Investigation of a DNA Profiling Method Using Only Cementum More Than 70 Years After Death.

Short tandem repeat (STR) typing is widely used not only for blood relationship identification but also for the personal identification of unidentified bodies. However, DNA is susceptible to the effects of environmental factors, consequently leading to reduced DNA yields. Therefore, to maximize the DNA yield required for identification, teeth are generally completely pulverized during DNA extraction.

Influence of the amount of saliva deposition and time elapsed after deposition on bite mark analysis.

Bite mark analysis is among the most interesting research fields in forensic odontology; however, it is limited by its dependence on the employed method as well as assessor subjectivity, particularly when using morphological analysis or DNA profiling. These limitations are due to differences in DNA collected from saliva adhering to a living or inanimate body, as well as differences in exocrine fluid secretion and deposition amount among individuals. This study aimed to analyze the effectiveness of DNA profiling when there are differences in the amount of saliva adhering to a living body and when time has elapsed since deposition.

A method for estimating time since death through analysis of substances deposited on the surface of dental enamel in a body immersed in freshwater.

Estimating the elapsed time after death of a corpse immersed in freshwater is often challenging owing to body temperature changes and the degree of postmortem lividity, and the tissues used for this assessment deteriorate drastically as the postmortem period progresses. In this study, assuming a corpse was immersed in freshwater, we analyzed changes in the amount of deposits on the enamel surface of teeth since the time of immersion using an electron probe microanalyzer. We calculated a regression equation for estimating the time of immersion in water (the time after death).

New Method of Dental Personal Identification of Disaster Victims Using Oral Scanner.

Dentistry plays an important role in the identification of victims in large-scale disasters. The current poor status of and problems with victim identification work were highlighted in the aftermath of the Great East Japan Earthquake of March 11, 2011, in which some 10,000 people lost their lives. The techniques of dental identification therefore need to be improved if they are to cope with the problems associated with identification that will accompany the predicted Tokai earthquake and other unexpected large-scale disasters in the future.

Personal Identification by Superimposition of Three-dimensional Intraoral Models.

Victim identification following disasters is an important task for the dentist. Use of records of previous dental treatment proved effective in victim identification after the crash of Japan Airlines Flight 123 in 1985. This dental identification procedure can be problematic, however.

Population Genetics in Malaysia and Japanese Populations Using Power Plex Y23 System.

Population flow between Southeast Asian countries and Japan continues to gather pace. Accordingly, the number of foreigners involved in incidents in Japan has markedly increased, which means that forensic dentistry is now increasingly being faced with the need to analyze DNA from persons of non-Japanese extraction. The DNA test currently used for personal identification mainly utilizes short tandem repeats (STRs) on autosomal chromosomes and the Y-chromosome.

Comparison of Characteristics of Dental Malpractice Trials between Medical Malpractice and Ordinary Divisions in District Courts.

The purpose of this study was to elucidate the characteristics of dental malpractice trials undertaken by medical malpractice divisions and ordinary divisions in district courts. Dentistry disputes in a total of 84 trials held between 1977 and 2014 were investigated. A total of 45 were conducted by medical malpractice divisions, resulting in 18 approvals and 27 dismissals, while 39 were undertaken by ordinary divisions, leading to 24 approvals and 15 dismissals.

Trial application of oxygen and carbon isotope analysis in tooth enamel for identification of past-war victims for discriminating between Japanese and US soldiers.

Stable isotope analysis has undergone rapid development in recent years and yielded significant results in the field of forensic sciences. In particular, carbon and oxygen isotopic ratios in tooth enamel obtained from human remains can provide useful information for the crosschecking of morphological and DNA analyses and facilitate rapid on-site prescreening for the identification of remains. This study analyzes carbon and oxygen isotopic ratios in the tooth enamel of Japanese people born between 1878 and 1930, in order to obtain data for methodological differentiation of Japanese and American remains from the Second World War.

Three-dimensional observation of decrease in pulp cavity volume using micro-CT: age-related change.

We investigated three-dimensional decrease in the volume of the pulp chamber caused by age-related secondary dentin formation using micro-CT and evaluated the applicability of the results to evaluation of age taking into account sex, age and tooth type. Decrease was slightly higher in females than in males, and a higher correlation between decrease and aging was observed in females. A comparison between age-groups revealed that decrease progressed between the fifties and sixties in males, and the forties and fifties in females.

Morphologic characteristics of the superior pharyngeal constrictor muscle in relation to the function during swallowing.

To clarify the morphologic characteristics of the superior pharyngeal constrictor muscle, which plays an important role in swallowing, the gross anatomy of the pterygopharyngeal, buccopharyngeal, mylopharyngeal, and glossopharyngeal parts of the muscle was examined. Morphology of the origin of the muscle at the buccopharyngeal part could be divided into three types: type A, membranous morphology from superior to inferior areas; type B, membranous only in superior area; and type C, complete lack of membrane. In all three types, the muscle at the buccopharyngeal part transitionally originated from the buccinator muscle.

Changes in muscle-fiber properties of the murine digastric muscle before and after weaning.

The digastric muscle is one of the suprahyoid muscles and consists of the anterior and posterior bellies. Because muscle fiber alignments in these two bellies are different, the functional roles are said to be different. Since the digastric muscle relates to mastication, its functions may change markedly before and after weaning, but many details remain unknown.

Anatomical study of accessory nerve innervation relating to functional neck dissection.

Purpose: The present study sought to clarify correlations of accessory nerve innervation in the neck region and innervation of the sternocleidomastoid and trapezius muscles with postoperative dysfunction after functional neck dissection by macroscopic observation.

Materials And Methods: The materials used in this study were 35 cadavers provided for anatomical practice to the Department of Anatomy, Tokyo Dental College. The accessory nerve was identified at the anterior margin of the trapezius muscle, and its innervation in the posterior triangle of the neck was examined in detail.

Experimental device for detecting laryngeal movement during swallowing.

It has been reported that swallowing is a rhythmic movement, in which the onset of the oro-pharyngeal stage of swallowing starts from the mylohyoid muscle, followed by movement of the oral and pharyngeal muscles, and reaching the superior esophageal sphincter muscle. This is defined as the oro-pharyngeal stage of swallowing. It has also been reported that along with this movement, the larynx elevates in an antero-superior direction.

Muscle-fiber characteristics in adult mouse-tongue muscles.

To clarify functions of the mouse-tongue muscles, proteins such as myocin heavy chain (MHC) 2a and MHC-2b, which are isoforms of the fast-twitch fiber type myosin heavy chain, in the lateral margin of the tongue were observed by reverse transcription polymerase chain reaction and immunohistochemical analyses. The main MHC isoform in the superior longitudinal muscle of the tongue was MHC-2b, with the fastest function and the main MHC isoform in the transverse muscle of the tongue was MHC-2a. These findings suggested that the fastest function is necessary for the superior longitudinal muscle of the tongue, which is useful for moving the tongue in and out of the mouth in the sagittal direction, showing different cellular biological properties of the myofibers from those of the transverse muscle of the tongue.

Temporomandibular joint ankylosis: a case report.

This report is based on a case of temporomandibular joint ankylosis discovered in a cadaver during routine student dissection in the Department of Anatomy at Tokyo Dental College. Extensive osseous ankylosis in the left temporomandibular joint was evident in this case which exhibited a distinctive bird-like facial deformity caused by a mandibular growth disorder. This resulted in the underdevelopment of the mental area in particular.