Study of Mandibular Canines and Its Role in Establishing Sex Identity in Subjects of North Bihar

In highly decomposed and mutilated dead body remains dentures are frequently sent for the medicolegal examination by the forensic experts for identification. Dental tissues like bones resist putrefaction for much more longer period and these are in many cases available for examination due to its tough texture and ability to escape destruction. Methods: The present prospective study was done on 450 subjects (225 males and 225 females) of known age and sex, from different socio-economic strata and religion belonging to north region of Bihar state. Their age ranges vary from 14-73 years. The mandibular and maxillary canines of both sides were measured in both sexes. Various dimensions namely, mandibular and maxillary canine crown width, crown length and canine separation width were taken in each case with the help of dividers and vernier calipers with a resolution of 0.1mm. Results: In the present study, regarding mandibular canines in males, crown length showed the maximum accuracy (92.0%) of sex identity in the age group (E) 54-63 years and canine separation width showed the minimum accuracy of 40% in the age group (D) 44-53 years. In females, crown width showed the maximum accuracy of 83.33% in the age group (D) 44-53 years and minimum accuracy of 30% by crown length in the age group (F) 64-73 years. Regarding the maxillary canines, in males, the crown length showed the maximum accuracy (90%) of sex identity in the age group (D) 44-53 years and the minimum accuracy of 44% in the age group (A) 14-23 years. In females, both crown width and crown length showed the maximum accuracy of 96.66% in the age group (D) 44-53 years and minimum accuracy of 22% by crown width in the age group (B) 24-33 years. Conclusion: The present study revealed this method could be useful as a reliable tool for sex identity when use of other methods are not possible or there is no definite features indicating the sex as in cases when parts of decomposed and skeletonised dead bodies are recovered after a mass disaster or exhumation and also in cases when smaller fragmented part of the body is only available for examination.

A study on the validity of reference points for edentulous patient / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the validity of reference points for edentulous patient by examining the correlation of teeth and face, and intraoral anatomic landmarks. MATERIALS AND METHODS: We examined a facial outline, length, bizygomatic width, nasion - gnathion length, glabella - nasion distance in 270 men and 280 women satisfied with inclusion criteria from Seoul National School of Dentistry. The shape of maxillary central incisor, mesiodistal crown width and length of maxillary 6 incisors, distance from incisive papilla to labial surface of maxillary central incisor, and perpendicular distance from incisive papilla to intercanine line were measured in the stone model. We analyzed the ratio and relevant relation statistically. RESULTS: The probability on having the same shape of face and the relative same shape maxillary incisor was 55.56% and 46.43% for men and women. The facial length proved to be a more valuable measurement in women in the tooth selection. The ratio of bizygomatic width to mesiodistal width of maxillary central incisor, and the ratio of bizygomatic width to width of maxillary 6 incisors were 16.8 : 1 and 3.0 : 1 and were positively correlated with each other. The distance of the canines from the maxillary incisal papilla was 1.33+/-1.28 mm. The distance between the center of the incisal papilla and the labial surface of their maxillary central incisor was 9.23+/-1.20 mm. CONCLUSION: It was showed that anatomical reference points in tooth selection and arrangement for edentulous patient are useful and have validity in our limited study.

Comparison of the retention of the full veneer casted gold crowns with varying convergence angle, crown length and dental cements / 대한치과보철학회지

PURPOSE: The aim of this research was to establish the effect and variation in differing convergence angle and length of abutment on the retention of full veneer casted gold crown. MATERIALS AND METHODS: Two different length,5 mm and 10 mm in height with convergence angles of 5, 10, 15 and 25 degrees crowns were fabricated. Cementation was done using cements; zinc phosphate cement (Fleck's zinc phosphate cement), resin-modified glass ionomer cement (Vitremer) and resin cement (Panavia 21). These were tested for tensile force at the point of separation by using Instron Universal Testing Machine. Statistical analysis was done by SAS 6.04 package. RESULTS: In all cements the mean retention decreased with significant difference on increase of convergence angle (P<.05). Increase in every 5 degree-convergence angel the retention rate decreased with resin-modified glass ionomer cement of 15.9% and resin cement of 14.8%. With zinc phosphate cement, there was largest decreasing rate of mean retention of 25.5% between convergence angles from 5 degree to 10 degree. When the crown length increased from 5 mm to 10 mm, the retention increased with the significant difference in the same convergence angle and in all types of cement used (P<.05). CONCLUSION: The retention was strongly dependent on geometric factors of abutment. Much care is required in choosing cements for an optimal retention in abutments with different convergence angles and crown lengths.