Part Of Face Research Articles

Insights into The Prenatal and Postnatal Knowledge & Critical Observations of Parents with Children who Have Down Syndrome: A Single Center Study

Introduction: Down syndrome (DS) is one of the many genetic syndromes commonly confronted by pediatricians. These people commonly share a few features which include a low level of muscle tone (hypotonia), learning disabilities, and abnormalities of the cranium and facial parts. Aims and Objectives: To assess the pre and postnatal knowledge, of parents with Down syndrome children. Place and Duration of study: This descriptive cross-sectional study was conducted in Shifa International Hospital (SIH), by Final year medical students, in association with the Cytogenetics Department. between December 2019 to September 2021 Material and Methods: All the chidren diagnosed with Down Syndrome at the SIH and their parents were invited to participate in our study. Convenience sampling was used depending solely on the number of parents who had accepted our invitation. A total sample size of 35 was included, of which 15 agreed to participate. A detailed questionnaire having both close ended and open questions in English and Urdu was filled out by those parents who consented. Data was entered and analysed using SPSS version 24.0. pvalue ?0.05 was taken as significant. Results: Our results showed that 11 of the 15 DS children i.e., 73.3% were male and 4 out of 15 i.e., 26.6% were females. None of these children had siblings with the same disorder. 13 of the 15 cases (86.6%) were diagnosed post- natally only 2 cases (13.3%) pre-natally. All the cases i.e., 100% were diagnosed by a pediatrician and none were diagnosed by an obstetrician. Surprisingly increasing age of either parent seemed to increase the incidence of DS offspring. 60.0% (9 of the 15) of parents did not know the condition could be diagnosed prenatally. While 10 of 15 (66.6%) of them were aware of its general complications. Answering open ended questions parents identified the lack of awareness, special educational institutes, and presence of communication gap between them and doctors as some of the factors that hindered the welfare of DS children. Conclusion: Only one parent knew about DS complications pre-natally and only a few were aware that a pre-natal diagnosis could be formed. Postnatal knowledge of parents was sketchy also, especially regarding the future complications faced by DS children, Parents critically observed insufficient public awareness, societal taboos, paucity of local DS data and prenatal medical DS training, and consequently lack of govermnnental support required by special needs DS children in our country.

FACE DETECTION SYSTEM USING CONVOLUTIONAL NEURAL NETWORKS: A REVIEW

Implementing a facial recognition system can help in identifying or verifying the identity of a person from a digital image. Accurate attendance records are critical to classroom assessment. However, manual attendance tracking can lead to errors, missed students, or duplicate records. The facial recognition attendance system includes facial recognition technology that recognizes and verifies an employee's facial features and automatically records attendance. The facial liveliness detection part is based on CNN, which creates a 3D model of the detected face to distinguish between real and fake images. The attendance system is written in Python and the user interface is designed using the WebView library. The main goal of facial recognition is to identify individuals, either individually or collectively. The number of positive faces may vary depending on the technology used for face recognition. Keywords: Face Recognition Attendance System, CNN Algorithm.

A novel large intragenic DPYD deletion causing dihydropyrimidine dehydrogenase deficiency: a case report

BackgroundDihydropyrimidine dehydrogenase (DPD), is the initial and rate-limiting enzyme in the catabolic pathway of pyrimidines. Deleterious variants in the DPYD gene cause DPD deficiency, a rare autosomal recessive disorder. The clinical spectrum of affected individuals is wide ranging from asymptomatic to severely affected patients presenting with intellectual disability, motor retardation, developmental delay and seizures. DPD is also important as the main enzyme in the catabolism of 5-fluorouracil (5-FU) which is extensively used as a chemotherapeutic agent. Even in the absence of clinical symptoms, individuals with either complete or partial DPD deficiency face a high risk of severe and even fatal fluoropyrimidine-associated toxicity. The identification of causative genetic variants in DPYD is therefore gaining increasing attention due to their potential use as predictive markers of fluoropyrimidine toxicity.MethodsA male infant patient displaying biochemical features of DPD deficiency was investigated by clinical exome sequencing. Bioinformatics tools were used for data analysis and results were confirmed by MLPA and Sanger sequencing.ResultsA novel intragenic deletion of 71.2 kb in the DPYD gene was identified in homozygosity. The deletion, DPYD(NM_000110.4):c.850 + 23455_1128 + 8811del, eliminates exons 9 and 10 and may have resulted from a non-homologous end-joining event, as suggested by in silico analysis.ConclusionsThe study expands the spectrum of DPYD variants associated with DPD deficiency. Furthermore, it raises the concern that patients at risk for fluoropyrimidine toxicity due to DPYD deletions could be missed during pre-treatment genetic testing for the currently recommended single nucleotide polymorphisms.

A randomised investigation of film-forming silicone gel in superficial partial thickness face and neck burn patients: Indication of improved early scar pigmentation outcomes

IntroductionBurns to the face and neck are a source of considerable distress and a challenge to manage with dressings. Further, these often superficial injuries pose a risk of scarring and altered pigmentation. Silicone gels have emerged as a potential solution to the challenges of conservative management for face and neck burn injuries. The aims of this study were to explore the effect of topical silicone compared to routine treatment of conservatively managed burns to the face and neck. MethodsThis single-blind, randomised, controlled trial compared topical silicone film-forming dressing to standard of care for superficial partial thickness burns to the face and neck. Time to healing was the primary outcome and secondary outcomes included: 1) scar assessments (modified Vancouver Scar Scale, Dermalab Combo and Patient and Observer Scar Assessment Scale) at six weeks and three months; and 2) pain intensity scale at wound review appointments. ResultsOf the 55 participants in the face/neck study, 34 were male and 21 were female. Median age was 36 years (range from 25 to 47 years). The median time to healing for the silicone group was 9 days (CI 7.6 −10.4) and the control group was 7 days (CI 5.3- 8.7), p = 0.056. Analysis demonstrated significantly reduced pigmentation at six weeks in mVSS scores for the silicone group (Md = 0, IQR = 0) compared to the control group (Md = 0, IQR = 0 – 3), p = 0.043. We found no evidence of differences in reported pain between the groups (Silicone - Md = 1.15, IQR 0.3 – 4.5 vs control group - Md = 1.5, IQR 0.6 – 3.8, z = −0.63, p = 0.53). No other differences were observed, and no adverse events were associated with the topical silicone in the study whereas an infection and a reaction were experienced in the control group. ConclusionFilm-forming silicone gel had comparable effects to standard of care emollient on wound healing of superficial partial thickness burns of the face and neck. Silicone treated wounds were associated with a significant improvement in scar pigmentation outcome at six weeks post-burn.

One level deep convolutional neural network for facial key points detection

Facial landmark detection has a lot of applications in face recognition, face alignment, facial expression recognition, video surveillance and security systems. In the existing literature, there are multiple methods utilizing convolutional neural networks (CNNs) that address this problem in various ways. In many cases, the models use a tree-like structure of CNNs to achieve better results. This paper proposes a combination of three parallel deep convolutional neural networks (DCNNs) to estimate the accurate localization of each keypoint. The first one focuses on the whole face to outperform five points, including the eyes, nose, and mouth corners. The second one focuses on the eyes-nose parts to outperform three points, specifically the eyes and nose. The last one focuses on the nose-mouth parts to outperform three points, namely the nose and mouth corners. Further, we combine all outputs of the three DCNNs and take the average value of each detected key point as the final output. In the first step, we improvthe the parameter efficiency and accuracy of each DCNNs through a set of experiments using the labeled face parts in-the-wild database (LFPW) and the helen facial feature dataset (Helen). Then, we demonstrate that our approach yields more accurate estimations of facial key points than two state-of-the-art methods and commercial software in terms of accuracy.

Analysis of the influence of dies geometry on the process extrusion force and properties of the extrudate obtained in the process of cold extrusion of 7075 aluminum alloy by the KOBO method

Abstract The KOBO extrusion process is an unconventional method of extrusion based on the phenomenon of superplasticity as an effect of a special state caused by the oscillatory motion of the die at a certain angle a certain frequency. It significantly lowers the extrusion force and makes it possible to extrude lightweight metals and alloys (e.g. aluminum and magnesium alloys) in cold extrusion with high extrusion ratios compared to conventional hot extrusion. This work studies the influence of the tool (die) geometry on process realization parameters and the properties of the extrudate. Experimental studies of cold KOBO extrusion were performed using dies with different face portion geometry. The obtained extrudate obtained from EN-AW 7075 aluminum billets was examined for mechanical properties and macro/microstructure, showing that, with adequate modifications to the tool face part geometry, it is possible to lower the extrusion force and obtain extrudate with desired properties.

ОПРЕДЕЛЕНИЕ ПРОТЕТИЧЕСКОЙ ПЛОСКОСТИ В КЛИНИКЕ ОРТОПЕДИЧЕСКОЙ СТОМАТОЛОГИИ (ОБЗОР ЛИТЕРАТУРЫ)

Positioning of the lower jaw in three mutually perpendicular planes – sagittal, frontal and transversal – significantly affects the position of the occlusal plane. Finding the occlusal plane is an important criterion for the success of planning and implementing dentures. The review presents analogue and digital methods for personalized identification and construction of the occlusal plane in the process of dental orthopedic rehabilitation.
 Objectives. The goal is to study known methods for constructing a personalized prosthetic plane using analog and digital methods.
 Methodology. An analysis of the scientific literature devoted to analog and digital methods for constructing a personalized prosthetic plane for dental orthopedic rehabilitation was carried out.
 Results. During orthopedic dental rehabilitation of patients with complete absence of teeth, one of the most important stages in the manufacture of removable dentures is the determination of the prosthetic plane. The quality of prosthetics in both aesthetic and functional aspects will depend on the accuracy of the determination. The shape and position of the occlusal plane depends on many factors: the shape of the head, the type of growth of the facial part of the skull, heredity, race. The scientific literature reflects various methods for orienting the occlusal plane in the facial part of the skull, and the authors used both cephalometric indicators and anatomical structures as reference points.
 Conclusions. Determining the prosthetic plane with the help of digital technologies makes it possible to fully achieve a guaranteed and predictable result of the entire treatment, therefore, today they are relevant, and in the future they will become the method of choice.

Robust partial face recognition using multi-label attributes

Partial face recognition (PFR) is challenging as the appearance of the face changes significantly with occlusion. In particular, these occlusions can be due to any item and may appear in any position that seriously hinders the extraction of discriminative features. Existing methods deal with PFR either by training a deep model with existing face databases containing limited occlusion types or by extracting un-occluded features directly from face regions without occlusions. Limited training data (i.e., occlusion type and diversity) can not cover the real-occlusion situations, and thus training-based methods can not learn occlusion robust discriminative features. The performance of occlusion region-based method is bounded by occlusion detection. Different from limited training data and occlusion region-based methods, we propose to use multi-label attributes for Partial Face Recognition (Attr4PFR). A novel data augmentation is proposed to solve limited training data and generate occlusion attributes. Apart from occlusion attributes, we also include soft biometric attributes and semantic attributes to explore more rich attributes to combat the loss caused by occlusions. To train our Attr4PFR, we propose an implicit attributes loss combined with a softmax loss to enforce Attr4PFR to learn discriminative features. As multi-label attributes are our auxiliary signal in the training phase, we do not need them in the inference. Extensive experiments on public benchmark AR and IJB-C databases show our method is 3% and 2.3% improvement compared to the state-of-the-art.

Morphometric features of the human parotid salivary gland depending on the shape of the skull according to radiation research methods

BACKGROUND: Intravital study of the parotid salivary gland individual characteristics using radiation research methods can be used by clinicians for more accurate diagnosis and planning of surgical treatment of the parotid salivary gland diseases.
 AIM: Study of the parotid salivary glands’ morphometric parameters in people with different shapes of the facial and cerebral skull using radiation research methods.
 MATERIAL AND METHODS: An analysis of the database of studies performed using magnetic resonance and computed tomography of 120 patients of different ages was carried out. Based on computed tomography data, cranial diameters were measured and cranial indices were calculated, according to which the studied material was divided into groups depending on the shape of the facial (leptena, mesena, eurienae) and cerebral (brachycranes, dolichocranes and mesocranes) parts of the skull. Based on magnetic resonance imaging data of the same patients, the morphometric parameters of the parotid salivary glands were analyzed in three planes. Groups were compared using the Kruskal–Wallis method, followed by pairwise comparisons using the Mann–Whitney method with the Bonferroni correction.
 RESULTS: In the leptene group, the frontal size of the gland was statistically significantly smaller compared to similar sizes in the group of euriens (right p 0.0001, left p 0.0001) and mesenes (right p=0.0057, left p=0.012). The sagittal size of the gland was statistically significantly different between the brachy-, meso- and dolichocranial groups (p 0.0001 on the right and left). A significant tendency was revealed for a decrease in the sagittal size of the parotid salivary glands from 4.27 (3.77; 4.66) cm (right) and 4 (3.8; 4.6) cm (left) in dolichocraniform individuals to 3.57 (3.22; 3.86) cm (right) and 3.37 (3.16; 3.99) cm (left) in individuals with a brachiocranial skull shape. When measuring the frontal size in people with different skull shapes, a statistically significant difference in gland thickness between groups was found (p 0.0001 on the right and left).
 CONCLUSION: In people with different forms of the facial skull, there is a difference in the vertical and frontal sizes of the parotid salivary glands, and with different forms of the brain skull, there is a difference in the sagittal and frontal sizes of the glands.

Evaluation of the color stability of three maxillofacial silicone materials after exposure to beverages: An in vitro study

PurposeOral cancer often requires treatments like surgical intervention, involving surgical resection of lips and other facial parts. For those patients, prosthetic rehabilitation following surgery promotes social reintegration. This study explores the color stability of various commercially available silicone materials for facial prostheses when exposed to everyday beverages like coffee and tea. The hypothesis is that these beverages can induce color changes in silicones, simulating conditions of daily use. Material and methodsA total of 90 specimens were fabricated. There were 30 specimens deefor each of 3 nonpigmented silicone elastomers: Silfy, A-2186-F and VST-50 and were immersed in tea or coffee at drinking temperature and evaluated for color changes at time points of 0 h, 1 h, and 6 h. The color was measured with a colorimeter that used the CIE L*a*b* system and the color change ΔΕ was calculated to quantify the color change. Statistical analysis was performed by using the Kruskal-Wallis test, the Mann-Whitney U test, and the Wilcoxon signed-rank Test. The threshold for statistical significance was P < .05. ResultsColor change was observed for each of the silicones exposed to the beverages (P < .05). The value of ΔE was significantly higher for A-2186-F compared with VST-50 and Silfy (P < .05 in all beverages at 6 h). The color of the elastomers progressively changed while immersed in the beverages over 6 h. The change in color was significantly greater for coffee compared with tea (P < .05). ConclusionsThe color stability of nonpigmented silicone elastomers is inherently low, which contributes to the overall color change of silicone prostheses when they are exposed to beverages that contain pigments. The elastomer A-2186-F had greatest values of ΔE among the materials tested. Color changes of silicone prostheses can be lessened by selecting materials with consideration of color stability to improve their longevity and extend their period of use.

ONTOGENETIC TRANSFORMATIONS OF THE FACIAL RUDIMENTS OF THE SKULL BONES IN THE FIRST TRIMESTER OF PRENATAL HUMAN ONTOGENESIS

The purpose of the research – to clarify the sources and terms of the rudiments, to findout the age-specific dynamics of changes and features of the morphogenesis of the bonesof the facial part of the skull in the first trimester of intrauterine development (IUD).Material and methods. Serial microspecimens of 20 embryos (4.0-13.5 mm parietalcoccygeal length (PCL)) and 25 prefetuses (14.0-80 mm PCL) covering the period fromthe 4th to the 12th weeks of the IUD were studied. A complex of methods of morphologicalresearch is applied: creation of series of consecutive histological sections, microscopy,morphometry, three- dimensional reconstruction.The results. The rudiments of the bones of the facial part of the skull are the mesenchyme ofthe five facial outgrowths of 4-week-old human embryos. The rudiment of the anterior partof the ectomeningeal capsule has a neuroectodermal origin, and its outer layer forms thesplanchnocranium – the rudiments of the frontal, zygomatic, nasal, lacrimal bones, vomer,and jaws. In 5-week-old embryos, the process of fusion of the frontal process, the medialand lateral nasal processes of maxillar process and mandibular process of the I branchialarch and the hyoid branchial arch begins, resulting in the formation of nasal pits and the primary nasal cavity. In 6-week-old embryos, the rudiments of the mandible are formed.During the 7-8th week of IUD, the cartilaginous rudiment of the skull becomes a continuousstructure. The mesenchyme of the mandibular branchial arch is the source of the developmentof the frontal, lacrimal, nasal bones, vomer, and premaxillary part of the maxilla. The sourcesof development of the maxilla and zygomatic bone are the mesenchyme of the maxillaryprocess of the I branchial arch, while the mandible and the tympanic part of the temporal boneare formed from the mesenchyme of the mandibular process of this branchial arch.Conclusions. Violation of the proliferation of processes of the I branchial arch, theirconsolidation and transformation of the branchial apparatus at the end of the embryonic period(5-6th week of IUD) can lead to the appearance of severe congenital defects of the face. Also,the 7th and 10th weeks of IUD are critical periods of the morphogenesis of the rudiments of thehuman skull, the time of the possible appearance of variants of the structure or birth defects.

Holistic Processing of Recognition Memory for Face Identity: Evidence from a Face Morphing Paradigm

AbstractHolistic face processing refers to a tendency to see face parts as a whole. This study examined whether and how holistic processing affects recognition memory for face identity in a learned/novel morphing continuum. In the study phase of each experiment reported here, adult participants were asked to memorize (i.e., learn) a set of unfamiliar face images by viewing them once or twice. In the test phase, the participants were presented with face images morphed from learned and novel ones and were asked to report whether they viewed the face in the study phase. In Experiment 1, we demonstrated that our morphing paradigm can capture memory selectivity changes (i.e., recognition boundary and sensitivity) associated with learned face identity. In Experiment 2, we demonstrated that whole‐face presentations improved sensitivity to learned/novel face identity, but did not alter the recognition boundary between learned and novel face identity. These results support the view that holistic processing contributes to accurate face identification in recognition memory, even under minimal learning situations.

Examining infantile facial features and their influence on caretaking behaviors in free-ranging Japanese macaques (Macaca fuscata).

Facial features of immature individuals play a pivotal role in eliciting caretaking behaviors in humans. It has been posited that non-human animals share particular infantile facial features with humans, which can elicit caregivers' attention and caretaking behaviors. Nevertheless, the empirical examination of this hypothesis is extremely limited. In this study, we investigated infantile facial features in Japanese macaques (Macaca fuscata), their developmental processes, and their correlation with caretaking and infant behaviors, based on 470 facial photographs from one free-ranging group. We measured the size of facial parts and evaluated these features using non-contact procedures with the animals. The results indicated that, although some partial species differences were observed, the infantile facial features in Japanese macaques were broadly consistent with those previously observed in humans and great apes. Furthermore, half of the infant subjects displayed non-linear developmental trajectories of infantile faces, similar to those suggested in humans. However, unlike previous studies in humans, infantile faces were not significantly associated with maternal or non-maternal caretaking behaviors, nor were their developmental changes correlated with infant behavioral development. These findings indicate that while many aspects of infantile facial features are shared among particular primates, humans may have evolved a uniquely elevated preference for selecting such features among the primate lineage.

Family of recognition algorithms based on the selection of two-dimensional representative pseudo-objects in the training set

Recognizing objects within large-dimensional feature spaces presents significant challenges in constructing effective recognition algorithms. This study proposes a groundbreaking approach that harnesses two-dimensional threshold functions to address the recognition problem with precision. The key innovation lies in the selection of representative pseudo-objects, which serve as the foundation for constructing two-dimensional threshold functions in the recognition algorithm model. Experimental studies were conducted, focusing specifically on face recognition, to assess the performance of these algorithms. The results of the above studies have shown that the proposed statistical algorithms increase the recognition accuracy and reduce the time of recognition of face parts and the face as a whole, described in the space of interrelated features. This study highlights the potential applications of these algorithms in diverse software systems tailored to solving practical recognition problems within the constraints of large-dimensional feature spaces.

The morphological peculiarities of the maxillo-facial region in children with cleft lips and palate

Considerable variation in malocclusion was found in children with cleft lip and palate. Class III malocclusionwere found more frequently due to congenital factors, such as maxillo-mandibular growth potential as well as the severity of the defect.Material and methods. In this study, 15 cephalometric x-rays were analyzed according to the methods proposed by McNamara, Tweed, Roth-Jarabak and Steiner, and 30 cephalometric parameters were calculated for each patient with complete unilateral cleft (so many on the left and so many on the right). The data obtained from the measurements are presented in the tables corresponding to each method. Results. Maxillary and mandibular length (Cond-A, Cond-Gn) statistically significantly reduced compared to normal mean values. The threshold of significance registered for these indices demonstrates significant deviations of the previous height of the face was statistically significantly reduced by the value p&lt;0.01 compared to the normal values (Sna-Me). The posterior vertical skeletal deficit is confirmed by the reduced value of the Hp parameter (posterior height, p&lt;0.01), which compared to Ha, reveals a type of posterior facial rotation. The enlarged lower anterior face is demonstrated by the increased value of the anterior height index, (Sna-Me) which registered an average deviation of 6.57 mm and an increased Ha/Hp ratio (p&lt;0.01). Conclusions. In the result of the analysis of the cephalometric analysis of the x-rays according to the McNamara, Roth-Jarabak, TweedMerriefield and Steiner methods, it was found that the cranio-facial morphology in children with unilateral cleft lips and palate was different from normal values due to the lack of growth of the facial part of the cranium both in sagittal and vertical planes.

PicassoNet: Searching Adaptive Architecture for Efficient Facial Landmark Localization.

Since recent facial landmark localization methods achieve satisfying accuracy, few of them enable fast inference speed, which, however, is critical in many real-world facial applications. Existing methods typically employ complicated network structure and predict all the key points through uniform computation, which is inefficient since individual facial part might take different computation to obtain the best performance. Taking both accuracy and efficiency into consideration, we propose the PicassoNet, a lightweight cascaded facial landmark detector with adaptive computation for individual facial part. Different from the conventional cascaded methods, PicassoNet integrates refinement submodules into a single network with group convolution, where each convolution group predicts landmarks from an individual facial part. Note that the groups' structures are flexible in the training process. Then, a novel grouping search algorithm is proposed to optimize the group division. With formulating the optimization as a network architecture search (NAS) problem, the grouping search adaptively allocates computation to each group and obtains an efficient structure. In addition, we propose a boundary-aware loss to optimize along tangent and normal of facial boundaries, instead of optimizing along horizontal and vertical as the conventional loss (L2, SmoothL1, WingLoss, and so on) do. The novel loss improves the joint locations of predicted keypoints. Experiments on three benchmark datasets AFLW, 300W, and WFLW show that the proposed method runs over 6× times faster than the state of the arts and meanwhile achieves comparable accuracy.

Frequency-discrimination and speech-perception characteristics of bone-conducted sound presented to the facial parts

Bone-conducted (BC) sound is typically presented to the mastoid process of the temporal bone or the condyle process of the mandible. However, a method of presenting BC sound to facial parts such as the nose and cheek have also been investigated recently. Since the face is one of the most complex structures in the human body, slight differences in the presentation parts of the vibrator will also change the perception and propagation mechanism. However, the characteristics of BC sound presented to the face have not yet been studied in detail. We have previously discussed the differences in perception (hearing thresholds) and propagation characteristics among facial parts. Here, to test the frequency-discrimination ability, we measured difference limens for frequency. We also conducted monosyllable articulation tests in Japanese to assess the speech-perception characteristics when BC sounds are presented to various facial (nasal, infraorbital region, zygomatic, jaw angle, and chin) and conventional (mastoid and condyle process) parts. The results obtained showed that the frequency resolution and intelligibility of the facial parts were about the same as those of the conventional parts. It is indicated that practical frequency information and speech perception are possible with BC devices attached to certain facial parts.

Effect of occlusion effects by bone-conduction sound on speech perception assessed by monosyllable articulation test and confusion in phoneme perception

Bone conduction (BC) has been applied to hearing aids for conductive hearing loss, earphones, and other audio devices including ones presenting sound to the face. One of the important characteristics of BC is the "occlusion effect (OE)", a phenomenon that low-frequency sound are perceived as being enhanced when the ear canal is occluded. Our previous study examining OE in facial parts reported that the OE in some facial parts was larger than OE in parts conventionally used. In this study, we conducted monosyllable articulation tests using bone-conducted speech with subjects' ear canal open and occluded, and investigated confusion in phoneme perception to evaluate the effect of OE on perception in the mastoid process, condylar process, nasal bone, and infraorbital region. The results showed that OE increased articulation. However, its effect varied depending on stimulus location and acoustic characteristics of the phonemes, and even confusions among unvoiced consonants even increased by OE. These findings are useful for optimizing BC devices using OE.

Variants of the typical variability of alveolar arches in different craniotypes

Background. The implementation of the principles of evidence-based medicine in applied and fundamental research consists in the precision of morphometric measurements in determining the types, dimensions and spatial location of the facial and cerebral parts of the skull. Published scientific data on the variability of morphometric parameters of the alveolar arches are contradictory and heterogeneous due to the lack of definition of interdependencies with gender, age characteristics and individual features of the skull.Goal. Investigation of the regularities between morphometric values and forms of the alveolar arches of the upper jaw in mesocrane, brachycrane and dolichocrane types of the skull.Materials and methods. Morphometry was performed on 93 preparations of skulls with lower jaws of both sexes of the first and second periods of adulthood with physiological types of bite and the shapes of the alveolar arches of the upper jaw were established. Taking into account the value of the transverse-longitudinal index, the skulls of mesocrane (n=54; 58.1%), brachycrane (n=23; 24.7%) and dolichocrane (n=16; 17.2%) types were identified. The length, width, depth and diagonal of the alveolar arches were studied as morphometric parameters.Results. The minimum and maximum limits of fluctuations of values, average statistical indicators, coefficients of variation are determined. The variability of the parameters of the alveolar arches of the upper jaw depending on the shape of the facial skull and gender characteristics was established. It is proved that the smallest values of the depth of the alveolar arch of the upper jaw are noted in brachycranes, the largest – in dolichocrans, while the smallest dimensions of the length, width of the alveolar arch of the upper jaw are determined in dolichocrans, and the largest – in brachycranes, while the smallest diagonal values of the alveolar arch of the upper jaw are revealed in mesocrans.Conclusions. The shape of the alveolar arches in the mesocrane type of skull has a proportional arcuate shape, in brachycrania − an arcuate «wide and short» shape, in dolichocrania − an arcuate «narrow and long» shape. The obtained new data on the variant variability of the alveolar arches should be used when planning treatment tactics for patients with complete adentia.

Middle Stone Age at Equatorial Guinea: Technical and use-wear analysis of lithic bifacial points

Lithic industries during the Upper Pleistocene in Equatorial Guinea may be broadly included in the Central African Middle Stone Age (MSA) Lupemban tradition. However, these industries present certain particularities related to their raw materials, and stone-knapping sequences. In the case of bifacial tools, bifacial points are commonly found with a cortical reserved proximal portion that keeps the cortex covering the base and part of both faces. Bifacial points made on thin stone slabs that keep the cortex on the center of one or both faces are also commonly found. This knapping technique gives the idea of unfinished preform artifacts. The edges, however, suggest that both points and other bifacial artifacts were used for some tasks. A sample of these tools was taken from the open-air Mabewele I site to decide whether the MSA points from Equatorial Guinea were finished artifacts, in spite of the preservation of their cortex. Petrographic studies and macro and microscopic analyses of the use-wear traces and residues from retouched edges were also performed. The analysis clearly shows that the Mabewele I bifacial artifacts were used for plant processing, among other activities. The results confirmed the fact that cortical reserved-base points with cortex on one or both faces were intentionally manufactured, finished tools, rather than unfinished preforms. The petrographic analysis also shows the schistous nature of raw material and explains the shape and stepped edges of bifacial knives, extending our understanding of the unique technical characteristics of the MSA in Equatorial Guinea. It also provides new insights into some of the hunter-gatherer's subsistence strategies in the Central African tropical rainforest at the end of the Pleistocene.