Ophthalmic manifestations of proboscis lateralis

Proboscis lateralis (PL) is a rare congenital malformation of the craniofacial structure with varied clinical associations. None of the studies documented a discrete review of ophthalmic presentations in PL. The principal aim of the present study is to explore the ophthalmic manifestations of PL. The ancillary goal is to derive a relationship between congenital deformity in PL and various ophthalmic anomalies. Databases were searched in order to obtain articles related to PL. A qualitative systematic analysis of 100 subjects was performed. In PL, eyelid coloboma (32.6%) is the most common ocular feature, followed by hypertelorism (25.3%), iris coloboma (22.4%), lacrimal system abnormality (20.7%), malpositioned eyebrow (14.4%) and retinochoroidal coloboma (12.9%). Sinonasal deformity is the most common systemic abnormality, detected in 87.9% of cases of PL, as compared with central nervous system involvement (56.2%) and other anomalies. The analysis showed a strong significant association between brain abnormalities and hypertelorism (p=0.000) and between brain abnormalities and micro-ophthalmia/anophthalmia (p=0.000). Statistically significant association was noted between cumulative ocular abnormalities and cumulative systemic abnormalities (p=0.001). The present study on PL reviewed the salient features of this rare congenital disorder. The study outcome provides a new aspect to concomitant ocular abnormalities. This study supports the view that other congenital anomalies in cases of PL had significant influence on certain ophthalmic anomalies.

Evaluation of Dento-craniofacial Characteristics in Monozygotic Twins - Case Study

Introduction: Monozygotic twins are a valuable sample for the study of human craniofacial growth and development. Aims: The aim of the present study was to analyze the dento-craniofacial characteristics in monozygotic twins and to discuss the genetic, epigenetic and environmental influences in the twin’s phenotypic features. Material and Methods: Two 21-year-old female twins attended the Dental Service of Universidade Federal dos Vales do Jequitinhonha e Mucuri were analyzed. For validation of this study, a genetic test of zygosity was performed to confirm the individuals' monozygosity. Intraoral buccal examination revealed occlusal differences as well as disagreement in the eruption of the third molars. Results: The analysis of models showed differences in the mesio-distal diameter of the teeth of both arches, as well as disagreement in the perimeter of the mandibular arches between the two individuals. The cephalometric analysis showed remarkable differences in the vertical and horizontal parameters of the craniofacial structure. The SNA, SNB and LAFH showed differences of 10º, 9º and 3mm respectively. Additionally, the components related to the dentition also showed discrepant results. Conclusion: It can be suggested that the dento-craniofacial characteristics present a genetic component; however, the interaction of epigenetic and environmental factors can lead to different phenotypes in univiteline twins.

ViceCT and whiceCT for simultaneous high-resolution visualization of craniofacial, brain and ventricular anatomy from micro-computed tomography

Up to 40% of congenital diseases present disturbances of brain and craniofacial development resulting in simultaneous alterations of both systems. Currently, the best available method to preclinically visualize the brain and the bones simultaneously is to co-register micro-magnetic resonance (µMR) and micro-computed tomography (µCT) scans of the same specimen. However, this requires expertise and access to both imaging techniques, dedicated software and post-processing knowhow. To provide a more affordable, reliable and accessible alternative, recent research has focused on optimizing a contrast-enhanced µCT protocol using iodine as contrast agent that delivers brain and bone images from a single scan. However, the available methods still cannot provide the complete visualization of both the brain and whole craniofacial complex. In this study, we have established an optimized protocol to diffuse the contrast into the brain that allows visualizing the brain parenchyma and the complete craniofacial structure in a single ex vivo µCT scan (whiceCT). In addition, we have developed a new technique that allows visualizing the brain ventricles using a bilateral stereotactic injection of iodine-based contrast (viceCT). Finally, we have tested both techniques in a mouse model of Down syndrome, as it is a neurodevelopmental disorder with craniofacial, brain and ventricle defects. The combined use of viceCT and whiceCT provides a complete visualization of the brain and bones with intact craniofacial structure of an adult mouse ex vivo using a single imaging modality.

Is male dimorphism under sexual selection in humans? A meta-analysis

Humans are sexually dimorphic: men and women differ in body build and composition, craniofacial structure, and voice pitch, likely mediated in part by developmental testosterone. Sexual selection hypotheses posit that, ancestrally, more ‘masculine’ men may have acquired more mates and/or sired more viable offspring. Thus far, however, evidence for either association is unclear. Here, we meta-analyze the relationship between six masculine traits and mating/reproductive outcomes (96 studies, 474 effects, N = 177,044). Voice pitch, height, digit ratios, and testosterone all predicted mating; however, strength/muscularity was the strongest and only consistent predictor of both mating and reproduction. Facial masculinity did not significantly predict either. There was insufficient evidence for any effects of masculinity on offspring viability. Our findings support arguments that strength/muscularity can be considered sexually selected in humans, but raise concerns over other forms of masculinity and highlight the need to increase tests of evolutionary hypotheses outside of industrialized populations.

The differences in parallelism between ala-tragus line and occlusal plane of down syndrome and normal individuals

People with down syndrome have a different craniofacial structure compared to normal individuals. Commonly, down syndrome patients have abnormal ear morphology with smaller size, and lower ear position compared to that of normalsubjects. These patients also have smaller nose, shorter maxilla structure and facial height. Other disorders are anomalies in tooth shape, numbers and size. The ala-tragus line is one of the anatomical landmarks to determine the occlusal plane orientation. Abnormalities in the anatomical structure of people with down syndrome can affect the parallelism between the ala-tragus line and the occlusal plane. The purpose of this research was to determine the differences in parallelism between the ala-tragus line and the occlusal plane of people with down syndrome and normal individuals. The sample in this study were people with down syndrome and normal individuals. The sample was photographed using a digital camera with a fox plane attached to the oral cavity. Parallelism of the ala-tragus line and the occlusal plane was analyzed by tracing these photographs. Photo tracing was done using the Autocad 2013 software. The mean value of angle on people with down syndrome (5.852° ± 5.367°) was greater than that of normal individuals (2.169° ± 2.557°). Based on the research, it was concluded that the parallelism of the ala-tragus line to the occlusal plane in people with down syndrome was different from that in normal individuals. The ala-tragus inferior line in normal individuals was more parallel to the occlusal plane compared to that in people with down syndrome.

Oral Manifestation in a Patient with Bilateral Duane Syndrome: A Case Report

Duane syndrome is a rare retraction anomaly characterized by congenital non-progressive horizontal ophthalmoplegia and other systemic signs. No data has been yet registered about oral manifestation of Duane syndrome. In this article we present a six years old male patient was diagnosed as having Duane retraction syndrome. He presented skeletal Class III with both maxillary and mandibular protrusion, counter clock-wise mandibular rotation, lingualized maxillary and mandibular incisors, first mandibular molar agenesis, asymmetric morphology of the mandibular condyles and multiple decay lesions. Posteroanterior x-ray showed an asymmetrical craniofacial structure. The aim of this case report was to describe the oral signs of a patient affected by DRS.

The Relationships Between Craniofacial Structure and Frontal Sinus Morphology: Evaluation With Conventional Anthropometry and CT-Based Volumetry

The purpose of this study was to investigate the effects of craniofacial structure and nasal septal deviation on frontal sinus morphology 3-dimensionally. This study of anatomy, anthropology, morphology, and radiology included 74 dry skulls as study sample. The craniofacial measurements were made through conventional anthropometric methods by the use of calipers. The nasal septal deviation measurements were done by computerized software on photographs taken from frontal view. Frontal sinus volumes were estimated by the computerized tomography-based volumetry. The relationships between craniofacial structure, nasal septal deviation, and frontal sinus morphology were tested by linear regression and correlation analysis. The analysis of numerical variables and categorical variables within different groups was done by Mann-Whitney U/Kruskal-Wallis, and χ2 tests, respectively. There appeared a positive relationship between the dimensions of the frontal sinuses and the maximal cranial length and the nasal height especially on the left side ( P < .05). However, after multivariate linear regression model for both factors was created, solely the nasal height kept being a positive factor for frontal sinus size as an independent variable. No statistical relevance was detected between the presence of metopic suture and frontal sinus morphology. Septal deviation itself affected frontal sinus morphometry, but the morphometry did not differ between the deviation side and the opposite side. In conclusion, the cranial structure does not affect the frontal sinus morphology but nasal structure affects. The true influences, among measured craniofacial elements, in relationship with the pneumatization of frontal sinus are appeared to be the nasal structure related.

Oligogenic effects of 16p11.2 copy number variation on craniofacial development

A copy number variant (CNV) of 16p11.2, which encompasses 30 genes, is associated with developmental and psychiatric disorders, head size and body mass. The genetic mechanisms that underlie these associations are not understood. To elucidate the effects of genes on development, we exploited the quantitative effects of CNV on craniofacial structure in humans and model organisms. We show that reciprocal deletion and duplication of 16p11.2 have characteristic “mirror” effects on craniofacial features that are conserved in human, rat and mouse. By testing gene dosage effects on the shape of the mandible in zebrafish, we show that the distribution of effects for all individual genes is consistent with that of the CNV, and some combinations have non-additive effects. Our results suggest that, at minimum, one third of genes within the 16p11.2 region influence craniofacial development, and the facial gestalt of each CNV represents a product of 30 dosage effects.HighlightsReciprocal CNVs of 16p11.2 have mirror effects on craniofacial structure. Copy number is associated with a positive effect on nasal and mandibular regions and a negative effect on frontal regions of the face.Effects of CNV on craniofacial development in human are well conserved in rat and mouse models of 16p11.2 deletion and duplication.7/30 genes each independently have significant effects on the shape of the mandible in zebrafish; these include SPN, C16orf54, SEZ6L2, ASPHD1, TAOK2, INO80E and FAM57B. Others (MAPK3, MVP, KCTD13) have detectable effects only in combination.Overexpression of 30 genes individually showed a distribution of effects that was skewed in the same direction as that of the full duplication, suggesting that specific facial features represent the net of all individual effects combined.

Simulation of a three-dimensional craniofacial structure under the application of orthodontic loads

The aim of this study was to develop a three-dimensional model of a patient’s craniofacial structure to be analysed using the finite element method in order to estimate the forces required to carry out a dental positioning’s correction. The three-dimensional model was composed by several anatomical structures, namely the teeth, the periodontal ligaments, and the trabecular and cortical bones, which were modelled with the aid of computed tomography cone beam images. The tomographic images were analysed and reconstructed using the 3D Slicer software, while the assembly of the anatomical structures modelled, as well as the contact surfaces between contiguous parts, was defined in computer-aided design software. Bone remodelling and the occurrence of tissue’s injuries were considered during the numerical simulations carried out. By imposing displacements to each tooth, it was possible to calculate the orthodontic loads needed to carry out dental correction (reaction forces), as well as the distributions of stresses and deformations inherent to the clinical treatment, allowing to obtain a craniofacial structure capable of simulating the dental movements of upper and lower arches with anatomical realism. In addition, this methodology constitutes a personalised dental medicine that could lead to the development of highly customised orthodontic appliances where different mechanical loads could be applied individually to each tooth to achieve the foreseen dental correction.