Altered thalamocortical tract trajectory growth with undisrupted thalamic parcellation pattern in human lissencephaly brain at mid-gestational stage.

Proper topographically organized neural connections between the thalamus and the cerebral cortex are mandatory for thalamus function. Thalamocortical (TC) fiber growth begins during the embryonic period and completes by the third trimester of gestation, so that human neonates at birth have a thalamus with a near-facsimile of adult functional parcellation. Whether congenital neocortical anomaly (e.g., lissencephaly) affects TC connection in humans is unknown. Here, via diffusion MRI fiber-tractography analysis of long-term formalin-fixed postmortem fetal brain diagnosed as lissencephaly in comparison with an age-matched normal one, we found similar topological patterns of thalamic subregions and of internal capsule parcellated by TC fibers. However, lissencephaly fetal brain showed white matter structural changes, including fewer/less organized TC fibers and optic radiations, and much less cortical plate invasion by TC fibers - particularly around the shallow central sulcus. Diffusion MRI fiber tractography of normal fetal brains at 15, 23, and 26 gestational weeks (GW) revealed dynamic volumetric change of each parcellated thalamic subregion, suggesting coupled developmental progress of the thalamus with the corresponding cortex. Moreover, from GW23 and GW26 normal fetal brains, TC endings in the cortical plate could be delineated to reflect cumulative progressive TC invasion of cortical plate. By contrast, lissencephaly brain showed a dramatic decrease in TC invasion of the cortical plate. Our study thus shows the feasibility of diffusion MRI fiber tractography in postmortem long-term formalin-fixed fetal brains to disclose the developmental progress of TC tracts coordinating with thalamic and neocortical growth both in normal and lissencephaly fetal brains at mid-gestational stage.

Longitudinal MRI of the developing ferret brain reveals regional variations in timing and rate of growth.

Normative ferret brain development was characterized using magnetic resonance imaging. Brain growth was longitudinally monitored in 10 ferrets (equal numbers of males and females) from postnatal day 8 (P8) through P38 in 6-d increments. Template T2-weighted images were constructed at each age, and these were manually segmented into 12 to 14 brain regions. A logistic growth model was used to fit data from whole brain volumes and 8 of the individual regions in both males and females. More protracted growth was found in males, which results in larger brains; however, sex differences were not apparent when results were corrected for body weight. Additionally, surface models of the developing cortical plate were registered to one another using the anatomically-constrained Multimodal Surface Matching algorithm. This, in turn, enabled local logistic growth parameters to be mapped across the cortical surface. A close similarity was observed between surface area expansion timing and previous reports of the transverse neurogenic gradient in ferrets. Regional variation in the extent of surface area expansion and the maximum expansion rate was also revealed. This characterization of normative brain growth over the period of cerebral cortex folding may serve as a reference for ferret studies of brain development.

Influence of the maxillary third molars and the surrounding cortical plate during maxillary tooth movement with TADS- A CBCT Study.

OBJECTIVE: To determine the influence of the presence/absence of third molars and intact/loss of cortical plate of the maxillary tuberosity on the amount of distal movement of the maxillary first permanent molar during distal movement of the maxillary dentition with mini-implants. MATERIALS AND METHODS: Thirty six maxillary tuberosity sites were evaluated in eighteen young adult patients. The distal movement of the entire maxillary dentition was performed with mini-implants with 200 g of distalising force applied from the mini-implant placed in the maxillary posterior buccal region to attachments placed on the arch wire between the maxillary lateral incisor and canine bilaterally. The distal movement of the maxillary first permanent molars was measured on lateral cephalograms. The maxillary tuberosity sites with intact cortical plate due to congenitally missing third molars or atraumatic extraction of third molars (G1), partial loss of cortical plate due to surgical removal of third molars (G2), fully erupted third molars (G4), third molars located at (G3), and below the cementoenamel junction (G5) were evaluated with cone beam computed tomography. One way Anova and Fisher LSD test was done. RESULTS: The order of greater to lesser amount of distal movement of the maxillary first permanent molar depending on the integrity of maxillary of tuberosity was partial loss of cortical plate, third molars at the cementoenamel junction, third molars below the cementoenamel junction, intact cortical plate and fully erupted third molars. CONCLUSION: The integrity of the cortical plate and the relative position of the maxillary third molar to the second molar influence the amount of distal movement of the maxillary first permanent molar during distal movement of the maxillary teeth with TADS. CLINICAL RELEVANCE: The amount of distal movement of the maxillary dentition appears to depend on the presence or absence of the third molars and the condition of the cortical plate in the region of the maxillary tuberosity and thereby greatly influence the outcome of treatment.

Combined distalization and lingual cortex remodeling during mandibular growth for facial profile improvement: a case report.

Borderline crowding poses a challenge in deciding whether or not to prescribe premolar extraction. This case report describes the two-phase nonextraction orthodontic treatment of an 11-year-old girl with a hyperdivergent skeletal Class I pattern exhibiting anterior crowding and moderate lip protrusion. The initial phase of treatment included maxillary and mandibular expansion to correct the transverse discrepancy as an early intervention. Subsequently, comprehensive treatment was initiated at the age of 13 years, with fully erupted permanent second molars and growth potential remaining. Phase II treatment involved a second round of maxillary expansion, followed by simultaneous bimaxillary total arch intrusive distalization, using interradicular, temporary skeletal anchorage devices to correct dental crowding and improve the facial profile. Although the limited retromolar space posed a challenge to mandibular tooth distalization, gradual bone remodeling was observed in the lingual cortex of the mandibular body, enabling sufficient orthodontic tooth movement without noticeable side effects. After 4 years 3 months of treatment, her dental crowding was relieved, with significant improvement in the facial profile and proper occlusion. The treatment outcomes remained stable 2 years 4 months after retention.

Telencephalon Organoids Derived from an Individual with ADHD Show Altered Neurodevelopment of Early Cortical Layer Structure.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that occurs in early childhood and can persist to adulthood. It can affect many aspects of a patient's daily life, so it is necessary to explore the mechanism and pathological alterations. For this purpose, we applied induced pluripotent stem cell (iPSC)-derived telencephalon organoids to recapitulate the alterations occurring in the early cerebral cortex of ADHD patients. We found that telencephalon organoids of ADHD showed less growth of layer structures than control-derived organoids. On day 35 of differentiation, the thinner cortex layer structures of ADHD-derived organoids contained more neurons than those of control-derived organoids. Furthermore, ADHD-derived organoids showed a decrease in cell proliferation during development from day 35 to 56. On day 56 of differentiation, there was a significant difference in the proportion of symmetric and asymmetric cell division between the ADHD and control groups. In addition, we observed increased cell apoptosis in ADHD during early development. These results show alterations in the characteristics of neural stem cells and the formation of layer structures, which might indicate key roles in the pathogenesis of ADHD. Our organoids exhibit the cortical developmental alterations observed in neuroimaging studies, providing an experimental foundation for understanding the pathological mechanisms of ADHD.

Autotransplantation of Maxillary Third Molar with Its Attached Buccal Cortical Plate Combined with a Connective Tissue Graft.

INTRODUCTION: Tooth replacement often leads to insufficient vertical volume in the recipient socket bone. The aim of this novel report is to present a successful fully guided autotransplantation of a maxillary right third molar (tooth #1) with its attached buccal plate. The procedure was combined with a palatal connective tissue graft to reconstruct a buccal hard and soft tissue defect of an irreparable maxillary right first molar (tooth #3). METHODS: A 45-year-old man complaining of pain in tooth #3 came to the clinic. Tooth #3 was non-restorable due to an extensive caries and a vertical root fracture of the mesiobuccal root, leading to a total loss of the buccal cortical plate. Guided autotransplantation of tooth #1 was completed by using 3-dimensional surgical templates for implant burs and a 3-dimensional-printed replica. After positioning the donor tooth, the cortical plate was fixed to the recipient socket with osteosynthesis screws. A connective tissue graft was also harvested to increase the band of keratinized gingiva and the thickness of the buccal soft tissue. At 6-month follow-up, the screws were removed, showing excellent regeneration throughout the buccal area. RESULTS: At 3-year follow-up, the transplanted tooth was asymptomatic, with a natural bone level and no signs of replacement or inflammatory root resorption. CONCLUSIONS: The use of a donor tooth and its attached bone cortical plate combined simultaneously with a connective tissue graft appears to improve hard and soft tissues in a single procedure.

Cone-beam computed tomography assessment of maxillary anterior alveolar bone remodelling in extraction and non-extraction orthodontic cases using stable extra-alveolar reference.

OBJECTIVE: To explore alveolar cortical positional change in response to tooth movement in extraction and non-extraction orthodontic cases, using cone-beam computed tomography (CBCT) and stable extra-alveolar references. MATERIALS AND METHODS: The pre-treatment (T1) and post-treatment (T2) CBCT scans of 25 extraction (EXT) and matched 25 non-extraction (Non-EXT) orthodontic cases were imported into Dolphin Imaging 3D, and oriented uniformly. Sagittal and axial CBCT cross-sections were traced using customized software-generated guides. The displacement of teeth and alveolar bone cortices were automatically measured using the palatal plane (PP) and the line perpendicular to PP and passing Sella as reference. Intra- and inter-group differences between T1 and T2 were analysed. Subjects were also superimposed three-dimensionally using Geomagic Control X for qualitative analysis of cortical remodelling. RESULTS: The EXT group showed incisor retraction, while the Non-EXT group exhibited statistically significant incisor anterior tipping (P < .05). In EXT, both the labial and palatal cortices are resorbed. Non-EXT showed labial cortex anterior modelling, and statistically significant palatal cortex resorption (P < .05). In both groups, statistically significant decrease in total and palatal alveolar widths, increase in labial widths, and palatal dehiscence were observed. Comparatively, EXT showed significantly more incisal total and palatal width decrease and palatal vertical bone loss. CONCLUSION: Labial cortical remodelling was shown to follow anterior tooth movement, but the palatal cortical response to incisor retraction and labial cortical remodelling in general remained inconclusive. Narrowing of the alveolar housing and palatal dehiscence were observed regardless of extraction following orthodontic treatment.

X-ray and anatomical features of the lower jaw alveolar cortical layer in children.

INTRODUCTION: the world studies showed the interest in measurement of the buccal or anterior cortical plate thickness. Data indicate a significant superiority of the spongy substance over the compact one in the distal part of the jaw, which makes it possible to think about a higher effectiveness of transcortical injections. The empirical "rule of 10″ provides for the choice of a method of anesthesia in children for primary teeth but demonstrates difficulties with high-quality anesthesia accompanied for permanent teeth. Therefore, the importance of clinical examination and anatomical investigation of the jaw cortical plate in children for competent planning of transcortical interventions has been determined. AIM: To study the features of the clinical and X-ray anatomy of the cortical layer in distal alveolar part of the mandible in children. MATERIAL AND METHODS: The assessment of the X-ray anatomical characteristics of the mandible was carried out according to 150 anonymized cone-beam computed tomograms of patients aged 6-12 years, performed for the treatment of major diseases. Qualitative assessment and examination of the cortical plate of the distal alveolar part of the mandible were carried out on the skeletonized certified preparations of aged 6-12 in the amount of 50. RESULTS: The age characteristics of the cortical plate in the area of the chewing group of teeth in the mandible were determined according to macro anatomical studies, which confirms with the X-ray results. Therefore, the obtained images serve as actual confirmation of X-ray studies, which are ranked by age. The thickness of the cortical plate in the second primary molar of the mandible in subgroups 6, 7 and 8 years has a proportional increase from the cervical region to the apical projection. The average thickness of the cortical plate is 1.57 mm at 6 years, 1.52 mm at 7 years, 1.6 mm at 8 years and 1.84 at 9 years. The cortical plate thickness in the first primary molar of the mandible in subgroups 6 and 7 years has a proportional decrease from the cervical region to the apical projection as well as an inverse proportion to age. The average thickness of the cortical plate is 1.33 mm. In the first molar of the mandible at the age limit of 6-12 years the attention is drawn to the linear increase in tissue volume from the cervical region to the apical projection up to 8 years. At 6-8 years the average thickness of the cortical plate in this age group is 1.74 ± 0.2 mm, at 9 years - 2.03 mm, at 10 - average value in the cervical region it is 1.53 ± 0.23 mm, in the root middle it is 2.19 ± 0.13 mm and in the apical projection it is 1.98 ± 0.16 mm, at 11-2.22 mm and at 12-2.35 mm. For the second primary molar the average thickness of the buccal cortical plate of the second primary molar is 1.4 mm in cervical part, 1.68 mm in the root middle and 1.81 mm in the apical projection. Finally, thickness of the buccal cortical plate in the cervical region of the first permanent molar is 2 mm in groups. CONCLUSION: The study makes it possible to determinate with noninvasive way the age limit for the least pronounced zone of the buccal cortical plate.

Fixation by Autogenous Cortical Plate Technique on Sites of Subtrochanteric Shortening Osteotomy Contributes to Early Bone Union in Total Hip Arthroplasty for Crowe Type IV Developmental Dysplasia of the Hip.

Aim: Subtrochanteric shortening osteotomy (SSO) is often applied during total hip arthroplasty (THA) in high hip dislocations. The aim of the present paper was to evaluate the results of fixation by autogenous cortical plate technique on sites of SSO in THA for patients with Crowe type IV developmental dysplasia of the hip (DDH). Methods: We conducted a historical prospective cohort study and reviewed 67 patients (82 THAs) with SSO performed between March 2016 and May 2020. Thirty-nine patients (48 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses and with or without prophylactic binding by stainless-steel wire after osteotomy and before stem implantation (group A). Twenty-eight patients (34 hips) were fixed with autogenous cortical plate technique and stainless-steel wire or cables (group B). Time of operations, complications, radiographic results and clinical scores were compared. Results: One intraoperative fracture and a dislocation occurred, while component loosening, ectopic ossification and osteolysis were not observed. Group B had a higher union rate at the 4th month than group A (P = 0.015) while there were no significant differences of union rates at the 8th (P = 0.811) and the 12th month (P = 0.722) and of the average healing time (P = 0.181). No significant differences were found in hip function scores (HHS and WOMAC Osteoarthritis Index) between two groups. Conclusion: Fixation with autogenous cortical plate from the cylinder of femoral bone contributes to early bone union of osteotomy ends in Crowe type IV DDH patients compared to those who do not apply the technique. Besides of application of autogenous cortical strut grafts, relevant measures are as well recommended to prevent nonunion after SSO.

Computer-guided buccal cortical plate separation for removal of calcified benign odontogenic tumors affecting the mandibular angle region.

PURPOSE: Surgical removal of intra-bony calcific benign lesions is technically challenging regarding its accessibility, proximity to vital structures, and deteriorating effect on the remaining bony structures. METHODS: Computer-guided buccal cortical plate separation was performed for ten patients using patient-specific osteotomy locating guides and pre-bent plates. The guide was designed to outline the osteotomy, the buccal cortical plate was separated, the lesion was removed, and finally, the pre-bent plates were used to fix the separated cortex. RESULTS: Surgical procedures were uneventful for all patients, operation time was 39.5 ± 13.01 min, postoperative pain decreased within the follow-up time intervals, and there was a statistical significant difference between the time intervals (P value < 0.001). Edema and trismus were acceptable. One case showed nerve affection which resolved after 4 weeks. CONCLUSION: Computer-guided buccal cortical plate separation for removal of intra-bony calcified benign lesions provides a promising approach, especially for inexperienced surgeons. TRIAL REGISTRATION: ClinicalTrials.gov NCT05329974 . Registered on 6 April 2022-retrospectively registered.

Proximity of maxillary molar apexes to the cortical bone surface and the maxillary sinus.

Objectives: This study aimed to analyze the proximity of maxillary molar roots to their overlying cortical bone surfaces and the maxillary sinus. Materials and Methods: Cone-beam computed tomographic images of 151 patients with completely erupted upper molars that had 3 separate roots were studied. The following distances were measured: from the root apex to the cortical plate and maxillary sinus floor, and from the apical 3-mm level of the root to the cortical plate. Differences between groups were analyzed with 1-way analysis of variance and the Scheffé post hoc test, the significance of differences between cone-beam computed tomography views with the paired t-test, and the significance of differences among age groups with linear regression analysis. The significance level was set at p < 0.05. Results: The mesiobuccal and distobuccal root apexes of maxillary second molars were more distant from the buccal cortical plate than the maxillary first molars (p < 0.05). The apical 3-mm level of the mesiobuccal root of the first molar was closer to the buccal cortical bone than the second molar (p < 0.05). In the maxillary first molars, the thickness of the buccal cortical bone decreased in all roots with age (p < 0.05). In all root apexes of both molars, the difference in the vertical level between the maxillary sinus floor and the root apex increased with age (p < 0.05). Conclusions: Awareness of the anatomical profile of maxillary molar apices in relation to the cortical bones and maxillary sinus will be beneficial for apical surgery.

Involvement of strawberry notch homologue 1 in neurite outgrowth of cortical neurons.

When the regulation of axonal and dendritic growth is altered, the neuronal network becomes disordered, which may contribute to the development of psychiatric disorders. Some genome analyses have suggested relationships between mutations in strawberry notch homologue 1 (SBNO1) and neurodevelopmental disorders. However, the function of SBNO1 has not yet been reported. Here, SBNO1 expression pattern during the development of the cerebral cortex in mice was examined. SBNO1 was strongly expressed in the cortical plate and its expression was maintained at a low level during the postnatal stage. CRISPR/Cas9-based knockout of Sbno1 in Neuro2A cultured cells showed delayed growth of neurites. A cortical neuron-specific conditional knockout mouse was constructed, which resulted in hypotrophy of axon bundles and dendrites in cortical neurons. Thus, when mutated, SBNO1 is a candidate gene for psychiatric diseases, such as schizophrenia, as suggested by human genome studies.

Comparison Between the Bone Lid Technique and the Traditional Technique in Surgical Treatment of the Posterior Mandibular Lesions: A Randomized Controlled Trial.

Introduction Cystic lesions of the jaws and the impacted teeth are two of the most common cases that require surgical intervention in oral and maxillofacial surgery; however, surgeons also frequently use a traditional technique that involves the removal of the buccal bone plate. This study was conducted to compare the clinical and radiologic outcomes of the bone lid technique and the traditional technique. Methods This randomized controlled trial included 20 patients who were randomly divided into two groups (n = 10 each): the T group, in which the lesions were accessed using the traditional technique with classical rotating instruments, and the BL group, in which the lesions were accessed with the bone lid technique performed using a piezoelectric device, with repositioning of the buccal bone plate. Operative time, pain, edema, inferior alveolar nerve injury, and bone defect healing were measured during clinical and radiological follow-ups at 24 h, 72 h, one week, one month, and six months after the surgery. Results Normal soft tissue and bone healing were observed in all cases except one case in the BL group. The T group had a shorter mean operative time than the BL group. In terms of pain, edema, and inferior alveolar nerve injury, the groups did not differ statistically significantly. The percentage of bone defect healing was significantly greater in the BL group than in the T group after six months of follow-up. Conclusion The bone lid technique performed using a piezoelectric device was effective and safe for managing lesions in the posterior mandibular region and was not associated with increased postoperative complications. The disadvantages of this technique include a longer operative time and the need for fixation tools in some cases. In contrast, this technique outperforms the traditional technique in terms of reducing bone loss and improving the healing of bone defects.

Anterior buccal mandibular depression: A descriptive study of CT findings.

Objective: This study aims to report the concurrence of the radiographic features of anterior buccal mandibular depressions (ABMDs) and anterior lingual mandibular depressions (ALMDs) by conventional computed tomography (CT) and cone beam CT scans. We also assess the effect of ABMDs and ALMDs on dental implant sites. Methods: A retrospective review of CT scans of the mandibles with ABMDs was conducted to assess the morphology, site, presence of foramina, ALMDs, and the integrity of the cortical plate. The superoinferior width of ABMD, the buccolingual depth, and mesiodistal length were measured and compared with the thickness of the cortical plate at the depression to the area superior to it. Results: Thirty-seven patients with 74 ABMDs were included in this study. All observed ABMDs occurred bilaterally, and ALMDs with ABMDs occurred in 13 sites (17.56%). In 20 (54%) cases, at least one foramen was noted. The buccal cortical bone was intact in all cases. The contents of ABMDs were found to be fatty. On an average, their superoinferior width was 7.1 mm, buccolingual depth 1.67 mm, and mesiodistal length 18.8 mm. The average buccal cortical bone plate thickness at the ABMD was 1.23 mm (range 0.4-1.9 mm), while the average buccal cortical bone plate thickness coronal to the ABMD was 1.34 mm (range 0.7-2.2 mm). The average buccolingual dimension of the mandible was 8.72 mm (range 4.15-13.4 mm) at ABMD sites without ALMD and 4.6 mm with ALMD (range 1.8-8 mm). Conclusion: When ALMD occurs in the presence of ABMD, the amount of bone available for implant placement is greatly reduced.

Identifying cortical plate inclination as a parameter to re-assess transverse discrepancies in untreated adults with different vertical facial heights-A retrospective CBCT study.

OBJECTIVE: To determine the inclination angles of buccal, palatal cortical plates and assess its harmony with existing molar buccolingual inclination in adults with different vertical facial heights. The aim of this study was to identify the role of cortical plate inclination as a diagnostic tool for determining alveolar support in adults with transverse discrepancies. MATERIALS AND METHODS: One-hundred and fifty seven CBCTs (50-Hypo-divergent, 51-Normo-divergent and 56-Hyper-divergent growth patterns) of untreated adults were utilized. Cross-sectional slices with respect to the maxillary first molar were taken as orientation landmarks in defined reference planes. Inclination angles for the first molar, buccal and palatal cortical plate were determined with respect to the palatal plane. ANOVA and Post Hoc Tukey's HSD test were carried out to determine significant differences between groups. RESULTS: Molar inclination was significantly greater in hyper-divergent groups compared to normo-divergent and hypo-divergent groups (P < .05). Greater variation between molar inclination and cortical plate inclination (buccal and palatal) was seen in hyper-divergent groups (P < .05). Hypo-divergent and normo-divergent groups showed almost similar molar and cortical plate inclinations; however, there was a significant difference between the buccal and palatal cortical plates (P < .05). CONCLUSIONS: Cortical plate inclination is in agreement with molar inclination in hypo- and normo-divergent groups when compared to hyper-divergent groups. In adults with decreased/normal facial heights, greater balance and harmony is observed between the dental and alveolar substructures in the posterior region. In adults with increased facial heights, a greater amount of dentoalveolar compensation is seen with respect to the molar and its surrounding bone support.

Mid-pregnancy maternal immune activation increases Pax6-positive and Tbr2-positive neural progenitor cells and causes integrated stress response in the fetal brain in a mouse model of maternal viral infection.

Maternal immune activation (MIA) in midpregnancy is a risk factor for neurodevelopmental disorders. Improper brain development may cause malformations of the brain; maldevelopment induced by MIA may lead to a pathology-related phenotype. In this study, a single intraperitoneal injection of 20 mg/kg polyriboinosinic-polyribocytidylic acid [poly(I:C)] was administered to C57BL/6J mice on embryonic day (E) 12.5 to mimic maternal viral infection. Histopathological analysis of neurogenesis was performed using markers for Pax6, Tbr2, and Tbr1. In these fetuses, significant increases were observed in the proportion of Pax6-positive neural progenitor cells and Pax6/Tbr2 double-positive cells 24 h after poly(I:C) injection. There were no differences in the proportion of Tbr1-positive postmitotic neurons 48 h after poly(I:C) injection. At E18.5, there were more Pax6-positive and Tbr2-positive neural progenitor cells in the poly(I:C)-injected group than in the saline-injected group. Gene ontology enrichment analysis of poly(I:C)-induced differentially expressed genes in the fetal brain at E12.5 demonstrated that these genes were enriched in terms including response to cytokine, response to decreased oxygen levels in the category of biological process. At E13.5, activating transcription factor 4 (Atf4), which is an effector of integrated stress response, was significantly upregulated in the fetal brain. Our results show that poly(I:C)-induced MIA at E12.5 leads to dysregulated neurogenesis and upregulates Atf4 in the fetal brain. These findings provide a new insight in the mechanism of MIA causing improper brain development and subsequent neurodevelopmental disorders.

Effect of prenatal exposure of green tea extract on the developing central nervous system of rat fetuses; histological, immune-histochemical and ultrastructural studies.

Although, several health benefits were associated with green tea, these effects may be beneficial up to a certain dose. Higher doses of green tea may cause several adverse effects. So, there is a need to test the potential negative effects of green tea during pregnancy. This study was designated to evaluate the effect of prenatal exposure of green tea extract on the development of the central nervous system of 20-day old rat fetuses. The pregnant rats were divided into 4 groups; the control group (received distal water) and the other 3 groups received green tea extract at different doses (200, 600 & 1000 mg/kg/day, respectively) from the 6th to 15th day of gestation i.e., during the organogenesis phase of development. Cerebral cortex, cerebellum and spinal cord specimens were subjected to histological, immunohistochemical and ultrastructure investigations. The body weight of both mothers and fetuses was significantly decreased in the groups that received 600 and 1000 mg green tea extract. Also, the neuronal tissues displayed various signs of degeneration which were evident with the 600 and 1000 mg doses. Green tea extract also increases the glial fibrillary acidic protein (GFAP) and decreases the proliferating cell nuclear antigen (PCNA) which were directly proportional with increasing the dose. Administration of green tea extract during rat organogenesis period induced various histological, immunohistochemical and ultrastructural degenerative changes in the cerebral cortex, cerebellum and spinal cord of 20-day old rat fetuses. These deleterious changes were directly proportional to increasing the green tea extract dose. Thus, it should be stressed that the effect of green tea is dose-dependent and therefore it can be either beneficial or adverse.

Morphological Development Trajectory and Structural Covariance Network of the Human Fetal Cortical Plate during the Early Second Trimester.

During the early second trimester, the cortical plate, or "the developing cortex", undergoes immensely complex and rapid development to complete its major complement of neurons. However, morphological development of the cortical plate and the precise patterning of brain structural covariance networks during this period remain unexplored. In this study, we used 7.0 T high-resolution magnetic resonance images of brain specimens ranging from 14 to 22 gestational weeks to manually segment the cortical plate. Thickness, area expansion, and curvature (i.e., folding) across the cortical plate regions were computed, and correlations of thickness values among different cortical plate regions were measured to analyze fetal cortico-cortical structural covariance throughout development of the early second trimester. The cortical plate displayed significant increases in thickness and expansions in area throughout all regions but changes of curvature in only certain major sulci. The topological architecture and network properties of fetal brain covariance presented immature and inefficient organizations with low degree of integration and high degree of segregation. Altogether, our results provide novel insight on the developmental patterning of cortical plate thickness and the developmental origin of brain network architecture throughout the early second trimester.

A Clinical Evaluation of Cone-beam Computed Tomography: Implications for Endodontic Microsurgery.

INTRODUCTION: Cone-beam computed tomographic (CBCT) imaging is a valuable diagnostic tool for endodontics. Some studies report that CBCT images have limitations in representing the true clinical presentation. This prospective, in vivo study compared limited field of view (LFOV) CBCT measurements with clinical measurements made during endodontic surgery. METHODS: Eighty-seven subjects requiring endodontic surgery and LFOV CBCT acquisition of the surgical site were enrolled. Data collection involved clinicians answering standardized questions during the radiographic and surgical assessment. Intraoperatively, data were collected and photographically documented. Postoperatively, CBCT scans were evaluated by 3 calibrated, board-certified specialists: 2 endodontists and 1 oral and maxillofacial radiologist. The 2 subsets of data were compared through statistical analysis to quantify their relationship. RESULTS: The subjects included 65 maxillary and 29 mandibular teeth from 87 subjects: 25 women and 62 men with an average age of 42 years old. The CBCT evaluators correctly identified the presence or absence of buccal plate fenestrations with 91.0% accuracy (95% confidence interval, 83.1-96.0) with 89.4% sensitivity and 92.9% specificity. The area of fenestrations measured clinically (mean = 19.6 ± 33.4 mm2) was generally larger than the area measured by CBCT imaging (mean across CBCT evaluators = 12.2 ± 19.1 mm2). Fenestration size in the maxillary arch was more likely to be underestimated than in the mandibular arch (P < .0001). Vertical bone height was also underestimated when measured on CBCT imaging. CONCLUSIONS: Based on the findings of this study, LFOV CBCT imaging accurately identifies the presence or absence of buccal plate fenestrations, yet, when a fenestration is present, underestimates its area.

Evaluation of facial and palatal alveolar bone thickness and sagittal root position of maxillary anterior teeth on cone beam computerized tomograms.

BACKGROUND: Amount of bone covering the facial and palatal surface of the root and the sagittal root position are important parameters while considering an immediate implant placement. AIMS: This study measures the distance from cement-enamel junction (CEJ) to alveolar crest and thickness of alveolar bone of maxillary anterior teeth facially and palatally at 5 different points. MATERIALS AND METHODS: CBCT scans of 79 systemically healthy patients were evaluated by two calibrated and independent examiners. Measurements like: 1) distance from CEJ to Crest. 2) Thickness of facial and palatal alveolar bone at five different points a) Crest, b) 2 mm from the crest, c) mid root level, d) apical 3rd, e) apex. 3) Sagittal root position. 4) Labiopalatal distance at the apex. 5) Length of the bone from apex to the nasal floor for incisors. 6) Presence of fenestrations and dehiscences were assessed. RESULTS: Healthy maxillary anteriors were evaluated and less than 2 mm bone was seen at all five points, 0.5 to 1 mm bone is seen in all anteriors at crest, 2 mm from crest, midroot, apical 3rd level. 1 to 2 mm is seen at apex. Labiopalatal width at apex ranged from 3 mm to 13 mm with a mean of 7.45 ± 2.24 mm for centrals, 7.69 ± 2.14 mm for lateral incisors, and 6.76 ± 2.42 mm for canines. CONCLUSION: The present study supports the finding of very thin facial bone over maxillary anteriors and frequent occurrence of fenestrations and dehiscences. Pre-treatment evaluation of alveolar bone surrounding the maxillary anteriors is important to avoid complications during implant placement.