Altered expression of serum lncRNA CASC2 and miRNA-21-5p in COVID-19 patients.

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has a high incidence of spread. On January 30, 2020, the World Health Organization proclaimed a public health emergency of worldwide concern. More than 6.9 million deaths and more than 768 million confirmed cases had been reported worldwide as of June 18, 2023. This study included 51 patients and 50 age- and sex-matched healthy subjects. The present study aimed to identify the expression levels of lncRNA CASC2 and miRNA-21-5p (also known as miRNA-21) in COVID-19 patients and their relation to the clinicopathological characteristics of the disease. The expression levels of noncoding RNAs were measured by RT-PCR technique. Results detected that CASC2 was significantly downregulated while miRNA-21-5p was significantly upregulated in COVID-19 patients compared to healthy subjects. A significant negative correlation was found between CASC2 and miRNA-21-5p. ROC curve analysis used to distinguish COVID-19 patients from controls. MiRNA-21-p serum expression level had a significant positive association with temperature and PO2 (p = 0.04 for each). These findings indicate that CASC2 and miRNA-21-p might be used as potential diagnostic and therapeutic biomarkers in COVID-19.

Toxic effects of AB-CHMINACA on liver and kidney and detection of its blood level in adult male mice.

BACKGROUND: AB-CHMINACA is a cannabimimetic indazole derivative. In 2013, it was reported in different countries as a substance of abuse. PURPOSE: This study evaluated the subacute toxic effects of AB-CHMINACA on the liver and kidneys and measured its blood level in adult male mice. METHODS: The histological and biochemical subacute toxic effects on the liver and kidneys were assessed after four weeks of daily intraperitoneal injections of one of the following doses: 0.3 mg/kg, 3 mg/kg, or 10 mg/kg as the highest dose in adult male albino mice. In addition, the blood concentration level of AB-CHMINACA was determined by GC-MS-MS. RESULTS: The histological effects showed congestion, hemorrhage, degeneration, and cellular infiltration of the liver and kidney tissues. Considering the control groups as a reference, biochemical results indicated a significant increase in the serum AST only in the highest dose group, while the ALT and creatinine levels did not significantly change. The mean values of AB-CHMINACA blood levels were 3.05 ± 1.16, 15.08 ± 4.30, and 54.43 ± 8.70 ng/mL for the three treated groups, respectively, one hour after the last dose of intraperitoneal injection. The calibration curves were linear in the 2.5-500 ng/mL concentration range. The intra-assay precision and accuracy of the method were less than 7.0% (RSD) and ± 9.2% (Bias). CONCLUSION: This research supports the available case reports on AB-CHMINACA toxicity that it has low lethality; still, the chronic administration causes evident liver and kidney histotoxic effects even at low doses with unnoticeable clinical effects in mice.

Seroprevalence of SARS-CoV-2 immunoglobulin G antibody during COVID-19 pandemic in Fayoum District, Egypt: a community-based pilot survey.

Introduction: controlling the worldwide pandemic, coronavirus disease (COVID-19), could be impossible due to the hesitancy about the available vaccines and the difficulty to implement strict restrictions. Little information is available about herd immunity in the highly vulnerable region of North East Africa, Egypt. The objective of this study was to assess the seroprevalence of SARS-CoV-2 during the pandemic in one of the highly vulnerable populations in Egypt, the Fayoum district of Fayoum Governorate. Additionally, to assess the predictive value of symptoms and other associated risk factors towards a positive COVID-19 test. Methods: in this cross-sectional community-based pilot study, immunoglobulin G (IgG) antibodies that are specific for the SARS-CoV-2 spike (S1-RBD) protein were tested during the period from February 2021 to July 2021. Results: out of 155 participants, 60.6% were SARS-CoV-2 seropositive. Out of symptomatic and asymptomatic individuals, 76.5% and 56.2% were seropositive, respectively. Surprisingly, only one individual had received the COVID-19 vaccine. Previous history of COVID-19; such as symptoms and gender are statistically significant predictors of high seroconversion independent of age, comorbidities, and level of education. Conclusion: this study which disclosed unexpectedly high SARS-CoV-2 seroconversion among the Egyptians, might provide a clear insight into COVID-19 transmission patterns and state of immunity. Further study with a larger sample size on a large scale is required to represent the whole local population.

Lead (Pb) and cadmium (Cd) blood levels and potential hematological health risk among inhabitants of the claimed hazardous region around Qaroun Lake in Egypt.

BACKGROUND: Lead (Pb) and cadmium (Cd) heavy metals are considered potentially hazardous toxins which cause serious health problems. Many studies reported that the water of Qaroun Lake in Fayoum, Egypt with its fish farms was contaminated with Pb and Cd above permissible levels. However, there is a lack of studies addressing levels of these toxic metals among inhabitants. OBJECTIVES: We aimed to evaluate blood levels of Pb and Cd and their potential health risk among inhabitants around Qaroun Lake. MATERIALS AND METHODS: This case-control study estimated Pb and Cd blood levels among 190 individuals from two destinations (near and far away) of Qaroun Lack using an atomic absorption spectrometer after full history taking and routine checkup investigations; Full blood count, serum ferritin, liver enzyme (ALT), and creatinine levels. RESULTS: There was a significant difference between blood levels of Pb and Cd heavy metals of inhabitants from near and far away Qaroun Lake destinations (p-value < 0.001). The majority of inhabitants around Qaroun Lake had Pb and Cd blood levels above permissible levels (100% and 60% respectively). Critical levels out of them were 12.1% and 30.3% respectively. In comparison to inhabitants faraway Qaroun Lake, three individuals (2.4%) had Cd above the permissible level, while all of them (100%) had Pb level within the permissible level. There were no statistically significant differences between the two sampled populations as regards hemoglobin level, ALT, creatinine, and ferritin serum levels (p-value > 0.05). The difference between studied populations regarding types of anemia was not statistically significant. Subclinical leucopenia was higher in the population near Qaroun Lake when compare to inhabitants far from the lake (13.6% vs. 4.8%, p-value 0.032). CONCLUSION: Bio-monitoring of populations exposed to Pb and Cd hazardous substances could help in generating an early warning system to reduce the disease burden associated with their toxicity.

Assessment of artificial intelligence-based remote monitoring of clear aligner therapy: A prospective study.

INTRODUCTION: Artificial intelligence remote monitoring of clear aligner therapy has recently gained popularity. It uses deep learning algorithms on a patient's mobile smartphone to determine readiness to progress to the next aligner (ie, GO vs NO-GO) and identify areas in which the teeth are not tracking with the clear aligners. This study aimed to assess the repeatability of the Go or No-Go instructions provided by the application and to determine the 3-dimensional discrepancies that constitute an unseat. METHODS: Thirty patients in treatment with clear aligners at an academic clinic were scanned twice using a remote monitoring application on a smartphone, and the results were compared. Gauge repeatability and reproducibility analysis were performed. Intraoral and remote monitoring scans were obtained on the same day from 24 additional clear aligner patients that completed treatment using their final aligners. The intraoral scan after using the final aligner and the stereolithography file of the planned position at the final aligner was compared with measure the maximum discrepancies between the actual and planned position of the teeth. RESULTS: Gauge compatibility of 44.7% was noted. In total 83.3% of patient instructions agreed between Scan 1 and 2, but 0% agreed completely on which and/or how many teeth had tracking issues. Patients who received GO instruction had mean greatest discrepancies of 1.997 mm, 1.901 mm, 0.530 mm, 8.911°, 7.827°, and 7.049° in mesiodistal, buccolingual, occlusogingival, tip, torque, and rotational dimensions, respectively. These discrepancies were not significantly different from patients receiving NO-GO instruction (1.771 mm, 1.808 mm, 0.606 mm, 8.673°, 8.134°, and 6.719° for the corresponding categories). CONCLUSIONS: Despite the study's limitations, these findings suggest concerns with the consistency of remote monitoring instructions because of gauge compatibility over the industry standard. Similarly, large discrepancies in tooth position for patients receiving GO and NO-GO instruction suggest that artificial intelligence decisions were inconsistent with quantitative findings.

Seroprevalence of SARS-CoV-2 immunoglobulin G antibody during COVID-19 pandemic in Fayoum District, Egypt: a community-based pilot survey

Introduction: controlling the worldwide pandemic, coronavirus disease (COVID-19), could be impossible due to the hesitancy about the available vaccines and the difficulty to implement strict restrictions. Little information is available about herd immunity in the highly vulnerable region of North East Africa, Egypt. Objectives: to assess the seroprevalence of SARS-CoV-2 during the pandemic in one of the highly vulnerable populations in Egypt, Fayoum district of Fayoum Governorate. Additionally, to assess the predictive value of symptoms and other associated risk factors towards a positive COVID-19 test. Methods: in this cross-sectional community-based pilot study, immunoglobulin G (IgG) antibodies that are specific for the SARS-CoV-2 spike (S1-RBD) protein were tested during the period from February 2021 to July 2021. Results: out of 155 participants, 60.6% were SARS-CoV-2 seropositive. Out of symptomatic and asymptomatic individuals, 76.5% and 56.2% were seropositive, respectively. Surprisingly, only one individual had received the COVID-19 vaccine. Previous history of COVID-19; such as symptoms and gender are statistically significant predictors of high seroconversion independent of age, comorbidities, and level of education. Conclusion: this study which disclosed unexpectedly high SARS-CoV-2 seroconversion among the Egyptians, might provide a clear insight into COVID-19 transmission patterns and state of immunity. Further study with a larger sample size on a large scale is required to represent the whole local population.

Quantitative OCT Angiography Assessment of the Effect of Peribulbar Anesthesia on Retinal Microvasculature in Primary Open-Angle Glaucoma Patients Undergoing Cataract Surgery.

Objective: To assess the effect of peribulbar anesthesia on retinal microvasculature in primary open-angle glaucoma (POAG) patients undergoing cataract surgery using OCT Angiography. Participants: Forty-nine patients undergoing cataract surgery were divided into two groups. Group I included patients with no history of glaucoma, while group II included patients previously diagnosed as POAG with controlled IOP. Each participant received 6 mL of peribulbar anesthetic injection of 4 mL lidocaine 2% containing 150 IU hyaluronidase and 2 mL bupivacaine 0.5%. They were scanned with the OCT-A 10 minutes before and 10 minutes after injection for foveal deep (DCP), superficial (SCP) capillary plexuses density and total vessel density, foveal avascular zone (FAZ) diameter, optic disc total vessel density, and radial peripapillary capillary (RPC) network density. In addition, IOP was checked before and 10 minutes after injection. Results: Median percent change in DCP post-injection was significantly greater in group II (-43%) than in group I (-2.5%) (P < 0.001). Also, DCP total density median percent change post-injection was significantly higher in group II (-21%) than in group I (-0.9%) (P < 0.001). Foveal SCP vessel density and total vessel density median percent change post-injection were -62.6% and -16.2%, respectively, in group II and were -2.6% and -1.1%, respectively, in group I, which are statistically significant (P < 0.001). The FAZ diameter median percentage change post-injection was higher in group II (40.6%) than in group I (2.5%) (P < 0.001). Optic disc total vessel density and radial peripapillary capillary (RPC) network density post-injection median percent change were significantly higher in group II (-13.6%) and (-13.1%) respectively than in group I (-1.1%) and (-1.25%) respectively (P < 0.001). Conclusion: Peribulbar anesthesia harbors a deleterious ischemic effect on the retinal vascular tree of glaucoma patients, which could harmfully affect the vision and the visual field in those vulnerable patients.

Demodex Mites in Relation to the Degree of Acne Vulgaris among Egyptian Patients.

<b>Background and Objective:</b> <i>Demodex</i> mites are considered to play a pathogenic role in facial dermatoses as <i>Acne vulgaris</i>. In this study the association between <i>Acne vulgaris</i> and <i>Demodex</i> spp. intensity, kind and activity were investigated. <b>Materials and Methods:</b> Two degrees of acne was included, mild acne (30 cases) and moderate to severe acne (30 cases), besides 30 healthy subjects as a control. Deep skin scraping followed by direct microscopic detection was applied to diagnose demodicosis. <b>Results:</b> All the detected mites in moderate to severe acne were <i>D. folliculorum</i> which was observed in a highly dynamic status with their entire life cycle stages with intensity >5 mites per cm^{<a href="2246157_ja">2</a>}. While very few inactive <i>D. brevis</i> mites were detected in the 2 subjects related to the control group<i>. </i>Despite that females comprised the majority of acne cases, males encompassed a statistically higher number than females among positive demodicosis cases. Itching and hair loss were the significant clinical signs within positive cases. Regarding risk factors, oily skins, repeated exposure to the sun, stressful lifestyle plus defective use of facial cleansers were found to be statistically significant. <b>Conclusion:</b> These results attained an association between moderate to severe acne and energetic <i>D. folliculorum</i> entire population. Thus, this study recommended lifestyle's modification for those cases suffering from <i>Acne vulgaris</i> with deep facial cleaning to avoid such infestation that worsens acne condition. Accordingly, once acne treatments are ineffective, consideration of <i>Demodex</i> mites with the needed acaricidal therapy is necessary.

Influence of COVID­19 on the Prognosis and Medication Compliance of Glaucoma Patients in the Nile Delta Region.

OBJECTIVE: To assess the influence of the COVID-19 pandemic on the medication adherence and follow-up of glaucoma patients in the Nile Delta region. SETTING: A tertiary care center in the Nile Delta region, Egypt. STUDY DESIGN: An observational, cross-sectional study. PARTICIPANTS: Patients' records (2019-2020; group A) and (2020-2021; group B) were assessed for missed follow-up visits, medication adherence, number of trabeculectomies performed, and uncontrolled patients. In addition, a telephone-based questionnaire involving randomly chosen 200 patients from B.G.U. was carried out to clarify the potential causes of poor patients' compliance. RESULTS: There was a marked decline in the number of newly diagnosed patients and patients on regular follow-up with incidence rates 0.208 and 0.088 in group (A) and group (B), respectively (P-value < 0.0001). The number of compliant patients in group B decreased with an incidence rate difference of 0.312. The number of trabeculectomies declined in group (B) with an incidence rate in group (A) 0.131 compared to 0.081 in group (B). On the other hand, the number of uncontrolled glaucoma patients increased in group B with an incidence rate difference -0.231 between the two groups. 21.5% of patients who participated in the questionnaire identified financial issues as the leading cause of non-compliance. Comorbidities (19.5%), lockdown and transportation difficulties were also highlighted. CONCLUSION: COVID-19 had greatly hampered glaucoma care in the Nile Delta region. As a result, we need to implement new technologies like telemedicine and improve patients' awareness of glaucoma care. Training orthoptists and using mobile glaucoma care services would also be helpful ways of managing glaucoma during that pandemic.

Pharmaceutical humanitarian assistance in the establishment of a drug compounding laboratory in a refugee camp.

In 1992 Medicus Mundi Mediterrània and the Sahrawi Arab Democratic Republic spearheaded a cooperation project to set up a small  drug compounding laboratory in the Sahrawi refugee camps located in the desert town of Rabouni (Algeria's Tindouf province). The goal of the  project was to build a drug compounding facility, create a training center  for local staff, and ensure local production of medicines in cases of  inadequate supply.With the help of external experts and of multiple public and private organizations and institutions, a small compounding laboratory was established with separate work areas, similar to the lines of the  laboratories found in Spanish hospitals. The laboratory now has a stable team of 10-12 pharmacy technicians led by a pharmacist. In the  last 25 years, 40 Sahrawis have been trained through internships in  hospital pharmacy departments abroad, visits to drug compounding labs in other countries, tutoring, and ongoing training programs. Products that  can be compounded in the laboratory include capsules, oral solutions,  creams and ointments, topical solutions, eye drops, and sterile irrigation  and lavage solutions. Over fifty different formulations of varying degrees of complexity have been prepared. One of the most significant challenges, given the political situation and the geographical environment, has been  the procurement and transportation of the active ingredients and the packaging materials/equipment required for the compounding process. After 25 years of continuous work, this project is now a reality thanks to the effort and direct involvement of the Sahrawi people. The experience gained in the last few years has shown the importance of coordinating drug preparation with local prescribing physicians, as well as having quality standards and facilities with homologated low complexity basic equipment that allows, in other areas that is required, the replication of this model.

En 1992, Medicus Mundi Mediterrània y la República Árabe Saharaui Democrática iniciaron un proyecto de cooperación para el  establecimiento de un pequeño laboratorio de producción de  medicamentos en los campamentos de refugiados del pueblo saharaui,  situado en pleno desierto del Sahara, concretamente en Rabuni, Tindouf  (Argelia). Los objetivos del proyecto fueron establecer una estructura e  instalaciones que permitieran la elaboración de medicamentos, crear un  centro de formación de personal local y facilitar cierta capacidad de  producción en situaciones de crisis o emergencia ante la falta de  medicamentos.Mediante el asesoramiento externo y la ayuda de múltiples organizaciones, instituciones y entidades privadas, se construyó un  pequeño laboratorio de características similares al que teníamos en los  hospitales españoles, con áreas diferenciadas de trabajo. El laboratorio  dispone de un equipo humano estable de 10-12 técnicos superiores de  farmacia dirigidos por un farmacéutico.A lo largo de estos 25 años se han formado y capacitado 40 saharauis, a través de estancias externas en servicios de farmacia, visitas a  laboratorios de producción de otros países, tutorización de farmacéuticos y cursos de formación continuada. Se han incluido varias líneas de  producción de medicamentos como: cápsulas, soluciones orales, cremas y  pomadas, soluciones tópicas, colirios, soluciones de irrigación y lavado  estériles. Se han elaborado más de 50 formulaciones distintas, todas ellas de diferente grado de complejidad. Una de las limitaciones más relevantes, por la situación y entorno, fue y sigue siendo la adquisición y envío de materia prima, material de acondicionamiento y/o equipos, necesarios en  cualquier proceso de elaboración. Después de estos 25 años de trabajo  continuado se evidencia la realidad de este proyecto, fruto del esfuerzo e  implicación del pueblo saharaui. La experiencia adquirida en estos años  plantea la extrema necesidad de coordinar las actividades de elaboración  con los equipos médicos y/o prescriptores de la zona, así como disponer  de estándares de calidad e instalaciones con equipos básicos homologados y de baja complejidad, que faciliten la replicación del modelo en distintos ámbitos y/o zonas de actuación.

Cooperación farmacéutica en el establecimiento de un laboratorio de producción de medicamentos en un campamento de refugiados / Pharmaceutical humanitarian assistance in the establishment of a drug compounding laboratory in a refugee camp

En 1992, Medicus Mundi Mediterrània y la República Árabe SaharauiDemocrática iniciaron un proyecto de cooperación para el establecimientode un pequeño laboratorio de producción de medicamentos en los campamentos de refugiados del pueblo saharaui, situado en pleno desiertodel Sahara, concretamente en Rabuni, Tindouf (Argelia). Los objetivos delproyecto fueron establecer una estructura e instalaciones que permitieran laelaboración de medicamentos, crear un centro de formación de personallocal y facilitar cierta capacidad de producción en situaciones de crisis oemergencia ante la falta de medicamentos.Mediante el asesoramiento externo y la ayuda de múltiples organizaciones, instituciones y entidades privadas, se construyó un pequeño laboratoriode características similares al que teníamos en los hospitales españoles, conáreas diferenciadas de trabajo. El laboratorio dispone de un equipo humanoestable de 10-12 técnicos superiores de farmacia dirigidos por un farmacéutico. (AU)

In 1992 Medicus Mundi Mediterrània and the Sahrawi Arab Democratic Republic spearheaded a cooperation project to set up a small drugcompounding laboratory in the Sahrawi refugee camps located in thedesert town of Rabouni (Algeria’s Tindouf province). The goal of the project was to build a drug compounding facility, create a training center forlocal staff, and ensure local production of medicines in cases of inadequate supply.With the help of external experts and of multiple public and privateorganizations and institutions, a small compounding laboratory wasestablished with separate work areas, similar to the lines of the laboratories found in Spanish hospitals. The laboratory now has a stableteam of 10-12 pharmacy technicians led by a pharmacist. In the last 25years, 40 Sahrawis have been trained through internships in hospitalpharmacy departments abroad, visits to drug compounding labs in other countries, tutoring, and ongoing training programs. Products that can becompounded in the laboratory include capsules, oral solutions, creamsand ointments, topical solutions, eye drops, and sterile irrigation andlavage solutions. (AU)

miR-155 T/A (rs767649) and miR-146a A/G (rs57095329) single nucleotide polymorphisms as risk factors for chronic hepatitis B virus infection among Egyptian patients.

Genetic variants in microRNAs (miRNAs) can alter the miRNAs expression and/or function, accordingly, affecting the related biological pathways and disease risk. Dysregulation of miR-155 and miR-146a expression levels has been well-described in viral hepatitis B (HBV). In the current study, we aimed to assess rs767649 T/A and rs57095329 A/G polymorphisms in miR-155, and miR-146a genes, respectively, as risk factors for Chronic HBV (CHBV) in the Egyptian population. Also, we aimed to do in silico analysis to investigate the molecules that primarily target these miRNAs. One hundred patients diagnosed as CHBV and one hundred age and sex-matched controls with evidence of past HBV infection were genotyped for miR-155 (rs767649) and miR-146a (rs57095329) using real-time polymerase chain reaction. The rs767649 AT and AA genotypes in CHBV patients confer four folds and ten folds risk respectively, as compared to control subjects [(AOR = 4.245 (95%CI 2.009-8.970), p<0.0001) and AOR = 10.583 (95%CI 4.012-27.919), p<0.0001, respectively)]. The rs767649 A allele was associated with an increased risk of developing CHBV (AOR = 2.777 (95%CI 1.847-4.175), p<0.0001). There was a significant difference in the frequency of rs57095329 AG and GG genotypes in CHBV patients compared to controls. AG and GG genotypes showed an increase in the risk of developing CHBV by about three and six folds respectively [AOR = 2.610 (95%CI 1.362-5.000), p = 0.004] and [AOR = 5.604 (95%CI 2.157-14.563), p<0.0001].We concluded that rs57095329 and rs767649 SNPs can act as potential risk factors for the development of CHBV in the Egyptian population.

Tumor necrosis factor (TNF)-α- 308 G/A gene polymorphism (rs1800629) in Egyptian patients with alopecia areata and vitiligo, a laboratory and in silico analysis.

PURPOSE & METHODS: Several single-nucleotide polymorphisms (SNPs) in the promoter region of the TNF-α gene can cause variations in the gene regulatory sites and act as risk factors for some autoimmune disorders as alopecia areata (AA) and vitiligo. This study aimed to detect the serum TNF-α (sTNF) level (by ELISA) and the rs1800629 (by real-time PCR) among AA and vitiligo Egyptian patients and to determine their relation with disease duration and severity. In silico analysis of this SNP to study the molecular regulation of the mutant genotypes was also done. RESULTS: In AA patients, no risk was associated with the mutant genotypes vs. the normal genotype, or with A allele vs. G allele. The risk of vitiligo was significantly higher with the G/A and A/A genotypes compared with HCs (p = 0.011). Similarly, a significantly increased risk was noted in patients with A allele vs. G allele (p<0.0001). In AA and vitiligo patients, a significant increase in sTNF-α levels was noted in the mutant G/A genotypes vs. the normal G/G genotype (p<0.0001) and in the A allele vs the G allele (p<0.0001). According to the in silico analysis, this SNP could mainly affect the SP1 transcription factor binding site with subsequent effect on TNF-α expression. CONCLUSION: According to results of the laboratory and the in silico study, the mutant TNF-α (308) genotypes were risk factors that conferred susceptibility to vitiligo among Egyptian patients but had no effect on the susceptibility to AA.

Can modifying shielding, field of view, and exposure settings make the effective dose of a cone-beam computed tomography comparable to traditional radiographs used for orthodontic diagnosis?

OBJECTIVES: To analyze the effect of changes in exposure settings, field of view (FOV), and shielding on radiation to an adult and child phantom from cone-beam computed tomography (CBCT) imaging compared to panoramic and lateral cephalometric radiographs. MATERIALS AND METHODS: The effective dose to an adult and child anthropomorphic phantom by the CS 9300 using various scan protocols was recorded. Absorbed radiation was measured with optically stimulated luminescence dosimeters and effective dose calculated using 2007 International Commission on Radiological Protection tissue weighting factors. Scan protocols included different FOVs, voxel sizes, and standard versus low-dose protocols. Radiation shielding was used when it did not interfere with FOV. Panoramic and lateral cephalometric radiographs were taken with the Orthophos SL. RESULTS: Even with shielding, smaller FOVs, and increased voxel sizes, the effective dose of standard CBCT scans was higher than panoramic and lateral cephalometric radiographs. A shielded limited FOV standard scan combined with a lateral cephalometric radiograph resulted in a lower dose (P < .001) than a full FOV standard scan. Low-dose shielded scans resulted in significant dose reductions to the adult (P < .05) and child (P < .001) phantoms compared to the respective panoramic and lateral cephalometric radiographs combined. Image quality analysis was not possible with radiation equivalent phantoms. CONCLUSIONS: Unlike standard CBCTs, shielded low-dose CBCT protocols in the CS 9300 have lower effective doses than conventional radiographs for adult and child phantoms. If high resolution and cranial base visualization are necessary, combining a shielded LFOV standard exposure with a cephalometric radiograph is recommended.

Dose reduction in head and neck organs through shielding and application of different scanning parameters in cone beam computed tomography: an effective dose study using an adult male anthropomorphic phantom.

OBJECTIVES: The aim of this study was to determine the effect of shielding and scanning parameters on radiation dose reduction to the organs in the head and neck region in cone beam computed tomography (CBCT). STUDY DESIGN: An anthropomorphic phantom and optically stimulated luminescent dosimeters were used to calculate the changes in effective or equivalent doses to 9 anatomic structures through the addition of a thyroid collar, radiation safety glasses, and a radiation safety cap and by using different scanning protocols on a CS 9300 CBCT unit. RESULTS: The thyroid collar alone yielded dose reductions of 46% to the thyroid gland and at least 38% to the esophagus, but no more than 12% to the salivary glands. The radiation safety cap significantly reduced doses to the brain and the pituitary gland. Full shielding resulted in dose reductions of at least 50% to the thyroid gland, at least 47% to the esophagus, and approximately 35% to the brain and the pituitary gland. Significant dose reductions were recorded for all tissues with the "low dose" setting compared with the standard setting. CONCLUSIONS: Increased protection of the organs in the head and neck regions can be achieved by using various forms of shielding in CBCT imaging, with selection of the most appropriate scanning parameters based on the purpose of the examination.

Orthognathic Surgery and Orthodontics: Inadequate Planning Leading to Complications or Unfavorable Results.

Complications in orthognathic surgery are commonly a result of inadequate preoperative planning and communication between the surgeon and orthodontist. Unfavorable outcomes can often be avoided when overall treatment goals along with a surgical and orthodontic plan are developed and agreed upon by the orthodontist, surgeon, and patient before the start of active tooth movement or any surgical procedures. Continuous evaluation of the patient's progress throughout treatment and subsequent communication between the surgeon and orthodontist are recommended to prevent frequent errors, such as inadequate dental decompensation, poor appliance selection or management, and occasional contraindicated orthodontic elastic traction or tooth movements.

The influence of labiolingual and mesiodistal anterior tooth dimensions on interarch relationships: A modified anterior Bolton analysis.

INTRODUCTION: Tooth size and morphology of anterior teeth influence interarch relationships. The Bolton analysis uses tooth width to calculate a sum of mandibular to maxillary tooth width ratios necessary for proper occlusion. Several parameters not factored in the Bolton analysis influence occlusion, such as tooth thickness. This study sought to use 3D modeling to develop and assess a tooth size analysis that encompasses labioligual thickness as well as mesiodistal width of anterior teeth. METHODS: The role of tooth thickness in interarch relationships was studied using simulations in a 3D modeling software (Suresmile). To develop a new chart of interarch ratios based on tooth thickness, a series of simulations were produced with varying tooth thicknesses and widths. The new ratios were evaluated on records from 50 patients. RESULTS: Findings from the simulations suggest that the ideal tooth thickness remains approximately 2 mm if the overall tooth width of the dentition increases and the interarch anterior ratio is maintained. The thickness-adjusted anterior mandibular to maxillary tooth ratio ranges from 0.70-0.79 depending on the tooth thickness. This thickness-adjusted ratio provides a superior prediction for the sum of anterior tooth width compared with the Bolton analysis. CONCLUSION: Tooth thickness affects interarch tooth width ratios and anterior occlusion. A thickness-adjusted ratio can be used to more accurately predict anterior tooth dimensions necessary to achieve proper occlusion.

The relationship between 3D dentofacial photogrammetry measurements and traditional cephalometric measurements.

OBJECTIVES: To determine the relationship between traditional cephalometric measurements and corresponding nonradiographic three-dimensional (3D) photogrammetry measurements. MATERIALS AND METHODS: This was a cross-sectional study of 20 orthodontic patients (10 male and 10 female) who received lateral cephalometric radiographs and 3D dentofacial photogrammetric records with each subject serving as his or her own control for a total sample size of 40 images (20 per method). A 3D analysis that resembled a traditional cephalometric analysis was established using the eyes and natural head orientation as substitutes for the cranial base. Pearson correlation coefficients and multivariable linear regression plots were calculated to evaluate the relationship between the photogrammetry measurements and the cephalometric measurements. RESULTS: The ANB angle, mandibular plane angle, lower anterior face height, upper incisor angle to SN, upper incisor angle to NA, and all measurements of lower incisor position and inclination had strong positive Pearson correlation coefficients with the corresponding 3D photogrammetry measurements ( P < .004). Statistically significant regression plots demonstrated that cephalometric relationships between the jaws and incisor orientation can be predicted from corresponding 3D photogrammetry measurements. CONCLUSIONS: 3D photogrammetry measurements relating the jaws to each other and incisor orientation has a strong positive correlation with corresponding traditional cephalometric measurements and can serve as cephalometric predictors. Capturing the eyes using 3D photogrammetry can obviate the need to expose the cranial base and allow limiting the radiographic field to the area of interest.

A modified Steiner's analysis that does not require radiographic exposure of the cranial base.

OBJECTIVE: To correlate traditional Steiner's skeletal and dental measurements to similar measurements that use the eyes and natural head position as references instead of the cranial base. SETTING AND SAMPLE: One hundred and fifty-two lateral cephalometric radiographs (66 female and 86 male) from the Harvard Forsyth twin sample were included in the study based on record availability. MATERIAL AND METHODS: This was an observational study in which all cephalometric radiographs were traced and analysed using Steiner's cephalometric analysis. Each cephalogram was then altered to perform a similar analysis that uses the maximum convexity of the cornea together with natural head position as references instead of the cranial base. A Pearson product-moment correlation coefficient was measured to determine the correlation between the conventional Steiner's analysis measurements and the novel measurements relying on the eyes and natural head position. RESULTS: Steiner's cephalometric measurements of the jaws to each other, the divergency and the orientation of the incisors had a strong positive correlation with their counterparts that relied on true horizontal and/or the eyes (P < 0.001). CONCLUSION: The eyes and true horizontal can be used as alternatives to the cranial base when diagnosing the relationship between the jaws and the position and orientation of the teeth. Since the eyes and natural head position are identifiable without ionizing radiation, future research should focus on the use of radiographic exposures limited to the upper and lower jaws for orthodontic diagnosis and outcome assessment.