Sex Determination and Sex Differentiation

Sex determination is arguably the most defining moment of our lives, the point where we inherit X or Y chromosome from our father. This initiates a cascade of events that sets in a train of morphological changes, genetic regulations and molecular mechanisms. Following this, our fate is further sealed during sex differentiation and gonadal development owing to the action of sex-specific gonadal hormones. Therefore, the profoundly divergent journeys of male and female lives are decided just by the toss of a genetic coin. The existence of a third gender is also an undeniable aspect of our society. The understanding of the functioning and genetic regulation of the complex process of sexual determination and differentiation is pivotal in comprehension of the basis of human life. Any deviation from the usual mechanisms in the critical stages of development leads to disorders of sexual differentiation leading to sexual ambiguity among individuals. This review discusses the mechanisms that contribute to female and male sex determination and gonadal development, in an attempt to understand the basics of human sex.

ABO Genotyping from Pulp and Dentin Using DNA - A PCR Study

Background: Blood grouping has a major role in forensic science in the field of human identification. Aim of the Study: Aim of this study was to determine ABO genotyping from pulp and dentin using PCR method. Objectives: To determine PCR based blood grouping from the DNA isolated from tooth Pulp and Dentin. Materials and Meathods: Dental pulp tissue and Dentin was collected from 20 permanent teeth and DNA extraction was carried out from pulp using (modified proteinase –K method) and from dentin using phenol/chloroform(organic method). PCR procedure was carried out and samples were subjected to agarose gel electrophoresis and blood group was determined using specific PCR primers for ABO genotyping. Results: Among the 20 samples of pulp tissue, 17 samples showed accurate results in PCR method in comparison with slide agglutination method. Among the 20 samples of dentin, blood grouping from dentin was not possible as the quantity and purity of DNA from dentin samples were not optimal. Sensitivity of 85% and specificity of 50% was noticed from the samples of pulp. Conclusion: PCR was found to be an effective method in determination of blood group from teeth. Thus our study states that isolation of DNA can be done from both pulp and dentin and the blood grouping can be done from tooth pulp by PCR method. Hence PCR method can be used for identification of individuals which adds beneficiary value to forensic dentistry.

Oral Autopsy – Dental Surgeon’s Perspective

Background: Autopsy is routinely performed by the coroner in all medico-legal cases but the dental expertise is rarely sought. However, oral autopsy involving careful visual examination, imaging and laboratory methods can aid in solving the enigma associated with legal aspects of crime scene and death investigation. Aim: To illustrate the importance of oral autopsy during routine post-mortem examination. Data Sources: Pub-Med, Google Scholar search engines were used to extract the data. Conclusion: Oral autopsy performed as an adjuvant to regular autopsy procedure will definitely benefit in the legal investigation related to visually identifiable, decomposed, burnt or skeletonized corpse.

Awareness of Forensic Odontology among Dental Students, Academicians, and Dental Practitioners in Gujarat: A Questionnaire Based, Cross Sectional Study

Aim: This survey aimed to evaluate the awareness of forensic odontology (FO) subject among dental students, dental academicians (DAs), and dental practitioners (DPs) in Gujarat state. Materials and Methods: A questionnaire sheet containing 14 questions was answered by 607 participants consisting of dental students, DAs, and DPs in Gujarat. Descriptive statistics were used to summarize the responses, and the results were presented as frequencies and percentages. The Chi‑square test was used to compare the responses among the groups, and the level of significance was set at P < 0.05. Results: A total of 607 participants answered the questionnaire form. Out of 212 UG students, 175 (82.5%) were aware of the FO branch and 181 (85.4%) agreed to FO as a promising field in dentistry. The majority of the undergraduate (UG) students agreed that FO should be taught as a separate subject at UG and postgraduate level. The majority of the participants (95.7%) agreed that dental evidence plays an important role in forensic cases. Nearly 80% of the respondents agreed for a separate PG course in FO and around 37% of them opted for MDS course in FO. Bitemark analysis and dental age estimations were considered the promising domains in FO by >80% of the participants. Conclusion: This questionnaire study was performed to analyze the awareness of FO among dental students, DPs, and DAs. The majority of the study participants were aware of FO. A thorough review of the literature on a similar topic was also done.

Radiologic Evaluation of Odontometric and Osteologic Traits for Gender Determination in Adult Ethnic Tamil Population

Background: Odontometric and osteologic trait have always served as an excellent resource in anthropological, genetic, odontologic, and forensic investigations. Traits: The aim of this study was to find the most reliable method for gender determination by correlating both the odontometric and osteologic variables. Materials and Methods: A retrospective study was conducted using digital panoramic radiographs of 400 individuals (200 males and 200 females) with age ranging from 20 to 50 years. Standardized digital panoramic radiographs of patients taken as part of pretreatment planning for implants, extractions of third molars, and for periodontal diseases were selected from the archives. Measurements were done using IMAGE Pro software. Results: Mesiodistal width of 17–47 exhibited significant gender variation. Osteologic parameters such as ramus dimension and the gonial angle also showed significant gender variation and the mandibular asymmetry was significant in both the genders. Conclusion: Correlation of the two group of traits showed strong positive predictive values attributable for gender determination.

A Comparative Evaluation between Dermatoglyphic Patterns and the Permanent Molar Relationships – An Attempt to Predict the Future Malocclusions

Background: Due to the similar duration of development, finding the dermatoglyphic patterns to predict malocclusions can help a pediatric dentist to attempt any necessary preventive and interceptive orthodontic therapies. Aim: To assess the correlation between different dermatoglyphic patterns with the permanent molar relationships. Materials and Methods: 300 children who are 14-16 years old with completely erupted 2nd permanent molars up to occlusal table were recruited and the pattern of molar terminal plane was recorded in the proforma. Finger prints of these subjects were recorded with ink and roller method. Forensic analyst analysed the prints and classified based on the classification given by Galton and also calculated the finger ridge count as given by Cummins and Midlo Statistical analysis used: Chi-Square test was applied to compare proportions between all the groups and also for gender comparison. Fisher’s exact test was used when any expected cell frequency of less than five were obtained. Paired t-Test and McNemar’s test were applied to compare values between right and left hand. Results: Class I children showed absence of arch pattern in thumb and little finger of left hand; and higher total finger ridge count in right hand when compared to left hand. Children with Class II molar relationship had a significant association with presence of arch pattern in thumb finger of left hand; and presence of whorl pattern in both left and right ring fingers. Class III had a significant association with presence of loop pattern in left thumb finger and little finger; absence of arch pattern in thumb of right hand. Conclusion: Dermatoglyphics can be a useful non-invasive analytical tool to predict malocclusions in permanent dentition and sometimes, to identify an individual. Further studies with larger sample size are required to provide an insight into its significant correlations.

Effect of Dentures on Palatal Rugae: An Investigation

Aims: The aim of this study is to evaluate the rugae pattern changes (rugae number, length, shape, direction, and unification) in completely edentulous patients treated with complete denture. Materials and Methods: A total of 100 subjects were selected for the study. The experimental group comprised 60 participants (30 males and 30 females) who had undergone complete denture treatment and the control group comprised 40 participants (20 males and 20 females) who were dentulous and patients with fixed partial denture treatment. Mucostatic maxillary alginate impressions were made for all the subjects, and casts were poured with gypsum. Patients were recalled at the regular intervals of 1, 6, and 18 months after the treatment. During those recalls, the same impression procedure was made, and all the palatal rugaes were observed for number, length, shape, direction, and unifications under magnifying lens. Changes in the palatal rugae were statistically analyzed using the unpaired t‑test. Results: A gradual decrease in the length was observed in primary, secondary, and fragmentary rugae for the experimental group after denture wearing (Group 1). Statistically, the change was significant (P < 0.001) in primary rugae only. A slight change in rugae shape was also observed in the experimental group after 18 months period of denture wearing which is statistically insignificant (P > 0.05). Conclusions: Significant decrease in primary rugae length in complete denture wearers was due to sustained mechanical stress posed by the dentures on palatal rugae. The other parameters such as rugae number, direction, and unification remained constant throughout the study. Palatal rugae analysis may not be helpful for human identification in complete denture wearers. Nevertheless, palatal rugae may serve as an adjuvant to other techniques such as DNA analysis and finger prints in forensic investigations.

An Overview of Three Dimensional (3D) Technologies in Forensic Odontology

Three-dimensional (3D) modalities are frequently applied in forensic practice as it tends to give complete information of the evidence merely by touching which has resulted in increased usage in legal medicine and forensic sciences. A number of sub-disciplines of forensic science utilises 3D modalities in an inter-disciplinary manner viz. forensic anthropology, forensic archaeology, forensic odontology, crime-scene investigation, pattern analysis and recovery, courtroom visualisation and ballistic comparison. With appropriate knowledge and utilisation of 3D scanning, modelling and printing technologies, innovative approaches can be implemented for identification in forensic cases. Given that these technologies are evolving rapidly and changing the face of forensic science, the present article collates current developments, working and applications of non-contact scanning techniques, modeling and 3D printing techniques.

Detection of Dried Saliva on Human Skin using an Ultra Violet Spectrometer: A Technical Report

Introduction: Human beings produce saliva, which is a vital secreted fluid. A significant quantity of saliva is left on the skin while biting, sucking, or licking. This saliva if effectively detected could be utilized as forensic evidence. DNA extraction and typing is complex and expensive technique; hence, ultraviolet (UV) spectroscopy could be used as an effective tool in detecting saliva. Aim: The aim was to detect the presence of dried saliva on the human skin using a UV spectrometer. Materials and Methodology: In this study, 50 volunteers deposited their saliva on their own arm. The saliva was air‑dried, then, the absorption spectra were recorded utilizing the UV spectrometer. Results: Saliva was detected with 64% of samples showing a peak at 282 nm. The technique proved to be very specific and sensitive, and it did not deteriorate the sample. Conclusion: UV‑spectroscopy is a specific and technique sensitive method that could detect the presence of saliva without deteriorating the quality of the given sample.

Editorial

No Abstract.