Mesiodistal Crown Dimensions of Permanent Teeth in Bangladeshi Population

Abstract

could have implication in the application of diagnostic criteria derived from specific populations, as in prediction equations used to estimate mesiodistal crown dimensions of unerupted permanent teeth. Without information about the size of individual teeth and groups of teeth, it is difficult for a clinician to make a diagnosis and plan treatment and to carry out a plan of therapy. Very few information are available about mesiodistal crown dimensions of permanent dentition in Bangladeshi population. Jahan 8 studied mesiodistal crown dimensions of permanent dentition of 60 (30 males and 30 females) Bangladeshi subjects with Class-I skeletal pattern. Ali 9 studied Bolton anterior tooth size discrepancies among different malocclusion groups. He measured the mesiodistal crown dimensions of permanent incisors and canines and used them for calculation of anterior Bolton ratio. But these studies could not provide sufficient data on mesiodistal crown dimension of permanent dentition in Bangladeshi population. In order to improve the quality of dental care available, there is a great need for data on the mesiodistal crown dimensions of the individual permanent teeth of Bangladeshi population. The main purpose of the study was to assess whether the diagnostic criteria derived from the mesiodistal crown dimensions of permanent dentition of other populations can be used interchangeably in Bangladeshi population. Morphologically normal all permanent teeth of both jaws from right second premolar to left second premolar were the study population. Casts with intact mesiodistal diameter of crown of permanent teeth, not affected by any attrition, caries, or restorations, no history of previous orthodontic treatment, proximal stripping or serious health problems were the inclusion criteria. Casts with gross dental abnormalities, apparent loss of tooth substance due to attrition or restorations affecting the mesiodistal diameter of the crown were excluded. A total of 244 Bangladeshi subjects meeting the above enrollment criteria attended at the above mentioned place for treatment were included in the study. Main outcome measure was mesiodistal crown dimension of each tooth class of permanent dentition. Mesiodistal crown dimensions were measured from dental casts of the permanent teeth. Impressions were made of the selected sample using irreversible hydrocolloid (alginate) impression material for both maxillary and mandibular arches. Impressions were poured immediately in dental stone. Then the study models were prepared. The dental casts measured in this investigation were not treated with soap or otherwise polished. The accuracy of plaster casts fabricated from alginate impressions as a representation of actual tooth size was investigated by Hunter and Priest 10 method. Hunter and Priest concluded that measurements made on dental casts are more reliable than those made directly in the mouth. The greatest mesiodistal dimension from anatomic mesial contact point to anatomic distal contact point of each tooth was taken to the nearest 0.1 mm by means of pointed calipers. For assessment of error in the recorded mesiodistal crown dimensions of permanent dentition, the data collection procedure was repeated in one dental cast of every five dental casts included. Then the second findings were matched with the first recorded findings. There were negligible differences between the two successive findings, which increases the authenticity of the collected data. A slide calipers with a vernier scale to read value of nearest up to 0.10 mm was used to measure the tooth size. The tips of the calipers were grounded to a point in order to facilitate the greatest degree of accuracy. Statistical analysis was performed using computer software Statistical Package for Social Sciences (SPSS) version 18. The descriptive statistics used were frequency mean and standard deviation. Comparisons between the groups were made by unpaired t-test as the data presented in this were continuous in nature. Level of significance was set at 0.05 and p-value < 0.05 was considered significant. Results: Of the 244 patients, 167 (68.4%) were female and 77(31.6%) were male. Age of the male patients ranged from 8-32 years (Mean 18.3 ± SD 5.9) and in female ranged from 7-36 years (Mean 18.3 ± SD 5.5) (Table-1).