Facial Soft Tissue Thickness Research Articles

2018 tallied facial soft tissue thicknesses for adults and sub-adults

The tallied facial soft tissue thicknesses (or T-Tables) represent grand means of published facial soft tissue thickness sample means. These sample means have been drawn from across the full-breadth of the facial soft tissue thickness (FSTT) literature, including forensic science, anthropology and odontology. The report of new summary statistics for >1290 new sub-adults and >2200 new adults since the last T-Table calculation, in 2008 for sub-adults and 2013 for adults respectively, makes their update timely. The maximum sample sizes at any landmark now stand at 3023 for individuals aged 0–11 years old (g–g′); 3145 for individuals aged 12–17 years old (n–se′); and 10,333 for adults (n–se′). Following the recalculation of grand weighted means and comparison to the original 2008 data, some shifts in the T-Table statistics are evident at specific landmarks, namely: 2–2.5mm increases at gonion (go–go′) and mid-mandibular border (mmb–mmb′) for adults; 3.5mm decrease at gonion (go–go′) for 12–17year olds; and 2.0mm decrease at menton (me–me′) for 0–11year olds. Differences at all other landmarks (91–100% depending on the dataset) were minimal being <1.0mm. Performance tests of the new grand means as point estimators (using individuals with known FSTT size from the C-Table), show the 2018 T-Table statistics to produce marginally less error than the 2013 means: 2018 standard error of the estimate=3.7mm in contrast to 2013 standard error of the estimate=3.9mm. The long run nature of the T-Table statistics (i.e., big data) and quantified performance test accuracies on known subjects, earmark the 2018 T-Table as the premier FSTT standard for craniofacial identification casework. In the distant future, this is likely to change as the C-Table raw data repository grows, allowing shorths and shormaxes to be calculated for large samples. Given current raw data repository sample sizes of 0–1574 for T-Table landmarks (notably lower for younger individuals), there is some way to go before enhanced central tendency estimators can entirely replace untrimmed arithmetic means.

DEVELOPING A UNIFIED FACIAL TISSUE THICKNESS MODEL FROM NEUROIMAGING DATA FOR SRI LANKA USING STATISTICAL ANALYSIS AND IMAGE PROCESSING TECHNIQUES

Facial soft tissue thickness (FSTT) is essential to forensic anthropologists for facial reconstruction- recreating a recognizable face from an unidentified skull and to plastic surgeons for treatment planning. Together with the age and sex of a person, the facial profile is related to facial soft tissue thickness, which is required for accurate facial reconstruction and recognition. Having such a facial profile in the national level is very important for a country since FSTT changes according to the geographical factors.&#x0D; In this paper we are presenting a review on literature associated with this topic describing the methods used for data collection, measuring FSTT and analyzing those values along with the method we are proposing to be followed in the research we are to conduct in the Sri Lankan context.

Facial Soft Tissue Thickness of Midline in an Iranian Sample: MRI Study.

Background and Aim:To identify human skeletal remains, different methods can be used and using these techniques, important data can be obtained. However, facial reconstruction is the last method to indentify unknown human faces which requires knowledge about facial soft tissue thickness in the different positions of the face. The present study determined the facial soft tissue thickness in the different landmark points on the MRI images of patients referred to Radiology Department of Shahid Madani Hospital.Materials and Methods:In this descriptive cross-sectional trial, MRI images of 179 patients (61 males, 118 females) in the age range of 18-76 years old who did not show any pathologic lesions, were selected. The measurements of the facial soft tissue were done on 12 landmark points on the midline area by two radiologist observers using specific software on the images. The differences in the soft tissue thickness in these landmark points were statistically analyzed by Mann-Whitney U (in term of gender) and Kruskal-Wallis tests (in terms of Body Mass Index [BMI] and age groups). P value less than 0.05 was considered statistically significant. The data were compared with the results of other studies.Results:The results obtained in the present study were higher than Turkish and American studies in most of the landmark points. Facial soft tissue thickness in most of the landmarks was more in males than females. In some of the landmarks, significant differences were found between emaciated, normal and overweight patients while in most cases, soft tissue thickness increased with the increased BMI. In some cases, significant differences were noted between soft tissue thickness values among the different age groups, in which the thickness increased or thinned with the increased age.Statistical Analysis:There were statistically significant associations between the presence and surface area of Haller cells and the occurrence of ipsilateral maxillary sinusitis. Neither the angulation of the uncinate process nor the size of the maxillary sinus ostium significantly correlates with the formation of maxillary sinusitis.Conclusion:The data achieved in the present study can be used for the facial reconstruction purposes in the Iranian population; however, the slight differences existing between the studied population and other subgroup races must be considered for accurate reconstructions.

Application of Enhanced Point Estimators to a Sample of In Vivo CT-derived Facial Soft Tissue Thicknesses.

Facial approximations based on facial soft tissue depth measurement tables often utilize the arithmetic mean as a central tendency estimator. Stephan et al. (J Forensic Sci 2013;58:1439) suggest that the shorth and 75-shormax statistics are better suited to describe the central tendency of non-normal soft tissue depth data, while also accommodating normal distributions. The shorth, 75-shormax, arithmetic mean, and other central tendency estimators were evaluated using a CT-derived facial soft tissue depth dataset. Differences between arithmetic mean and shorth mean for the tissue depths examined ranged from 0 mm to +2.3 mm (average 0.6 mm). Differences between the arithmetic mean plus one standard deviation (to approximate the same data points covered by the 75-shormax) and 75-shormax values ranged from -0.8 mm to +0.7 mm (average 0.2 mm). The results of this research suggest that few practical differences exist across the central tendency point estimators for the evaluated soft tissue depth dataset.

In vivo facial soft tissue depths of a modern adult population from Germany.

Forensic facial reconstruction may be the final option available to draw public attention in cases where the identity of an individual cannot be established by standard identification methods. Two fundamental components of all forensic facial reconstruction techniques are cranial morphology and soft tissue depth databases. The purpose of this study was to extend such databases by providing a complete set of accurate facial soft tissue thickness measurements, acquired from a contemporary adult population from Germany. The material for the study consisted of 320 (160 male, 160 female) anonymised multi-slice computerised tomography (MSCT) scans of individuals drawn from a German population. In Amira®, 3D models of the surfaces of the skull and the facial skin were semi-automatically segmented using calculated thresholds and surface extraction algorithms. Facial soft tissue depth was measured at 10 midline and 28 bilateral anatomical landmarks. The analysis of facial soft tissue thickness versus BMI, sex and age indicated that, at a number of the landmarks, facial soft tissue depth is significantly (p<0.05) influenced by all three biometric variables. Facial soft tissue thickness increased with increasing BMI. The differences between males and females were statistically significant (p<0.05) for almost all anatomical landmarks with the exception of a few in the region of the nasal root and orbitals. Asymmetry was noted at over half of the bilateral landmarks. The differences between the results from this sample and those obtained from comparable databases contradict the hypothesis that population specificity significantly influences facial soft tissue thickness.

Progress in Application of Measuring Skeleton by CT in Forensic Anthropology Research

Individual identification by measuring the human skeleton is an important research in the field of forensic anthropology. Computed tomography （CT） technology can provide high-resolution image of skeleton. Skeleton image can be reformed by software in the post-processing workstation. Different skeleton measurement indexes of anthropology, such as diameter, angle, area and volume, can be measured on section and reformative images. Measurement process is barely affected by human factors. This paper reviews the literatures at home and abroad about the application of measuring skeleton by CT in forensic anthropology research for individual identification in four aspects, including sex determination, height infer, facial soft tissue thickness measurement and age estimation. The major technology and the application of CT in forensic anthropology research are compared and discussed, respectively.

A Dense Statistical Model of Facial Soft Tissue Thickness

A Dense Statistical Model of Facial Soft Tissue Thickness

Facial Soft Tissue Depth Measurement: Validation of the 75-Shormax.

The shorth and 75-shormax were recently posited as an improved alternative to the arithmetic mean for describing facial soft tissue thicknesses in craniofacial identification. The shorth better estimates the data peak, while the 75-shormax provides improved provisions for a long right tail. When first proposed, the 75-shormax was subjectively gauged. Herein, shormax errors are calculated at every whole percentile to quantitatively determine zones of error minimization in two large samples: (a) CT data of French adults, n-range = 211-469 individuals; and (b) all C-Table data, n-range = 60-1065 individuals [including part but not all of sample (a)]. The smallest residuals were found at the 79th percentile (mean of raw residuals) and the 74th percentile (mean of absolute residuals). The 75-shormax is subsequently verified as good error minimizer since the absolute differences carry the greatest weight and the 74th percentile closely approximates the 75th percentile.

Densely calculated facial soft tissue thickness for craniofacial reconstruction in Chinese adults

Craniofacial reconstruction (CFR) is used to recreate a likeness of original facial appearance for an unidentified skull; this technique has been applied in both forensics and archeology. Many CFR techniques rely on the average facial soft tissue thickness (FSTT) of anatomical landmarks, related to ethnicity, age, sex, body mass index (BMI), etc. Previous studies typically employed FSTT at sparsely distributed anatomical landmarks, where different landmark definitions may affect the contrasting results. In the present study, a total of 90,198 one-to-one correspondence skull vertices are established on 171 head CT-scans and the FSTT of each corresponding vertex is calculated (hereafter referred to as densely calculated FSTT) for statistical analysis and CFR. Basic descriptive statistics (i.e., mean and standard deviation) for densely calculated FSTT are reported separately according to sex and age. Results show that 76.12% of overall vertices indicate that the FSTT is greater in males than females, with the exception of vertices around the zygoma, zygomatic arch and mid-lateral orbit. These sex-related significant differences are found at 55.12% of all vertices and the statistically age-related significant differences are depicted between the three age groups at a majority of all vertices (73.31% for males and 63.43% for females). Five non-overlapping categories are given and the descriptive statistics (i.e., mean, standard deviation, local standard deviation and percentage) are reported. Multiple appearances are produced using the densely calculated FSTT of various age and sex groups, and a quantitative assessment is provided to examine how relevant the choice of FSTT is to increasing the accuracy of CFR. In conclusion, this study provides a new perspective in understanding the distribution of FSTT and the construction of a new densely calculated FSTT database for craniofacial reconstruction.

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.

Forensic facial approximation assessment: can application of different average facial tissue depth data facilitate recognition and establish acceptable level of resemblance?

Facial soft tissue thicknesses (FSTT) are important guidelines for modeling faces from skull. Amid so many FSTT data, Forensic artists have to make a subjective choice of a dataset that best meets their needs. This study investigated the performance of four FSTT datasets in the recognition and resemblance of Brazilian living individuals and the performance of assessors in recognizing people, according to sex and knowledge on Human Anatomy and Forensic Dentistry. Sixteen manual facial approximations (FAs) were constructed using three-dimensional (3D) prototypes of skulls (targets). The American method was chosen for the construction of the faces. One hundred and twenty participants evaluated all FAs by means of recognition and resemblance tests. This study showed higher proportions of recognition by FAs conducted with FSTT data from cadavers compared with those conducted with medical imaging data. Targets were also considered more similar to FAs conducted with FSTT data from cadavers. Nose and face shape, respectively, were considered the most similar regions to targets. The sex of assessors (male and female) and the knowledge on Human Anatomy and Forensic Dentistry did not play a determinant role to reach greater recognition rates. It was possible to conclude that FSTT data obtained from imaging may not facilitate recognition and establish acceptable level of resemblance. Grouping FSTT data by regions of the face, as proposed in this paper, may contribute to more accurate FAs.

Facial soft tissue thickness database of Gujarati population for forensic craniofacial reconstruction

The forensic facial reconstruction is a scientific art to construct the ante-mortem face from the human skull. The facial recognition is made by reconstructing the contours of the facial soft tissue thickness (FSTT).These FSTT data are essential for probable face reconstruction but the data of FSTT at particular anthropological landmarks differ in various ethnic groups. Until now several works have been reported on different population but no study exists in which the FSTT of a Gujarati population has been measured. The aim of this study is to compile a set of soft tissue depth data of Gujarati population of India to add to existing literature on FSTT. Computed tomography (CT-scan) has been utilized to measure the 25 different FSTT landmarks of 324 male and 165 female. Present study shows significant differences in certain FSTT of Gujarati population from that of other populations. Our compiled data set of FSTT for the Gujarati population is important in understanding craniofacial characteristics of the Gujarati population and potentially be helpful in forensic identification.

Facial soft tissue thickness in a sample of Sudanese adults with different occlusions

Facial soft tissue thickness is essential to orthodontists and plastic surgeons for treatment planning, and to forensic anthropologists for facial reconstruction, a process combining science and art to recreate a recognizable face from an unidentified skull. The facial profile, together with the age and sex of a person, is related to facial soft tissue thickness, which is required for accurate facial reconstruction and recognition. Skeletal occlusions in orthodontics are classified according to the basic human facial profiles: straight, convex, and concave or skeletal class I, II, and III, respectively. In the present study, the facial soft tissue thickness of 233 Sudanese subjects (105 men and 128 women), ranging in age from 18 to 35 years, with different facial profiles at 20 landmarks was measured (10 soft tissue and 10 dentoskeletal).Sexual dimorphism was noted, with males having thicker facial soft tissue at all measured points. The facial soft tissue thickness varied among different occlusions. Individuals with skeletal class II occlusion had the thickest lower lip, and class III individuals had the thickest upper lip. In general, the Sudanese sample had a unique spectrum of measurements, with thick upper and lower lips, compared with African and Caucasoid subjects, pointing to the need for ethnic-specific data.

The study on facial soft tissue thickness using Han population in Xinjiang

Facial profile is an important aspect in physical anthropology, forensic science, and cosmetic research. Thus, facial soft tissue measurement technology plays a significant role in facial restoration. A considerable amount of work has investigated facial soft tissue thickness, which significantly varies according to gender, age, and race. However, only few studies have considered the nutritional status of the investigated individuals. Moreover, no sufficient research among Chinese ethnic groups, particularly Xinjiang population in China, is currently available. Hence, the current study investigated the adaptability of facial soft tissue to the underlying hard tissue among young adults of Han population in Xinjiang, China; the analysis was performed on the basis of gender, skeletal class, and body mass index (BMI). Measurements were obtained from the lateral cephalometric radiographs of 256 adults aged 18–26 years old. Differences in soft tissue thickness were observed between genders and among skeletal classes. With regard to gender, significant differences in soft tissue thickness were found at rhinion, glabella, subnasale, stomion, labrale superius, pogonion, and gnathion among different BMI groups. Thus, nutritional status should be considered when reconstructing an individual's facial profile. Results showed that the thinnest and thickest craniofacial soft tissues existed in rhinion and lip regions, respectively. Overall, this research provides valuable data for forensic facial reconstruction and identification of young adults in Xinjiang, China.

Repeatability of facial soft tissue thickness measurements for forensic facial reconstruction using X-ray images

The repeatability of facial soft tissue thickness measurements at 10 standard anatomical landmarks was evaluated using lateral X-ray images obtained from 50 adult subjects. The intra-and inter-observer error rates were calculated after four practitioners took measurements using Denta Pacs 8.1 software. The results indicated high inter- and intra-observer repeatability, suggesting X-ray images can be used to measure facial soft tissue thicknesses for the purpose of craniofacial reconstruction and superimposition.

Radiographic assessment of facial soft tissue thickness in South Indian population – An anthropologic study

Facial reconstruction is a technique used in forensic anthropology to identify an unknown person. Various methods used for facial reconstruction are drawings, sculpture and computer aided image building which is mainly based on facial soft tissue thickness measurement. Several methods have been established for measuring facial soft tissue thickness (FSTT) with each one having certain limitations. There is limited data available on FSTT among South Indian population. Hence the present study was ventured to determine the FSTT among South Indian adults and also to find FSTT difference between male and female.308 subjects of South Indian origin (18–27years) having full set of permanent dentition who require orthodontic treatment were included in the study. Subjects were assessed for Body Mass Index (BMI) and diagnostic digital x-ray of lateral cephalogram (LC), Lateral oblique (LO) view and posterior-anterior (PA) view was obtained. The digital image was transferred to Adobe Photoshop CS4 software and 23 different soft tissue points were measured.Mean FSTT was more in males compared to females except for three landmarks. Statistically significant difference was observed in 20 landmarks when height and weight was compared in males, whereas in females only 12 landmarks showed significant difference. BMI showed good correlation with FSTT in both males and females, which was confirmed by linear regression. The best regressor in terms of estimating FSTT in association with age/sex/BMI were nasion, sub nasale, labial superioris, labrale inferius, gnathion, inferior border of zygomatic, right and left gonion. Stepwise discriminant analysis using all variables showed 94.8% of overall accuracy in sex determination.The observation of present study suggests that LO and PA view along with LC gives information regarding mean FSTT among South Indian population. Even though BMI plays a dominant role in determining FSTT, but age, sex, height and weight should also be considered with care while facial reconstruction. Additionally the present regression equation contributes towards increase in the specificity of the tissue depths and can be used in real cases by allowing the practitioners to calculate individual tissue depth.

Facial soft tissue thicknesses in the present Czech Population

The aim of this study was to find any relation between soft facial tissue thickness (FSTT) and sex, age and asymmetry in the contemporary Czech population. The studied sample consisted of head CT scans of 102 adult Czech individuals between the ages of 21 and 83. Forty FSTTs were evaluated and analysed using PCA, Hotelling's T2 test, LDA, the Kolmogorov-Smirnov test, MANOVA, the Kruskal-Wallis test and Wilcoxon's paired test. The greatest sexual dimorphism was detected in the lower part of the face, which had discriminant power almost the same as the entire faces (approximately 80%). On the other hand, a significant influence of aging was shown, mostly in the area of the upper face (In females, twice as many landmarks displayed a significant influence, compared with males). The influence of asymmetry was confirmed in seven bilateral landmarks, five of them favouring the right side.

Age and sex-related variations in facial soft tissue thickness in a sample of Pakistani children

A facial soft tissue thickness (FST) database forms the backbone of different facial reconstruction methods. Various studies have identified age, sex and ethnicity as the core factors affecting the FST of an individual. The aims of this study were to explore the changes in FST occurring during the adolescent growth period and to develop the FST database for Pakistani children. The lateral cephalograms of 231 children, aged 9–18 years, were analysed and FST was determined at the 11 midline points. Subjects were divided into five age groups (9–10, 11–12, 13–14, 15–16 and 17–18 years) to evaluate age-related variations in FST. To compare FST between males and females and among different age groups, multivariate analysis of variance (MANOVA) was used. Moreover, the FST of Pakistani children was compared with those of Japanese and Canadian-Caucasoid children. Significant age-related variations in FST were present at four landmarks in boys and at six landmarks in girls. Marked ethnic differences in FST (>2 mm) were also observed at five landmarks in some of the age groups. These age-related and ethnic variations in FST warrant the use of data of appropriate age groups for a specific population for reliable outcome of facial reconstruction.

Flapless Postextraction Socket Implant Placement, Part 2: The Effects of Bone Grafting and Provisional Restoration on Peri-implant Soft Tissue Height and Thickness- A Retrospective Study.

This article presents the results of evaluating the changes in peri-implant soft tissue dimensions associated with immediate implant placement into anterior postextraction sockets for four treatment groups: no BGPR (no bone graft, no provisional restoration), PR (no bone graft, provisional restoration), BG (bone graft, no provisional restoration), and BGPR (bone graft, provisional restoration). The vertical distance of the peri-implant soft tissue was greater for grafted sites than for nongrafted ones (2.72 mm vs 2.29 mm, P < .06). The facial soft tissue thickness at the gingival third also was greater for grafted than for nongrafted sites (2.90 mm vs 2.28 mm, P < .008) and for sites with provisional restorations compared to sites without them (2.81 mm vs 2.37 mm, P < .06), respectively. The net gain in soft tissue height and thickness was about 1 mm. The increases in vertical and horizontal dimensions for grafted sites were between 0.5 and 1.0 mm, as compared to sites with no bone graft and no provisional restoration.

Facial soft tissue thickness among various vertical facial patterns in adult Pakistani subjects

Facial reconstruction techniques are used to obtain an approximation of an individual's appearance thus helping identification of unidentified decedents from their dried skeletal remains. Many of these techniques rely on the sets of average facial soft tissue thickness (FST) values at different anatomical landmarks provided by the previous studies. FST is influenced by the age, sex, ethnicity and the body mass index of the individual. Recent literature has shown that the anthropological variations of the skull may also affect FST at certain points. This study was designed to evaluate the effect of such variations in vertical skull morphology on FST as around one third of different population groups have either a long or short facial pattern as compared to the average facial pattern. Moreover, this study also provides a FST database for the adult Pakistani subjects that may have potential implications in the facial reconstruction of the local subjects.A retrospective analysis of 276 lateral cephalograms of adult subjects having normal sagittal facial pattern was performed. Subjects were categorized into three vertical facial patterns (long face=95, average face=102, short face=79) according to the vertical dimensions of the skull and the FST was measured at 11 midline points. To compare the FST between males and females Mann-Whitney U test was used. Kruskal-Wallis test was applied to compare FST among three vertical facial patterns. The results of our study revealed significant differences in FST at nine landmarks between males and females. These sex-based differences were more pronounced in the long and short facial patterns as compared to the average facial pattern. FST at stomion, pogonion, gnathion and menton was significantly greater in the short facial pattern as compared to the long facial pattern in both the sexes. The results of the present study highlight the importance of anthropological analysis of the skull and taking the vertical skeletal dimension into consideration while performing facial reconstruction.