Corpus Height Research Articles

Linear measurements of the mandible on panoramic radiograph for sex estimation in populations in Yogyakarta, Indonesia

BackgroundIdentification is one of the main aspects of forensics. Sex estimation is an essential part of identification because it can simplify the whole process. Mandible is the largest, strongest, and sexually dimorphic bone and is part of the orofacial structure, which has the second highest level of dimorphism after the pelvic bone. Sex estimation using the mandible can be performed by conducting various linear measurements on a panoramic radiograph, including right minimum ramus width (RMiRW), left minimum ramus width (LMiRW), right projective height of ramus (RPHR), left projective height of ramus (LPHR), right maximum ramus width (RMxRW), left maximum ramus width (LMxRW), right coronoid height (RCH), left coronoid height (LCH), symphysis height (SH), right mandibular corpus height (RMCH), and left mandibular corpus height (LMCH). This study aimed to analyze how linear measurements in panoramic radiographs differ between men and women and to estimate sex by utilizing these parameters.ResultsIn this study, 195 panoramic radiographs from 95 men and 100 women aged 20–40 years obtained from our dental hospital were used as a training data. Meanwhile, 61 panoramic radiographs from 29 men and 32 women outside the training data with same characteristics were used as the testing data. The linear measurements of the mandible using panoramic radiographs were taken with EzDent-i Vatech software. Independent t-test showed significant difference (p < 0.05) in some linear measurements of the mandible between adult men and women. These significantly different linear measurements were then subjected to discriminant function analysis to produce sex estimation equations. The equation accuracy percentage ranged between 63.6 and 94.4% for the training sample and 59.5% and 85% for the testing sample.ConclusionThe linear measurements of the mandible using diagnostically acceptable panoramic radiographs taken from a patient with standardized head positioning can serve as an alternative method for sex estimation. The accuracy of discriminant analysis for sex estimation varies depending on the parameter used in the estimation.

Impact of Diet Consistency on the Mandibular Morphology: A Systematic Review of Studies on Rat Models.

Apart from genetics, environmental factors, such as food consistency, may affect craniofacial morphology and development. The present systematic review aims to systematically investigate and appraise the available evidence regarding the effect of diet consistency on the anatomical structures of the basal bone of the rat mandible. The search was performed without restrictions in five databases (PubMed, Scopus, Web of Science, ProQuest Dissertations and Theses Global, including grey literature) and hand searching through January 2022. A total of 14,904 references were initially identified, and 16 articles were finally included in the systematic review. Rats that consumed hard diets were found to exhibit an increase inbigonial width, corpus height, condylar depth, condylar base inclination, condylar process inclination, mandibular plane inclination, height and length of angular process, mandibular body height, depth of antegonial notch, growth rate in the gonial angle, angular process convexity and height of condylar process. It was also noted that mandibular depth, mandibular height, ramus angle and angle between the angular process and mandibular plane were decreased in rats that were fed with a hard diet. On the other hand, there were conflicting results about the growth of mandibular length and width, corpus length, mandibular body length, ramus height, condylar length and width, gonial angle and height of coronoid process. From the abovementioned results, it can be concluded that food consistency may affect the morphology of anatomical structures and the overall growth and development of rat mandibles in various ways.

How did modern morphology evolve in the human mandible? The relationship between static adult allometry and mandibular variability in Homo sapiens

Key to understanding human origins are early Homo sapiens fossils from Jebel Irhoud, as well as from the early Late Pleistocene sites Tabun, Border Cave, Klasies River Mouth, Skhul, and Qafzeh. While their upper facial shape falls within the recent human range of variation, their mandibles display a mosaic morphology. Here we quantify how mandibular shape covaries with mandible size and how static allometry differs between Neanderthals, early H. sapiens, and modern humans from the Upper Paleolithic/Later Stone Age and Holocene (= later H. sapiens). We use 3D (semi)landmark geometric morphometric methods to visualize allometric trends and to explore how gracilization affects the expression of diagnostic shape features. Early H. sapiens were highly variable in mandible size, exhibiting a unique allometric trajectory that explains aspects of their ‘archaic’ appearance. At the same time, early H. sapiens share a suite of diagnostic features with later H. sapiens that are not related to mandibular sizes, such as an incipient chin and an anteroposteriorly decreasing corpus height. The mandibular morphology, often referred to as ‘modern’, can partly be explained by gracilization owing to size reduction. Despite distinct static allometric shape changes in each group studied, bicondylar and bigonial breadth represent important structural constraints for the expression of shape features in most Middle to Late Pleistocene hominin mandibles.

Assessment of Mandibular Asymmetries in Adults: A Radiographic Study

The mandibular asymmetry is important because of its direct effect on facial appearance. Aims: The aim of the present study was to determine the prevalence and severity of mandibular asymmetries between right and left sides. Materials and methods: The sample consisted of 22 males and 23 females having lateral cephalometric and orthopantomographic radiographs. Four linear and two angular measurements were compared between right and left sides of the mandible. These measurements were: ramus height(RH), ramus width(RW), corpus height(CH), corpus length(CL), gonial angle(Go) and condylar angle(Co). Results: The study revealed no significant differences between right and left sides of the mandible, in both gender, regarding the 4 linear measurements. Whereas for the angular measurements there was a significant difference in condylar angle between right and left sides in both male and female groups. Also no significant gender differences were found regarding all measurements except in corpus height. Conclusion: No significant facial asymmetry was found between right and left sides of the mandible for the population being studied in both genders except in condylar angle. In addition it was found out that severe mandibular asymmetry is not so a common occurrence

Lomber Osteoporotik Kompresyon Kırığının Tedavisinde Polimetilmetakrilat Miktarının Etkinliği

Objective: We aimed to investigate the effectiveness of the amount of polymethylmethacrylate used in pain control and maintenance of long-term vertebra corpus height in patients undergoing percutaneous vertebroplasty due to osteoporotic compression fracture of the lumbar vertebra. Method: A total of 60 patients who underwent unilateral percutaneous vertebroplasty between 2014 and 2019 due to osteoporotic compression fracture of the lumbar vertebrae were included in the study. Patients who received 5 ml and 3 ml cement injection were retrospectively analyzed. Of patients, postoperative visual analogue scale (VAS) score and anterior vertebral height of the patients at 1st-year control were evaluated. Results: In the postoperative period, the mean visual analogue scale score was 2.3±0.46 in the 5 ml injected group and 2.2±0.4 in the 3 ml injected group (p5 ml=0.001, p3 ml= 0.001). There was a statistically significant decline in pain control in both groups. The mean anterior vertebral height loss (AVHL) in the 5 ml injected group was 31.5±0.40%, and 32.6±0.47% in the 3 ml injected group (p5 ml=0.820, p3ml= 0.870). There was no statistically significant alteration in both groups. Conclusion: Our results indicate that the 3 ml polymethylmethacrylate injection during the percutaneous vertebroplasty procedure provides adequate pain control and stabilization in patients with lumbar vertebral osteoporotic fracture. Therefore we think that small amount of polymethylmethacrylate (3 ml) is sufficient to avoid undesirable complications in this patient group.

Comparison of Four Different Posterior Screw Fixation Techniques for the Treatment of Thoracolumbar Junction Fractures

The purpose of this study was to compare clinical and radiologic outcomes of patients who underwent short-segment posterior instrumentation with screw augmentation at the fracture level and long-segment instrumentation for thoracolumbar junction fractures. Sixty-three patients were retrospectively evaluated by being divided into the following 4 groups: Groups A, B, C, and D included patients who had undergone 4-level instrumentation without insertion of screws at the fracture level, 3-level instrumentation by insertion of screws at the fracture level, 4-level instrumentation by insertion of screws at the fracture level, and 5-level instrumentation by insertion of screws at the fracture level, respectively. No significant difference was observed in preoperative local kyphosis angle (LKA) (P > 0.05), whereas there was a significant decrease in early postoperative LKA in Group C compared with the other groups (P < 0.05). However, there was no significant difference of LKA in the 4 groups measured on radiographs obtained at the final follow-up (P > 0.05). Anterior corpus height loss, Cobb angle of the fractured vertebra, and sagittal index, measured pre- and postoperatively and at the final follow-up, showed no significant difference (P > 0.05). There was no statistically significant difference between clinical scores of the 4 groups (P > 0.05). Short-segment posterior instrumentation with screw augmentation at the fracture level provides at least as much mechanical stability as long-segment instrumentation. Moreover, there is no difference between short-segment instrumentation with screw augmentation at the fracture level and long-segment instrumentation in terms of clinical outcomes.

Author Correction: New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens.

In the originally published version of this Letter, the x axis in Fig. 3a should have been: 'PC1: 26%' rather than 'PC1: 46%', and the yaxis should have been: 'PC2: 16%' rather than 'PC2: 29%'. We also noticed an error in the numbering of the fossils from Qafzeh: Qafzeh 27 should be removed, and Qafzeh 26 is actually Qafzeh 25, following Tillier (2014)1 and Schuh et al. (2017)2 and personal communication with B. Vandermeersch and M. D. Garralda. The correct enumeration of Qafzeh samples in the 'Mandibular metric data' section of the Methods is therefore: 'Qafzeh (9, 25)' rather than 'Qafzeh (9, 26, 27)'. Owing to the removal of Qafzeh 27, the convex hull of early modern humans changes slightly in Extended Data Fig. 1c. The sample sizes in Extended Data Fig. 1c should have read: Middle Pleistocene archaic Homo n=19 (instead of 11), Neanderthals n=40 (instead of 41), early modern humans n=12 (instead of 7), and recent modern humans n=46 (instead of 48). In Extended Data Table 2, the mean and standard deviation of corpus height and breadth at mental foramen for early modern humans should have been: x̅=33.15, σ=3.26 for height (rather than x̅=34.23, σ=4.57); and x̅=16.25, σ=1.28 for breadth (rather than x̅=16.04, σ=1.75). Accordingly, n=12 (rather than n= 13) for both breadth and height. These errors have been corrected in the Letter online (the original Extended Data Fig. 1 is shown in Supplementary Information to this Amendment). These changes do not alter any inferences drawn from the data.

A test of a skeletal ageing method based on resorption of the alveolar crest following tooth loss using a skeletal population of documented age at death.

Resorption of the alveolar process occurs following tooth loss, and appears to continue for a prolonged period. Previous study (Mays, ) with a known-age collection of human remains suggested the potential of this phenomenon for age estimation in remains of adults who have lost one or more molar teeth. This article tests this ageing technique on another known age group, and attempts to evaluate the impact of some extraneous factors on the method. The study group comprises adult skeletons (N = 110) of documented age at death from 18th to 19th century London. It examines the relationship between a previously described standardized measure of posterior corpus height (SPCH) in mandibles showing loss of one or more molars. The potential influence of a general tendency to form or lose bone (identified by the presence of ossification into the anterior longitudinal ligament of the spine and cortical thickness at the metacarpal) and (for females) parity are also investigated. Negative age correlation was found for SPCH in females but not in males. In females, the age-association was weaker, and the rate of loss slower, than in a previously studied 19th century European population. None of the other factors investigated showed a relationship with SPCH. As with other bony age indicators, the relationship between SPCH and age varies in different populations. Further work is needed to evaluate the extraneous factors that affect the relationship with age.

The Relationship of Mandibular Morphology with Residual Ridge Resorption Associated with Implant-Retained Overdentures.

The objective of this clinical study was to determine the relationship of mandibular morphology with residual ridge resorption (RRR) of implant-retained overdenture (IRO) patients. RRR was quantified as change in bone volume over 1- and 2-year periods using cone beam computed tomography and a medical imaging program. Features of the mandibular morphology, namely the gonial angle, ramus length, ramus width, corpus length, and corpus height, were measured on three-dimensional models and correlated to the RRR. A total of 25 participants were treated with mandibular IROs opposing maxillary complete dentures. By the 2-year follow-up, radiographic data for 18 patients were complete for analysis. Of these 18 participants, half fall into the low gonial angle category and the other half into the high angle. The extent of RRR was highly variable among participants and ranged from -2 to +2 mm in depth over the 2-year period. The mean decrease in bone volume after the first year was 3.8 ± 4.5%. This rate decreased to 3.2 ± 4.1% after the second year. RRR occurs either by translation of the entire thickness of cortical layer apically or by thinning of the outer cortical layer. RRR was significantly correlated to gonial angle (r = .471; P = .048) and predominantly occurred in the molar region in low-angle participants and more anteriorly in high-angle participants. There was no association between RRR and ramus length (r = -.341; P = .166), ramus width (r = -.183; P =.468), corpus length (r = .057; P = .821), and corpus height (r = .097; P = .702). Within the limitations of this study, it may be concluded that gonial angle is significantly related to RRR associated with IROs.

Comparison of brucellar and tuberculous spondylodiscitis patients: results of the multicenter “Backbone-1 Study”

Background ContextNo direct comparison between brucellar spondylodiscitis (BSD) and tuberculous spondylodiscitis (TSD) exists in the literature. PurposeThis study aimed to compare directly the clinical features, laboratory and radiological aspects, treatment, and outcome data of patients diagnosed as BSD and TSD. Study DesignA retrospective, multinational, and multicenter study was used. Patient SampleA total of 641 (TSD, 314 and BSD, 327) spondylodiscitis patients from 35 different centers in four countries (Turkey, Egypt, Albania, and Greece) were included. Outcome MeasuresThe pre- and peri- or post-treatment spinal deformity and neurologic deficit parameters, and mortality were carried out. MethodsBrucellar spondylodiscitis and TSD groups were compared for demographics, clinical, laboratory, radiological, surgical interventions, treatment, and outcome data. The Student t test and Mann-Whitney U test were used for group comparisons. Significance was analyzed as two sided and inferred at 0.05 levels. ResultsThe median baseline laboratory parameters including white blood cell count, C-reactive protein, and erythrocyte sedimentation rate were higher in TSD than BSD (p<.0001). Prevertebral, paravertebral, epidural, and psoas abscess formations along with loss of vertebral corpus height and calcification were significantly more frequent in TSD compared with BSD (p<.01). Surgical interventions and percutaneous sampling or abscess drainage were applied more frequently in TSD (p<.0001). Spinal complications including gibbus deformity, kyphosis, and scoliosis, and the number of spinal neurologic deficits, including loss of sensation, motor weakness, and paralysis were significantly higher in the TSD group (p<.05). Mortality rate was 2.22% (7 patients) in TSD, and it was 0.61% (2 patients) in the BSD group (p=.1). ConclusionsThe results of this study show that TSD is a more suppurative disease with abscess formation requiring surgical intervention and characterized with spinal complications. We propose that using a constellation of constitutional symptoms (fever, back pain, and weight loss), pulmonary involvement, high inflammatory markers, and radiological findings will help to differentiate between TSD and BSD at an early stage before microbiological results are available.

Variation in regional diet and mandibular morphology in prehistoric Japanese hunter–gatherer–fishers

Previous research has identified a relationship between mandibular morphology and diet (e.g., coarse or tough diets result in more robust mandibles). Prehistoric Japan is an excellent place to explore the significance of this relationship in shaping mandibular morphology due to the pronounced regional dietary variation. South/West Honshu Jōmon engaged in broad spectrum foraging, Northeastern Honshu Jōmon were fisher–gatherers, Hokkaido Jōmon were maritime (sea mammal) foragers. We test the hypothesis that diet variation across temporal and spatial zones will be reflected in mandibular morphological traits. Metric measurements were utilized to test for regional differences with both archaeological time period and biological sex as covariants. ANOVA results for region with time period as a covariate indicates all variables except corpus height and breadth are significantly different among regions but for the time period covariate, only corpus breadth and dimensions of ascending ramus are significant. ANOVA for region with biological sex as a covariate indicates all variables except corpus height are significantly different. Biological sex as a covariate demonstrates significant p-values for chin height, bicondylar breadth and minimum ascending ramus breadth. Generally, North Hokkaido and Southwest Hokkaido, exhibit the largest mandibular ascending rami and tallest anterior mandibles, whereas Northeast and South/West Honshu have smaller mandibles. Multivariate analysis indicates a separation between North and Southwest Hokkaido and South/West Honshu, whereas Northeast Honshu partially overlaps these dietary zones. Differences in mandibular morphology are better explained by regional diets than by temporal trends and biological sex.

Identifying the pollen of an extinct spruce species in the Late Quaternary sediments of the Tunica Hills region, south‐eastern United States

ABSTRACTLate Quaternary fluvial deposits in the Tunica Hills region of Louisiana and Mississippi are rich in spruce macrofossils of the extinct species Picea critchfieldii, the one recognized plant extinction of the Late Quaternary. However, the morphology of P. critchfieldii pollen is unknown, presenting a barrier to the interpretation of pollen spectra from the last glacial of North America. To address this issue, we undertook a morphometric study of Picea pollen from Tunica Hills. Morphometric data, together with qualitative observations of pollen morphology using Apotome fluorescence microscopy, indicate that Picea pollen from Tunica Hills is morphologically distinct from the pollen of P. glauca, P. mariana and P. rubens. Measurements of grain length, corpus width and corpus height indicate that Picea pollen from Tunica Hills is larger than the pollen of P. mariana and P. rubens, and is slightly larger than P. glauca pollen. We argue that the morphologically distinctive Tunica Hills Picea pollen was probably produced by the extinct spruce species P. critchfieldii. These morphological differences could be used to identify P. critchfieldii in existing and newly collected pollen records, which would refine its paleoecologic and biogeographic history and clarify the nature and timing of its extinction in the Late Quaternary.

Resorption of mandibular alveolar bone following loss of molar teeth and its relationship to age at death in a human skeletal population

Estimating adult age at death in skeletal remains is problematic, particularly in older adults. Molar wear is arguably the most reliable ageing technique for palaeopopulations, but many older adult skeletons have lost their molar teeth ante mortem, precluding its application. Resorption of the alveolar process occurs following tooth loss, and this appears to continue for a prolonged period. The current work investigates the relationship of this process to individual age in a nineteenth century AD European archaeological skeletal series of known age at death (N = 92 individuals), and discusses its potential as an age indicator. Mandibular corpus height was measured at the different molar positions. In females, reduction of corpus height with age was found at molar positions showing ante mortem loss. In both sexes, a relationship was found between age and a simple composite measure of corpus height in the molar region in those showing ante mortem loss of one or more mandibular molars. The correlation was stronger in females (r = -0.74) than in males (r = -0.49), appeared approximately linear, and continued into the ninth decade, the oldest age group in the study material. The results suggest that investigation of height of the posterior part of the mandibular corpus as a skeletal age indicator for individuals that have lost one or more molar teeth is merited in other palaeopopulations.

Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles

The Plio-Pleistocene hominin sample from Dmanisi (Georgia), dated to 1.77 million years ago, is unique in offering detailed insights into patterns of morphological variation within a paleodeme of early Homo. Cranial and dentoalveolar morphologies exhibit a high degree of diversity, but the causes of variation are still relatively unexplored. Here we show that wear-related dentoalveolar remodeling is one of the principal mechanisms causing mandibular shape variation in fossil Homo and in modern human hunter-gatherer populations. We identify a consistent pattern of mandibular morphological alteration, suggesting that dental wear and compensatory remodeling mechanisms remained fairly constant throughout the evolution of the genus Homo. With increasing occlusal and interproximal tooth wear, the teeth continue to erupt, the posterior dentition tends to drift in a mesial direction, and the front teeth become more upright. The resulting changes in dentognathic size and shape are substantial and need to be taken into account in comparative taxonomic analyses of isolated hominin mandibles. Our data further show that excessive tooth wear eventually leads to a breakdown of the normal remodeling mechanisms, resulting in dentognathic pathologies, tooth loss, and loss of masticatory function. Complete breakdown of dentognathic homeostasis, however, is unlikely to have limited the life span of early Homo because this effect was likely mediated by the preparation of soft foods.

Relationship between canine dimorphism and mandibular morphology in the hamadryas baboon and the Japanese monkey

To examine morphological interrelationships between canine size and mandibular corpus shape, inter-sex comparisons were made in the hamadryas baboon and the Japanese monkey, known to display extreme and moderate canine dimorphism, respectively. Results of adult comparisons showed that all mandibular dimensions were significantly larger in the males than in the females in both species. In the hamadryas baboon, the males also exhibited a higher ratio of anterior to posterior corpus height than the females. This sex difference in corpus shape was not significant in the Japanese monkey, indicating lack of involvement of canine dimorphism. Analysis of mandibular growth patterns in the hamadryas baboon demonstrated that significant sexual size difference did not occur before incisor eruption, and that the anteriorly high corpus of the adult male mandible was associated with a rapidly increasing symphyseal height after incisor eruption. It was also shown that the female canine started to erupt shortly after incisor eruption, while the forming male canine continued to stay near the mandibular base and developed further in size until eruption. The relative positions of the incisors kept shifting upwards even after eruption in the males, while they hardly changed in the females. It is therefore suggested that the prolonged development and size increase of the male canine is accompanied by further enlargement of the symphysis, resulting in the higher anterior corpus of the adult males compared to the adult females. The results thus indicate the importance of understanding the spatial relationships of the developing teeth in interpreting mandibular morphology.

Prevalence of mandibular asymmetries in growing patients

The aim of the present study was to determine the prevalence of mandibular asymmetries during the mixed dentition in growing children. For this purpose, a retrospective study was designed where various measurements were performed on the right and left sides of the mandible of panoramic radiographs of 327 children (males: 169; females: 158), 8-12 years old. Four linear measurements, mandibular ramus height, ramus width, corpus height, and corpus length, and two angles, mandibular gonial (Go) and mandibular condyle (Co), and the developmental stage of the permanent lower second molar were analysed. All measurements were adjusted for the magnification factor. The final data were then processed for the asymmetry index (AI) to determine the severity of the asymmetries and statistically analysed by Wilcoxon paired tests at the 95 per cent level of confidence. A moderate-to-severe mandibular asymmetry for the linear dimensions when both sides of the mandible were contrasted was found in more than a half of the sample. There was also a high prevalence of moderate and severe asymmetries when comparing Go and Co angles on both sides of the mandible. No differences were observed in the developmental stage of the lower permanent second molar between either side. There was a high prevalence of both dimensional and angular mandibular asymmetries in the studied population.

Influence of size and placement of developing teeth in determining anterior corpus height in prehistoric Jomon and modern Japanese mandibles

The juvenile mandible of the modern Japanese has a lower symphysis than that of the prehistoric Jomon, while the adult symphysis is conversely higher in the modern Japanese. This cannot be explained from population differences in masticatory environments. As an alternative factor that may influence symphyseal height, we examined tooth crypt size and placement patterns in the skeletal growth series of the two populations. Results showed that although the Jomon mandible had larger bicanine breadth than in the modern Japanese during growth, the modern Japanese has faster growing anterior teeth that became larger than those of the Jomon by the time of eruption, necessitating greater space. This is expressed as the faster growth rate of anterior alveolar height in the modern Japanese, measured as corpus height above the mandibular canal. Canine eruption distance and root length were greater in the modern Japanese than in the Jomon, corresponding to the increased difference of anterior corpus height between the two populations after canine eruption. However, the influence of tooth root length on anterior corpus height during later growth cannot be evaluated by this study. The present study suggests that the size and spatial dispositions of the developing anterior teeth have significant effects on symphyseal dimensions of the mandible until the time of tooth eruption.

Anatomic basis of anterior and posterior instrumentation of the spine: morphometric study

A morphometric study of the linear and angular parameters of the spinal vertebra was conducted by computerized tomographic scans and comparison with previous studies in literature. Detailed knowledge of the spinal vertebral morphometry is important for proper instrumentation. The morphologic measurements vary among races. Morphometric studies have been conducted in white populations. This study aims to suggest dimensions for anterior and posterior spinal implants and to improve the instrumentation techniques. The vertebral pedicles, bodies and intervertebral disc spaces of the subaxial cervical, thoracic and lumbar spine were studied in 48 healthy individuals by computerized tomographic scan methods. The following parameters were studied: pedicle length, pedicle width, transverse pedicle angle (TPA), sagittal pedicle angle, anterior corpus height, posterior corpus height, anterior disc height, middle disc height and posterior disc height. Our results were slightly different compared to previous studies. Individual differences were found in the same subgroups. The transverse pedicle diameter was largest at L5 (14.95 mm) and smallest at C3 (5.1 mm). The pedicle was longest at L5 (19.9 mm) and shortest at T10 (15.7).The TPA was largest at C3 (47.6 degrees ) and smallest at T6 (11.3 degrees ). The vertebral body was largest at L5 (34.9 mm) and smallest at C3 and C5 (15.6 mm). The vertebral body width was largest at L5 (46.6 mm) and smallest at C4 (22 mm). The intervertebral disc space height was largest at L2-3 (10 mm) and smallest at T1-2 (2.85 mm). There were no significant differences between the left and right sides. In our morphometric study of the spinal vertebrae, we found differences compared to a number of previous morphometric studies performed mainly on a white population. Also, we documented the individual morphometric differences of the same parameters in the same subgroups. These results emphasize the importance of preoperative computed tomography and conventional radiography of each patient in planning a surgical procedure and selecting the appropriate size of the instruments, thus avoiding possible postoperative complication related to implants.

Comparative analysis of the Gran Dolina-TD6 (Spain) and Tighennif (Algeria) hominin mandibles

We present a comparative study of the Tighennif (Algeria) and Gran Dolina-TD6 (Spain) hominin mandibles, which represent two geographically near and contemporaneous populations separated by the Mediterranean sea, in order to test the hypothesis that these populations belong to the same evolutionary lineage, as it has been suggested by some authors. The Tighennif mandibles show a clear primitive structural pattern, derived in some features with regard to the oldest Homo specimens from H. habilis, as well as from the Javanese H. erectus. In addition, the Tighennif specimens share all these derived features with H. ergaster and, some of them, with H. antecessor. However, the Gran Dolina-TD6 specimens are remarkably smaller than those of Tighennif, and lack the robustness which characterizes the African Pleistocene mandibles. The main difference between both groups in terms of mandibular dimensions can be related to the higher corpus height characteristic of Tighennif specimens. The dental evidence reveals that North African Middle Pleistocene populations are morphologically closer to African Early Pleistocene populations than to TD6 fossils. We conclude that the Spanish and Algerian hominins belong to different hominin lineages. The Tighennif hominins, together with other contemporaneous (Thomas Quarry and Oulad Hamida 1), and perhaps later North African specimens (Sidi Abderrahaman, Salé, and Rabat [Kebitat]) should be considered as a subspecies of the H. ergaster species, i.e. H. ergaster mauritanicus, and may be the result of an evolution in isolation in this African area. In agreement with the mandibular and dental evidences, the Gran Dolina-TD6 hominins could belong to an exclusive Eurasian lineage.

Correlations between feeding type and mandibular morphology in the sika deer

AbstractMorphological comparisons of the sika deer Cervus nippon mandible and molars were conducted between two (northern and southern) Japanese subspecific lineages and among local populations of different (‘grazer’ or ‘intermediate feeder’) feeding types. The northern lineage showed greater M1 breadth, M3 hypsodonty and mandibular corpus height than the southern lineage. Such differences were not observed between the ‘grazer’ and ‘intermediate feeder’ populations of the northern lineage. However, a northern population, which inhabits a particularly harsh environment (Kinkazan Island), had the largest values of relative molar size and hypsodonty, although this was not statistically significant. These results imply that, in the Japanese sika deer, the selective pressures acting on the current ‘grazer’ populations are not strong enough to bring out noticeable adaptive change in molar size and hypsodonty, but adaptive change in these traits may occur in an environment that promotes excessive molar wear, more than that seen in the current sika deer habitats of Japan. Combined with what is known of the Pleistocene history of the sika deer, we infer that the ancestral population of the northern Japanese lineage likely acquired their relatively larger and more hypsodont molars in an extremely harsh environment during the last or previous glacial periods.