Introduction
The Tooth size dimensions play an important role in diagnostic process in orthodontic planning, and could be the only key to solve some complex cases and obtain an excellent result. So we need to know the optimum tooth size so we can identify any disproportion between the upper and lower teeth in early stage of orthodontic treatment and achieve the perfect results. Otherwise we will end up with unsatisfactory results.
Many studies try to understand the relation between size of the teeth and some of type of Malocclusion and also compared it to jaw size.
Tooth size has some variation among different population and ethnicities and affected with multiple factors such as genetic factors ( ), ethnicity () and Gender (), for that we need to have a data base for every ethnic group and gender, this is to enable us to have Data which will be a reference to compare patients to. These data also important for other medical and dental field like forensic dentistry, and in dental industrial for dental and orthodontic manufacturer even dental technicians and labs.
A lot of studies done for deferent ethic groups ( White Americans ,Black Americans ,Spanish ,Hispanic, Chinese ,Malay ) and area In the Middle East there is some studies done in turkey( ) ,Saudi Arabia ( ) Yamen ( ) Jordan () ,in Jordan only tooth size discrepancy was done on Center and North population of Jordan
The aim of this study is to provide average a mesio-distal tooth size of south Jordanian population and the difference between Genders and compare it to previous studies done in center and north of Jordan and nearby area, in addition to asymmetry between both sides.
Material and methods
The present study was approved by Royal Medical services ethical comity and was conducted in 2015.
A cross sectional study done on population in south of Jordan in Karak, Tafela and Aqaba.
These cities consider as (30%) of Jordanian population.
A total sample of 543(130 Male, 413 Female), Average age 14.02 ± 0.97,
Alginate Impression ( ) taken and poured by use of dental stone ( ) in the same day by orthodontic technicians
Dental cast was measured by the use of Digital caliper (Maketa ,0-150mm,japan) providing measurements to +0.01mm was used to measure the meso- distal width-between Anatomical contact- of the teeth in perpendicular to the long axis, all teeth are included in upper and lower jaws (incisors ,canines ,premolar 1st Molar and 2nd Molar) with except of third molars.
A criteria was use to select the appropriate and representative sample:
- Jordanian Ancestor at least from two previous generation.
- Full erupted permanent tooth/teeth.
- No Mesodistal restoration
- No Obvious Malformed teeth (Peg shape teeth, Microdontia, Macrodontia or Supernumerary teeth).
- No current or previous orthodontic treatment.
Only 543 achieve the criteria out of total 621.
All the cast was examined by the same examiner (A.W), 30 Dental cast was re-examined after one month and there was no significant deference between two results.
Statistical Package for Social Science (Version 20, SPSS Inc. Chicago, Illinois, USA) Chi Square test was use which the Significance level was set at 5 per cent level (P≤0.05).
Result
The result shows in table I to V
The total sample was 621 ( 145 Male, 576 Female) the final sample after exclusion was 543 (130 male, 413 Female) with average age 14.02 ±0.97.
The mesodistal dimension of all teeth are larger in female more than male in exception of upper left 1st permanent molar and upper permanent canines .
Table 1-4 shows the mean and standard deviation and range of deference between maximum and minimum value for upper right, upper left, lower right and lower left quadrant respectively.
Table I show that mean mesodistal dimension of all teeth are larger in male in exception of upper 1st permanent molar. With the least range of variation of teeth in upper right permanent canine 2.5mm(34% of the average size) and largest in upper right 1st permanent molar 6.0 mm (58% of average size) and largest ratio of deference associated with upper right lateral 4.5mm(71% of the average size) .
Table II show larger dimension of teeth for male for all teeth with exception of upper left permanent canine and upper 1st left permeant molar With the least range of variation of teeth in upper left 1st premolar 2.5mm (36% of the average size) and largest in upper left 1st permanent molar 6.0 mm (58% of average size) and largest ratio of deference associated with upper left permanent lateral 5.0 mm (78% of the average size).
Table III show that all teeth are larger in male. With the least range of variation of teeth in lower right canine 2.5mm(37% of the average size) and largest in lower right 1st permanent molar & lower 2nd premolar with 6.0 mm (56% , 91% of average size respectively ).
Table IV show that all teeth are larger in male. With the least range of variation of teeth in lower left permanent central incisors ,lower left permanent lateral incisors and lower left 1st premolar 3.0 mm(56% ,54% and 46% of average size respectively ). And largest in lower left 1st permanent molar & lower 2nd premolar with 6.0 mm (60% of the average size).
Discussion
In the present study, the random sample was taken and choosing randomly by Ministry of education in south cities in Jordan (Karak, Tafela and Aqaba) and it was the first study done with large sample size in south of Jordan. The age group of the sample was chosen to eliminate gradual tooth size wear to resemble the actual mesiodistal size of the teeth and to be fully erupted for almost all teeth.in addition to measuring the 2nd permanent molars which was the first time to be measured in all studies in the region.
The average size of the teeth show found in the present study was smaller than result found by studies done in Amman Al-Omari (27) and Hattab (28) with exception of upper 2nd premolars.
In present study it show that all teeth in males are larger than female with exception of upper 1st permanent molars and equal between male and female in upper left canine which is different than studies done in center and North of Jordan (27,28,29) , Yamen (30) and Saudi Arabia (31) .
Larger variability of dimension of teeth was upper permanent lateral incisors which was agreed with Hattab (32) followed by lower 1st and 2nd premolars which dis agree with Hattab (32).
