1. health and fitness
2. dental care

Original Article
APPLICABILITY OF TANAKA AND JOHNSTON MIXED DENTITION
ANALYSIS IN A PESHAWAR SAMPLE
1
MUHAMMAD TAYYAB, BDS, Diploma in Orthodontics, Fellowship in Laser Dentistry
2
UMAR HUSSAIN, BDS
3
AYESHA, BDS
4
SUMAYYA, BDS
5
ALI AYUB, BDS, FCPS (Orthodontics)
ABSRACT
The objective of this study was to evaluate the applicability of Tanaka and Johnston method
in predicting the size of unerupted permanent canines and premolars in a section of Peshawar Population. Convenience sampling technique was utilized for collection of data from 100 patient’s casts
on printed proforma. The teeth were measured using an electronic digital caliper with an accuracy
of ± 0.01 mm. The predictions of the width of the canines and the first and second premolars in both
arches were made with the Tanaka-Johnston analysis. For the maxillary arch, 11 mm was added to
half of the total value of the mesiodistal widths of the four mandibular incisors, whereas 10.5 mm
was added to half of the total value of the four mandibular incisors regarding to the mandibular
arch. Both genders in both occlusal arches showed high level of applicability of Tanak and Jhonston
mixed dentition analysis with p<0.05.
Key Words: Tanaka and Johnston, digital caliper Mixed Dentition Analysis, occlusal arch, incisor.
INTRODUCTION
Clinicians must recognize normal occlusion and
differentiate normal from abnormal, and be able to do
this in the primary, mixed, and adult dentitions.1 It is
essential to carry out mixed dentition analysis before
the commencement of orthodontic treatment.2,3 One of
the important aspects of diagnosis in the mixed dentition is the determination of the tooth size-arch length
discrepancy. Such determination is often required
before eruption of the permanent canines and first and
second premolars.4 Prediction of space deficiency is an
essential entity of preventive as well as interceptive
orthodontics during mixed dentition.5,6 An accurate
mixed dentition space analysis is one of the important
criteria in determining whether the treatment plan may
involve serial extraction, guidance of eruption, space
maintenance, space regaining or just periodic observation of the patients.7,8 The prediction of unerupted
permanent canine and premolar size in patients in
the mixed dentition is important in early orthodontic
diagnosis and treatment.9 Accurate estimation of the
Senior Clinical Lecturer in orthodontics Khyber College of Dentistry, Peshawar Email: dr_tayabk@yahoo.com Mob: 0346-9000059
Res: Khalily House 70, Street I, Sector N/4, Phase IV, Hayatabad,
Peshawar
2
Dental Surgeon, KCD
3,4
House Surgeons
5
Lecturer
Received for Publication: February 28, 2014
Revision Received:
April 4, 2014
Revision Accepted:
April 17, 2014
1
Pakistan Oral & Dental Journal Vol 34, No. 2 (June 2014)
sizes of canines and premolars allows the dentist to
better handle tooth/arch length discrepancies.10
The main approaches that have been used to estimate the mesio-distal crown widths of the permanent
canine and premolars in the mixed dentition patients
are (i) Measurement of the unerupted teeth on the
radiographs.11 (ii) Use of the regression equation
that relate the mesio-distal widths of erupted teeth
to the mesio-distal widths of unerupted teeth.12 (iii)
A combination of measurements from erupted and
radiographs of unerupted teeth.13 (iv) Moyer’s table of
predictability.12 The most accurate predictions of the
mesio-distal widths of unerupted canines and premolars can be obtained by measurements of mesio-distal
widths of these teeth by radiographic method.14 In the
developing countries like Pakistan, the availability of
the dental x-ray machines is inadequate and thus use
of radiographic prediction techniques for estimation of
tooth size may be difficult.6 Moyer devised tables for
prediction of mesio-distal width of permanent canine
and premolars for both arches and genders; however,
it not applicable to our population.12
Tanaka and Johnston15 have developed formulae
for both arches that are based on simple linear regressions. The authors used erupted four mandibular incisors to estimate the mesio-distal width of canines and
premolars in Northern European children. However,
research has shown variation in some dental characteristics among different populations.16 As a result, the
Tanaka-Johnston formula should only be used in other
322
Applicability of Tanaka and Johnston Mixed Dentition
populations when specific data have been analyzed for
the different ethnic groups.
The objective this study was to evaluate the applicability of Tanaka and Johnston method in predicting
the size of unerupted permanent canines and premolars
in a section of Peshawar Population.
METHODOLOGY
This descriptive (cross-sectional) study was undertaken in the Department of Orthodontics at Khyber
College of Dentistry, Peshawar from 14th July 2013 to
27th September 2013. Convenience sampling technique
was utilized for collection of data from 100 patient’s
casts. A total of 500 plaster casts of dental arches from
the Department of Orthodontics Khyber College of
Dentistry, Peshawar were examined and selected for
study according to the criteria (Table 1).
After approval from institutional ethical review
committee, the data was recorded on specifically designed proforma from the casts fulfilling the inclusion
criteria. The teeth were measured using an electronic
digital caliper with an accuracy of ± 0.01 mm. The
largest distance between the contact points of the
four mandibular incisors and the right maxillary and
mandibular canines and premolars was measured
with the caliper held parallel to the occlusal plane
and perpendicular to the long axis of the tooth. The
predictions of the width of the canines and the first and
second premolars in both arches were made with the
Tanaka-Johnston analysis.17 For the maxillary arch,
the calculation was performed by adding 11mm to half
of the total value of the mesiodistal widths of the four
mandibular incisors, whereas 10.5mm was added to
half of the total value of the four mandibular incisors
regarding to the mandibular arch. The predictions of
the width of the three teeth were compared to the width
of the plaster cast models.
Arithmetic means, standard deviations, and simple
and percentage frequency distributions were calculated
by SPSS version 16.0. Comparison between the actual
and predicted sum of the mesiodistal widths of canine
and premolars was made by using paired sample t-test.
The significance level was set at P < 0.05.
RESULTS
There were 35 males (35%) and 65 females (65%)
with males to females ratio of 1: 1.85 in this study.
Their ages ranged from 15 to 27 years with a mean of
20.95±3.37 years. The most common age group was
second decade (26.67%). The details of age distribution are given in the Table 2. Tanaka and Jhonston’s
formula was highly significant for both genders and
dental arches with p-value< 0.05 (Table 3) in Peshawar’s
population. Further details can be seen in Table 1-4.
DISCUSSION
During the mixed dentition, prediction of the mesiodistal dimensions of unerupted permanent canines
and premolars is of clinical importance in the diagnosis
Pakistan Oral & Dental Journal Vol 34, No. 2 (June 2014)
and planning treatment. Correct assessment of the size
of the canines and premolars allows the dentist for better deal with tooth size/arch length discrepancies.17,18
Tanaka-Johnston analysis for predicting mesiodistal
diameters of canines and premolars was based on
Northern European children, the present study was
performed to assess the test’s precision among Peshawar
individuals across gender.19 Literature review showed
that of all the three methods applied in mixed dentition
analysis, Tanak and Jhoston is widely used.6
Myriad studies significantly correlated the sum
of mandibular incisors mesiodistal width to size of
unerupted canine and premolars in both dental arches
and genders.5,12,20 Most of the previous studies used
mandibular incisors in their mixed analysis.18,12,23
Multiple advantages of using mandibular incisors in
mixed dentition analysis including early eruption,
ease of measurement, least prone to caries and less
anomalies have been reported.21,22 Legovic23 established
prediction equations for the purpose of accurately predicting the widths of the crowns of unerupted canines
and premolars on the basis of the measured mesiodistal
diameter and vestibulo-oral diameter of the crowns of
the erupted central and lateral incisors and first permanent molars. On the plaster casts of 120 subjects
(60 boys and 60 girls), mesiodistal and vestibulo-oral
diameter of the crowns of central, lateral, canines, both
premolars, and first permanent molar on both sides in
both jaws were measured twice. Prediction equations
were derived on the basis of the measurement results,
by which the sums of the widths of crowns of canine
and both premolars can be predicted. In the present
study first molars were not measured for predicting
canine and premolars width but incisor can be used
significantly for cuspid and premolars width.
TABLE 1: INCLUSION AND EXCLUSION
CRITERIA
Inclusion Criteria
Exclusion Criteria
1 Both genders
1 Carious teeth
2 Age range :13- 30 years 2 Missing
3 No interproximal wear 3 Restored at the meaon the mandibular insured landmarks
cisors
4 Healthy teeth in good 4 Malformed teeth
position to be measured
5 No enamel defects
6 No interproximal caries
TABLE 2: AGE DISTRIBUTION
Age (years)
N
%
15-20
46
46.00%
21-25
43
43.00%
26-30
11
11.00%
323
Applicability of Tanaka and Johnston Mixed Dentition
TABLE 3: COMPARISON OF MEAN, STANDARD DEVIATION, MAXIMUM, MINIMUM AND RANGE OF
ESTIMATED AND ACTUAL WIDTH OF CANINE AND PREMOLARS, WIDTH OF LOWER INCISORS
AND DIFFERENCE OF ACTUAL AND ESTIMATED WIDTHS IN BOTH ARCHES
Gender of patient Estimated
width of
upper 345
Male
Estimated width
of lower 345
Mesiodistal width
of mandibular
incisors
Actual
width
of upper 345
Actual
width
lower
345
22.4360
21.9571
22.8697
20.9966
20.6954
1.3511
1.2013
35
35
35
35
35
35
35
Std. Deviation
.91372
.88517
1.82266
1.47268
1.40979
1.31907
1.01413
Minimum
20.68
20.40
19.37
18.55
18.48
-2.05
-0.50
Maximum
24.75
24.25
27.50
24.32
24.50
3.81
3.27
Range
4.07
3.85
8.13
5.77
6.02
5.86
3.77
Mean
22.4360
21.9571
22.8697
20.9966
20.6954
1.3511
1.2013
Mean
N
Male
N
Difference Difference
Between
between
upper
lower estiestimated mated and
and actual actual 345
345 width
width
35
35
35
35
35
35
35
Std. Deviation
.91372
.88517
1.82266
1.47268
1.40979
1.31907
1.01413
Minimum
20.68
20.40
19.37
18.55
18.48
-2.05
-0.50
Maximum
24.75
24.25
27.50
24.32
24.50
3.81
3.27
Range
4.07
3.85
8.13
5.77
6.02
5.86
3.77
22.0119
21.7548
22.5703
20.7493
20.2848
1.5307
1.4910
100
100
100
100
100
100
100
Std. Deviation
2.40111
.86086
1.71180
1.37014
1.35101
1.07094
1.03574
Minimum
20.00
20.03
19.06
17.96
17.62
-2.05
-0.50
Maximum
24.75
24.25
27.50
24.32
24.50
3.91
4.34
Range
2.75
4.22
8.44
6.36
6.88
5.96
4.84
Both
Mean
Gender
N
TABLE 4: COMPARISON OF ACTUAL SUM OF CANINE AND PREMOLARS AND THE ESTIMATED
ONES FROM TANAKA JHONSTON EQUATION FOR THE SAME SUBJECTS
Male
Actual & Estimated width of
upper canine and
premolars
Female
Actual &EstimatActual & EstiActual & Estimated width lower
mated width of
ed width lower
of canine and
upper canine and
of canins and
premolars
premolars
premolars
Pearson’s correla- 0.488
tion
0.706
0.384
0.531
p-value
0.00*
0.002*
0.00*
0.003*
Test of significance: paired t test
Level of significance: P< 0.01
*significant value P<0.05
John and co-workers24 carried out a study on study
casts of an unselected sample from a 12-year-old Hong
Kong Oral Health Survey of 12-year-old children
(n=459; 295 males and 164 females) were measured in
the mesiodistal dimension. A Chinese mixed dentition
Pakistan Oral & Dental Journal Vol 34, No. 2 (June 2014)
analysis based on the Tanaka and Johnston method was
constructed with linear regression equations for prediction of the mesiodistal widths of unerupted canines and
premolars. Sexual dimorphism was evident between
southern Chinese males and females in incisors, canines, and premolars in the mesiodistal dimension. They
predicted that space (in mm) required for alignment of
unerupted canine and premolars in southern Chinese
children, halve the sum of the mesiodistal dimensions
324
Applicability of Tanaka and Johnston Mixed Dentition
of the four mandibular incisors and add the respective
constants for males (upper, 11.5; lower, 10.5) or females
(upper, 11.0; lower, 10.0). Present study differs from
Jhon’s study because Tanaka and Jhonston’s formula
was applicable to both gender equally. Our sample size
is much smaller than Jhon’s study.
Vilella19 conducted a study on 95 casts. The largest
distance between the contact points of mandibular and
maxillary incisors as well as mandibular canines and
premolars were recorded using a calliper held parallel
to occlusal plane and perpendicular to the long axis of
the tooth. A prediction of the width of canines, and first
and second premolars in both arches was made by using
the Tanaka-Johnston analysis. Predicted and actual
dental sizes were compared in relation to the gender
and ethnic group the sample subjects. Their results
showed that Tanaka-Johnston analysis overestimated
the sum of mesiodistal widths of maxillary and mandibular canine and premolars only in the white female
group. The difference between the Tanaka-Johnston
prediction and the actual measurement was significant.
For the other groups studied no statistical difference
was observed. They concluded that Tanaka-Johnston
analysis can predicts the sum of mesiodistal widths
of maxillary and mandibular canines and premolars
in black and white Brazilian men, but not in white
Brazilian women. No ethnic considerations were taken
into account in current study to control confounding
factors. Contrary to Brazilian’s population, Peshawar’s
population has no sexual dimorphism.
Ibad Ullah Kundi6 tested the applicability of Tanaka
and Jhonston mixed dentition analysis in Pakistani
population on 80 dental casts (40 male and 40 female),
obtained data from patients reporting at the department
of orthodontics, Islamic International Dental College,
Islamabad with the age range between 12 to 21 years.
Mesiodistal tooth widths were measured with a digital vernier caliper. Significant difference was found
between predicted upper canine and premolars and
actual upper canine and premolars for both male and
female together and when both genders were compared
separately. He concluded that Tanaka and Johnston
method is only applicable in predicting the space for
unerupted canine and premolars in mandible in both
male and female sample. Present study comprises of
100 cases but achieved high degree of applicability in
both gender and dental arches.
3
Proffit WR, Fields HW. Contemporary Orthodontics. 4th Ed.
St. Louis: Mosby Inc; 2000: 165-70.
4
Lee-Chan S, Jacobson B N, Chwa KH, Jacobson RS. Mixed dentition analysis for Asian-Americans. Am J Orthod Dentofacial
Orthop 1998; 113: 293-99.
5
Huckaba GW. Arch size analysis and tooth size prediction. Dent
Clin North Am 1964; 11: 431-40.
6
Kundi IU, Dil F, Shah A, Bashir U. Applicability of Tanaka and
Johnston mixed dentition Analysis in a contemporary Pakistani
population. Pak Oral Dent J 2012; 32 (2): 253-259.
7
Smith HP, King DL, Valencia R. A comparison of three methods
of mixed-dentition analyses. J Pedod 1979; 3: 291-302.
8
Graber LW, Varnsdall RL, Vig WL. Current Principles and
Practice in Orthodontics. 5th ed. Elseviere. 2012; 428-35.
9
Tanaka MM, Johnston LE. The prediction of the size of unerupted
canines and premolars in a contemporary orthodontic population.
J Am Dent Assoc 1974; 88: 798-801.
10 Ta TA, Ling JYK, Ha¨gg U. Tooth-size discrepancies among
different occlusion groups of southern Chinese children. Am J
Orthod Dentofacial Orthop 2001; 120: 556-58.
11 Bull RL. Radiographic method to estimate the mesio-distal
dimension of unerupted teeth. Am J Orthod 1959; 45: 711-12.
12 Moyers RE. Handbook of Orthodontics. 4th ed. Chicago Ill: Year
Book; 1988: 235-39.
13 Staley RN, Hoag JF. Prediction of the mesio-distal tooth width
of maxillary permanent canines and premolars. Am J Ortho
1978;73:169-77.
14 Rwin RD, Herold JS, Richardson A. Mixed dentition analysis:
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15 Bailit HL. Dental variations among populations. An anthropologic view. Dent Clin North Am 1975; 19: 125-39.
16 Al-Bitar ZB, Al-Omari IK, Sonbol HN, Al-Ahmad HT, Hamdan
AM. Mixed dentition analysis in a Jordanian population. Angle
Orthod 2008; 78: 670-5.
17 Diagne F, Diop-Ba K, Ngom PI, Mbow K. Mixed dentition
analysis in a Senegalese population: elaboration of prediction
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18 Memon S, Mubbasir F. Comparison of Three Mixed Dentition
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19 Vilella OV, Assuncao PS, Assuncao RL. The Tanaka-Johnston
orthodontic analysis for Brazilian individuals. Rev Odonto Cienc
2012; 27: 15-9.
20 Ballard ML, Wylie WL. Mixed dentition case analysis: Estimating size of unerupted permanent teeth. Am J Orthod Oral Surg
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CONCLUSION
21 Motokawa W, Ozaki M, Soejima Y, Yoshida Y. A method of
mixed dentition analysis in the mandible. J Dent for Children
1987; 54: 114-18.
Tanaka and Jhonston method is valid for predicting
the size of unerupted canine and premolars in both
jaws for males as well females.
22 Peck S, Peck L, Kataja M. Mandibular lateral incisor-canine
transposition, concomitant dental anomalies, and genetic control.
Angle Orthod 1998; 68: 455-66.
REFERRENCES
23 Legovic M, Novosel A, Legovic A. Regression equations for determining mesio-distal crown diameters of canines and premolars.
Angle Orthod 2003; 73: 314-18.
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24 John YK, L Ricky WK, Wong. Tanaka–Johnston mixed dentition
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325