Small-bodied males invest in larger testes when highly ornamented.

Sperm competition and male mating rate are two non-mutually exclusive key evolutionary pressures selecting for larger testes within and across animal taxa. A few studies have tried to test the role of mating rate in the absence of sperm competition. Under the mating rate hypothesis, particular phenotypes of a given population that are expected to gain more mates (e.g., more ornamented males) are expected to make higher investments in testes size (a proxy for sperm production). We test this prediction in Polistes simillimus, a neotropical paper wasp in which females are single mated (no sperm competition) and males can mate with multiple partners. Testes size was predicted by body size (positive association), sexual ornamentation (negative association), and their interaction (among small males, testes size was positively related to ornamentation, but the opposite pattern was observed among large males). We propose that small-bodied well-ornamented males may face the highest risk of sperm depletion. Small-bodied males make relatively higher investment in testes size when highly ornamented. This strategy might be less profitable to large males, as they have overall larger testes. Our results provide strong evidence for the mating rate hypothesis.

OCEANIA: real-world study of ovarian cancer treatment patterns across multiple lines of therapy in Argentina and Brazil.

Aim: To evaluate real-world data on treatment patterns in Argentina and Brazil in patients with ovarian cancer. Methods: This study evaluated de-identified antineoplastic exposure data from a private healthcare provider in Argentina and health claims database (Orizon) in Brazil from 2010 to 2019 and 2015 to 2020, respectively. Results: Platinum-based chemotherapy was the most common first-line therapy (Argentina: n =311 [87.6%]; Brazil: n = 1142 [79.3%]). The proportion of patients receiving platinum-based chemotherapy declined across both populations from first- to second-line, while use of non-platinum-based, targeted, and hormone therapies increased. Duration of platinum-based treatment and time to next treatment decreased from first- to fourth-line. Conclusion: There is an unmet need for effective therapies that can prolong time to next treatment in ovarian cancer in Argentina and Brazil.

[Box: see text].

Smelly shark, smelly ray: what is infecting you?

AIMS: Although elasmobranchs are consumed worldwide, bacteriological assessments for this group are still sorely lacking. In this context, this study assessed bacteria of sharks and rays from one of the most important landing ports along the Rio de Janeiro coast. METHODS AND RESULTS: Bacteria were isolated from the cloacal swabs of the sampled elasmobranchs. They were cultured, and Vibrio, Aeromonas, and Enterobacterales were isolated and identified. The isolated bacteria were then biochemically identified and antimicrobial susceptibility assays were performed. Antigenic characterizations were performed for Salmonella spp. and Polymerase Chain Reaction (PCR) assays were performed to identify Escherichia coli pathotypes. Several bacteria of interest in the One Health context were detected. The most prevalent Enterobacterales were Morganella morganii and Citrobacter freundii, while Vibrio harveyi and Vibrio fluvialis were the most prevalent among Vibrio spp. and Aeromonas allosacharophila and Aeromonas veronii bv. veronii were the most frequent among Aeromonas spp. Several bacteria also displayed antimicrobial resistance, indicative of Public Health concerns. A total of 10% of Vibrio strains were resistant to trimethoprim-sulfamethoxazole and 40% displayed intermediate resistance to cefoxitin. Salmonella enterica strains displayed intermediate resistance to ciprofloxacin, nalidixic acid and streptomycin. All V. cholerae strains were identified as non-O1/non-O139. The detected E. coli strains did not exhibit pathogenicity genes. This is the first study to perform serology assessments for S. enterica subsp. enterica isolated from elasmobranchs, identifying the zoonotic Typhimurium serovar. Salmonella serology evaluations are, therefore, paramount to identify the importance of elasmobranchs in the epidemiological salmonellosis chain. CONCLUSIONS: The detection of several pathogenic and antibiotic-resistant bacteria may pose significant Public Health risks in Brazil, due to high elasmobranch consumption rates, indicating the urgent need for further bacteriological assessments in this group.

Frequent Telomerase Reverse Transcriptase Promoter and Fibroblast Growth Factor Receptor 3 Mutations Support the Precursor Nature of Papillary Urothelial Hyperplasia of the Urinary Bladder.

The precursor nature of papillary urothelial hyperplasia of the urinary bladder is uncertain. In this study, we investigated the telomerase reverse transcriptase (TERT) promoter and fibroblast growth factor receptor 3 (FGFR3) mutations in 82 patients with papillary urothelial hyperplasia lesions. Thirty-eight patients presented with papillary urothelial hyperplasia and concurrent noninvasive papillary urothelial carcinoma, and 44 patients presented with de novo papillary urothelial hyperplasia. The prevalence of the TERT promoter and FGFR3 mutations is compared between de novo papillary urothelial hyperplasia and those with concurrent papillary urothelial carcinoma. Mutational concordance between papillary urothelial hyperplasia and concurrent carcinoma was also compared. The TERT promoter mutations were detected in 44% (36/82) of papillary urothelial hyperplasia, including 23 (23/38, 61%) papillary urothelial hyperplasia with urothelial carcinoma and 13 (13/44, 29%) de novo papillary urothelial hyperplasia. The overall concordance of TERT promoter mutation status between papillary urothelial hyperplasia and concurrent urothelial carcinoma was 76%. The overall FGFR3 mutation rate of papillary urothelial hyperplasia was 23% (19/82). FGFR3 mutations were detected in 11 patients with papillary urothelial hyperplasia and concurrent urothelial carcinoma (11/38, 29%) and 8 patients with de novo papillary urothelial hyperplasia (8/44, 18%). Identical FGFR3 mutation status was detected in both papillary urothelial hyperplasia and urothelial carcinoma components in all 11 patients with FGFR3 mutations. Our findings provide strong evidence of a genetic association between papillary urothelial hyperplasia and urothelial carcinoma. High frequency of TERT promoter and FGFR3 mutations suggests the precursor role of papillary urothelial hyperplasia in urothelial carcinogenesis.

Uncertainty model for automated gunshot residue particle length measurements obtained from electron microscopy images.

Currently, the use of algorithms and computer vision systems for metrological purposes has increased in different areas of knowledge to reduce human error and process deviations, consequently increasing reliability and reducing measurement uncertainties. This study presents a model for estimating the uncertainty of Feret's diameter (DF ) measurements of scanning electron microscopy (SEM) images from regular and irregular gunshot residue (GSR) particles at different magnifications. The data were extracted using the automatic measurement algorithm developed by the Brazilian Institute of Metrology, Quality and Technology (Inmetro). The proposed uncertainty model was based on the recommendations of the guide to the expression of uncertainty in measurement (GUM). The gold standard technique to identify and detect GSR particles is the SEM coupled to energy dispersive X-ray spectroscopy (SEM/EDS), which was used in the study. The low uncertainty values obtained in this study are justified by the refinement of the measurements performed at each stage of digital image procedures. The proposed uncertainty model contributes in an innovative way to the metrological evaluation of regular and irregular GSR particles at different images magnifications. The correct morphometry definition of these particles allows to study their distinction from other possible sources of GSR and, above all, their correlation with the type of ammunition used when firing the firearm. These measurement uncertainty calculations can be applied to any object images acquired by SEM, which provides more confidence in the results of measurements of the object of interest.

Effect of dental implant therapy on the preservation of orofacial tissues: A systematic review and meta-analysis.

OBJECTIVE: Fundamentally, this review addresses the following question: In partially or fully edentulous patients, do implant-supported dental prostheses preserve orofacial tissues when compared to conventional prostheses or no therapy? MATERIALS AND METHODS: This study was conducted according to the 2020 PRISMA guidelines for systematic reviews. Electronic searches were conducted at PubMed and Embase databases followed by manual search. Clinical studies comparing the effect of implant-supported prostheses with conventional rehabilitation or no treatment on alveolar bone resorption, remaining teeth, and jaw muscle thickness were considered for inclusion. A qualitative synthesis was conducted with all included studies, and data from selected studies were pooled quantitatively to perform a meta-analysis. RESULTS: A total of 14 studies were selected for analysis. Six studies reported on the effect of implant therapy on alveolar bone resorption (n = 453), six on the remaining teeth (n = 1014), while four studies evaluated masseter muscle thickness (n = 158). The results of the meta-analyses assessing alveolar bone resorption in the posterior mandible and in the anterior area of the maxilla, both fixed and random effects models, yielded no benefit of rehabilitation with implant-supported prostheses when compared to conventional prostheses. For masseter bone thickness, however, a significant benefit for implant-supported prosthesis was observed. CONCLUSIONS: This systematic review and meta-analysis were unable to unequivocally answer the focus question. There are some indicators of the benefit of implant-supported prostheses over conventional prostheses or no therapy in preserving orofacial tissues, particularly for masseter muscle thickness. However, the evidence is still insufficient to confirm such perception.

Group 4 ITI Consensus Report: Patient benefits following implant treatment in partially and fully edentulous patients.

OBJECTIVES: The aim of Working Group 4 was to address patient benefits associated with implant dentistry. Focused questions on (a) dental patient-reported outcomes (dPROs), (b) improvement in orofacial function, and (c) preservation of orofacial tissues in partially and fully edentulous patients following provision of implant-retained/supported dental prostheses were addressed. MATERIALS AND METHODS: Three systematic reviews formed the basis for discussion. Participants developed statements and recommendations determined by group consensus based on the findings of the systematic reviews. These were then presented and accepted following further discussion and modifications as required by the plenary of the 7th ITI Consensus Conference, taking place in 2023 in Lisbon, Portugal. RESULTS: Edentulous patients wearing complete dentures (CD) experience substantial improvements in overall dPROs and orofacial function following treatment with either complete implant-supported fixed dental prostheses (CIFDP) or implant overdentures (IODs). With respect to dPROs, mandibular IODs retained by two implants are superior to IODs retained by one implant. However, increasing the number of implants beyond two, does not further improve dPROs. In fully edentulous patients, rehabilitation with CIFDP or IOD is recommended to benefit the preservation of alveolar bone and masseter muscle thickness. CONCLUSIONS: Completely edentulous patients benefit substantially when at least the mandible is restored using an CIFDP or an IOD compared to CD. In fully edentulous patients, implant prostheses are the best option for tooth replacement. The availability of this treatment modality should be actively promoted in all edentulous communities, including those with limited access and means.

Accuracy of static computer-aided implant surgery (S-CAIS) using CAD-CAM surgical templates fabricated from different additive manufacturing technologies.

STATEMENT OF PROBLEM: Different 3D printers are available for guided implant surgery, but studies that evaluate their source of errors and their cost-effectiveness are lacking. PURPOSE: The purpose of this in vitro study was to compare the accuracy of different 3-dimensional (3D) printed surgical templates made using different additive manufacturing technologies and to evaluate the effect of implant location on the accuracy of fully guided implant placement. MATERIAL AND METHODS: Fifty partially edentulous maxillary typodonts with edentulous sites in the right second premolar (SP), right lateral incisor (LI), left central incisor (CI), and left first molar (FM) locations were scanned and printed from the standard tessellation language (STL) datasets. The study compared 5 groups for the fabrication of implant surgical templates: Varseo S-Bego (Bego), Polyjet-Stratasys (Poly), Low Force Stereolithography-FormLabs (LFS), P30+-Straumann (P30), and M2-Carbon (M2). After fully guided implant placement, the typodont was scanned, and the 3D implant positions were compared with the master model by superimposing the STL files. Descriptive statistics were calculated for groups and subgroups, and comparisons among the groups and subgroups were conducted via 2-way mixed analysis of variance, Tukey honest significant difference, and post hoc Bonferroni tests (α=.05). RESULTS: The results were site specific and not consistent within each group. For angle deviation, the within-group analysis for P30 demonstrated significantly lower values for implants positioned at site SP (1.4 ±0.8 degrees) than for sites LI (2.3 ±0.7 degrees; P=.001) and CI (2.3 ±0.8 degrees; P=.007). For 3D offset at base for implant CI, LFS was significantly higher than Bego (P=.002), Poly (P=.035), or M2 (P=.001); P30 was also significantly higher than Bego (P=.014) and M2 (P=.006). LFS had a significantly higher 3D offset at the tip than Bego (P=.001) and M2 (P=.022) for implant CI. CONCLUSIONS: The choice of 3D printer seemed to influence fully guided implant surgery in terms of the final implant position compared with initial implant planning. However, although statistically significant differences were present across groups, all additive manufacturing technologies were within clinically acceptable values.

Digital vs Conventional Full-Arch Implant Impressions: A Retrospective Analysis of 36 Edentulous Jaws.

PURPOSE: There is a paucity of comparative clinical studies assessing the accuracy of full-arch digital scans versus conventional implant impressions. The aim of this retrospective study was to compare the three-dimensional (3D) deviations between full-arch digital scans and conventional implant impressions for edentulous maxillae and mandibles. MATERIALS AND METHODS: Twenty-seven patients (36 edentulous jaws) were treated with one-piece, screw-retained implant-supported fixed complete dental prostheses (IFCDPs). Twenty-one jaws were maxillary, and 15 were mandibular. Full-arch conventional impressions and intraoral digital scans with scan bodies and an intraoral scanner had been taken during the impression phase. Following verification of the conventional stone casts, the casts were digitized. The generated standard tessellation language (STL) files from both impression techniques were merged and analyzed with reverse engineering software. The primary aim was to evaluate the accuracy between conventional and digital full-arch scans, while the effect of the edentulous jaw in 3D accuracy was the secondary aim. RESULTS: The cumulative 3D (mean ± SD) deviations between virtual casts from intraoral full-arch digital scans and digitized stone casts generated from conventional implant impressions were found to be 88 ±24 µm. In the maxillary group, the mean ± SD 3D deviation was 85 ±25 µm, compared to 92 ±23 µm for the mandibular group (p = 0.444). CONCLUSION: The 3D implant deviations found between the full-arch digital and conventional impressions lie within the clinically acceptable threshold. No statistically significant difference was identified between maxillary and mandibular jaws in terms of 3D deviations.

Cosmopolis: public spaces, cosmopolitanism, and democracy.

What is the role of public spaces in contemporary cities? Despite the growing interest in the theme of public spaces in the last decades, a significant number of authors appeal, directly or indirectly, to ideas of the "regression", "decay", and "crisis" of public life, public sphere, and public spaces. Without disregarding this hegemonic point of view, in the present article we would like to consider other perspectives, which recognize the importance of public spaces, public sociability, and cosmopolitanism for the democratic societies in the context of the contemporary city, the cosmopolis. We therefore propose a bibliographic review that deals with the political nature of public spaces, the dimension of contestation within public sociability, the advent of virtual public spaces, and the geography of cosmopolitan encounters. The article concludes that urban public spaces remain essential for the existence and functioning of democratic societies and institutions.

Delaying testicular sperm extraction in 47,XXY Klinefelter patients does not impair the sperm retrieval rate, and AMH levels are higher when TESE is positive.

STUDY QUESTION: Should testicular sperm extraction (TESE) in non-mosaic 47,XXY Klinefelter syndrome (KS) patients be performed soon after puberty or could it be delayed until adulthood? SUMMARY ANSWER: The difference in sperm retrieval rate (SRR) in TESE was not significant between the 'Young' (15-22 years old) cohort and the 'Adult' (23-43 years old) cohort of non-mosaic KS patients recruited prospectively in parallel. WHAT IS KNOWN ALREADY: Several studies have tried to define predictive factors for TESE outcome in non-mosaic KS patients, with very heterogeneous results. Some authors have found that age was a pejorative factor and recommended performing TESE soon after puberty. To date, no predictive factors have been unanimously recognized to guide clinicians in deciding to perform TESE in azoospermic KS patients. STUDY DESIGN, SIZE, DURATION: Two cohorts (Young: 15-22 years old; Adult: 23-43 years old) were included prospectively in parallel. A total of 157 non-mosaic 47,XXY KS patients were included between 2010 and 2020 in the reproductive medicine department of the University Hospital of Lyon, France. However 31 patients gave up before TESE, four had cryptozoospermia and three did not have a valid hormone assessment; these were excluded from this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data for 119 patients (61 Young and 58 Adult) were analyzed. All of these patients had clinical, hormonal and seminal evaluation before conventional TESE (c-TESE). MAIN RESULTS AND THE ROLE OF CHANCE: The global SRR was 45.4%. SRRs were not significantly different between the two age groups: Young SRR=49.2%, Adult SRR = 41.4%; P = 0.393. Anti-Müllerian hormone (AMH) and inhibin B were significantly higher in the Young group (AMH: P = 0.001, Inhibin B: P < 0.001), and also higher in patients with a positive TESE than in those with a negative TESE (AMH: P = 0.001, Inhibin B: P = 0.036). The other factors did not differ between age groups or according to TESE outcome. AMH had a better predictive value than inhibin B. SRRs were significantly higher in the upper quartile of AMH plasma levels than in the lower quartile (or in cases with AMH plasma level below the quantification limit): 67.7% versus 28.9% in the whole population (P = 0.001), 60% versus 20% in the Young group (P = 0.025) and 71.4% versus 33.3% in the Adult group (P = 0.018). LIMITATIONS, REASONS FOR CAUTION: c-TESE was performed in the whole study; we cannot rule out the possibility of different results if microsurgical TESE had been performed. Because of the limited sensitivity of inhibin B and AMH assays, a large number of patients had values lower than the quantification limits, preventing the definition a threshold below which negative TESE can be predicted. WIDER IMPLICATIONS OF THE FINDINGS: In contrast to some studies, age did not appear as a pejorative factor when comparing patients 15-22 and 23-44 years of age. Improved accuracy of inhibin B and AMH assays in the future might still allow discrimination of patients with persistent foci of spermatogenesis and guide clinician decision-making and patient information. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by a grant from the French Ministry of Health D50621 (Programme Hospitalier de Recherche Clinical Régional 2008). The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: NCT01918280.

A comparative retrospective study of different surgical guide designs for static computer-assisted implant surgery in posterior single edentulous sites.

AIM: The aim of this retrospective clinical study was to compare the accuracy of static Computer-assisted implant surgery (sCAIS) in posterior single edentulous patients using different surgical guide designs. MATERIALS AND METHODS: Thirty-seven partially edentulous patients with a total of 54 implants were included in the study. Seventeen implants were included in Group 1-Unbounded Tooth-Mucosa Supported; 18 implants in Group 2-Unbounded Tooth Supported; and 19 implants in Group 3 (Control)-Bounded Tooth Supported. All partially edentulous patients were treated with fully guided implant surgery using the corresponding surgical guide. Discrepancies between the pre-planned and post-operative implant position were evaluated. RESULTS: The mean angular deviation ± standard deviation (SD) was 2.91 ± 1.56°, 3.33 ± 1.72° and 2.25 ± 1.13° for Groups 1, 2, and 3, respectively. The mean ± SD 3D offset at base was 0.66 ± 0.29 mm, 0.77 ± 0.24 mm, and 0.49 ± 0.22 mm; and 3D offset at tip was 0.84 ± 0.45 mm, 1.07 ± 0.38 mm, and 0.75 ± 0.25 mm for Groups 1, 2, and 3, respectively. No statistically significant differences between groups were found for angular deviation. There were statistically significant differences between Groups 2 and 3 for 3D offset at base (p = .002) and 3D offset at tip (p = .010). CONCLUSIONS: Different surgical guide designs for posterior single edentulous areas appear to be associated with the accuracy level of sCAIS. In unbounded sites, having additional posterior attached soft tissue support is preferable.

Association between pre-operative complications, comorbidities, and in-hospital mortality in a hip fracture cohort: a register study in a tertiary hospital in Brazil.

PURPOSE: The incidence of hip fractures is increasing exponentially due to an aging Brazilian population. Older people had significant comorbidities which increases the risk of post-operative mortality. Our purpose was to examine the association between pre-operative infections and comorbidities on the risk of post-operative in-hospital mortality after proximal femur fracture surgery's, beyond that, to evaluate the association between comorbidities and time to surgery. METHODS: This is a population-based cohort retrospective study, using medical records of all six year consecutive surgical procedures for correction of hip fracture in a tertiary teaching Hospital in Brazil. The exclusion criteria aimed to exclusively allocate patients who had their first hip fracture secondary to low-energy trauma. Multivariate logistical regression was performed and receiver operating characteristic (ROC) curve with area under curve (AUC) to evaluate the sensitivity and specificity of the model. p-value < 0.05 was considered significant. RESULTS: Final sample was composed by 856 consecutive patients with 81 years of median and 164 patients were excluded. The median length of hospital say was five days with - l mortality at 3.6%. Significant variables for increased mortality included the presence of pre-operative infection (odds ratio (OR): 3.9(1.12-8.54), chronic obstructive pulmonary disease (COPD) (OR: 3.83(1.36-10.82)), and systemic arterial hypertension (SAH) (OR: 4.1(1.18-14.25)). Development of pre-operative infection was associated with a delay to surgery (OR: 1.1 (1.08-1.13)). CONCLUSIONS: In older people with proximal femur fracture, the presence of pre-operative infection, COPD and SAH were the strongest risk factor for post-operative in-hospital mortality. Pre-operative infection was associated with statistically significant delay to surgery.

Periodontal plastic surgery for esthetic crown lengthening by using data merging and a CAD-CAM surgical guide.

This article introduced a digital workflow by using data merging and a computer-aided design and computer-aided manufacturing (CAD-CAM) milled surgical guide for an esthetic crown lengthening procedure. The superimposition of intraoral scanning, digital photographs, cone beam computed tomography, and a CAD-CAM surgical guide should increase the predictability of esthetic crown lengthening surgery.

Accuracy of Different Surgical Guide Designs for Static Computer-Assisted Implant Surgery: An In Vitro Study.

The aims of this study were to evaluate the effect of (1) the different surgical guide designs and (2) implant placement location on the accuracy of fully guided implant placement in single edentulous sites using an in vitro study model. Forty-five partially edentulous models were scanned and divided into 3 groups: group 1, tooth-supported full-arch surgical guide; group 2, 3 different tooth-supported shortened surgical guides (SSGs); and group 3, tooth-supported full-arch surgical guide with a crossbar. All surgical guides were printed and used for fully guided implant placement. A total of 180 implants (60 per group) were placed, and scan bodies were positioned on all models, and postoperative surface scan files (STL) files were obtained. Superimposition of preoperative and postoperative STL files was performed, and the accuracy of implant position was evaluated. The interaction between group and implant location was statistically significant for angle, 3D offset at the base, and at the tip (P < .001). The post-hoc tests showed a statistically significantly higher deviation for group 2 compared to group 3 for all outcomes for implants #4 (P < .05) and #7 (P < .05). There was also a statistically significant difference in all outcomes between groups 1 and 3 for implant #7 (P < .05). All surgical guide designs presented satisfactory performance with clinically acceptable levels of deviation. However, SSGs presented higher accuracy for guided implant placement in a single-edentulous site, whereas a full-arch surgical guide with a crossbar presented superior outcomes when 2 or more guided implants were placed simultaneously.

Digital Workflow in Implant Treatment Planning For Terminal Dentition Patients.

Treatment planning for the transition of patients from terminal dentition to full-arch implant rehabilitation poses challenges. Such challenges pertain to achieving the new orientation of the occlusal and esthetic plane as well as the change of vertical dimension of occlusion (VDO), while the fixed provisionalization using a digital workflow still tends to be considered complex and hard to perform. This article illustrates step-by-step the utilization of a digital workflow protocol in the treatment planning for rehabilitation of terminal dentition patients, simplifying the smile design and ensuring that fixed provisionalization serves both functional and esthetic requirements. This protocol includes facially driven, three-dimensional (3D) digital smile design and chairside mock-up restoration workflows that enable prosthetically driven assessment prior to implant treatment planning and 3D printing of surgical templates and prefabricated interim prostheses, which can predictably reduce chairside time and adjustments at the surgical and fixed provisionalization appointment.

Screw-retained surgical guide for implant placement in terminal dentition patients with existing implants.

For patients with existing implants in need of additional implant placement, the use of the existing implants for guide fixation seems to be a logical alternative. Current options for the fabrication of surgical guides involve creating surgical guides that are mucosa-borne and/or retained by fixation pins. Since these existing techniques involve inherent inaccuracies, the fabrication of surgical guides that are screw-retained at the implant- or abutment-level would eliminate the introduction of those same fundamental inaccuracies. The purpose of the present technical report is to illustrate a step-by-step digitally planned guided implant placement protocol for terminal dentition patients with salvageable existing implants requiring full-arch implant rehabilitation. The advantages of this protocol include enhancing the accuracy of guided implant placement with screw-retention versus the traditional mucosa- or fixation pin support. Thus, this simplifies the transition from failing teeth to implants by ensuring that fixed provisionalization serves both functional and esthetic requirements. This protocol can also predictably reduce chairside time and adjustments at the surgical implant placement appointment.

The Use of Surgical Splints in Orthognathic Surgery: A Bibliometric Study.

Introduction Orthognathic surgeries require the use of surgical splints (SS) to stabilize the occlusion and the segments fixed with plates and screws. Technological advances in the field of computing and the possibility of generating three-dimensional (3D) images have brought different possibilities for making SS, which has generated greater predictability and customization of surgical plans. The bibliometric study can have a qualitative character through the scope of articles in a certain area of knowledge. It is a selection process that can track a topic or scientific production. Methods The present study aimed to carry out a bibliometric literature review, in order to assess the evolution of the use of SS and the different planning protocols in orthognathic surgery. The Scopus database was used, with the terms "splint" and "orthognathic surgery." Results A total of 331 articles were found. These were exported to Rayyan for application of the inclusion and exclusion criteria and selection of articles. A total of 76 references were selected and exported to the VOSviewer application for the analysis of bibliometric data. Conclusions Orthognathic surgery was initially not associated with any computerized technological resource; however, it underwent updates between the years 2010 to 2012. These advances allowed surgical planning to become faster, cheaper, and more accurate.

Comparative analysis of dimensional alterations following extraction of maxillary molars using three-dimensional images' superimposition: a CBCT study.

The aims of this study were to (i) evaluate the bone alterations following maxillary molar extraction and (ii) identify the factors associated with bone alterations using a tomographic analysis. Cone Beam Computer Tomographies (CBCTs) of 17 subjects with 25 maxillary molars were analyzed, before and, in average, 12 months following extraction. Fifty CBCTs were segmented as 3D models that were used as reference for analysis. Cross-sectional planes were established to measure the dimensional changes in the vertical, horizontal aspects, and the area of the alveolar bone. Associations between root divergence, initial bone location related to the maxillary sinus, and the thickness of buccal and palatal bone at baseline was assessed using mixed-effect models. Overall, the average reduction in vertical bone height was 35.23% (2.61 ± 1.76 mm). The mean reduction of area of alveolar process and horizontal bone width were 18.89% (56.08 ± 44.23 mm2) and 65.10% (8.33 ± 4.51 mm), respectively. There was a marginal significant association between horizontal bone changes and the thickness of palatal bone (p = 0.05). The results of the present study indicated that following maxillary molar extraction, significant dimensional changes occur in both the vertical and horizontal directions. The vertical changes were mainly attributed to remodeling on the coronal aspect of the alveolar ridge and sinus pneumatization was rare.

Influence of zirconia crown artifacts on cone beam computed tomography scans and image superimposition of tomographic image and tooth surface scan: An in vitro study.

STATEMENT OF PROBLEM: Zirconia restorations create significant artifacts on 3D cone beam computed tomography (CBCT) imaging. Static computer-assisted implant surgery (s-CAIS) relies on the accuracy of superimposition between an intraoral surface scan and CBCT imaging. However, how the artifacts from zirconia on the tomographic image might affect the predictability of s-CAIS is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of zirconia crown restorations on the superimposition process for s-CAIS. MATERIAL AND METHODS: Four stone casts generated 4 groups: a control group (CG) with no crowns and 3 experimental groups with 4 (TG4), 7 (TG7), and 13 (TG13) zirconia crowns. A total of 40 CBCT scans were made for the 4 groups (n=10). All CBCTs were imported into a computer planning software program, and the casts from all 4 groups were scanned by using a high-resolution laboratory scanner. The standard tessellation language (STL) files were imported, segmented, and the 3 files superimposed for all groups. The accuracy of the superimposition was assessed, in millimeters, in 3 planes corresponding to anterior-posterior, horizontal, and vertical, as well as the overall measurement, and the results were analyzed statistically (α=.05). RESULTS: The overall analysis demonstrated statistically significant differences between all groups (P<.001), except between CG and TG4. The anterior-posterior dimension demonstrated significant differences between CG and TG7 (P<.001), CG and TG13 (P<.001), TG4 and TG7 (P=.004), and TG4 and TG13 (P=.001). For the vertical dimension analysis, significant differences were found between CG and TG7 (P=.001), CG and TG13 (P<.001), and TG4 and TG13 (P<.001). For the horizontal variable, statistically significant differences were found between CG and TG7 (P=.049), CG and TG13 (P<.001), TG4 and TG13 (P<.001), and TG7 and TG13 (P=.003). CONCLUSIONS: The accuracy of the superimposition of the images was influenced by the number of zirconia crowns, with an increased number reducing the superimposition accuracy.