Dilemma of Gonial Angle in Sex Determination: Sexually Dimorphic or Not?

BACKGROUND AND AIM: The determination of sex from human remains has a crucial role in forensic anthropology. It has been known that the mandible has several useful traits for sex determination. The gonial angle, which is one of them, has been evaluated by forensic practitioners to identify sexual dimorphism with morphologic and metrical analyses. However, there are opposing approaches on the sexual dimorphism of the gonial angle in the literature, which contradict each other. There are also some other studies asserting that it cannot be employed in sex determination. The purpose of this study is first to figure out the reason for this dilemma and then establish the significance of the gonial angle in sex determination in a white sample. METHODS: Computed tomography scans were obtained from 300 adults (150 males and 150 females), which were divided into 3 age groups (20-39, 40-59, 60-80 years). The gonial angle, which is formed by 2 lines: (1) between the most posterior point of the mandibular condyle and the gonion and (2) between the most inferior point of the mandibular symphysis and gonion, was measured on computed tomography scans. In order to observe differences among the 3 age groups, the collected data were analyzed using 1-way analysis of variance followed by a least significant difference post hoc test. Two-way analysis of variance was used to compare sex differences in each age group. DISCUSSION: It is suggested that the probable reason of this dilemma is the unsubtle samples of the researches. Categorizing the sample into age groups with statistically sufficient number makes the data more valuable in terms of examining the differences related to sexual dimorphism. This study also reported that males showed slightly smaller gonial angle values than those of females in all age groups. No statistically significant difference was observed in the gonial anthropometric values for middle age groups (20-39 and 40-59 years), whereas it shows statistically sexual dimorphism for senior adult group (60-80 years). However, the results revealed that the gonial angle is not a particularly good indicator to identify the sex from the cranium and should not be used as a sole criterion.

Prediction of nasal morphology in facial reconstruction: Validation and recalibration of the Rynn method.

BACKGROUND: Prediction of the nose from the skull remains an important issue in forensic facial approximation. In 2010, Rynn et al. published a method of predicting nose projection from the skull. With this method, three craniometric measurements (x, y, z) are taken, and these are then used in regression formulae to estimate the nasal dimensions. AIM: The purpose of this study was to examine and test the accuracy of the Rynn et al. method and if necessary to adapt the formulae for this population. SUBJECTS AND METHODS: A sample of 90 CT scans of Turkish adults was used in the study. The actual and predicted dimensions were compared using t-test. The age of the individuals ranged from 20 to 40 years by sex. RESULTS: The descriptive statistics and correlations were calculated, and the actual and predicted measurements were compared. The differences between the actual and predicted values were statistically significant (p < 0.01), with -1 mm for males and -1.5 mm for females. Validation accuracies ranged from 76 to 92% in females and 72 to 82% in males. Recalibration equation accuracies ranged from 88 to 100% in females and 90 to 100% in males. CONCLUSION: The results showed that the recalibration of the Rynn et al. method and its formulae gave satisfactory results with less error and can be employed in facial approximation cases.

Variations of midline facial soft tissue thicknesses among three skeletal classes in Central Anatolian adults.

Facial reconstruction is a technique employed in a forensic investigation as a last resort to recreate an individual's facial appearance from his/her skull. Forensic anthropologists or artists use facial soft tissue thickness (FSTT) measurements as a guide in facial reconstructions. The aim of this study was to develop FSTT values for Central Anatolian adults, taking into consideration sex and skeletal classes; first, to achieve better results obtaining the likenesses of deceased individuals in two or three-dimensional forensic facial reconstructions and, second, to compare these values to existing databases. Lateral cephalograms were used to determine FSTT values at 10 midline facial landmarks of 167 adults. Descriptive statistics were calculated for these facial soft tissue thickness values, and these values were compared to those reported in two other comparable databases. The majority of the landmarks showed sex-based differences. Males were found to have significantly larger landmark values than female subjects. These results point not only to the necessity to present data in accordance with sexual dimorphism, but also the need to consider that individuals from different geographical areas have unique facial features and that, as a result, geographical population-specific FSTT values are required.

Comparison of Toxocara eggs in hair and faecal samples from owned dogs and cats collected in Ankara, Turkey.

This study was undertaken to determine the prevalence of Toxocara eggs on hair and in faeces of healthy owned cats and dogs and to make comparisons between data (sex, age, host factor, etc.) collected from dogs and cats. Toxocara eggs were found on the hair of 14% of 100 dogs and 22% of 100 cats. In total, 58 and 136 eggs were recovered from the hair samples of examined cats and dogs, respectively. Of the total number of eggs, 2 were classified as embryonated in cats. One of the eggs recovered was embryonating in dogs. The maximum number of eggs was found in the tail bottom of cats (28 eggs) and dogs (58 eggs). As well as finding Toxocara eggs in dogs and cats hair, we also found eggs of some helminthic parasites; such as Dicrocoelium sp., Fasciola sp., Taenia sp., Dipylidium caninum and Toxascaris leonina. In addition, faecal samples of same dogs and cats were also examined by two techniques (centrifugal flotation and sedimentation): Toxocara eggs were found in 5% and 13% of dogs and cats faeces, respectively. But, 14% of the dogs and 22% of the cats were positive for Toxocara eggs on hair. The prevalence of eggs in faecal samples was lower than those detected from hair samples (P < 0.05). Two techniques for recovering Toxocara eggs from faecal samples were tested for efficiency and suitability for routine use. The results were expressed as the percentage rate of recovery of Toxocara eggs in positive faecal samples. The recovery rate was better with the method of sedimentation than with the method of flotation (P < 0.05). This study indicates that dogs and cats without internal infections were shown to have eggs on their hair and so uninfected animals also pose a threat in terms of the eggs present on their hair, albeit a small risk.

Seroprevalence of Neospora caninum and coexistence with Toxoplasma gondii in dogs.

Neospora caninum is a protozoal agent causing abortion and infertility problems in dairy cattle. The objective of the present study was to detect the seroprevalence of N.caninum in dogs and its co-existence with Toxoplasma gondii in some rural and urban regions of Kirikka-le province. A total of 121 blood samples were examined with indirect immunoflorescent antibody test to detect the presence of N.caninum IgG antibodies. The seropositivity of N.caninum was 28.9% in dogs. The seropositivity rate was higher in male dogs than that of females (p < 0.05). The seropositivity rate of N.caninum was 36.5% and 20.7% for pure breed and mongrel dogs, respectively (p > 0.05). There was no significant difference amongst the age groups and location of the dogs (rural or urban) (p > 0.05). The N.caninum positive serum samples were also examined for the presence of antibodies for T.gondii by Sabin-Feldman Dye test in order to identify the possible serological co-infection, 1/16 and higher titres were evaluated as positive. According to test results, 19 out of 35 N.caninum seropositive dogs (54.3%) showed T.gondii seropositivity.