Mandible Morphology Research Articles

Biting behavior against Varroa mites in honey bees is associated with changes in mandibles, with tracking by a new mobile application for mite damage identification

Certain populations of feral or wild European Honey Bees (EHB), Apis mellifera, have developed a tolerance of or persistence against the parasitic mite Varroa destructor in the USA. Although the grooming or mite-biting behavior is a trait bees use to defend against parasitic Varroa mites, little information is available concerning the grooming or mite-biting behavior of feral EHBs. Accordingly, we observed damaged mites of feral bees in Ohio (Apis mellifera ligustica) and commercial bees in four field seasons, 2020 to 2023, as well as feral bees in Kentucky (A. mellifera mellifera) in 2023, for a total of 7494 mites. When the mite-biting behavior was compared among these three populations, feral bees of Ohio (A. m. ligustica) and Kentucky (A. m. mellifera) displayed a significantly higher percentage (22% and 27% more) than the commercial bees. To investigate the mechanism of the mite-biting behavior, we examined bee mandibles. Mandibles are the primary mouthparts and tools used to remove or amputate the Varroa mites. Gentle Africanized honey bees (gAHB, A. mellifera scutellata-hybrid) in Puerto Rican exhibit mite resistance through microevolution on the island. Asian honey bees (A. cerana) are the original natural host of V. destructor. However, little has been reported on the morphometric analysis of mandibles between the two species A. cerana and A. mellifera and between the subspecies A. m. scutellata-hybrid and A. m. ligustica. Utilizing X-ray micro-computed tomography (microCT), we then examined the three-dimensional morphology of mandibles in (1) A. cerana, (2) gAHB A. m. scutellata-hybrid, (3) Ohio feral A. m. ligustica, and (4) package or commercial colonies A. m. ligustica. Our findings revealed distinctive three-dimensional shapes of mandibles, indicating substantial variations among these populations. These variations suggest that mandible morphology has an integral role in the bee’s defensive mechanisms against parasitic mites. We also developed the first smartphone application to quantify the mite damage by applying artificial intelligence to image analysis. This research contributes valuable insights into the prospective selection and breeding of honey bees with enhanced mite resistance, thus promoting the sustainability of apiculture.

Adaptive trade-offs between vertebrate defence and insect predation drive Amazonian ant venom evolution.

Stinging ants have diversified into various ecological niches, and selective pressures may have contributed to shape the composition of their venom. To explore the drivers underlying venom variation in ants, we sampled 15 South American rainforest species and recorded a range of traits, including ecology, morphology and venom bioactivities. Principal component analysis of both morphological and venom bioactivity traits reveals that stinging ants display two functional strategies where species have evolved towards either an exclusively offensive venom or a multi-functional venom. Additionally, phylogenetic comparative analysis indicates that venom function (predatory, defensive or both) and mandible morphology correlate with venom bioactivity and volume. Further analysis of the venom biochemistry of the 15 species revealed switches between cytotoxic and neurotoxic venom compositions among species. Our study supports an evolutionary trade-off between the ability of venom to deter vertebrate predators and to paralyse insect prey which are correlated with different venom compositions and life-history strategies among Formicidae.

A cephalometric analysis of the antegonial notch in relation to the direction of mandibular growth.

Masticatory muscle forces influence craniofacial morphology development. The antegonial notch (Notch) is a bony concavity on the inferior border of the mandible. Considering the Notch is located anteriorly to the insertion of the masseter muscle and varies among individuals, we hypothesised that these muscles influence the formation of the Notch. Therefore, this study aimed to investigate the correlation between mandible morphology and Notch formation. Sixty Japanese patients who visited the Department of Orthodontics at our university hospital were retrospectively evaluated. Morphological and morphometric analyses of the Notch and related craniofacial parameters were conducted using lateral cephalograms taken at the patients' initial visits. Standard values for the Notch area and depth were determined, and the morphology of the Notch and mandible was analysed using Spearman's rank correlation coefficient (p < 0.05). The mean Notch area and depth was 78.71 ± 36.54 mm2 and 3.11 ± 1.09mm, respectively. The Notch area was significantly correlated with ramus inclination (p = 0.044, r = 0.261) and with the Y-axis (p = 0.039, r = 0.267). This study indicated that both the masticatory muscles and mandibular growth could contribute to the Notch formation.

Anatomical variations of the human mandible and prevalence of duplicated mental and mandibular foramina in the collection of the State University of Londrina

BackgroundThe knowledge of the morphology of the human mandible is essential for diverse dental procedures. The potential anatomical variations of the bone, including the presence of accessory foramina, may culminate in significant clinical outcomes and implications, directly impacting dental surgery and anesthesia. Aim of studyThis study aimed to evaluate the general morphology of human mandibles in the collection of the State University of Londrina, South Brazil, and to determine the presence of anatomical variations. Materials and methodsA total of 63 mandibles were measured bilaterally with a pachymeter for various dimensions, and a proportional calculation of each parameter was obtained, based on the size of the length of each mandibular base. In addition to the general descriptive morphology of the mandibles, considering that six mandibles presented duplicated foramina, they were divided into two groups, and the mandibles with no anatomical variation (normal group, N = 57) were compared to those with duplicated foramina (N = 6). Data were checked for normal distribution and then tested statistically. ResultsSix out of 63 mandibles (9.52 %) presented duplicated foramina, either mental or mandibular. Significant differences between the normal group and the duplicated foramina group were found in the lengths between mandibular angle and condylar process on both sides (right: 65.14 mm vs. 74.91 mm, p = 0.001; left: 65.04 mm vs. 72.34 mm, p = 0.019); between mandibular angle and coronoid process on the right side (59.55 mm vs. 67.67 mm, p = 0.007); and in the diameter of the left mandibular foramen (3.71 mm vs. 4.64 mm, p = 0.04), with the duplicated foramina group presenting a higher average for all parameters. ConclusionThese findings provide a morphological pattern for the Department of Anatomy of the State University of Londrina collection and highlight the presence of anatomical variations of the human mandible, specifically regarding duplicated foramina. The presence of accessory mental and mandibular foramina is clinically significant for dental procedures, potentially impacting the anesthesia. Understanding these variations is crucial for dental surgeons to prevent complications. Future research should further explore the functional implications and clinical significance of these variations.

Mechanical and elemental characterization of ant mandibles: consequences for bite mechanics.

Mandible morphology has an essential role in biting performance, but the mandible cuticle can have regional differences in its mechanical properties. The effects of such a heterogeneous distribution of cuticle material properties in the mandible responses to biting loading are still poorly explored in chewing insects. Here, we tested the mechanical properties of mandibles of the ant species Formica cunicularia by nanoindentation and investigated the effects of the cuticular variation in Young's modulus (E) under bite loading with finite-element analysis (FEA). The masticatory margin of the mandible, which interacts with the food, was the hardest and stiffest region. To unravel the origins of the mechanical property gradients, we characterized the elemental composition by energy-dispersive X-ray spectroscopy. The masticatory margin possessed high proportions of Cu and Zn. When incorporated into the FEA, variation in E effectively changed mandible stress patterns, leading to a relatively higher concentration of stresses in the stiffer mandibular regions and leaving the softer mandible blade with relatively lower stress. Our results demonstrated the relevance of cuticle E heterogeneity in mandibles under bite loading, suggesting that the accumulation of transition metals such as Cu and Zn has a relevant correlation with the mechanical characteristics in F. cunicularia mandibles.

Mechanical Influence of Edentulous Mandible Morphology on Peri-implant Bone in Implant Prosthetics: 3D Finite Element Analysis.

To examine the mechanical influence of edentulous mandible morphology on peri-implant bone in implant prosthetics via finite element analysis (FEA). Computed tomographic (CT) data from 25 patients with edentulous mandibles were selected. Measurements such as the radius of mandibular curvature and the height of the mandible at the midline were taken to clarify the morphologic characteristics of the mandible. From the measurements, two patients with the smallest and largest radii of the mandible were selected. Two types of 3D finite element models were created from the two selected edentulous mandibles (small and large radius), and they included superstructures (a cantilever bridge), implants, and abutments. In both models, four implants were placed between the right and left mental foramina. The upper surface of the mandibular condyle was constrained, and a vertical load of 100 N was applied on the occlusal surface of the right first molar. 3D FEA of each model was performed to examine the mechanical influence of the edentulous mandible morphology on the peri-implant bone. The mandibular morphology measurement in the CT images indicated that the smaller the mandibular height, the larger the radius of the anterior mandibular curvature. FEA revealed that higher equivalent stress was generated in the model of the peri-implant bone with a larger radiusof curvature than that of the model with a smaller radius of curvature. The highest equivalent stress in the mandible was generated in the distal margin of the peri-implant bone posterior to the loaded side of the large-radius model. The mandibular morphology had a mechanical influence on the peri-implant bone.

Loss of TBC1D2B causes a progressive neurological disorder with gingival overgrowth

Biallelic loss-of-function variants in TBC1D2B have been reported in five subjects with cognitive impairment and seizures with or without gingival overgrowth. TBC1D2B belongs to the family of Tre2-Bub2-Cdc16 (TBC)-domain containing RAB-specific GTPase activating proteins (TBC/RABGAPs). Here, we report five new subjects with biallelic TBC1D2B variants, including two siblings, and delineate the molecular and clinical features in the ten subjects known to date. One of the newly reported subjects was compound heterozygous for the TBC1D2B variants c.2584C>T; p.(Arg862Cys) and c.2758C>T; p.(Arg920*). In subject-derived fibroblasts, TBC1D2B mRNA level was similar to control cells, while the TBC1D2B protein amount was reduced by about half. In one of two siblings with a novel c.360+1G>T splice site variant, TBC1D2B transcript analysis revealed aberrantly spliced mRNAs and a drastically reduced TBC1D2B mRNA level in leukocytes. The molecular spectrum included 12 different TBC1D2B variants: seven nonsense, three frameshifts, one splice site, and one missense variant. Out of ten subjects, three had fibrous dysplasia of the mandible, two of which were diagnosed as cherubism. Most subjects developed gingival overgrowth. Half of the subjects had developmental delay. Seizures occurred in 80% of the subjects. Six subjects showed a progressive disease with mental deterioration. Brain imaging revealed cerebral and/or cerebellar atrophy with or without lateral ventricle dilatation. The TBC1D2B disorder is a progressive neurological disease with gingival overgrowth and abnormal mandible morphology. As TBC1D2B has been shown to positively regulate autophagy, defects in autophagy and the endolysosomal system could be associated with neuronal dysfunction and the neurodegenerative disease in the affected individuals.

Simulated biomechanical performance of morphologically disparate ant mandibles under bite loading

Insects evolved various modifications to their mouthparts, allowing for a broad exploration of feeding modes. In ants, workers perform non-reproductive tasks like excavation, food processing, and juvenile care, relying heavily on their mandibles. Given the importance of biting for ant workers and the significant mandible morphological diversity across species, it is essential to understand how mandible shape influences its mechanical responses to bite loading. We employed Finite Element Analysis to simulate biting scenarios on mandible volumetric models from 25 ant species classified in different feeding habits. We hypothesize that mandibles of predatory ants, especially trap-jaw ants, would perform better than mandibles of omnivorous species due to their necessity to subdue living prey. We defined simulations to allow only variation in mandible morphology between specimens. Our results demonstrated interspecific differences in mandible mechanical responses to biting loading. However, we found no evident differences in biting performance between the predatory and the remaining ants, and trap-jaw mandibles did not show lower stress levels than other mandibles under bite loading. These results suggest that ant feeding habit is not a robust predictor of mandible biting performance, a possible consequence of mandibles being employed as versatile tools to perform several tasks.

A new species of Brasixenos Kogan & Oliveira, 1966 (Strepsiptera: Xenidae) from Mexico.

The first record of the genus Brasixenos Kogan & Oliveira is presented for Mexico with the description of B. mesoamericanus, a species found in localities from central Veracruz state. The males of this species are characterized by the mouthparts shape, wing venation, and genitalia. The females are identified by their reduced size and the mandible morphology. Polybia plebeja is identified as the host of this species. The biology and distribution of Brasixenos, and challenges in the study of this genus in the Neotropical region are discussed.

Evolution, divergence, and convergence in the mandibles of opossums (Didelphidae, Didelphimorphia).

Didelphid marsupials are considered a morphologically unspecialized group with a generalist diet that includes vertebrates, invertebrates, and plant matter. While cranium and scapula variation has already been examined within Didelphidae, variation in mandible shape, usually associated with diet or phylogeny in other mammalian groups, has not yet been properly assessed in the family. We evaluated the variation in mandible shape and size of didelphids (2470 specimens belonging to 94 species) using 2D geometric morphometrics. We classified the diet of the didelphids into four broad categories to assess whether morphospace ordination relates to dietary habits. We also provided the most comprehensive phylogeny for the family (123 out of the 126 living species) using 10 nuclear and mitochondrial genes. We then mapped mandible size and shape onto that phylogeny for 93 selected taxa and ancestral size and shapes were reconstructed by parsimony. We found phylogenetically structured variation in mandible morphology between didelphid groups, and our results indicate that they have a significant phylogenetic signal. The main axis of shape variation is poorly related to size, but the second is strongly allometric, indicating that allometry is not the main factor in shaping morphological diversity on their mandibles. Our results indicate that the shape and size of the ancestral mandible of didelphids would be similar to that of the current species of the genus Marmosa.

Suggestion of a new standard in measuring the mandible via MRI and an overview of reference values in young women

PurposeAdult idiopathic condylarresorption (AICR) mainly affects young women, but generally accepted diagnostic standards are lacking. Patients often need temporomandibular joint (TMJ) surgery, and often jaw anatomy is assessed by CT as well as MRI to observe both bone and soft tissue. This study aims to establish reference values for mandible dimensions in women from MRI only and correlate them to, e.g., laboratory parameters and lifestyle, to explore new putative parameters relevant in AICR. MRI-derived reference values could reduce preoperative effort by allowing physicians to rely on only the MRI without additional CT scan.MethodsWe analyzed MRI data from a previous study (LIFE-Adult-Study, Leipzig, Germany) of 158 female participants aged 15–40 years (as AICR typically affects young women). The MR images were segmented, and standardized measuring of the mandibles was established. We correlated morphological features of the mandible with a large variety of other parameters documented in the LIFE-Adult study.ResultsWe established new reference values for mandible morphology in MRI, which are consistent with previous CT-based studies. Our results allow assessment of both mandible and soft tissue without radiation exposure. Correlations with BMI, lifestyle, or laboratory parameters could not be observed. Of note, correlation between SNB angle, a parameter often used for AICR assessment, and condylar volume, was also not observed, opening up the question if these parameters behave differently in AICR patients.ConclusionThese efforts constitute a first step towards establishing MRI as a viable method for condylar resorption assessment.

Mandibular shape as a proxy for the identification of functional feeding traits of midge larvae (Diptera: Chironomidae)

The identification of functional feeding traits in aquatic macroinvertebrates often requires a morphology-based identification of species, which is important for trait-based methods of biological assessment. The extent of functional homogenization is compared along scales of impairment, where trait-based information is used as an input in models that examine degradation pathways. However, trait-based information is not always readily available for all groups of aquatic insects, especially for species diverse families, such as chironomids (Diptera: Chironomidae). Taxonomic challenges and ambiguous traits complicate the use of chironomid larvae in trait-based bioassessment. Here, we examine the use of geometric morphometric analysis (GMA), deep learning (Convolutional Neural Networks), and computer vision (deep CNN) applied to the mouthparts (mandibles) of chironomid larvae as a proxy for identifying the relationship between the functional morphology and food acquisition behaviour. We determined the variability in morphology of mandibles for 23 taxa of chironomid larvae from different genera, subfamilies, and their Functional Feeding Group (FFG). Analysis using GMA showed that the five different FFGs examined had different mandibular traits that significantly varied in shape and size. A deep CNN model was then built that was able to classify the 23 taxa into their respective FFG automatically with 92.31 % accuracy. A gradient-weighted Class Activation Mapping (Grad-CAM) algorithm found that the most important part of mandibles for classification were the gula and mandibular joint. We introduced three additional species to the deep CNN models to test whether automatic classification would directly and automatically identify traits of the specimens independently from taxonomic identification. The deep CNN process avoids issues surrounding both taxonomic identification and previous knowledge of a specific taxon’s feeding trait, and in all cases the model classified taxa correctly based on their mandibular traits. The use of deep learning approaches could substantially enhance the use of trait-based approaches and increase the reliability and use of chironomids in bioassessment.

Inferring feeding habits of Carabidae (Coleoptera) larvae based on mandible morphology: Case studies of Lesticus magnus and Chlaenius costiger

AbstractIn the beetle family Carabidae, feeding habits are important life history traits that determine their role in ecosystems and suitability as bioindicators. However, they have not been elucidated for most species, especially in the larval stages. Using laboratory‐rearing experiments, this study examined the larval feeding habits of two large carabid species: Lesticus magnus (tribe Pterostichini) and Chlaenius costiger (tribe Chlaeniini). Although previous studies failed to rear these larvae on insect larva diets, the mandible morphology of the first instars described in those studies, together with subsequently obtained knowledge of the relationship between mandible morphology and feeding habits in other carabid larvae, suggests that they are earthworm feeders. Rearing experiments with three types of animal diet (insect larvae, mixed snail and slug, and earthworm diets) showed that as expected, their larvae are earthworm feeders. In L. magnus, although the larvae accepted the mixed snail and slug diet and the earthworm diet, only larvae reared on the earthworm diet reached adulthood. In C. costiger, the larvae accepted only the earthworm diet and reached adulthood. This is the first report of earthworm feeding during the larval stage for the genus Lesticus (tribe Pterostichini) and tribe Chlaeniini. The importance of these results is discussed from ecological and evolutionary perspectives.

Skull ecomorphological variation of narwhals (Monodon monoceros, Linnaeus 1758) and belugas (Delphinapterus leucas, Pallas 1776) reveals phenotype of their hybrids.

Narwhals and belugas are toothed whales belonging to the Monodontidae. Belugas have a circumpolar Arctic and sub-Artic distribution while narwhals are restricted to the Atlantic Arctic. Their geographical ranges overlap during winter migrations in the Baffin Bay area (Canada/West Greenland) and successful interbreeding may occur. Here, we employed geometric morphometrics on museum specimens to explore the cranium and mandible morphology of a known hybrid (NHMD MCE 1356) and the cranium morphology of a putative hybrid (NHMD 1963.44.1.4) relative to skull morphological variation in the parental species. Specifically, we used 3D models of skulls from 69 belugas, 86 narwhals, and the two known/putative hybrids and 2D left hemi-mandibles from 20 belugas, 64 narwhals and the known hybrid. Skull shape analyses allowed clear discrimination between species. Narwhals are characterised by a relatively short rostrum and wide neurocranium while belugas show a more elongated and narrower cranium. Sexual size dimorphism was detected in narwhals, with males larger than females, but no sexual shape dimorphism was detected in either species (excluding presence/absence of tusks in narwhals). Morphological skull variation was also dependent on different allometric slopes between species and sexes in narwhals. Our analyses showed that the cranium of the known hybrid was phenotypically close to belugas but its 2D hemi-mandible had a narwhal shape and size morphology. Both cranium and mandible were strongly correlated, with the pattern of covariation being similar to belugas. The putative hybrid was a pure male narwhal with extruded teeth. Comparison of genomic DNA supported this result, and stable carbon and nitrogen isotope values suggested that the putative hybrid had a more benthic foraging strategy compared to narwhals. This work demonstrates that although the known hybrid could be discriminated from narwhals and belugas, detection of its affinities with these parental species was dependent on the part of the skull analysed.

Mesolithic and Chalcolithic Mandibular Morphology: Using Geometric Morphometrics to Reconstruct Incomplete Specimens and Analyse Morphology

Abstract Human skeletal remains are routinely used to examine cultural and biological aspects of past populations. Yet, archaeological specimens are frequently fragmented/incomplete and so excluded from analyses. This leads to decreased sample sizes and to potentially biased results. Digital methods are now frequently used to restore/estimate the original morphology of fragmented/incomplete specimens. Such methods include 3D digitisation and Geometric Morphometrics (GM). The latter is also a solidly established method now to examine morphology. In this study, we use GM-based methods to estimate the original morphology of incomplete Mesolithic and Chalcolithic mandibles originating from present Portugal and perform ensuing morphological analyses. Because mandibular morphology is known to relate to population history and diet, we hypothesised the two samples would differ. Thirty-seven specimens (12 complete and 25 incomplete) were CT-scanned and landmarked. Originally complete specimens were used as reference to estimate the location of absent anatomical landmarks in incomplete specimens. As predicted, our results show shape differences between the two samples which are likely due to the compounded effect of contrasting population histories and diets.

Description of a new species of Kovalevskiella (Ostracoda, Limnocytheridae, Timiriaseviinae) from groundwater of the Danube river in Austria

Abstract The species name Kovalevskiella elisabethae n. sp. is proposed for a new taxon of a Recent ostracod found in interstitial sediments of the alluvial plain of the Danube in the surroundings of Vienna, Austria. The main characters that differentiate Kovalevskiella elisabethae n. sp. from its congeners K. bulgarica, K. cvetkovi, K. dani, K. rudjakovi and K. phreaticola are based on the morphology and chaetotaxy of antennula, antenna and mandible. Important diagnostic characters of the new species are the 5-segmented antennula, the presence of 2 setae on the posterior margin of its fourth segment, the presence of only 1 seta (besides the conjoined seta and aesthetasc) on its last segment, as well as the presence of 1 seta on the basis and 3 on the endopodite of the mandibula. An identification key for the Recent species of the genus is provided.

Bat Dentitions: A Model System for Studies at The Interface of Development, Biomechanics, and Evolution.

The evolution of complex dentitions was a major innovation in mammals that facilitated the expansion into new dietary niches that imposed selection for tight form-function relationships. Teeth allow mammals to ingest and process food items by applying forces produced by a third-class lever system composed by the jaw adductors, the cranium, and the mandible. Physical laws determine changes in jaw adductor (biting) forces at different bite point locations along the mandible (outlever), thus individual teeth are expected to experience different mechanical regimes during feeding. If the mammal dentition exhibits functional adaptations to mandible feeding biomechanics, then teeth are expected to have evolved to develop mechanically-advantageous sizes, shapes, and positions. Here, we present bats as a model system to test this hypothesis and, more generally, for integrative studies of mammal dental diversity. We combine a field-collected dataset of bite forces along the tooth row with data on dental and mandible morphology across 30 bat species. We (1) describe, for the first time, bite force trends along the tooth row of bats, (2) use phylogenetic comparative methods to investigate relationships among bite force patterns, tooth and mandible morphology, and (3) hypothesize how these biting mechanics patterns may relate to the developmental processes controlling tooth formation. We find that bite force variation along the tooth row is consistent with predictions from lever mechanics models, with most species having the greatest bite force at the first lower molar. The cross-sectional shape of the mandible body is strongly associated with the position of maximum bite force along the tooth row, likely reflecting mandibular adaptations to varying stress patterns among species. Further, dental dietary adaptations seem to be related to bite force variation along molariform teeth, with insectivorous species exhibiting greater bite force more anteriorly, narrower teeth and mandibles, and frugivores/omnivores showing greater bite force more posteriorly, wider teeth and mandibles. As these craniodental traits are linked through development, dietary specialization appears to have shaped intrinsic mechanisms controlling traits relevant to feeding performance.

The aberrant hamster Melissiodon (Cricetidae, Rodentia) from the early Miocene of Echzell and other German and French localities

ABSTRACT Melissiodon is a rare cricetid with a long stratigraphic range, present from the Oligocene until the Miocene, only found in western and central Europe except some specimens recovered in Anatolia. What makes Melissiodon special is its unique dental and mandible morphology that has led to many questions regarding its relationship to other cricetid genera and its type of diet. In this work, we have studied new material attributed to Melissiodon from the German localities Echzell (MN4) and Petersbuch (MN3 and MN4), and from the French locality Beaulieu (MN3). Moreover, we compared these specimens with the already published material from other localities across western and central Europe during the early Miocene (MN3 and MN4). In conclusion, the studied specimens and the comparison with other material from different European localities allow us to ascribe this new material as Melissiodon dominans, a widely dispersed species across Europe during the early Miocene

Three-dimensional analysis of mandible ramus morphology and transverse stability after intraoral vertical ramus osteotomy

ObjectivesThe purpose of this study was to investigate short- and long-term postoperative changes of both morphology and transverse stability in mandibular ramus after intraoral vertical ramus osteotomy (IVRO) in patients with jaw deformity using three-dimensional (3D) orthognathic surgery planning treatment software for measurement of distances and angles.Study designThis retrospective study included consecutive patients with skeletal Class III malocclusion who had undergone intraoral vertical ramus osteotomy and computed tomography images before (T0), immediately after (T1), and 1 year after (T2) surgery. Reference points, reference lines and evaluation items were designated on the reconstructed 3D surface models to measure distances, angles and volume. The average values at T0, T1, T2 and time-dependent changes in variables were obtained.ResultsAfter surgery, the condylar length, ramal height, mandibular body length and mandibular ramus volume were significantly decreased (P < 0.01), while clinically insignificant change was observed from T1 to T2. The angular length was increased immediately after surgery (P < 0.05), but it was decreased 1 year after surgery (P < 0.05). Lateral ramal inclination showed significant increase after surgery (P < 0.05) and maintained at T2.ConclusionChanges in the morphology of the mandibular ramus caused by IVRO do not obviously bring negative effect on facial appearance. Furthermore, despite position and angle of mandibular ramus changed after IVRO, good transverse stability was observed postoperatively. Therefore, IVRO technique can be safely used without compromising esthetic results.

Trends in Ancient Populations’ Osteobiography during the Holocene: the Levantine Perspective

Abstract. The rapid changes in our surroundings during the Holocene challenge the human body. The current study, carried out on the terminal Pleistocene-Holocene populations of the Levant, presents several examples of how changes in the habitation and diet have affected the disease patterns and the gross morphology of long bones and mandibles. Our major findings were that the prehistoric Natufian (67%) and the protohistoric Chalcolithic (80%) populations exhibited a much higher rate of ear inflammation (otitis media) than all other populations: Neolithic, Roman/Byzantine, and Ottoman (50% ± 5%). A general continuous significant decrease in the relative femoral bone cortical area from the Natufian (77.8%) to present times (64.7%) was noticed (the Chalcolithic population was the exception). Mandibular shape has changed considerably, mainly between the pre-agricultural population (the Natufian) and the succeeding ones (i.e., the ramus became taller and narrower, the coronoid higher and pointed, the mandibular notch narrower and deeper, and the body more triangular). Possible behavioral, economic, and environmental factors associated with these changes are discussed.