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.

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.

The effect of range and ammunition type on fracture patterns in porcine postcranial flat bones.

Pig half-carcasses were shot in scapulae, ribs and mandibles with either 0.243 hunting rifle using high velocity expanding ammunition (N = 30) or AK47 using full metal jacketed (FMJ) ammunition (N = 12) from a range of either 5 or 20 m. Fracture patterns related to distance of fire and ammunition type were compared on de-fleshed, macerated, and reconstructed bones. For expanding ammunition, location of fracture on ribs affected the resulting pattern. Scapulae shot from 5 m presented a comminuted pattern different from those shot from 20 m. Mandibles shot from 20 m showed a characteristic radiating pattern at entrance with the opposite ramus un-fractured; those shot from 5 m exhibited fractures to both rami. Using decision tree analysis provided accuracies of 93.8% for scapulae and 87.5% for mandibles. For FMJ, no distance dependent fracture differences were apparent in any bone. Decision tree analysis facilitated the interpretation of fracture patterns caused by projectile trauma.

Comparison of three-dimensional facial morphology between upright and supine positions employing three-dimensional scanner from live subjects.

Facial soft tissue thicknesses (FSTT) measurements collected from Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) imaging techniques are most commonly taken in the supine position for forensic craniofacial reconstruction. FSTT have been shown to be different in comparison to the upright position due to gravity. The variation of facial morphology between the upright and supine position of laser-scanned images taken from 44 individuals was investigated using volumetric analysis with deviation maps. Between 82.4% and 86.7% of the facial surface area were within the error range of ±2mm between the supine and the upright position. This indicates that most anatomical landmarks taken from the MRI and CT data can be an accurate representative of the FSTT in the upright position. Seven landmarks located around the buccal region, masseteric region and the nasolabial region of the face showed the greatest FSTT deviation between the upright and supine position, thus these landmarks may affect the accuracy of facial reconstructions when using a CT or MRI database.

Turning the tables of sex distinction in craniofacial identification: Why females possess thicker facial soft tissues than males, not vice versa.

Males are universally reported to possess larger facial soft-tissue thickness (FSTT) than females, however, this observation oversimplifies the raw data yielding an underpowered assessment of FSTT sex-patterning where: differences are small (η(2) < 5%) and inconsistent (females are routinely larger than males at the cheeks). Here we investigate body-size normalized data to assess whether more general and improved understanding of FSTT sex-variation in humans is possible. FSTTs were measured in 52 healthy living Australians aged 18 to 30 years using B-mode ultrasound. Participants' stature and body mass were also measured. Sex differences were calculated before and after normalization by the aforementioned body-composition variables. Methods were repeated in three other independent samples to evaluate reproducibility: 100 American Whites and 60 American Blacks measured by B-mode ultrasound; and 50 Turkish residents measured by regular supine CT. Compared to raw mean differences (F < M, by -6%), females displayed much thicker FSTTs than males when normalized for body mass (F > M, by +16%). Consequently, while the sexes share similar raw values, females possess much larger FSTTs for their relatively lighter bodies. The relative FSTT difference was 2.7× larger than the raw mean difference. Sex differences in FSTT are of larger magnitude and reversed direction in mass normalized data. Contrary to popular thought, females possess much larger FSTTs than males owing to their generically lighter bodies (-18 kg). These data patterns help explain why the pooling of sex-categorized FSTT does not jeopardize the sex-difference-it is encoded more strongly in terms relative to body mass.

Sexual dimorphism in frontal bone roundness quantified by a novel 3D-based and landmark-free method.

In this study we present a novel and landmark-free method for quantifying shape differences between male and female frontal bones. CT scans were recorded for 80 male and 80 female Turkish hospital patients, age 25-40. The frontal bones were first isolated from the 3D models by digital cutting along the bordering sutures, and then aligned to a CAD-based sphere. This allowed us to quantify the amount of frontal bone overlapping with the sphere (on average 43.2 ± 6.5% for males and 33.9 ± 6.6% for females, the difference is significant at p<0.0001), and to identify areas of shape difference and deviation from the sphere surface in male and female bones. The larger proportion of spherical frontal bone surface in males challenges the common description of the female forehead as "rounder". Based on the overlap data, we developed discriminant functions able to correctly classify 77.5% of the frontal bone models as male/female. This demonstrates that 3D-based and landmark-free approaches to statistical shape analysis may become a viable alternative to the currently dominating landmark-based approaches for shape investigation.

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.

Facial soft tissue thickness database for craniofacial reconstruction in the Turkish adult population.

320 Turkish adults (160 men, 160 women) who had undergone brain CT in the radiology clinic and showed no sign of maxillofacial pathology were analyzed in order to create a facial soft-tissue thickness database of the Turkish adult population. The soft-tissue thicknesses were measured at 31 landmarks, 10 midline and 21 bilateral anatomical landmarks. Average thickness values for each landmark as well as the standard deviation and range classified according to gender and age are reported. The differences of these mean values related to age and sexes were calculated. The values were then statistically compared to the findings of the European and Korean adults. Overall, the soft-tissue thickness measurements obtained in this study can be used as a database for the forensic craniofacial reconstruction of Turkish adult faces.

Non-operative management (NOM) of blunt hepatic trauma: 80 cases.

BACKGROUND: Liver is the most frequently injured organ upon abdominal trauma. We present a group of patients with blunt hepatic trauma who were managed without any invasive diagnostic tools and/or surgical intervention. METHODS: A total of 80 patients with blunt liver injury who were hospitalized to the general surgery clinic or other clinics due to the concomitant injuries were followed non-operatively. The normally distributed numeric variables were evaluated by Student's t-test or one way analysis of variance, while non-normally distributed variables were analyzed by Mann-Whitney U-test or Kruskal-Wallis variance analysis. Chi-square test was also employed for the comparison of categorical variables. Statistical significance was assumed for p<0.05. RESULTS: There was no significant relationship between patients' Hgb level and liver injury grade, outcome, and mechanism of injury. Also, there was no statistical relationship between liver injury grade, outcome, and mechanism of injury and ALT levels as well as AST level. There was no mortality in any of the patients. CONCLUSION: During the last quarter of century, changes in the diagnosis and treatment of liver injury were associated with increased survival. NOM of liver injury in patients with stable hemodynamics and hepatic trauma seems to be the gold standard.

Factors affecting hypocalcaemia following total thyroidectomy: a prospective study.

OBJECTIVE: After thyroidectomy hypocalcaemia is the most significant complication for clinicians. In this study, we investigated the factors associated with development of hypocalcaemia after thyroidectomy. MATERIALS AND METHODS: We investigated the patients prospectively for age, gender, preoperative diagnosis, hormonal status, operative time, operating surgeon, existence of parathyroid gland injury at the operation, parathyroid gland auto-transplantation, preoperative use of anti-thyroid drugs and amount of bleeding at the operation. After operation in 1 and 2 days, serum calcium and phosphor, and in the 1 day parathyroid hormone values were evaluated. The chi-square test was applied in the analysis of categorical variables. Logistic regression model was used to determine the risk of hypocalcaemia in the univariate analysis. RESULTS: Hypocalcaemia developed in 47 of 196 patients. Female gender, preoperative diagnosis of thyroid cancer and toxic nodular goitre, <3cm nodule size, parathyroid injury and auto-transplantation and low vitamin D levels were factors found to be associated with hypocalcaemia in the Logistic regression analysis. CONCLUSION: The factors associated with hypocalcaemia were defined to be "gender, preoperative diagnosis, parathyroid gland injury, nodule size and vitamin D deficiency", it is a multifactorial problem and it would not be proper to define a few etiological factors.