parent SES were -.42 and -.25 for biological and adoptive children, respectively. Controlling for the average BMI of the rearing father and mother (i.e., mid-parental BMI) reduced the SES coefficient by 47% in their biological offspring (p≤.0001), and by 12% in their adoptive offspring (p = .09). Thus, despite the differing structures of the two adoption studies, both suggest that shared genetic diathesis and direct environmental transmission contribute about equally to the association between rearing SES and offspring BMI.     

Tooth eruption in Reeves' muntjac (Muntiacus reevesi) and its use as a method of age estimation (Mammalia: Cervidae)

The sequence of tooth eruption and replacement in Reeves' muntjac was determined from captive animals of known age. Pronounced sexual dimorphism is shown by the permanent upper canine which in the male is large, tusk-like and is used as a weapon. The upper canine was the first deciduous tooth to be replaced in males, at approximately 21 weeks of age, compared with 53–57 weeks in the female. The permanent mandibular teeth erupted in the order: molars, first and second incisors, premolars, third incisor and canine. The maxillary teeth erupted in the order: first molar, canine (in male), second and third molars, canine (in female), premolars. The full complement of 34 functional permanent teeth was attained by 83–92 weeks of age.