Influence of metabolic-linked early life factors on the eruption timing of the first primary tooth

Single-Nucleotide Polymorphisms in MMP3, TIMP1, and MTR Genes are Associated With Delayed Deciduous Tooth Eruption

To analyze whether the single-nucleotide polymorphisms (SNPs) in Matrix metalloproteinases 2, 3, and 9 (MMP2, MMP3, and MMP9), Tissue Inhibitor of Metalloproteinases 1 and 2 (TIMP1 and TIMP2), methionine synthase (MTR) and methionine synthase reductase (MTRR) influence delayed deciduous tooth eruption (DDTE). This cross-sectional study included 1060 biologic unrelated children (aged between 6 and 36 months) of both sexes, selected from 25 public schools in Nova Friburgo, Rio de Janeiro, Brazil. Oral examination was conducted and DDTE was defined by the absence of gingival eruption according to a chronology based on the Brazilian population. Genotyping of selected SNPs (rs243847, rs52261, rs17576, rs4898, rs7501477, rs1805087, and rs1801394) was performed using TaqMan real-time PCR with genomic DNA extracted from buccal cells. The association between genotypes and DDTE was evaluated using univariate and multivariate analyses (p < 0.05). A total of 224 children and caregivers were included after the eligibility criteria. The heterozygous genotype for the SNPs MTR (rs11805087) was associated with DDTE in both the univariate (p = 0.004) and multivariate (p < 0.001) codominant models, as well as in the univariate (p = 0.010) and multivariate (p = 0.001) recessive models. TIMP1 (rs4898) and MMP3 (rs522616) were associated with DDTE only in the univariate model (p < 0.05). The SNPs in MTR (rs11805087), MMP3 (rs522616) and TIMP (rs4898) genes are associated with DDTE. The factors affecting the chronology of deciduous tooth eruption has been insufficiently studied. This article brings novel knowledge regarding the role of genetics polymorphisms on timing variation of deciduous tooth eruption. Understanding the factors that impact tooth eruption is crucial for the fields of pediatric dentistry and orthodontics.

Oral and systemic health in Singapore: Revisiting the past to define the future

OBJECTIVES

This study aimed to identify studies exploring oral and systemic conditions using Singapore data.

METHODS

Studies were searched using the databases PubMed, Embase and Web of Science, with no publication date or language restrictions. Studies analysing Singaporean data were included in this review.

RESULTS

Six domains were identified: pregnancy and gingivitis; tooth eruption, dental caries and early-life factors; Crohn's disease and oral microbiome; diabetes and periodontal diseases; number of teeth, chewing ability and cognitive status; and oral health and pneumonia. Using data from Singapore, oral-systemic studies have prompted reflections on the aetiopathogenesis of oral disorders, such as common causes connecting oral and systemic chronic conditions. Moreover, it is speculated whether oral conditions could be used as a marker to predict future systemic diseases or whether early-life factors could affect the development of oral and systemic immune responses.

CONCLUSIONS

While Singapore provides opportunities to explore challenges connected to healthy ageing, it also explores health development in many stages of life. Singapore has been prioritizing investigations on a healthier life, and new initiatives are paving the way for oral health research across the lifespan.

Timing of Primary Tooth Eruption in Infants Observed by Their Parents

BACKGROUND

The timing of primary teeth eruption is a visible indicator of infant physical growth other than body weight or height. It also reflects neurological integrity and development as well as nutrition, socioeconomic state, or underlying diseases. Therefore, the timing of primary teeth eruption is one of the major concerns for parents in health checkups for infants and children. However, the detailed developmental timing of teeth eruption differs depending on the survey methodology, country, or generation. We hypothesized that the timing of primary teeth eruption differs between the medical checkup by dentists and the daily records by parents.

METHODS

We conducted a questionnaire survey on the date of eruption of primary teeth as an adjunct study among Miyagi Regional Center participants in the Japan Environment and Children's Study (JECS), a large-scale birth cohort study. A total of 1695 responses (3793 participants) were analyzed.

RESULTS

The median ages of eruption were 7.1 months (male) and 7.6 months (female) for mandibular primary central incisors, 8.7 months (male) and 9.2 months (female) for maxillary primary central incisors, 10.0 months (male) and 10.3 months (female) for maxillary primary lateral incisors, and 10.4 months (male) and 10.8 months (female) for mandibular primary lateral incisors, which were earlier than the reported timings based on dental check-ups. Comparing the eruption time of preterm and term infants, the eruption time was earlier in preterm infants in the corrected ages.

CONCLUSIONS

The eruption timing observed and described by the parents is earlier than that examined by dentists at regular check-ups. In addition to examining the primary teeth eruption of full-term birth children, we also examined that of preterm birth children because of the increasing number of premature births. To the best of our knowledge, this is the first report from a large cohort study to clarify the eruption time of primary teeth monitored by parents.

General correlation between neonatal factors, primary and permanent tooth eruption and their interrelation in a population in german orthodontic practices

BACKGROUND

The purpose of the study was to determine the possible relationship between the eruption of primary and permanent teeth and neonatal factors in German children according to gender.

METHODS

A cross-sectional survey study was performed in 10 German orthodontic practices. Using a questionnaire information about gender, time of birth (week of pregnancy), birth weight (g) and height (cm), and the age of first primary and first permanent tooth eruption (months/years) of 405 children (230 girls and 175 boys) were collected. A Mann-Whitney U-test was used for group comparisons, and correlations were verified using a Pearson test.

RESULTS

No correlation was found between neonatal factors (time of birth, birth weight, and birth height) and primary tooth eruption for male participants. However, for females a low correlation was found between the eruption of the first primary tooth and birth weight (r = -0.18, CI: -0.30 to -0.042, p = 0.011) and birth height (r = -0.19, CI: -0.32 to -0.054, p = 0.006). No correlations between neonatal factors and the eruption of the first permanent tooth were found for either gender. A moderate correlation was found between the first primary and first permanent tooth eruption (females: r = 0.30, CI: 0.16 to 0.43, p < 0.001; males: r = 0.22, CI: 0.059 to 0.35, p = 0.008).

CONCLUSIONS

An earlier eruption of the primary teeth can be assumed with greater body weight and height at the time of birth for girls. For boys, the tendency is the opposite. However, there seems to be a catch-up growth effect due to the missing differences between both permanent tooth eruption times. Nevertheless, the first primary and the first permanent tooth eruption correlates in a German children population.

Path Analysis of the Relationships between the Eruption Time of the First Primary Teeth and Various Factors in Twins

The timing of primary tooth eruption is critical for children's health planning and the diagnosis of specific growth disorders. The purpose of this study is to assess the relationship between twin pairs' birth weight, gestational age, and gender, which are indicators of prenatal factors; breast-feeding duration, which is an indicator of postnatal factors; type of delivery, which is an indicator of maternal as well as genetic factors; and age of the primary tooth. Twin children aged from 3 to 15 years who applied to the clinic for the first dental examination constituted the sample group. In this twin study, 59 monozygotic (MZ) twin pairs and 143 dizygotic (DZ) twin pairs were included. Genetic (MZ vs. DZ), maternal (type of delivery, gestational age), perinatal (birth weight, gender), and postnatal (duration of breastfeeding) information was obtained, and effects on the children's Eruption Timing of the First Primary Tooth (ETFPT) were examined. Statistical analysis was performed using the consistent partial least squares structural equation model (robust PLSc) technique. As birth weight increased, the age at first eruption became younger, but this change was different between MZ and DZ twins (p < 0.05). While the age at first tooth eruption was older in identical twins who were breastfed for the first 6 months, this increase was not observed in DZ twins. The mean of ETFPT was calculated as 7.31 months in MZ twins and 6.75 months in DZ twins. The effect of breastfeeding and birth weight on ETFPT may differ according to zygosity in twins. MZ twins may tend to take longer to experience the eruption of their first primary teeth.

Effect of Neonatal Factors on the Eruption of Primary Teeth in Children: A Longitudinal Prospective Cohort Study

Introduction

Eruption of first primary teeth is a normal physiological process. Antenatal nutritional deficiency and prenatal and neonatal factors play an important role in eruption of primary teeth. Neonatal factors, such as gestational age (GA), degree of prematurity, severity of neonatal illness, and birth weight are primarily related to eruption of primary teeth. The relation between neonatal factors and the timing of eruption of primary teeth has not been studied prospectively among Indian preterm infants.

Aims

To evaluate the influence of neonatal factors on the eruption of primary teeth in children born preterm.

Materials and methods

A prospective longitudinal cohort study design was adopted. A total of 150 subjects were recruited by simple random sampling. Each child was followed up from birth up to 36 months. Intraoral examination was done and the teeth present in each visit were recorded. Data were statistically analyzed and interpreted.

Statistical analysis used

Descriptive statistics, t-tests for independent sample, and Pearson's chi-squared tests were applied. Tooth showing statistically significant difference in mean age of eruption between term and preterm categories was studied for the effect of maternal and neonatal characteristics on eruption using multivariate regression analysis.

Results

The mandibular central incisor was the first tooth to erupt. Significant determinant of eruption of mandibular incisor in term children was found to be parity, weight for GA, and complementary feeding, whereas for preterm children, significant determinants were parity, birth weight birth length, weight for GA, and complementary feeding.

Conclusion

Neonatal factors, such as birth weight, birth length, weight for GA, and introduction of complementary feeding have a strong significant association with the eruption of primary teeth.

Clinical significance

The findings of this study will guide in the preventive management of oral health in preterm children.

How to cite this article

Indira MD, Nandlal B, Narayanappa D, et al. Effect of Neonatal Factors on the Eruption of Primary Teeth in Children: A Longitudinal Prospective Cohort Study. Int J Clin Pediatr Dent 2023;16(2):321-326.

Eruption Timing and Sequence of Primary Teeth in a Sample of Romanian Children

Teething is considered a significant event in the growth and development of the child by parents and especially by paediatric dentists and forensic scientists. They constantly need an “up-to-date mirror” of its variability for different geographic regions. The aims of the current study were to determine the timing and sequence of primary tooth emergence, and to establish a correlation between tooth eruption and general growth and external parameters in a sample of Romanian children. This study included 70 healthy children (53% girls and 47% boys), and the analysed data resulted from the questionnaires completed by parents during the whole process. General and specific data on primary teeth eruption were obtained. The differences between sexes were insignificant, except for the maxillary and mandibular canines (p = 0.047 and p = 0.018) and lower temporary second molars (p < 0.001), which were significantly increased in boys. The differences found between the two hemiarches were insignificant (p = 0.197). The mean age of eruption of the first tooth erupted was 7.07 ± 1.990 months. The unpaired t-test was used for comparison of the timings of eruption of the first primary teeth, according to the number of previous births and type of diet, and it was insignificant (p = 0.665 and p = 0.983 respectively).

Evaluation of eruption of deciduous teeth among infants born after low risk pregnancy compared to infants diagnosed with Intra Uterine Growth Restriction

PURPOSE

The impact of IUGR on holistic growth of an infant is established however, limited evidence has been reported regarding its implication on eruption of deciduous dentition.

AIM

Comparative evaluation of eruption of deciduous teeth among infants born after low risk pregnancy and infants diagnosed with Intra Uterine Growth Restriction (IUGR).

METHODS

The cross-sectional study included 110 neonates recruited at birth using stratified random sampling based on inclusion and exclusion criteria. Neonates diagnosed without IUGR were allocated to Group I (n = 55) and those diagnosed with IUGR were allocated to Group II (n = 55). Perinatal case history was obtained followed by intraoral examination at birth, 6 months and monthly up to 1 year or till first evidence of teeth eruption.

RESULTS

The first evidence of eruption of deciduous teeth was found delayed in Group II (p = 0.0001). The mean gestational age at delivery, estimated fetal weight, frequency of NICU admission, birth weight and infant weight at 6 months was found statistically higher (p = 0.001) in Group I.

CONCLUSION

First evidence of deciduous teeth eruption was found delayed among IUGR infants therefore, IUGR along with prematurity, LBW, LSCS delivery, NICU admission can be considered as risk factor for delayed eruption.

Morphological variation of the deciduous second molars in the Baka Pygmies

The Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka's dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka's deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka's and South Americans' dm2s were confirmed among the largest in our sample. Despite the Baka's unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s' morphology only.

Nutritional Status is Associated with Permanent Tooth Eruption in a Group of Brazilian School Children

The present study aimed to investigate the association between nutritional status with delayed tooth eruption (DTE). Oral examination was performed in schoolchildren (8-11 years old), and DTE was defined by absence of dental gingival emergence or when primary tooth was still present in the oral cavity after the expected time. BMI z-score of each child were collected and nutritional status was defined. Chi-square test and binary logistic regression adjusted by age and gender were performed. Odds ratio (OR) and 95% Confidence Interval (95% CI) were calculated. The established alpha was 5%. Among 353 included children, 247 were classified as eutrophic, 16 as underweight, 64 as overweight, and 26 as obese. Underweight was associated as a risk factor to DTE (P = .014; OR = 3.5; 95% CI = 1.3-9.8), and underweight girls had more chance to present DTE than eutrophic girls (P = .048; OR = 4.4; 95% CI = 1.1-17.2) in chi square test. In logistic regression, underweight was associated as a risk factor to DTE (OR = 4.21; CI 95% = 1.42-12.43; P = .009). Underweight children have a higher risk of DTE in permanents.

Early Weight Gain Forecasts Accelerated Eruption of Deciduous Teeth and Later Overweight Status during the First Year

OBJECTIVES

To determine whether early diet and weight gain velocity have independent or interactive effects on deciduous teeth emergence and overweight status during the first year.

STUDY DESIGN

Monthly measures of anthropometry and teeth eruption were collected during a 1-year trial (0.5-12.5 months) on formula-fed infants in which the type of randomized infant formula (cow milk or extensively hydrolyzed protein) diet significantly affected early (0.5-4.5 months) weight gain velocity. Generalized linear mixed models determined whether early diet and weight gain velocity had independent or interactive effects on timing and pattern of teeth eruption. Data from a trial on breastfed infants were used to explore effects of breast milk vs infant formula diets on teeth eruption and overweight status at 10.5 months.

RESULTS

Independent of infant formula diet, velocities of weight gain had direct effects on the age of first deciduous tooth (P < .04) and number of erupted teeth over time (P < .002). Greater velocity of weight gain from 0.5 to 4.5 months caused earlier and more frequent eruption of deciduous teeth from 4.5 to 12.5 months. Exploratory follow-up analyses on the breastfed and formula-fed diet groups found early weight gain velocity (P = .001), but not diet or its interaction, had significant effects. Infants in the upper quartile for weight gain velocity had more primary teeth (P = .002), and a greater proportion of them were overweight (P < .001) at 10.5 months.

CONCLUSIONS

Faster weight gain accretion forecasted accelerated primary teeth eruption and increased percentage of children who were overweight-risk factors for dental caries and obesity.

TRIAL REGISTRATION

ClinicalTrials.govNCT01700205 [2012-2015] and NCT01667549 [2012-2015].

A metabolomic study on the association of exposure to heavy metals in the first trimester with primary tooth eruption

BACKGROUND

The influence of prenatal heavy metals exposure on primary tooth eruption in humans is rarely reported.

AIM

Based on the cohort study design, we investigated the association of exposure to 12 heavy metals in the first trimester with primary tooth eruption, and the maternal metabolisms in the first trimester which might be related to the above relationship.

METHODS

Maternal urine samples were collected in their first trimester, and 12 metals (Ti, V, Fe, Co, Cu, As, Se, Cd, Sn, Hg, Tl, U) were measured using the inductively coupled plasma mass spectrometry method. The maternal metabolome in the first trimester was analyzed by ultrahigh performance liquid chromatography coupled mass spectrometry based metabolomics using urine samples. The infant's first tooth eruption time and number of teeth at age one were recorded by oral examination and questionnaire.

RESULTS

No significant associations were observed between heavy metals exposure in the first trimester and primary tooth eruption, except for Co. The level of Co was positively associated with time of infant's first tooth eruption, and was negatively associated with the number of teeth at age one. Based on metabolomic profiling, glycine was revealed as the key mediating metabolite, which showed negative correlation with Co and opposite effect of Co in the primary tooth eruption.

CONCLUSIONS

Prenatal Co exposure in the first trimester might delay the primary tooth eruption in children through the decreased glycine-disrupted dentin formation, providing the first evidence and novel insights into the control of prenatal heavy metals exposure for ensuring normal (timely) primary tooth eruption.

Chronology and sequence of deciduous teeth eruption in children with microcephaly associated to the Zika virus

INTRODUCTION

Deciduous teeth eruption is connected to children's growth and development. In Brazil, with the increase in the occurrence of children born with microcephaly associated to exposure to Zika virus, studies about orofacial alterations were necessary.

OBJECTIVE

Describe the chronology and sequence of deciduous teeth in children with microcephaly due to the fetal exposure to Zika virus.

METHODOLOGY

A cross-sectional study involving 74 children of a neuropediatric reference unit in Salvador, Bahia, in 2017 was conducted. Through use of secondary data, interviews with mothers and children's exam, the population was characterized, the chronology and sequence of deciduous teeth eruption was registered, and the analysis of the variables was proceeded.

RESULTS

The first eruption happened between 4 and 17 months of age and 52.70% had a delay in the eruption of incisors. The average eruption time for the maxilla varies from 17.92 (16.56-19.28; 95% CI) to 20.43 (19.35-21.51; 95% CI) months, and the jaw from 11.57 (6.85-18.99; 95% CI) to 20.20 (19.09-21.31; 95% CI) months. In 77.94% of population, the eruption of the first teeth was in the lower arch and in 33.82%, molars and/or canines erupted before the incisors.

CONCLUSIONS

There were alteration in the chronology and sequence of deciduous teeth eruption.

Low birth weight and the delay on the eruption of deciduous teething in children

Abstract Objectives: To analyze the association between low birth weight (LBW) and the occurrence of the delay on the eruption of deciduous teething (DEDT) in children from 04 to 30 months, living in Salvador, Bahia. Methods: A cross-sectional study involved 520 children at four to thirty months of age, from public, private and philanthropic daycares from two districts in Salvador. A descriptive analysis and unconditional logistic regression were done to estimate the odds ratios (ORs), using the Confidence Interval of 95% as a criterion for accepting associations. Poisson regression was used as an analytical strategy to obtain the prevalence ratio. Results: the prevalence of the delay on the eruption was 10.29%. There was a positive association between LBW and occurrence of DEDT among children with less than 24 months, both in the unadjusted model (PR=2.07, 95%CI= 0.96 4.44) as in the adjusted (adjusted PR=2, 27, 95%CI= 1.02 5.07). Conclusions: the variables of development and nutritional at birth and during the early life may be important predictors of the chronology of eruption. Further investigations should be carried out towards the adequate evaluation of the LBW role in the occurrence of the delay on the eruption.

Dependence of Deciduous Tooth Eruption Terms and Tooth Growth Rate on the Weight-Height Index at Birth in Macrosomic Children over the First Year of Life

The aim of this research is to study the effect of body overweight at birth (fetal macrosomia) on the processes of tooth eruption and tooth growth during the first year of life in children in the Kharkiv City (Ukraine) population. One of the research tasks is to examine the features of deciduous teeth eruption in children who were born with macrosomia with different values of the weight-height index at birth. Materials and methods. The medical records of the children born between 1977 and 2013 have been analyzed. The database has been collected in one of the Kharkiv City clinic. The Main Group is comprised of the medical records of the children (separately for boys and girls) born with fetal macrosomia. All the medical records of the Main Group have been divided into subgroups taking into account the gender and the harmonious (well-balanced) development coefficient. The Comparison Group is comprised of the medical records of the children also born within the normal term range, but with weight and height that correspond to the gestation age (fetal normosomia). To determine the average time of the first tooth eruption, as well as the deciduous teeth growth rate for each of the groups under the study, we have used the hypothesis about a linear dependence between the number of erupted teeth and the age of the child. The statistical data processing and verification of the consistency of this hypothesis is performed using the multiple linear regression analysis with the STATISTICA 6.0 software package (Multiple Regression module). The number of delayed eruption and premature eruption cases observed is calculated along with the corresponding confidence intervals for the significance level, p, of less than 0.05, taking into account the binomial distribution of the random variable. The results of the study indicate a slowed growth rate of deciduous teeth in children born with macrosomia, as well as an increased number of cases (by a factor of 2 to 4 times) of deviations in the timing of teeth eruption compared to regional norms. The smallest growth rate of deciduous teeth and the smallest number of teeth at the age of one year are registered in macrosomic boys and macrosomic girls with a long body and a relatively reduced birth weight, as well as in macrosomic girls with intrauterine obesity. The macrosomic girls with intrauterine acceleration with obesity at the background have the largest average tooth growth rate and the largest percentage of premature eruption cases among all subgroups. Conclusions. The somatometric features of fetal macrosomia suggest the influence on the number of teeth that erupt by a certain age. The data on the deviation from the generally accepted terms of teeth eruption in children born with macrosomia, can be the basis for developing new and improving existing prevention programs aimed at preserving dental health.

Associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth

We recruited 1296 mothers in their first trimester from the Affiliated Obstetrics and Gynecology Hospital of Nanjing Medical University between May 2014 and September 2015 to investigate the associations of maternal, perinatal and postnatal factors with the eruption timing of the first primary tooth (ETFPT) in a Chinese population. We collected maternal demographic information and clinical data during the perinatal and postnatal period, and oral examinations of the infants were performed by a doctor at 6, 9 and 12 months of age. Multiple regression analysis was used to identify significant explanatory variables for ETFPT. The mean age at eruption of the first primary tooth for all the infants was 6.82 ± 1.90 months. After adjustment for confounders, higher maternal childbearing age (β = 0.57; 95%CI = 0.13–1.02), female sex (β = 0.26; 95%CI = 0.07–0.52), and low birth weight (β = 0.98; 95%CI = 0.20–1.76) were significantly associated with delayed eruption of the first primary tooth, while macrosomia (β = −0.79; 95%CI = −1.30–−0.28) was significantly associated with earlier eruption of the first primary tooth. Maternal childbearing age, infant sex and infant birth weight were significant determinants of ETFPT.

Erupção do primeiro dente decíduo em lactentes nascidos pré-termo: acompanhamento de 12 meses

Resumo Objetivo Analisar a idade de erupção do primeiro dente decíduo de lactentes nascidos pré-termo, egressos de unidade de terapia intensiva neonatal, além de relacionar os dados obtidos com fatores natais e pós-natais. Material e método Este estudo longitudinal prospectivo foi realizado com lactentes provenientes de unidades de terapia intensiva neonatal (n=215). O critério de inclusão foi prematuridade e o de exclusão, indisponibilidade para acompanhamento e recém-nascidos portadores de síndromes/más formações congênitas, permanecendo, após aplicação desses critérios, 62 participantes. O exame foi realizado por um único operador. Os dados foram processados pelo SPSS e pela estatística descritiva e comparativa. Resultado Ao considerar a idade cronológica, apenas um lactente apresentou incisivos inferiores erupcionados aos seis meses. Constatou-se atraso na erupção (60%), quando comparado com padrão da literatura, porém, ao analisar pela idade corrigida para prematuridade, este atraso foi menos frequente (32%). Entre os fatores natais e pós-natais, o atraso na erupção não apresentou relação com peso ao nascimento, idade gestacional, sexo, aleitamento materno, sucção de dedo/chupeta, escolaridade materna e renda familiar. A maior frequência de atraso na erupção, pela idade corrigida, ocorreu nos casos em que o recém-nascido foi avaliado como pequeno para a idade gestacional (p=0,006). Conclusão A idade de erupção do primeiro dente decíduo em lactentes pré-termo apresentou-se com atraso, quando avaliada pela idade cronológica. Porém, não houve atraso quando utilizada a idade corrigida para prematuridade. Dos fatores natais e pós-natais, apenas a relação peso/idade gestacional influenciou na idade de erupção.

Association of weight and height with timing of deciduous tooth emergence

OBJECTIVES

The aim of this study was to associate weight and height with the timing of deciduous tooth emergence.

METHODS

1756 children, aged from 1 to 33 months (755 females and 1001 males) had been previously examined for the timing of deciduous tooth emergence and their weights and heights measured. Children were categorized into weight and height groups (underweight, normal, overweight, short stature, normal and tall stature). Probit regression analysis was used to calculate the ages at emergence of each deciduous tooth. Tooth emergence ages were compared pairwise across the weight and height groups.

RESULTS

The deciduous dentition emerged between 7.9-31.5, 7.8-29.6 and 6.3-26.5 months in the underweight, normal and overweight children, respectively. In the height groups, the ranges were 9.0-31.3, 7.4-27.0 and 6.7-24.3 in the short, normal and tall children, respectively. The extremes of weight and height were related to the times at deciduous tooth emergence where a substantial increase in weight or height was associated with earlier emergence, and vice versa. However, only canines, lateral incisors and upper central incisor showed statistically significant association with weight and none of the teeth exhibited statistically significant association with height. Moreover, no emergence sequence change was associated with weight and height.

CONCLUSIONS

The present study provides the first weight and height- specific data on the timing of deciduous tooth emergence. Although both weight and height are generally associated with the timing of deciduous tooth emergence, weight shows a stronger association for canines, lateral incisors and upper central incisor. The findings will aid assessing normal emergence timing in children with variant weights and heights.