A safe procedure? The unusual case of a fatal airway obstruction by silicone during the production process of a tracheostomal epithesis in a 13-year-old boy.

A tracheostomal epithesis is a plastic prosthesis that serves for sealing a tracheostoma and ensuring the position of the tracheostomy tube. The production of a tracheostomal epithesis requires an impression of the tracheostoma. To this end, silicone impression material is applied by an anaplastologist in and around the tracheostomal region, including the trachea. The blocked cuff of the tracheostomy tube serves to prevent aspiration of the material. We report on a 13-year-old boy who died during this procedure because the lower airways were obstructed with cured silicone. Forensic autopsy confirmed asphyctic suffocation as cause of death. Forensic physical investigation of the tracheostomy tube and its cuff revealed no structural or functional defects. Yet, the investigation results prove that the viscous silicone must have passed the cuff. To conclude, this case report demonstrates that the production of an impression of a tracheostoma is a procedure with a potentially lethal outcome. Hence, professional guidelines, including clear safety precautions, are urgently needed.

Dental age estimation based on the radiographic visibility of the periodontal ligament in the lower third molars: application of a new stage classification.

The purpose of the present study was to test whether a new stage classification based on radiographic visibility of the periodontal ligament in lower third molars in a Chinese population can be used for the 18- and 21-year thresholds. A total of 1300 orthopantomograms, including equal numbers of northern Chinese males and females evenly distributed between the ages of 15 and 40 years, were analyzed. The stages were defined according to the visibility of periodontal ligament for the outer parts of lower third molar roots because the visibility status of the periodontal ligament between the roots of lower third molars is none valuable in many Chinese individuals. Stage 0 was first achieved at the age of 17.05 years in males and 17.46 years in females. The earliest appearance of stage 1 was 17.47 years in males and 17.86 years in females. Stage 2 was first observed in males at the age of 21.43 years and in females at the age of 21.96 years. The onset of stage 3 was first observed at the age of 25.83 years in males and 23.14 years in females. Compared with the stage classification of Olze et al., which also considers the mesial parts of the roots, the number of assessable cases could be significantly increased. Therefore, our novel approach is effective for age estimation in the Chinese population.

Age assessment in the living using modified Gustafson's criteria in a northern Chinese population.

Regressive dental changes appear to be suitable for age assessment in living adults. In 2012, Olze et al. showed that several criteria presented by Gustafson for extracted teeth can also be applied to orthopantomograms. The objective of this study was to test the applicability and reliability of this method in a Chinese population. For this purpose, 1300 orthopantomograms of 650 female and 650 male Chinese aged between 15 and 40 years were evaluated. The characteristics of secondary dentin formation, periodontal recession, attrition, and cementum apposition were reviewed in all the mandibular premolars. The sample was split into a training and test dataset. Based on the training set, the correlation of the individual characteristics with chronological age was studied with a stepwise multiple regression analysis, in which individual characteristics formed the independent variable. According to the results, the R values amounted to 0.80 to 0.83; the standard error of estimate was 4.29 to 4.75 years. By analyzing the test dataset, the accuracy of the present study, Olze's and Timme's formulas were determined by the difference between the estimated dental age (DA) and chronological age (CA). Taking both mean differences and mean absolute differences into account, the Chinese age estimation formula did not always perform better compared with Olze's and Timme's formulas for both males and females. It was concluded that this method can be used in Chinese individuals for age assessment. However, the applicability of the method is limited by the quality of the X-ray images, and the method should only be applied by experienced forensic odontologists.

Studies on the radiographic visibility of the periodontal ligament in lower third molars: can the Olze method be used in the Chinese population?

The purpose of the present research is to study the radiographic visibility of the periodontal ligament in third molars from a northern Chinese population to determine if this methodology could be used for the 18-year threshold. A total of 1300 conventional orthopantomograms from 650 males and 650 females of northern Chinese subjects aged between 15 and 40 years were analyzed. The radiographic visibility of the periodontal membrane of fully mineralized third molars was assessed using the stages described by Olze et al. (2010). Stage 0 first appeared at the age of 17.05 years in males and at the age of 18.76 years in females. Stage 1 was first detected at 18.52 years in males and 19.59 years in females. Stage 2 was first achieved by males at the age of 22.33 years and by females at the age of 21.37 years. The earliest appearance of stage 3 was 26.85 years in males and 24.92 years in females. If stage 1 is determined, it is possible to prove that an individual has already attained the age of 18 years. Stages 2 and 3 can be used to determine that a person is over 21 years of age. However, it should also be noted that in 271 cases of tooth 38 and 255 cases of tooth 48, the visibility stage could not be reliably assessed because of fused roots or narrowed furcations. Therefore, this method seems to be of limited value for age estimation in the Chinese population.

Application of age assessment based on the radiographic visibility of the root pulp of lower third molars in a northern Chinese population.

The purpose of the present study was to explore the potential application of radiographic visibility of the root pulp in lower third molars in a northern Chinese population, in order to determine if this methodology can be used to prove whether a person has surpassed the thresholds of 18 and 21 years of age. A total of 1300 orthopantomograms comprising equal numbers of females and males evenly distributed between the ages of 15 and 40 years were analyzed. The radiographic visibility of the root pulp of the lower third molars was assessed using the stages described by Olze et al. (2010). Stage 1 first appeared at 19.25 years in males and at 20.73 years in females. The earliest appearance of stage 2 happened at 22.33 years in males and at 22.41 years in females. Stage 3 was achieved first at 26.45 years in males and at 27.66 years in females. It was concluded that stages 1, 2, and 3 can be used to show that a person is over 18 years of age. If stages 2 or 3 are determined, it is possible to prove that an individual has already attained the age of 21 years.

Age estimation of Chinese children based on second molar maturity.

In forensic medicine and many other fields, age estimation by the use of teeth is of great importance for the purpose of individual identification. In the past, however, age estimation based on the second molar mineralization was scarcely performed. In this study, a total of 1657 panoramic radiographs taken from 834 males and 823 females of northern Chinese origin in the age bracket 5 to 25 years were assessed. The mineralization status of the second molars was determined using the classification described by Demirjian et al. Results showed that the left and right, as well as maxillary and mandibular second molars were generally at similar stages of mineralization. The maxillary left second molars (27) at stage D, mandibular left second molars (37) at stages C, D, F, and G, and mandibular right second molars (47) at stages D, F, and G showed a significantly lower average age in female subjects than in male subjects. In males, fully developed second molars first appeared with 12 years of age; in females, stage H occurred with 11 years at the earliest. One male individual and one female individual with second molars showing stage G were 23 years old. It was concluded that second molars showing stage H do not exclude an age under 14 years and that second molars showing stage G do not exclude an age above 18 years.

[Forensic age estimation in juveniles and young adults: Reducing the range of scatter in age diagnosis by combining different methods]. / Forensische Altersschätzung bei Jugendlichen und jungen Erwachsenen: Streubreitenreduktion der Altersdiagnose durch Kombination der Methoden.

The dramatic rise in the number of refugees entering Germany means that age estimation for juveniles and young adults whose age is unclear but relevant to legal and official procedures has become more important than ever. Until now, whether and to what extent the combination of methods recommended by the Study Group on Forensic Age Diagnostics has resulted in a reduction of the range of scatter of the summarized age diagnosis has been unclear. Hand skeletal age, third molar mineralization stage and ossification stage of the medial clavicular epiphyses were determined for 307 individuals aged between 10 and 29 at time of death on whom autopsies were performed at the Institutes of Legal Medicine in Berlin, Frankfurt am Main and Hamburg between 2001 and 2011. To measure the range of scatter, linear regression analysis was used to calculate the standard error of estimate for each of the above methods individually and in combination. It was found that combining the above methods led to a reduction in the range of scatter. Due to various limitations of the study, the statistical parameters determined cannot, however, be used for age estimation practice.

Dental age estimation in living individuals using 3.0 T MRI of lower third molars.

In order to increase the validity of age estimation in adolescents and young adults when there is no legitimation for X-ray examinations, it seems desirable to be able to assess the mineralization of third molars using X-ray-free imaging procedures. In the present study, the mineralization stages of lower third molars were determined prospectively in 269 male and 248 female individuals aged 12 to 24 years using 3.0 T MRI. The classification system of Demirjian et al. was used to determine the stages. This study presents the minima and maxima, means and standard deviations, median values, and lower and upper quartiles separately for both sexes, for the mineralization stages B-H. Statistically significant sex differences were observed for the mineralization stages C, E, F, and G, and a faster developmental rate was observed for males. It was concluded that magnetic resonance imaging is an X-ray-free alternative to orthopantomography when assessing mineralization of third molars.

Radiographic evaluation of Gustafson's criteria for the purpose of forensic age diagnostics.

The main criteria used in dental age estimation in living young individuals are mineralisation and eruption of the third molars. In order to further diversify the spectrum of characteristics after completion of third molar development, tests were undertaken to determine whether the characteristics studied by Gustafson can be ascertained with the required forensic certainty with the aid of the orthopantomogram and whether the evaluation of these could render forensic odontological age diagnoses possible beyond the 18th year of life. For this purpose, 1,299 conventionally produced orthopantomograms of 650 female and 649 male Germans aged from 15 to 40 years were studied. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with chronological age was studied with the aid of a multiple regression analysis in which chronological age formed the dependent variable. Depending on the tooth studied, the R values amounted to 0.65 to 0.73; the standard error of estimate was 5.3 to 5.7 years. Basically, the regression equations calculated can be recommended for age estimation in living individuals, although it should be borne in mind that the applicability of the new method presented is limited by the quality of the X-ray images.

The influence of impaction on the rate of third molar mineralisation in male black Africans.

One of the main criteria used in dental age diagnostics in living adolescents and young adults is assessment of the mineralisation stage of the third molars. In the case of Europid populations, it has been established that impaction status has an influence on the rate of mineralisation of the third molars. In view of this, a study was undertaken to determine whether the chronological process of wisdom tooth mineralisation is dependent upon impaction status in black Africans too. Orthopantomograms (553) of 437 male and 116 female black South Africans with verified birth dates in the age group between 10 and 26 years were studied. Mineralisation stage and impaction status were determined for all third molars. Statistical measures were calculated for the mandibular wisdom teeth at stages F, G and H and for the maxillary wisdom teeth at stage H in the male gender for both impacted and non-impacted third molars. It was ascertained that the minimum age in persons with impacted third molars, depending on the wisdom tooth observed, was 0.19-2.57 years higher than in those with non-impacted wisdom teeth. Test persons with impacted mandibular wisdom teeth at stage F or G were on average between 0.32 and 1.88 years older than those with non-impacted mandibular wisdom teeth. The 50 % probability values of impacted wisdom teeth at stage H were 1.85-3.31 years higher than those in non-impacted wisdom teeth. The conclusion was drawn that in male black Africans, impacted mandibular wisdom teeth mineralise more slowly than non-impacted lower third molars. The presence of impacted mandibular wisdom teeth in mineralisation stage H in male black Africans does not, however, furnish proof of completion of the 18(th) year of life beyond reasonable doubt.

[Application of a modified stage classification in evaluating wisdom tooth eruption in a German population]. / Anwendung einer modifizierten Stadieneinteilung zur Beurteilung der Weisheitszahneruption bei einer deutschen Population.

The evaluation of the eruption status of the wisdom teeth constitutes a significant component of the spectrum of dental methods available for purposes of forensic age diagnostics. In the present study, the status of wisdom tooth eruption was identified in 606 conventionally created orthopantomograms of 515 female and 91 male Germans, divided by sex and tooth, using a modified classification comprising four stages. Instead of the original stage C (gingival eruption) which cannot always be reliably identified on X-ray images of suboptimal quality, stage C of the modified classification was considered reached when the erupting wisdom tooth had reached at least half the length of the crown of the adjacent second molar, without however having yet reached the occlusal plane. The new stage classification is especially recommended for age estimation based on X-ray images in which a conclusive delimitation of the gingiva is not possible.

Evaluation of the radiographic visibility of the root pulp in the lower third molars for the purpose of forensic age estimation in living individuals.

The question of whether an individual has reached the age of 18 is of crucial importance in forensic age estimation practice. In some countries, the age threshold of 21 years is relevant as well. A completed mineralization of third molars is not a sufficient criterion for a diagnosis of a minimum age of 18 years with the required probability. In a material of 1,198 orthopantomograms from 629 females and 569 males aged between 15 and 40 years, the visibility of the root pulp of fully mineralized lower third molars was evaluated according to stages 0, 1, 2, and 3. In females, stage 0 was first noticed at age 17.2 years, in males at age 17.6 years. In either sex, the earliest observation of stage 1 was between 21.0 and 22.4 years. Stage 2 was first achieved by males between 22.3 and 22.7 years, by females between 23.4 and 24.7 years. The occurrence of stage 3 was first found in both sexes between 25.1 and 25.9 years. These findings indicate that for stage 0, an age below 18 years cannot be excluded. However, for stage 1, the examined individual must be over 18 years of age and most probably over 21 years of age. For stages 2 and 3, the age can safely be stated to be over 21 years of age. This method may be a powerful tool for forensic dentists in age estimation in asylum and criminal proceedings.

Assessment of the radiographic visibility of the periodontal ligament in the lower third molars for the purpose of forensic age estimation in living individuals.

The main criterion for dental age estimation in living individuals is the mineralisation of third molars. However, the mineralisation of third molars can be completed before the forensically relevant age of 18 years has been attained. In a material of 1,198 orthopantomograms from 629 females and 569 males aged between 15 and 40 years, the radiographic visibility of the periodontal membrane of fully mineralised third molars was assessed according to stages 0, 1, 2 and 3. Stage 0 first appeared at the age of 17.2 years in females and at the age of 17.6 years in males. Stage 1 was first achieved by females between 18.9 and 20.0 years and by males between 20.1 and 20.2 years. The earliest appearance of stage 2 was between 22.5 and 23.1 years in females and at 22.3 years in males. The occurrence of stage 3 was first found between 24.6 and 25.2 years in females and between 25.4 and 26.2 years in males. If stage 1 is determined, it is, therefore, possible to prove that an individual has already attained the legally relevant age of 18 years. For stages 2 and 3, it can be stated beyond reasonable doubt that a person is over 21 years of age.

Studies on the chronology of third molar mineralization in First Nations people of Canada.

Forensic age estimation of living subjects has become increasingly important in recent years. One main criterion for dental age estimation in the relevant age group is the evaluation of third molar mineralization. In the present study, we determined the stages of third molar mineralization in 347 female and 258 male First Nations people of Canada aged 11 to 29 years based on radiological evidence from 605 conventional orthopantomograms. The results presented here provide useful data on the mineralization stages of third molars that can be used for forensic estimation of the minimum and most probable ages including the range of scatter of investigated persons.

Studies of the chronological course of wisdom tooth eruption in a Black African population.

The importance of forensic age estimation in living subjects has grown over the last few years. In dental age estimation, tooth eruption is a parameter of developmental morphology that can be analyzed by either clinical examination or by evaluation of dental X-rays. In the present study, we determined the stage of wisdom tooth eruption in 410 male and 106 female Black South African subjects of known age (12-26 years) based on radiological evidence from 516 conventional orthopantomograms. Four eruption stages were determined (no emergence, alveolar emergence, gingival emergence, complete emergence). Statistical scores were determined for the individual stages separately for both sexes. The data presented here can be utilized for forensic estimation of the minimum and most probable ages of investigated persons.

Studies in use of the Greulich-Pyle skeletal age method to assess criminal liability.

In recent years, skeletal age determination has become increasingly important for determining the age of live subjects as part of criminal investigation. The most widely used method worldwide to determine skeletal age is the Greulich-Pyle atlas method. The present study examines the suitability of the Greulich-Pyle method given the particular requirements of forensic age estimates. It is a retrospective analysis of 649 hand radiographs originally taken from persons aged between 1 and 18 years, separately for each sex. If the Greulich-Pyle method is used exclusively, it can be claimed with a probability of 95% that a young man has reached the age of 14 years and thus the age of criminal liability if his skeletal age is at least 15.5 years. In the case of female subjects, even if they are estimated as being 16.0 years old, it cannot be asserted with a probability of 95% that they have reached the age of 14. To reduce the margin of error of age estimates, determining the skeletal age should always go hand in hand with a physical examination to determine indications of sexual maturity and a dental examination to record dental status. The reference values given in the present study can be applied to members of all ethnic groups for age estimate purposes. If the person under examination has a different socio-economic status, the expert performing the age estimate should address this issue in his expert opinion and discuss the possible effects that might have on the age diagnosis.