Craniofacial syndromes and class III phenotype: common genotype fingerprints? A scoping review and meta-analysis.

Skeletal Class III (SCIII) is among the most challenging craniofacial dysmorphologies to treat. There is, however, a knowledge gap regarding which syndromes share this clinical phenotype. The aims of this study were to: (i) identify the syndromes affected by the SCIII phenotype; (ii) clarify the involvement of maxillary and/or mandibular structures; (iii) explore shared genetic/molecular mechanisms. A two-step strategy was designed: [Step#1] OMIM, MHDD, HPO, GeneReviews and MedGen databases were explored; [Step#2]: Syndromic conditions indexed in [Step#1] were explored in Medline, Pubmed, Scopus, Cochrane Library, WOS and OpenGrey. Eligibility criteria were defined. Individual studies were assessed for risk of bias using the New Ottawa Scale. For quantitative analysis, a meta-analysis was conducted. This scoping review is a hypothesis-generating research. Twenty-two studies met the eligibility criteria. Eight syndromes affected by the SCIII were targeted: Apert syndrome, Crouzon syndrome, achondroplasia, X-linked hypohidrotic ectodermal dysplasia (XLED), tricho-dento-osseous syndrome, cleidocranial dysplasia, Klinefelter and Down syndromes. Despite heterogeneity between studies [p < 0.05], overall effects showed that midface components were affected in Apert and Down Syndromes, lower face in Klinefelter Syndrome and midface and lower face components in XLED. Our review provides new evidence on the craniofacial characteristics of genetically confirmed syndromes exhibiting the SCIII phenotype. Four major regulatory pathways might have a modulatory effect on this phenotype. IMPACT: What does this review add to the existing literature? To date, there is no literature exploring which particular syndromes exhibit mandibular prognathism as a common trait. Through this research, it was possibly to identify the particular syndromes that share the skeletal Class III phenotype (mandibular prognathism) as a common trait highlighting the common genetic and molecular pathways between different syndromes acknowledging their impact in craniofacial development.

East Asian and Southern European craniofacial class III phenotype: two sides of the same coin?

OBJECTIVES: The skeletal class III phenotype is a heterogeneous condition in populations of different ethnicities. This study aimed to analyse the joint and ethnicity-specific clustering of morphological features in skeletal class III patients of Asian and European origins. MATERIALS AND METHODS: This cross-sectional study involved South Korean and Spanish participants who fulfilled the cephalometric, clinical, and ethnic-related selection criteria. Radiographic records were standardised, calibrated, and measured. A total of 54 skeletal variables were selected for varimax factorial analysis (VFA). Subsequently, a cluster analysis (CA) was performed (mixed method: k-means and hierarchical clustering). Method error and precision were assessed using ICC, Student's t-test, and the Dahlberg formula. RESULTS: A total of 285 Korean and Spanish participants with skeletal class III malocclusions were analysed. After performing VFA and CA, the joint sample revealed three global clusters, and ethnicity-specific analysis revealed four Korean and five Spanish clusters. Cluster_1_global was predominantly Spanish (79.2%) and male (83.01%) and was characterised by a predominantly mesobrachycephalic pattern and a larger cranial base, maxilla, and mandible. Cluster_2_global and Cluster_3_global were mainly South Korean (73.9% and 75.6%, respectively) and depicted opposite phenotypes of mandibular projection and craniofacial pattern. CONCLUSIONS: A distinct distribution of Spanish and South Korean participants was observed in the global analysis. Interethnic and interethnic differences were observed, primarily in the cranial base and maxilla size, mandible projection, and craniofacial pattern. CLINICAL RELEVANCE: Accurate phenotyping, reflecting the complexity of skeletal class III phenotype across diverse populations, is critical for improving diagnostic predictability and future personalised treatment protocols.

Chronic obstructive pulmonary disease mortality in Spain between 1999 and 2019 / Mortalidad por enfermedad pulmonar obstructiva crónica en España entre 1999 y 2019

Introduction Mortality from COPD has decreased in Spain in recent years, but it is unknown whether this decline has been homogeneous among the different regions. Methods From the Statistical Portal of the Ministry of Health of Spain we obtained the age-adjusted mortality rates/100,000 inhabitants for men and women in Spain and the Autonomous Communities for the years 1999–2019, using the coding of the International Classification of Diseases (ICD 10, sections J40–J44). With the adjusted rates we performed a jointpoint regression analysis to estimate an annual percentage change (APC), as well as identify possible points of trend change. Statistical significance was considered for a value of p<0.05. Results During the study period, COPD mortality rates adjusted in Spain decreased from 28.77 deaths/100,000 inhabitants in 1999 to 12.14 deaths/100,000 inhabitants in 2019. We observed a linear decline in COPD mortality in men at national level of −3.67% per year (95% CI −4.1 to −3.4; p<0.001), with differences between the Autonomous Communities. Mortality in women also experienced a decrease in mortality in two phases, with a first period from 1999 to 2006 with a fall of −6.8% per year (95% CI −8.6 to −5.0; p<0.001) and a second period from 2006 to 2019 with a decrease in mortality of −2.1% (95% CI −2.8 to −1.3; p<0.001), with again differences between the Autonomous Communities. Conclusion Mortality rates from COPD have decreased heterogeneously among the different Autonomous Communities in both men and women (AU)

Introducción La mortalidad por EPOC ha disminuido en España en los últimos años, pero se desconoce si esta caída ha sido homogénea entre las diferentes comunidades autónomas. Metodología consultando el Portal Estadístico del Ministerio de Sanidad de España obtuvimos las tasas ajustadas por edad/100.000 habitantes para hombres y mujeres de España y las CCAA para los años 1999 a 2019, utilizando la codificación de la Clasificación Internacional de Enfermedades (CIE 10, secciones J40 a J44). Con las tasas ajustadas realizamos un análisis de regresión de jointpoint con el objetivo de estimar un porcentaje anual de cambio (APC), así como identificar posibles puntos de cambio de tendencia. Se consideró la significación estadística para un valor de p<0.05. Resultados Durante el periodo de estudio, las tasas de mortalidad global ajustada por EPOC en España pasaron de 28.77 muertes/100.000 habitantes en 1999 a 12.14 muertes/100.000 habitantes en 2019. Observamos una caída de la mortalidad por EPOC en varones a nivel de España lineal del -3.67% anual (IC 95% -4.1 a -3.4; p<0.001), con diferencias entre las CCAA. La mortalidad en mujeres también experimentó una disminución de mortalidad en dos fases, con un primer periodo de 1999 a 2006 con caída del -6.8% anual (IC 95% -8.6 a -5.0; p<0.001) y un segundo periodo de 2006 a 2019 con un descenso de la mortalidad del -2.1% (IC 95% -2.8 a -1.3; p<0.001), encontrando diferencias entre las CCAA. Conclusiones Las tasas de mortalidad por EPOC han disminuido de forma heterogénea entre las diferentes CCAA (AU)

Chronic obstructive pulmonary disease mortality in Spain between 1999 and 2019.

INTRODUCTION: Mortality from COPD has decreased in Spain in recent years, but it is unknown whether this decline has been homogeneous among the different regions. METHODS: From the Statistical Portal of the Ministry of Health of Spain we obtained the age-adjusted mortality rates/100,000 inhabitants for men and women in Spain and the Autonomous Communities for the years 1999-2019, using the coding of the International Classification of Diseases (ICD 10, sections J40-J44). With the adjusted rates we performed a jointpoint regression analysis to estimate an annual percentage change (APC), as well as identify possible points of trend change. Statistical significance was considered for a value of p<0.05. RESULTS: During the study period, COPD mortality rates adjusted in Spain decreased from 28.77 deaths/100,000 inhabitants in 1999 to 12.14 deaths/100,000 inhabitants in 2019. We observed a linear decline in COPD mortality in men at national level of -3.67% per year (95% CI -4.1 to -3.4; p<0.001), with differences between the Autonomous Communities. Mortality in women also experienced a decrease in mortality in two phases, with a first period from 1999 to 2006 with a fall of -6.8% per year (95% CI -8.6 to -5.0; p<0.001) and a second period from 2006 to 2019 with a decrease in mortality of -2.1% (95% CI -2.8 to -1.3; p<0.001), with again differences between the Autonomous Communities. CONCLUSION: Mortality rates from COPD have decreased heterogeneously among the different Autonomous Communities in both men and women.

Skeletal Class III phenotype: Link between animal models and human genetics: A scoping review.

This study aimed to identify evidence from animal studies examining genetic variants underlying maxillomandibular discrepancies resulting in a skeletal Class III (SCIII) malocclusion phenotype. Following the Manual for Evidence Synthesis of the JBI and the PRISMA extension for scoping reviews, a participant, concept, context question was formulated and systematic searches were executed in the PubMed, Scopus, WOS, Scielo, Open Gray, and Mednar databases. Of the 779 identified studies, 13 met the selection criteria and were included in the data extraction. The SCIII malocclusion phenotype was described as mandibular prognathism in the Danio rerio, Dicentrarchus labrax, and Equus africanus asinus models; and as maxillary deficiency in the Felis silvestris catus, Canis familiaris, Salmo trutta, and Mus musculus models. The identified genetic variants highlight the significance of BMP and TGF-ß signaling. Their regulatory pathways and genetic interactions link them to cellular bone regulation events, particularly ossification regulation of postnatal cranial synchondroses. In conclusion, twenty genetic variants associated with the skeletal SCIII malocclusion phenotype were identified in animal models. Their interactions and regulatory pathways corroborate the role of these variants in bone growth, differentiation events, and ossification regulation of postnatal cranial synchondroses.

Reorganization of the Flagellum Scaffolding Induces a Sperm Standstill During Fertilization.

Mammalian sperm delve into the female reproductive tract to fertilize the female gamete. The available information about how sperm regulate their motility during the final journey to the fertilization site is extremely limited. In this work, we investigated the structural and functional changes in the sperm flagellum after acrosomal exocytosis and during the interaction with the eggs. The evidence demonstrates that the double helix actin network surrounding the mitochondrial sheath of the midpiece undergoes structural changes prior to the motility cessation. This structural modification is accompanied by a decrease in diameter of the midpiece and is driven by intracellular calcium changes that occur concomitant with a reorganization of the actin helicoidal cortex. Although midpiece contraction may occur in a subset of cells that undergo acrosomal exocytosis, live-cell imaging during in vitro fertilization showed that the midpiece contraction is required for motility cessation after fusion is initiated. These findings provide the first evidence of the F-actin network's role in regulating sperm motility, adapting its function to meet specific cellular requirements during fertilization, and highlighting the broader significance of understanding sperm motility. Significant statement: In this work, we demonstrate that the helical structure of polymerized actin in the flagellum undergoes a rearrangement at the time of sperm-egg fusion. This process is driven by intracellular calcium and promotes a decrease in the sperm midpiece diameter as well as the arrest in motility, which is observed after the fusion process is initiated.

Debilidad pulmonar asociada a COVID-19 (DPAC): revisión sistemática y metaanálisis / COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis

Objetivo: Evaluar la mortalidad y diversos factores clínicos derivados del desarrollo de neumotórax (NTX) y/o neumomediastino (NMD) atraumáticos en pacientes críticos como consecuencia de la debilidad pulmonar asociada a la COVID-19 (DPAC). Diseño: Revisión sistemática con metaanálisis. Ámbito: Unidad de cuidados intensivos (UCI). Participantes: Investigaciones originales en las que se evaluase a pacientes, con o sin necesidad de ventilación mecánica invasiva (VMI), con diagnóstico de COVID-19 que hubiesen desarrollado NTX o NMD atraumáticos al ingreso o durante su estancia hospitalaria. Intervenciones: Se obtuvieron los datos de interés de cada artículo que fueron analizados y evaluados por la Escala Newcastle-Ottawa. El riesgo de las variables de interés principales se evaluó por los datos derivados de los estudios que incluyeron a pacientes que desarrollaron NTX o NMD atraumáticos. Variables de interés principales: Mortalidad, estancia media en la UCI y PaO2/FiO2 media en el momento diagnóstico. Resultados: Se recogieron datos de 12 estudios longitudinales. En el metaanálisis se incluyeron datos de un total de 4.901 pacientes, entre los cuales 1.629 presentaron un episodio de NTX y 253 de NMD atraumáticos. A pesar de encontrar asociaciones significativamente fuertes, la alta heterogeneidad entre los estudios hace que la interpretación de los resultados deba hacerse con cautela. Conclusiones: La mortalidad de los pacientes con COVID-19 fue mayor en los que desarrollaron NTX y/o NMD atraumáticos con respecto a los que no lo hicieron. La media del índice PaO2/FiO2 fue menor en los pacientes que desarrollaron NTX y/o NMD atraumáticos. Proponemos agrupar bajo el término DPAC estos casos. (AU)

Objectives: To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW). Design: Systematic review with meta-analysis. Setting: Intensive care unit (ICU). Participants: Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19 who had developed atraumatic PNX or PNMD on admission or during their hospital stay. Interventions: Data of interest were obtained from each article and analysed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed by data derived from studies including patients who developed atraumatic PNX or PNMD. Main variables of interest: Mortality, mean ICU length of stay and mean PaO2/FiO2 at diagnosis. Results: Data were collected from 12 longitudinal studies. Data from a total of 4,901 patients were included in the meta-analysis. A total of 1,629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite finding significantly strong associations, the high heterogeneity between studies means that interpretation of the results should be made with caution. Conclusions: Mortality of COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose to group these cases under the term CAPD. (AU)

COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis.

OBJECTIVES: To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW). DESIGN: Systematic review with meta-analysis. SETTING: Intensive Care Unit (ICU). PARTICIPANTS: Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19, who developed atraumatic PNX or PNMD on admission or during hospital stay. INTERVENTIONS: Data of interest were obtained from each article and analyzed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed with data derived from studies including patients who developed atraumatic PNX or PNMD. MAIN VARIABLES OF INTEREST: Mortality, mean ICU stay and mean PaO2/FiO2 at diagnosis. RESULTS: Information was collected from 12 longitudinal studies. Data from a total of 4901 patients were included in the meta-analysis. A total of 1629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite the finding of significantly strong associations, the great heterogeneity between studies implies that the interpretation of results should be made with caution. CONCLUSIONS: Mortality among COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose grouping these cases under the term COVID-19-associated lung weakness (CALW).

[COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis]. / Debilidad pulmonar asociada a COVID-19 (DPAC): revisión sistemática y metaanálisis.

Objectives: To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW). Design: Systematic review with meta-analysis. Setting: Intensive care unit (ICU). Participants: Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19 who had developed atraumatic PNX or PNMD on admission or during their hospital stay. Interventions: Data of interest were obtained from each article and analysed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed by data derived from studies including patients who developed atraumatic PNX or PNMD. Main variables of interest: Mortality, mean ICU length of stay and mean PaO2/FiO2 at diagnosis. Results: Data were collected from 12 longitudinal studies. Data from a total of 4,901 patients were included in the meta-analysis. A total of 1,629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite finding significantly strong associations, the high heterogeneity between studies means that interpretation of the results should be made with caution. Conclusions: Mortality of COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose to group these cases under the term CAPD.

Structured Illumination Microscopy Improves Spot Detection Performance in Spatial Transcriptomics.

Spatial biology is a rapidly growing research field that focuses on the transcriptomic or proteomic profiling of single cells within tissues with preserved spatial information. Imaging-based spatial transcriptomics uses epifluorescence microscopy, which has shown remarkable results for the identification of multiple targets in situ. Nonetheless, the number of genes that can be reliably visualized is limited by the diffraction of light. Here, we investigate the effect of structured illumination (SIM), a super-resolution microscopy approach, on the performance of single-gene transcript detection in spatial transcriptomics experiments. We performed direct mRNA-targeted hybridization in situ sequencing for multiple genes in mouse coronal brain tissue sections. We evaluated spot detection performance in widefield and confocal images versus those with SIM in combination with 20×, 25× and 60× objectives. In general, SIM increases the detection efficiency of gene transcript spots compared to widefield and confocal modes. For each case, the specific fold increase in localizations is dependent on gene transcript density and the numerical aperture of the objective used, which has been shown to play an important role, especially for densely clustered spots. Taken together, our results suggest that SIM has the capacity to improve spot detection and overall data quality in spatial transcriptomics.

DIAGNOSTIC PERFORMANCE OF CONE-BEAM COMPUTED TOMOGRAPHY TO DIAGNOSE IN VIVO/IN VITRO ROOT RESORPTION: A SYSTEMATIC REVIEW AND META-ANALYSIS.

BACKGROUND: This review analyses the diagnostic performance of cone-beam computed tomography (CBCT) for the in vivo/in vitro detection of external root resorption (ERR) and critically analyses current and past methods of measuring or classifying ERR in vivo/in vitro in terms of radiation doses and cumulative radiation risks. METHODS: A diagnostic test accuracy (DTA) protocol was used for a systematic review of diagnostic methods following PRISMA guidelines. The protocol was registered with PROSPERO (ID: CRD42019120513). A thorough and exhaustive electronic search of 6 core electronic databases was performed, applying the ISSG Search Filter Resource. The eligibility criteria were designed [problem-intervention-comparison-outcomes (PICO) statement: Population, Index test, Comparator, Outcome] and methodological quality was assessed by QUADAS-2. RESULTS: Seventeen papers were selected from a total of 7841 articles. Six in vivo studies were assessed as having a low risk of bias. The overall sensitivity and specificity of CBCT for diagnosis of ERR was 78.12% and 79.25%, respectively. The highest and lowest sensitivity and specificity of CBCT for diagnosis of external root resorption are 42%-98% and 49.3%-96.3%. DISCUSSION: Most of the selected studies reported quantitative diagnoses with single linear measurements of ERR even though multislice radiographs were available. The cumulative radiation dose (µS) to radiation-sensitive structures, such as the bone marrow, brain and thyroid, was observed to increase using the 3-dimensional (3D) radiography methods reported. CONCLUSIONS: The highest and lowest sensitivity and specificity of CBCT for diagnosis of external root resorption are 42%-98% and 49.3%-96.3%. The minimum and maximum effective doses of dental CBCT for external root resorption diagnosis are 34 µSv and 1073 µSv.

Craniofacial characteristics in Van der Woude syndrome.

AIM: To describe the particular craniofacial characteristics of Van der Woude syndrome(VWS) patients compared to patients with a non-syndromic cleft (CG1) and to a malocclusive healthy population (CG2). MATERIAL AND METHODS: Retrospective case-control study. A sample of 110 matched-patients was recruited (VWS (n = 7), CG1 (n = 49), CG2 (n = 49)). Subsequently, 37 radiometric variables were analysed and the dental-skeletal ages were determined. The intra/inter-observer method errors were quantified. Descriptive statistics were computed, and different inferential analysis tests were used depending on the normality of the data (Chi-square test, Fisher's exact test, paired Student's T-test, Mann-Whitney U test) (p-value < 0.05). Pairwise comparisons were corrected by Bonferroni's criteria. RESULTS: VW-patients presented specific craniofacial characteristics and morphology. A marked tendency to the vertical growth pattern was found in VW-patients compared to CG1-CG2 (p < 0.001); at the sagittal level, skeletal class II caused by mandibular retrognathism, with a greatly increased ANB angle compared to CG1 (p = 0.042). Dental analysis showed that the lower incisor was more retruded and retroclined (p < 0.05 in all cases) and the interincisal angulation was increased (p < 0.001 (CG2)). At the profile level, an open nasolabial angle (p = 0.040; CG1) and a more protruding lower lip with respect to the Sn-Pg plane (p = 0.040 (CG1); p = 0.044 (CG2)) were observed. CONCLUSIONS: VW-patients present particular characteristics in the facial skeletal structures. There is a critical necessity to increase the evidence regarding specific clinical features and orofacial pathology of rare diseases such as VWS, which will help to these minorities to gain access in the future to a better quality of care with precise treatment and diagnostic necessities.

Extending resolution within a single imaging frame.

The resolution of fluorescence microscopy images is limited by the physical properties of light. In the last decade, numerous super-resolution microscopy (SRM) approaches have been proposed to deal with such hindrance. Here we present Mean-Shift Super Resolution (MSSR), a new SRM algorithm based on the Mean Shift theory, which extends spatial resolution of single fluorescence images beyond the diffraction limit of light. MSSR works on low and high fluorophore densities, is not limited by the architecture of the optical setup and is applicable to single images as well as temporal series. The theoretical limit of spatial resolution, based on optimized real-world imaging conditions and analysis of temporal image stacks, has been measured to be 40 nm. Furthermore, MSSR has denoising capabilities that outperform other SRM approaches. Along with its wide accessibility, MSSR is a powerful, flexible, and generic tool for multidimensional and live cell imaging applications.

Fluorescence fluctuation-based super-resolution microscopy: Basic concepts for an easy start.

Due to the wave nature of light, optical microscopy has a lower-bound lateral resolution limit of approximately half of the wavelength of visible light, that is, within the range of 200 to 350 nm. Fluorescence fluctuation-based super-resolution microscopy (FF-SRM) is a term used to encompass a collection of image analysis techniques that rely on the statistical processing of temporal variations of the fluorescence signal. FF-SRM aims to reduce the uncertainty of the location of fluorophores within an image, often improving spatial resolution by several tens of nanometers. FF-SRM is suitable for live-cell imaging due to its compatibility with most fluorescent probes and relatively simple instrumental and experimental requirements, which are mostly camera-based epifluorescence instruments. Each FF-SRM approach has strengths and weaknesses, which depend directly on the underlying statistical principles through which enhanced spatial resolution is achieved. In this review, the basic concepts and principles behind a range of FF-SRM methods published to date are described. Their operational parameters are explained and guidance for their selection is provided.

Due to light's wave nature, an optical microscope's resolution range is 200 to 350 nanometers. Several techniques enhance resolution; this work encompasses several fluorescence fluctuation super-resolution (FF-SMR) methods capable of achieving nanoscopic scales. FF-SRM is known to be suitable for fixed or live-cell imaging and compatible with most conventional microscope setups found in a laboratory. However, each FF-SRM approach has its strengths and weaknesses, which depend directly on the underlying principles through which enhanced spatial resolution is achieved. Therefore, the basic concepts and principles behind diverse FF-SRM methods are revisited in this review. In addition, their operational parameters are explained, and guidance for their selection is provided for microscopists interested in FF-SRM.

Assessment of metal ion accumulation in oral mucosa cells of patients with fixed orthodontic treatment and cellular DNA damage: a systematic review.

Intraoral fixed appliances remain in the potentially corrosive environment of the mouth for an average of two years. Over time, corrosion causes the release of metal ions, such as nickel and chromium. These metals can become allergenic and cytotoxic, causing different conditions in the human body. The aim of this study therefore is to carry out a systematic review of the available scientific evidence on the accumulation of metal ions, and the genotoxic and cytotoxic effects in oral mucosa cells deriving from short- and long-term exposure to them. The systematic review is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome (quantification of metal ion deposits and assessment of their genotoxic and/or cytotoxic effects) and secondary outcome (complementary analysis of cytotoxic and genotoxic effects) were examined. The Cochrane Collaboration tool and Toxicological data Reliability Assessment Tool (ToxRTool) were used for quality assessment. Once the search was performed, a total of seven articles met the inclusion criteria and were included in this study. Two main techniques were used to assess genotoxic effects: alkaline comet assay (6/7) and micronucleus method (1/7). Cytotoxicity was evaluated (4/7) using the trypan blue dye test. Accumulations of nickel (7/7), chromium (5/7), and other metals (zinc, cobalt, iron, manganese, molybdenum, titanium) were also quantified. The results allowed us to conclude that release of metal ions and acute cell and DNA damage in oral mucosa cells takes place in the early stages of treatment. However, more long-term studies are needed to evaluate chronic exposure to metals and DNA damage, as well as cellular capacity to recover DNA integrity.

Orthodontic root resorption.

External apical root resorption (EARR) is one of the most frequently reported iatrogenic side effects of orthodontic movement. Nevertheless, no robust and unequivocal scientific evidence is yet available in the literature regarding the clinical and biological factors that trigger EARR. The purpose of the present position paper is to provide clinicians, residents, and investigators a summary of our current understanding about root resorption caused by orthodontic tooth movement, based on up-to-date available scientific evidence. Morphological, structural, biomechanical, and biological differences account for predisposing the apical third to EARR compared to other root surfaces during orthodontic treatment. In addition, a relevant number of patient and treatment-related factors increase risk of EARR. The main patient-related factors are reviewed and discussed: genetic factors, tooth anatomy, demographic factors, malocclusion factors, previous endodontic treatment, medical history, short root anomaly. Similarly, the influence of treatment-related factors are analyzed with regard to the effect of: biomechanical factors, type of orthodontic appliance, adjunctive therapies to accelerate tooth movement, early treatment, maxillary expansion, teeth extractions, the duration of treatment and the amount of apical displacement. Clinical management of EARR from pre-treatment records to the monitoring strategy as well as recommendations for the post orthodontic-treatment period are presented as a guide for the clinician. Despite years of studies, we still do not fully understand EARR, but the future is promising. True three-dimensional imaging with higher resolution and low radiation, and predictive tools towards an earlier detection without radiographs, will mark future developments in the field of EARR in orthodontics.

Genetic factors contributing to skeletal class III malocclusion: a systematic review and meta-analysis.

OBJECTIVES: The present systematic review aims to report and critically assess the findings of the available scientific evidence from genetic association studies examining the genetic variants underlying skeletal class III malocclusion and its sub-phenotypes. MATERIAL AND METHODS: A pre-piloted protocol was registered and followed. The PubMed, Scopus, WOS, Cochrane Library, Gray Open literature, and CADTH databases were explored for genetic association studies following PICOS-based selection criteria. The research was reported in accordance with PRISMA statement and HuGE guidelines. The Q-genie tool was applied to assess the quality of genetic studies. Meta-analysis of genetic association studies was done by means of Meta-Genyo tool. RESULTS: A total of 8258 articles were retrieved, of which 22 were selected for in-depth analysis. Most of the studies did not differentiate between sub-phenotypes, and the cohorts were heterogeneous regarding ethnicity. Four to five principal components of class III malocclusion explained the phenotypic variation, and gene variants at MYO1H(rs10850110), BMP3(rs1390319), GHR (rs2973015,rs6184, rs2973015), FGF7(rs372127537), FGF10(rs593307), and SNAI3(rs4287555) (p < .05) explained most of the variation across the studies, associated to vertical, horizontal, or combined skeletal discrepancies. Meta-analysis results identified a statistically significant association between risk of class III malocclusion of A allele of the FBN3 rs7351083 [OR 2.13; 95% CI 1.1-4.1; p 0.02; recessive model]. CONCLUSION: Skeletal class III is a polygenic trait substantially modulated by ethnicity. A multicentric approach should be considered in future studies to increase sample sizes, applying multivariate analysis such as PCA and cluster analysis to characterize existing sub-phenotypes warranting a deeper analysis of genetic variants contributing to skeletal class III craniofacial disharmony. CLINICAL RELEVANCE: Grasping the underlying mechanisms of this pathology is critical for a fuller understanding of its etiology, allowing generation of preventive strategies, new individualized therapeutic approaches and more accurate treatment planification strategies.

GWAS of Post-Orthodontic Aggressive External Apical Root Resorption Identified Multiple Putative Loci at X-Y Chromosomes.

Personalized dental medicine requires from precise and customized genomic diagnostic. To conduct an association analysis over multiple putative loci and genes located at chromosomes 2, 4, 8, 12, 18, X, and Y, potentially implicated in an extreme type of external apical root resorption secondary to orthodontic forces (aEARR). A genome-wide association study of aEARR was conducted with 480 patients [ratio~1:3 case/control]. Genomic DNA was extracted and analyzed using the high-throughput Axiom platform with the GeneTitan® MC Instrument. Up to 14,377 single nucleotide polymorphisms (SNPs) were selected at candidate regions and clinical/diagnostic data were recorded. A descriptive analysis of the data along with a backward conditional binary logistic regression was used to calculate odds ratios, with 95% confidence intervals [p < 0.05]. To select the best SNP candidates, a logistic regression model was fitted assuming a log-additive genetic model using R software [p < 0.0001]. In this sample the top lead genetic variants associated with aEARR were two novel putative genes located in the X chromosome, specifically, STAG 2 gene, rs151184635 and RP1-30E17.2 gene, rs55839915. These variants were found to be associated with an increased risk of aEARR, particularly restricted to men [OR: 6.09; 95%CI: 2.6-14.23 and OR: 6.86; 95%CI: 2.65-17.81, respectively]. Marginal associations were found at previously studied variants such as SSP1: rs11730582 [OR: 0.54; 95%CI: 0.34-0.86; p = 0.008], P2RX7: rs1718119 [OR: 0.6; 95%CI: 0.36-1.01; p = 0.047], and TNFRSF11A: rs8086340 [OR: 0.6; 95%CI: 0.38-0.95; p = 0.024]), found solely in females. Multiple putative genetic variants located at chromosomes X and Y are potentially implicated in an extreme phenotype of aEARR. A gender-linked association was noted.

Influence of heritability on occlusal traits: a systematic review of studies in twins.

BACKGROUND: The aim of this systematic review was to identify, evaluate, and provide a current literature about the influence of heritability on the determination of occlusal traits. MATERIALS AND METHODS: MEDLINE, SCOPUS, Web of Science, LILACS, and Google Scholar were searched without restrictions up to March 2020. Studies with twin method were considered and the risk of bias assessment was performed using quality of genetic association studies checklist (Q-Genie). The coefficient of heritability (h2), model-fitting approaches, and coefficient correlation were used to estimate the genetic/environmental influence on occlusal traits. The GRADE tool was used to assess the quality of the evidence. RESULTS: Ten studies met the eligibility criteria. Three studies presented good quality, five moderate quality, and two poor quality. Most studies have found that the intra-arch traits, mainly the maxillary arch morphology, such as width (h2 16-100%), length (h2 42-100%), and shape (h2 42-90%), and the crowding, mainly for mandibular arch (h2 35-81%), are under potential heritability influence. The traits concerning the inter-arch relationship, as overjet, overbite, posterior crossbite, and sagittal molar relation, seem not to be genetically determined. The certainty of the evidence was graded as low for all outcomes. CONCLUSIONS: Although weak, the available evidence show that the heritability factors are determinant for the intra-arch traits, namely, arch morphology and crowding. Possibly due they are functionally related, the occlusal traits concerning the maxillary and mandibular relationship seem to have environmental factors as determinants. In this scenario, early preventive approaches can offer a more effective and efficient orthodontic treatment.

Novel Sub-Clustering of Class III Skeletal Malocclusion Phenotypes in a Southern European Population Based on Proportional Measurements.

Current phenotypic characterizations of Class III malocclusion are influenced more by gender or ethnic origin than by raw linear skeletal measurements. The aim of the present research is to develop a Class III skeletal malocclusion sub-phenotype characterization based on proportional cranial measurements using principal component analysis and cluster analysis. Radiometric data from 212 adult subjects (115 women and 96 men) of southern European origin affected by Class III skeletal malocclusion were analyzed. A total of 120 measurements were made, 26 were proportional skeletal measurements, which were used to perform principal component analysis and subsequent cluster analysis. The remaining 94 supplementary measurements were used for a greater description of the identified clusters. Principal component analysis established eight principal components that explained 85.1% of the total variance. The first three principal components explained 51.4% of the variance and described mandibular proportions, anterior facial height proportions, and posterior-anterior cranial proportions. Cluster analysis established four phenotypic subgroups, representing 18.4% (C1), 20.75% (C2), 38.68% (C3), and 22.17% (C4) of the sample. A new sub-clustering of skeletal Class III malocclusions that avoids gender influence is provided. Our results improve clinicians' resources for Class III malocclusion and could improve the diagnostic and treatment approaches for this malocclusion.