Rajiv Gandhi University of Health Science, Bangalore,

Karnataka.

MDS

Oral Medicine & Radiology

SYNOPSIS FOR REGISTRATION OF DISSERTATION.

M R Ambedkar Dental College and Hospital

#1/36, Cline Road, Cooke Town

Bangalore, Karnataka- 560005

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

KARNATAKA, BANGALORE.

ANNEXURE II

SYNOPSIS FOR REGISTRATION OF DISSERTATION

1 / NAME OF THE CANDIDATE AND ADDRESS / Dr. B.N.RAJARATHNAM
Dept. Of Oral Medicine & Radiology
M. R. Ambedkar Dental College & Hospital
#1/36, Cline Road ,Cooke Town
Bangalore-560005.
2 / NAME OF INSTITUTION / M. R. Ambedkar Dental College & Hospital
3 / COURSE OF STUDY AND SUBJECT / M.D.S., ORAL MEDICINE & RADIOLOGY
4 / DATE OF ADMISSION / 30/05/11
5 / TITLE OF THE TOPIC:
MANDIBULAR CANINE DIMENSIONS AS AN AID IN GENDER DETERMINATION.
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6.1
6.2
6.3
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7.1
7.2
7.3
7.4
8 / BRIEF RESUME OF WORK:
NEED FOR THE STUDY:
Dental forensics forms a vital branch of forensic science which deals with proper handling, examination and evaluation of dental evidences for identification of victims of crime, accidents or calamities.
Sex determination is considered an important step in reconstructing the biological profile of unknown individuals from a forensic context. It enables a more focused search of missing persons’ files, with the potential of recovering antemortem records for comparison and establishing identity. The most commonly used techniques are based on the assessment of the morphological characteristics of the pelvis and skull. Among skeletal parameters, the pelvic and skull bones are known to produce 100% success in sex identification.
Teeth are known to be unique organs made of the most enduring mineralized tissues in the human body. They are tissues characterized by structures of extraordinary resistance to putrefaction and effects of external agents that cause destruction of soft tissues of the body. Hence teeth form an excellent structure for forensic investigation.
Teeth are extremely durable even at high temperatures and may be identified even when the rest of the body has undergone decomposition. The major advantage of the dentition is that it is highly resistant to postmortem insults, surviving a variety of destructive effects caused by trauma and incineration; also human jaws have a complement of 32 teeth and, hence, even though some teeth are missing or destroyed, others may still be well-preserved. This characteristic of teeth gives them an advantage for sex determination in forensic cases and mass graves, where bones are frequently fragmentary.
Mandibular canines are found to exhibit the greatest sexual dimorphism amongst all teeth. The mandibular canines are not only exposed to less plaque, abrasion from brushing, or heavy occlusal loading than other teeth, they are also less severely affected by periodontal disease and so, usually the last teeth to be extracted with respect to age. These findings indicate that mandibular canines can be considered as the” key” teeth for personal identification.
Odontometric data and its usefulness in sexing South Asian populations, however, are still largely unexplored. With this background this study will be undertaken to examine and analyze sexual dimorphism in mandibular canine.
REVIEW OF LITERATURE:
M. Muller, L. Lupi-Peguriera, G. Quatrehomme, M. Bollaa (2001):
Rao et al’s method of sex determination, which considered the mandibular canine index (MCI) is one giving satisfying results. However their study did not take occlusion into consideration So Muller et al conducted a study which involved the students enrolled in the University of Nice-Sophia Antipolis. 210 girls and 214 boys were randomly sampled 1/20). Both tooth sizes and dental arches were measured using a Vernier caliper to calculate MCI for both sexes. The results were compared to standard MCI, taking into account tooth alignment. The authors concluded that Rao et al method can only be used in the case of correct lower anterior dental alignment and by using the standard MCI of the local population.
Kaushal, S., Patnaik, VVG., Agnihotri, G. (2003):
To define the morphometric criteria for mandibular canines in North Indian population, this study was conducted in 60 subjects (M:F::30:30) in the age group of 17-21 years. Intercanine distance & width of both right with left mandibular canines were measured intra orally as well as on the casts of same subjects & the mandibular canine index was calculated. It was seen that a definite statistically significant sexual dimorphism existed in the mandibular canines whether measurements were taken intraorally or on casts. Out of the two canines, the left one exhibited greater sexual dimorphism as compared with the right one. It was also concluded that whenever the width of either canine was >7mm the probability of sex being male is 100%. While if it is <7mm, the sex could be either.
Vandana M Reddy, Susmitha saxena, Puja Bansal. (2008):
This study was conducted to establish the effectiveness of mandibular canine index in predicting sex in Western Uttar Pradesh population. 200 subjects belonging to Western Uttar Pradesh (100 males; 100 females) in the age group of 17-25 years were included in their study. Impressions were made with alginate and study models prepared with dental stone. Maximum mesiodistal diameter of mandibular canines and the linear distance between the tips of mandibular canines were measured using a Vernier caliper. Observed mandibular canine index (MCI0) was calculated as the ratio between the maximum mesiodistal width of mandibular canine and canine arc width. The authors found that left canine exhibited greater sexual dimorphism i.e. 9.05% as compared with right canine i.e. 8.782%. Sex could be predicted correctly in approximately 70% of subjects examined. This study concluded that with the standard MCI it was possible to detect sex in the population of Western Uttar Pradesh to an extent of about 72%. Hence it was considered as a quick, easy and reproducible method for determining the sex of an individual.
Karen boaz, Chhavi gupta (2009):
This study was performed on 100 dental casts of a South Indian population in the age group of 14-20 years in an attempt to assess the dimorphism of human permanent maxillary and mandibular canines and to evaluate the possibility of dimorphism of the canines being used as a valid tool in the forensic and legal identification of an individual. The mesiodistal and buccolingual measurements were subjected to statistical analysis using the ‘t’ test to determine whether significant differences existed between tooth sizes in males and females. Their study revealed that the mean values of the buccolingual and mesiodistal dimensions of the mandibular left canine (33) were greater in females than in males and the mean values of the mesiodistal dimensions of the mandibular right canine (43) in females were greater than that in males in their sample( reverse dimorphism) They found that their findings could be attributable to evolution resulting in a reduction in sexual dimorphism, causing an overlap of tooth dimensions in modern males and females.
Mughal IA, Saqib AS, Manzur F (2010):
The present study was performed on 200 students, between the age group of 18-25 years, randomly sampled with informed consent. Mandibular canine width and intercanine distance were measured with the help of Vernier caliper after observing aseptic conditions. Mandibular canine index was calculated and the observed MCI was compared with the standard MCI value. The data was analyzed using student’s “t” test. No significant statistical difference was noted between the right and left mandibular canines amongst males and females (same sex) but when comparing between males and females, there was a high statistically significant difference (P < 0.001). The calculated standard MCI for canines of males and females was found to be 0.2504. With these calculations they could predict sex correctly at 75.97% (Male: 71.67% and Female: 78.72%). Thus they concluded that MCI was a quick and reliable method for sexual identification when a standard for the population is available. With these calculations, they could predict the sex correctly at 75.97 % and found this method to be an adjunct to other available tools for sex determination.
AIMS AND OBJECTIVES:
1)  To measure mesio distal width of right mandibular canine
2)  To measure mesio distal width of left mandibular canine.
3)  To measure inter canine distance.
4)  To calculate mandibular canine index.
5) To assess usefulness of mandibular canine as an aid in gender determination
MATERIALS AND METHODS:
SOURCE OF DATA:
Subjects will be selected from patients reporting to the O.P.D in the Department of Oral Medicine and Radiology, M. R. Ambedkar Dental College and Hospital, Bangalore.
METHOD OF COLLECTION OF DATA:
The study will be performed on 200 subjects, inclusive of 100 males and 100 females between the age group of 18-25 years, who will be randomly selected after an informed consent. The subjects with the following criteria will be included in the study:
·  Subjects having a healthy state of gingiva & periodontium.
·  Subjects having mandibular canines free from dental caries. .
·  Subjects having normal overjet & overbite of teeth (2-3 mm).
·  Subjects with an absence of spacing in the anterior teeth.
·  Subjects having Angle’s Class 1 molar and canine relationship.
The exclusion criteria employed for selection of subjects will be the presence of partially erupted or ectopically erupted teeth and missing teeth, subjects with dental or occlusal abnormalities such as rotation, crowding, occlusal disharmony e.t.c., teeth showing physiologic or pathologic wear and tear (e.g. attrition, abrasion, abfraction, and erosion) and subjects with deleterious habits like bruxism.
The following measurements will be made intraorally and later on the casts obtained from the same subjects using digital Vernier caliper. Alginate impressions of mandibular arches will be made using metallic perforated impression trays and the resultant impressions will be thoroughly cleaned and disinfected. Type III dental stone will be used to make study models from the alginate impressions which will be used for conducting the measurements after complete setting.
The following measurements will be made both intraorally and on the study models of the subjects as listed below:
·  Right mandibular canine width: measured as the greatest mesiodistal dimension of right mandibular canine.
·  Left mandibular canine width: measured as the greatest mesiodistal dimension of left mandibular canine.
·  Intercanine width: measured linear from the cusp tip of right mandibular canine to the cusp tip of left mandibular canine.
The observed mandibular canine index (MCI) will be calculated using the following formula
Mandibular canine index = Mesio-distal width of mandibular canine
Intercanine width
The measurements obtained will be subjected to statistical analysis using discriminant functional analysis.
DOES THE STUDY REQUIRE ANY INVESTIGATIONS TO BE CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS?
NO
HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE OF 7.3?
Yes
LIST OF REFERENCES :
1)  Muller M, Peguriera LL, Quatrehomme G, Bolla M. Odontometrical method useful in determining gender and dental alignment. Forensic Science International 2001;121:194-197.
2)  Kaushal, S, Patnaik, VVG, Agnihotri G. Mandibular canines in sex determination 2003;52:(2):119-124.
3)  Reddy VM, Saxena S, Bansal P. Mandibular canine index as a sex determinant: A study on the population of Western Uttar Pradesh. Journal of Oral Maxillofacial Pathology 2008;12:56-59.
4)  Boaz K & Gupta C. Dimorphism in human maxillary and mandibular canines in establishment of gender. Journal of Forensic Dental Sciences 2009;1:42-44.
5)  Mughal IA, Saqib AS, Manzur F. Professional Medical Journal 2010;17(3):459-463.