Toward Oral Thanatomicrobiology-An Overview of the Forensic Implications of Oral Microflora.

Introduction: The oral cavity is home to numerous microorganisms including bacteria, fungi, and viruses which together form the oral microflora. It is the second most diverse microbial site in the human body after the gastrointestinal tract. Microbial degradation is a common phenomenon that occurs after death, with the early and advanced stages of decomposition being closely associated with oral microbial activity. Methods: This article reviews the current state of knowledge on the role of the oral microflora in postmortem events, and highlights the growing importance of terms such as forensic microbiology and thanatomicrobiome. This article also discusses next-generation sequencing, metagenomic sequencing studies, and RNA sequencing to study the oral thanatomicrobiome and epinecrotic communities in forensic oral genetics. Results: The indigenous microorganisms in the oral cavity are among the first to respond to the process of decomposition. DNA/RNA sequencing is a relatively simple, precise, and cost-effective method to estimate biological diversity during various stages of postmortem decomposition. The field of thanatomicrobiology is rapidly evolving into a key area in forensic research. Conclusion: This article briefly narrates oral microflora and its implications in forensic odontology. The role of microbial activity in postmortem events is gaining importance in forensic research, and further studies are needed to fully understand the potential applications of advanced technology in the study of the oral thanatomicrobiome.

Inter-observer agreement in the radiographic interpretation of Demirjian's developmental stages in the mandibular second and third molars - A comparative study.

Background: The developmental stages of the teeth in the radiographs are graded on an ordinal scale. The present study was conducted using 123 digital orthopantomograms from individuals in the age group of 5 to 22 years and to analyze and evaluate the inter-observer agreement in grading the developmental stages of second and third molars. Four observers with different levels of practical experience in age estimation participated in the study. The development stages of both the molars in the lower left quadrant (3rd quadrant) were assigned based on the Demirjian's 10 stage chart. The percentage agreement and Kappa statistics were used to test the agreement between the observers. The data of the observer 1 were used as the standard for the comparison. RESULTS: There was 70.0%-75.6% agreement among the observers in staging second molar and 52%-68.3% for the third molars. There was an excellent agreement (k > 080) between observer 1 and observer 2 and a good agreement (k = 060-0.79) between observer 1 and the other two observers for both the molars. The Fleiss Kappa revealed moderate to a good overall agreement for both the molars (k = 0.51-0.66). The Freidman's test revealed a significant difference in the grading of third molars between all the raters (χ2= 25.02, df 3, P < 0.001) and for the second molar the difference was not significant (χ2= 3.89, df 3, P > 0.05). The stage-wise overall agreement was fair for Stage 3 in the second molar and Stage 9 and Stage 4 in the third molar. Conclusions: In conclusion, proper training in the radiographic interpretation of developmental stages may minimize the errors during the age estimation methods.

Qualitative assessment of the dental groove pattern and its uniqueness for forensic identification.

INTRODUCTION: Teeth are invaluable in both the living and the deceased for forensic identification and profiling purposes. The occlusal surface patterns in the molars of an individual depend on both intrinsic and extrinsic factors. The individualistic nature of the groove pattern can be used to determine the identity of an individual by the process of comparative identification. AIM AND OBJECTIVE: The objective of this study is to determine the uniqueness of the groove pattern among individuals by the means of digital analysis. MATERIALS AND METHODS: An experimental study was conducted on 80 dental casts where the occlusal groove patterns of 1st and 2nd molars from each cast were traced digitally using image analysis software GIMP (v 2.10.6). The traced patterns were then examined to determine their uniqueness. RESULTS: The most common groove patterns for the maxillary 1st and 2nd molars were found to resemble "Branched H" and "H", respectively. "Y" pattern was observed to be the most common in mandibular 1st molar, whereas mandibular 2nd molar most commonly exhibited "+" pattern. No two groove patterns were similar in the analysis. CONCLUSION: Digital method of analysis is preferable over conventional manual methods as it is noninvasive and precise. The individualistic nature of occlusal groove patterns may play an important role in comparative forensic identification.