Vol.3, No.5, 253-257 (2011)
opyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Assessment of the relationship between body mass
index (BMI) and dental age
Maryam Zangouei-Booshehri1, Fatemeh Ezoddini-Ardakani1*, Hosein Agha Aghili2,
Akbar Sharifi3
1Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran;
*Corresponding Aut hor: ezoddini@gmail.com
2Department of Ort h o d o ntics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran;
3Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Received 29 March 2011; revised 21 April 2011; accepted 27 April 2011.
The aim of the study was to determine the rela-
tionship between Body Mass Index (BMI) and
accelerated dental development. The dental
developmental ages of 100 children aged be-
tween 8 and 12 years were determin e d us ing th e
Demirjian method and panoramic radiographs.
BMI status was determined for each subject on
the basis of the system developed by the Inter-
national Obesity Task Force. There was a sig-
nificant direct relationship between dental de-
velopment and BMI (P < 0.01). Obese children
have a higher rate of dental development com-
pared to normal children. CLINICAL RELE-
VANCE: This is an important variable to be con-
sidered when planning for dental and orthodon-
tic treatment s in obese children. Brief objectiv es
st atement: Over weight or obesity can accelerate
dental development. Accelerated dental devel-
opment in overweight children is important to
be considered in pediatric dentistry and ortho-
Keywords: Dental Age; Body Mass Index (BMI);
Bone Age; Overweight
Knowledge of the potential growth of a patient is one
of the important tools for successful orthodontic and
orthopedic treatments and such variables as chronologi-
cal age, sexual maturity, skeletal growth stages, dental
developmental stages, height and weight have been used
to study the various stages of growth [1], although the
relationship between height, weight and sexual maturity
has not been confirmed yet [2].
If there is a strong correlation between skeletal matur-
ity and dental calcification stages, these stages can be
used as a diagnostic tool for estimating the starting point
of growth. Determination of the patient’s age is also very
important in forensic medicine in criminals or those
without recorded birth certificates both above and below
18 years old [3].
Considering the increased prevalence of obesity, there
is a need for information about its possible effect on
dental development as a part of epidemiological studies
Body Mass Index (BMI) is a reliable index of over-
weight and obesity in most children and adolescents.
Obesity in children can lead to skeletal problems in the
head and neck region. BMI is dependent on age and
gender in children and adolescents and is generally re-
ferred to as specific for a certain age [5]. Percentage
range of less than 5% is considered as underweight, 5% -
85% normal, 85% - 95% overweight and more than 95%
is overweight. Alteration in the order of teeth eruption
denotes a disorder in normal development of the teeth,
rather than delayed or accelerated growth. The more
time deviation of teeth eruption from normal, the more
possible the presence of a problem in development of
teeth [6].
Panoramic radiographs of developing teeth are used in
various scientific fields for exact assessment of dental
age in order to evaluate maturity and age. In clinical
dentistry, dental age information is used for diagnosis
and planning for treatment. In situations where there is
insufficient information about the identity of the indi-
vidual or correct birth date, dental age can be used to
determine the age of the individual.
Radiological evaluation of the dental age in children is
important for the dentist in order to have a better under-
standing of the dental development. Sometimes when the
exact birth date of the individual is not known, his (her)
M. Zangouei-Booshehri et al. / Health 3 (2011) 253-257
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
somatic maturity rate is used to evaluate th e chronologi-
cal age, but as there is little difference between the den-
tal and chronological age, the evaluation of the rate of
teeth development and formation is more accurate for
determining the historical age than the somatic maturity
Prabhakaran N. reported that teeth are the most stable
structures in the human body and their developmental
pattern can be used as a reliable technique for estimating
the age of unidentifiable corpses. In this study, dental
age was estimated using various stages of dental devel-
opment based on literature. Radiographic images de-
picting various stages of dental growth could be used for
estimating the chronological age [8].
In studies performed in the fifth and sixth decades of
the last century, there was a weak relationship between
age of erupted teeth and skeletal age. Therefore re-
searches concentrated on the calcification stages of the
teeth [9].
Hilgers and coworkers studied the relationship be-
tween obesity and dental development in children. In
this study 104 children were evaluated by the Demirjian
method. The body mass index was normal in 63 cases,
and 23 and 18 subjects were overweight and obese, re-
spectively. They showed that dental development sig-
nificantly accelerates with increase in body mass index
Sadeghianrizi studied the relationship between cra-
niofacial development and obesity. In this study, 50 lat-
eral cephalometries were compared and it was reported
that the rate of growth, development and length of cra-
niofacial structures was more in obese individuals. They
also stated that orthodontic treatment in these cases
needs special considerations as their development and
growth speed is more than normal individuals [11].
In the present study, the authors decided to study
whether the increase in BMI is related to acceleration in
teeth eruption or not.
This was a descriptive-analytical study performed by
a cross-sectional method. Children referred to the dental
college of Yazd who needed panoramic radiography for
dentistry treatment entered the study and the develop-
mental state of their teeth (dental age) were evaluated.
Dental age was determined using radiographic images
and developmental stage of the roots. BMI was meas-
ured by dividing the height by the square of the weight.
The difference between the chronological age and dental
age was determined for each sex and in relation to BMI.
A total of 100 children aged between 8 - 12 years were
selected by simple sampling method. After obtaining the
radiographic images, their height and weight was meas-
ured according to the metric standards. Then BMI was
calculated and compared with the respective age and
gender charts .
According to the international BMI standards, chil-
dren with BMI below 5% of standard were considered as
thin or underweight, between 5% - 85% as normal and
above 85% as obese. As the number of samples below
5% of standard was few (only 2 cases), they were in-
cluded in the normal group.
The panoramic radiographic images were taken by a
SE 00810 Planmeca 2002 EC praline machine (Helsinki,
finland). On the basis of Demirjian standard [6], dental
development is related to root development and teeth
eruption according to a known process (Table 1). Dental
age was determined for each case as a single digit num-
ber. Data was segregated on the basis of gender with
dental age of each specimen, chronological age and BMI
of each individual. SPSS was used for analysis and sta-
tistical tests included t test and regression analysis. Level
of significance was set at 0.05.
One hundred children entered the study (30 boys and
70 girls). After obtaining panoramic radiographic images
and evaluating the root ends and rate of calcification, the
mean (± standard deviation) eruption age in boys and
girls was 9.796 ± 1.88 and 9.514 ± 1.55, respectively
(Table 1).
In the next stage, Body Mass Index (BMI) of the chil-
dren was calculated and they were divided into two
groups: normal and above normal. 85% of children were
in the normal group and 15% were in the above normal
group (Ta b le 2 ). The mean eruption age was evaluated
separately in each group (Table 3). The minimum and
maximum dental age on the basis of BMI is depicted in
Table 4.
At the end, in order to evaluate the effect of BMI on
eruption age, the difference in mean BMI of various
groups was studied. There was a statistically significant
difference between the mean BMI of two groups (P
value = 0.41).
3.1. Coefficient Ratio between Variables
In order to study the effect of various variables on
growth, coefficient ratio between various variables was
evaluated (Table 5).
The present study was performed to study the rela-
tionship between dental age and BMI in 8 - 12 year-old
children. Panoramic radiographic images were used to
determine the dental age.
M. Zangouei-Booshehri et al. / Health 3 (2011) 253-257
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Table 1. Distribution of children on the basis of gender and
mean eruption age in each group.
Gender Number Mean
Mean Eruption
Age Standard
Boys 30 10.6 9.8 1.88
Girls 70 9.5 9.6 1.55
T = 1.039; P value = 0.488.
Table 2. Distribution of the percentage of children on the basis
of BMI.
Number Percentage
Normal 85 85%
Above Normal 15 15%
Total 100 100%
Table 3. Mean eruption age on the basis of normal and above
normal BMI.
BMI Distribution
Mean Eruption
Age Standard
Normal 85 9.5 1.7
Above Nor-
mal 15 10.0 1.8
T = 1.309; P value = 0.301.
Table 4. Minimum and maximum dental age on the basis of
BMI Minimum Dental Age Maximum Dental Age
Normal 6 13
Above Normal 12 13
Table 5. Coe fficient ra ti o between various variables.
Dental age Height Weight
Body Mass
Index (BMI)
Ratio 1 0.509 0.436 0.047
Nathile and coworkers stated that awareness about the
growth potential of a patient is on e of the imp ortant too ls
for successful orthodontic and orthopedic treatment and
such parameters as chronological age, gender, stages of
skeletal growth, stages of dental development height and
weight are used to measure stages of growth [1]. In an-
other study by Solhem and coworkers, it was stated that
significant and relatively major differences are present
among children with same chronological age and there-
fore the physiological and biological ages need to be
studied. Physiological age is the speed of progress to-
ward the maturity and can be determined by dental,
skeletal and sexual maturity. Annul increase in height
and weight is the index of physical body maturity.
Nathalie Bosmans and coworkers reported that the use
of panoramic radiographic images is useful for evaluat-
ing dental age and there isn’t any significant difference
between this method and peri-apical and other radio-
graphic techniques [12]. Suhalze and coworkers evalu-
ated the accuracy of panoramic radiographic images and
concluded that horizontal measurements are more reli-
able than vertical ones [13]. Solheim and coworkers
showed that radiographic techniques which estimate the
dental age based on dental morphology are the best
techniques [14]. In the present study, panoramic radio-
graphic images were used to estimate the dental age and
BMI of the children under study was also determined.
Evelyn P stated that the obesity in children and adults is
associated with some complications and the rate of obe-
sity has doubled in the last 25 years [13]. Similarly,
studies have shown that obesity can affect various sys-
tems and bones of the body [15,16]. Considering the
increase in rate of obesity in children with its associated
skeletal and dental complications, the effect of BMI on
dental age was studied in the present study.
Gbstein and coworkers studied the effects of gender
on obesity in children. Obese children usually have less
physical activity which is more prominent in girls and
becomes more apparent with increasing age [17]. As a
result, obesity and increased BMI result in more com-
plications, one of which can be alterations in skeletal and
developmental growth. In the present study, there was a
stronger coefficient ratio between increased BMI in boys
and increased eruption of teeth. The difference can be
related to genetic factors and difference in diet between
Iranian and European children. The present study in-
cluded 100 children (30 boys and 70 girls) with a mean
eruption age of 9.766 in boys and 9.514 in girls, from
which, 85% had normal Body Mass Indices and 15%
had above normal BMI. In Evelyn P study, there was a
double rate of obesity and increased incidence of high
BMI was reported [18].
In the normal BMI group, the mean eruptive age was
9.5176 ± 1.63745, wh ile in the above nor mal BMI group,
it was 10.00 which shows that increased BMI results in
increased eruptive age. In the study by Sudeghrianrizr
and coworkers, it was shown that genetic control is re-
sponsible for 1/3 of the changes in BMI. In obese indi-
viduals, there is a significant reduction in secretion of
growth hormone and as a result, changes in growth hor-
mone secretion can affect the growth of the facial skele-
ton. The radiographic images of obese individuals were
compared with that of normal individuals and results
showed that there were significant differences between
M. Zangouei-Booshehri et al. / Health 3 (2011) 253-257
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
sexes. They also concluded that these growth changes
due to obesity require that alterations be made in den-
tistry treatment plans, especially orthodontic treatments
Hilgers K. K. studied the effect of children obesity on
dental development and concluded that children with
increase in weight and/or increase in BMI have in-
creased dental development even if they are evaluated in
relation to the age and sex of the child. This increased
dental development is considered as an important vari-
able in pediatric dentistry and orthodontic treatment
The present study showed that there is a high level of
relationship between chronological and dental age (r =
0.784). Similarly, there was inverse relationship between
height and BMI (r = 1.21). Akinbami and coworkers
studied the role of BMI, mandibular bone and dental
mandibular angle in impaction of the third mandibular
molar teeth. Two factors determining the impaction were
length of the mandible and difference between length of
the alveolar angle and the total measurement of the teeth.
The BMI of each case was measured and it was reported
that prediction of the third mandibular molar teeth im-
paction depends upon two factors: length of the mandi-
ble and difference between the length of the arch and
total dental measurement [19].
Tureli and coworkers studied the relationship between
state of mastication and dental changes and BMI in 97
children aged 8 - 12 years old. The dental state, BMI and
socio-economical status of the population under study
were evaluated and they concluded that children with
normal weight have better mastication compared to chil-
dren with above normal BMI. State of weak mastication
had a significant relationship with decrease in weight
and position of the permanent teeth in children with
normal weight [20].
Sanchez-Perez L. et al. studied the possible associa-
tion between dental caries, and body mass index (BMI)
and the effect of BMI on tooth eruption in a cohort of
elementary school children. They concluded that the
obese childr en had more erupted teeth an d a lower caries
index. The relationship of body composition and oral
health should be considered in pediatric patients [21].
Overweight or obese can accelerate dental development. Accelerated
dental development in overweight children is important to be consid-
ered in pediatric dentistry and orthodontics.
[1] Demirjan, A., Buschang, R., Tanguay, R. and Patterson,
K. (1985) Inter relationship among measure of somatic,
skeletal, dental and sexual maturity. American Journal of
Orthodontics, 88, 433.
[2] Grave, K.C. and Brown, T. (1976) Skeletal maturation
and adolescent growth spurt. American Journal of Or-
thodontics, 69, 611-620.
[3] Bang, G. and Ramm, E. (1970) Determination of age in
humans from root dentin transparency. Acta Odontolo-
gica Scandinavica, 28, 3-35.
[4] Flegul, K.M. (1999) The obesity epidemic in children
and adults: current evidence and research issues. Medi-
cine & Science in Sports & Exercise, 31, 509-514.
[5] Grummer-Strawn, M.Z. L.M, Pietrobelli, A., Goulding,
A., et al. (2002) Validity of body mass index compared
with other body composition screening indexed for the
assessment of body fitness in children and adolescents.
American Journal of Clinical Nutrition, 75, 978-985.
[6] Profit, W.R. and Fields, H.W. (2000) Contemporary or-
thodontics. 3rd Edition, Mosby Year Book, St Louis.
[7] Lewis, A.B. and Garn, S.M. (1960) The relationship be-
tween tooth formation and other maturational factors.
The Angle Orthodontist, 30, 70-77.
[8] Phrabhakaran, N. (1995) Age estimation using third mo-
lar development. Malaysian Journal of Pathology, 17,
[9] Avery, D.R. and Macdonald, E.M. (2000) Pediatric den-
tistry for the child and adolescent. 7th Edition, Mosby
Year Book, St Louis.
[10] Hilgers, K.K. and Kinane, D.E. (2006) Association be-
tween childhood obesity and dental development. Pedi-
atric Dentistry, 28, 23-28.
[11] Sadeghrianrizi, A., Forsberg, C.M., et al. (2006) Obesity
appeared associated with more pronounced prognathisms
and greater facial dimensions. Craniofacial Development
in Obese Adolescents, 70-80.
[12] Nathile, B., Peirs, A., Medhet, A. and Gwy, W. (2006)
The application of kvaal’s dental age calculation tech-
nique on panoramic dental radiographs. Forensic Science
International, 153, 208-212.
[13] Schulze, R., Krummenauer, F. and Schallduch, F. (2000)
Precision and accuracy of measurements in drgitol pano-
ramic radiography. Dentomaxillofacial Radiology, 29,
52-56. doi:10.1038/sj.dmfr.4600500
[14] Solheim, T. (1993) A new method for dental age estima-
tion in adults. Forensic Science International, 59, 137-
147. doi:10.1016/0379-0738(93)90152-Z
[15] Lobstein, T., Baur, L. and Uallu, R. (2004) Obesity in
children and young people: A crisis in public health.
Obesity Reviews, 5, 4-85.
[16] Hilgers, K.K., Axridge, M., Scheetz, J.P. and Kinane,
D.E. (2006) Childhood obesity and dental development.
Pediatric Dentistry, 18, 16-22.
[17] Leonard, H. and Epitein, R.A. (2001) Sex differences in
obese children and sibling in family-based obesity treat-
ment. Obesity Research, 9, 746-753.
[18] Evalgn, P., Selvi, B., Rachel, G. and Paula, R.S. (2005)
Screening and Interventions for childhood over weight.
M. Zangouei-Booshehri et al. / Health 3 (2011) 253-257
Copyright © 2011 SciRes. http://www.scirp.org/journal/HEALTH/Openly accessible at
Journal of Pediatrics, 116, 502-529.
[19] Akinbami, B.O. and Didia, B.C. (2010) Analysis of body
mass index, the mandible, and dental alveolar arch fac-
tors in prediction of mandibular third molar impaction: A
pilot study. Journal of Contemporary Dental Practice, 11,
[20] Tureli, M.C., Barbosa, T. and Gaviao, M.B. (2010) Asso-
ciations of masticatory performance with body and dental
variables in children. Pediatr Dent, 32, 283-288.
[21] Sanchez-Perez, L., Irigoyen, M.E. and Zepda, M. (2010)
Dental caries, tooth eruption timing and obesity: A lon-
gitudinal study in a group of Mexican schoolchildren.
Acta Odontologica Scandinavica, 68, 57-64.