Efficacy of the methods of age determination using artificial intelligence in panoramic radiographs - a systematic review.

The aim of this systematic review is to analyze the literature to determine whether the methods of artificial intelligence are effective in determining age in panoramic radiographs. Searches without language and year limits were conducted in PubMed/Medline, Embase, Web of Science, and Scopus databases. Hand searches were also performed, and unpublished manuscripts were searched in specialized journals. Thirty-six articles were included in the analysis. Significant differences in terms of root mean square error and mean absolute error were found between manual methods and artificial intelligence techniques, favoring the use of artificial intelligence (p < 0.00001). Few articles compared deep learning methods with machine learning models or manual models. Although there are advantages of machine learning in data processing and deep learning in data collection and analysis, non-comparable data was a limitation of this study. More information is needed on the comparison of these techniques, with particular emphasis on time as a variable.

In situ formation of inhibitor species through catalytic surface reactions during area-selective atomic layer deposition of TaN.

Small molecule inhibitors (SMIs) have been gaining attention in the field of area-selective atomic layer deposition (ALD) because they can be applied in the vapor-phase. A major challenge for SMIs is that vapor-phase application leads to a disordered inhibitor layer with lower coverage as compared to self-assembled monolayers, SAMs. A lower coverage of SMIs makes achieving high selectivity for area-selective ALD more challenging. To overcome this challenge, mechanistic understanding is required for the formation of SMI layers and the resulting precursor blocking. In this study, reflection adsorption infrared spectroscopy measurements are used to investigate the performance of aniline as an SMI. Our results show that aniline undergoes catalytic surface reactions, such as hydrogenolysis, on a Ru non-growth area at substrate temperatures above 250 °C. At these temperatures, a greatly improved selectivity is observed for area-selective TaN ALD using aniline as an inhibitor. The results suggest that catalytic surface reactions of the SMI play an important role in improving precursor blocking, likely through the formation of a more carbon-rich inhibitor layer. More prominently, catalytic surface reactions can provide a new strategy for forming inhibitor layers that are otherwise very challenging or impossible to form directly through vapor-phase application.

Elucidating the Reaction Mechanism of Atomic Layer Deposition of Al2O3 with a Series of Al(CH3)xCl3-x and Al(CyH2y+1)3 Precursors.

The adsorption of metalorganic and metal halide precursors on the SiO2 surface plays an essential role in thin-film deposition processes such as atomic layer deposition (ALD). In the case of aluminum oxide (Al2O3) films, the growth characteristics are influenced by the precursor structure, which controls both chemical reactivity and the geometrical constraints during deposition. In this work, a systematic study using a series of Al(CH3)xCl3-x (x = 0, 1, 2, and 3) and Al(CyH2y+1)3 (y = 1, 2, and 3) precursors is carried out using a combination of experimental spectroscopic techniques together with density functional theory calculations and Monte Carlo simulations to analyze differences across precursor molecules. Results show that reactivity and steric hindrance mutually influence the ALD surface reaction. The increase in the number of chlorine ligands in the precursor shifts the deposition temperature higher, an effect attributed to more favorable binding of the intermediate species due to higher Lewis acidity, while differences between precursors in film growth per cycle are shown to originate from variations in adsorption activation barriers and size-dependent saturation coverage. Comparison between the theoretical and experimental results indicates that the Al(CyH2y+1)3 precursors are favored to undergo two ligand exchange reactions upon adsorption at the surface, whereas only a single Cl-ligand exchange reaction is energetically favorable upon adsorption by the AlCl3 precursor. By pursuing the first-principles design of ALD precursors combined with experimental analysis of thin-film growth, this work enables a robust understanding of the effect of precursor chemistry on ALD processes.

Mandibular shape prediction model using machine learning techniques.

OBJECTIVE: To create a mandibular shape prediction model using machine learning techniques and geometric morphometrics. MATERIALS AND METHODS: Six hundred twenty-nine radiographs were used to select the most appropriate craniomaxillary variables in different craniofacial pattern classifications using a support vector machine. To obtain the three-dimensional mandibular shape, a Procrustes fit was used on 55 tomograms, in which 17 three-dimensional landmarks were digitized. A partial least square regression was employed to find the best covariation between craniomaxillary angles and the symmetric components of mandibular shape. The model was applied to a new sample of six tomograms and evaluated by the mean absolute error. Each mandible predicted was assessed using the Hausdorff distance (HDu) and a color scale. The model was also exploratively applied to six new radiographs. RESULTS: Covariation was 88.66% with a significance of < 0.0001 explained by twelve craniomaxillary variables. Low differences between the original and predicted models were obtained, with a mean absolute error of 0.0143. The mean distance between meshes ranged from 0.0033 to 0.0059 HDu and each color scale demonstrated general similarity between the surfaces. CONCLUSIONS: This approach offered promising results in obtaining a mandibular prediction model that enhances shape properties in an economical way and is applicable to a Latin American population. Clinical proof of this method will require further studies with larger samples. CLINICAL RELEVANCE: This method offers a reliable, economic alternative to traditional mandibular prediction methods and is applicable to the Latin American population.

Efficiency of maxillomandibular advancement for the treatment of obstructive apnea syndrome: a comprehensive overview of systematic reviews.

OBJECTIVES: To evaluate the efficiency of maxillomandibular advancement using aggregated individual patient data from multiple studies. MATERIALS AND METHODS: This overview was structured according to the PICO strategy. It adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist and was recorded on the international prospective register of systematic reviews (PROSPERO-CRD42020206135). Searches were conducted in the PubMed/MEDLINE, Scopus, Embase, Web of Science, LILACS, and Cochrane databases for studies published until January 1, 2021. Data from the included studies were collected by one author, while another reviewed the compilation. RESULTS: Twelve systematic reviews were included. The outcome measures studied were the apnea-hypopnea index, respiratory disturbance index, mean oxygen saturation, lowest oxygen saturation, sleepiness data, posterior air space, sella-nasion point A angle, sella-nasion point B angle, surgical success, and surgical cure in patients who underwent surgery. The AMSTAR scale presented moderate evaluations, with grades varying between 6 and 10 points. The Glenny scale revealed that the study selection did not include all languages. Only three reviews identified quality assessments conducted by at least two reviewers and only five related possible searches for unpublished data. CONCLUSIONS: Bimaxillary advancement surgery improved respiratory indicators, sleepiness data, and increased upper airway size. However, it is necessary to standardize the surgical criteria to establish measurable efficiency of the procedure. CLINICAL RELEVANCE: This overview makes a critical analysis of the results of the selected systematic reviews with the aim of presenting the most clinically relevant data on the maxillomandibular advancement for treating obstructive apnea syndrome, with a focus on improving respiratory, anatomical, and quality of life indices. There are no overviews that approach this theme from a well-structured perspective.

Differences in skeletal growth patterns: an exploratory approach using elliptic Fourier analysis.

OBJECTIVE: Apply elliptic Fourier analysis to find shape differences among the hypodivergent, normodivergent, and hyperdivergent growth patterns in skeletal classes I, II and, III in mandibular and maxillary curves and evaluate the discriminatory capacity of these differences. MATERIALS AND METHODS: A total of 626 adult patients were included: 354 Brazilian patients (52 with tomographic information and 302 with radiographic information) and 272 Colombian patients with radiographic information. Lateral views were selected. The maxillary and mandibular curves were digitized. Elliptic Fourier analysis was employed considering with 20 harmonics as well as filtering size, rotation, and translation properties. One-way non-parametric MANOVA was employed to determine differences. A confusion matrix tool was employed to analyze the discriminatory capacity of the model. RESULTS: Significant shape differences in the mandibular and maxillary contours were found among the hypodivergent, normodivergent, and hyperdivergent growth patterns in classes I, II, and III (p < 0.05). The accuracies obtained from the confusion matrix were respectively 74.1, 79.5, and 90.1% in classes I, II, and III in the mandibular curves and respectively 71.9, 73.9, and 75% in classes I, II, and III in the maxillary curves. CONCLUSIONS: Elliptic Fourier analysis can be used to find shape differences with an acceptable discriminatory capacity, especially in the mandible contour. Maxillary and mandibular bone curves each significantly defined facial biotypes regardless of the size and position properties. CLINICAL RELEVANCE: This exploration offers a way to quantify mandibular morphology for the construction of an economic mandibular prediction system applicable to the Latin American population.

Formation of Germa-ketenimine on the Ge(100) Surface by Adsorption of tert-Butyl Isocyanide.

Reactions of the (100) surfaces of Ge and Si with organic molecules have been generally understood within the concept of "dimers" formed by the 2 × 1 surface reconstruction. In this work, the adsorption of tert-butyl isocyanide on the Ge(100)-2 × 1 surface at large exposures is investigated under ultrahigh vacuum conditions. A combination of infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed desorption experiments along with dispersion-corrected density functional theory calculations is used to determine the surface products. Upon adsorption of a dense monolayer of tert-butyl isocyanide, a product whose structure resembles a germa-ketenimine (N=C=Ge) with σ donation toward and π back-donation from the Ge(100) surface appears. Formation of this structure involves divalent-type surface Ge atoms that arise from cleavage of the Ge(100)-2 × 1 surface dimers. Our results reveal an unprecedented class of reactions of organic molecules at the Ge(100) surface.

Adsorption of Homotrifunctional 1,2,3-Benzenetriol on a Ge(100)-2 × 1 Surface.

The adsorption of the homotrifunctional 1,2,3-benzenetriol on Ge(100)-2 × 1 has been investigated by density functional theory calculations, Fourier transform infrared spectroscopy, and X-ray-photoelectron spectroscopy. The results show that the adsorption can occur through OH dissociation of all three hydroxyl groups, and that all three reaction pathways are kinetically and thermodynamically favorable. A coverage-dependent analysis shows that at low coverage, the molecule reacts to form a mix of trifold and dually bound adsorbates. As the coverage increases, the reactions are limited to dissociative adsorption through single and dual attachments. Calculations on the three possible dually bound configurations further reveals that the dissociative adsorption of the third hydroxyl group is limited by geometrical constraints to only two reaction channels. Finally, the proximity between OH-groups in the molecule favors intra- and intermolecular hydrogen bonding, which stabilizes singly and dually bound adsorbate configurations and limits the reactivity of the functional groups.

A prospective non-fatal injuries assessment: A multivariate analysis in medical-legal examinations.

OBJECTIVE: To prospectively determine injury recovery time in the medical-legal examinations of non-fatal injuries and their associated factors, carried out by the National Institute of Legal Medicine and Forensic Sciences of Colombia to create a multivariate analysis. METHODS: A prospective medical-legal assessment of non-fatal injuries was carried out on 281 individuals with complete follow-up, in which the observational unit of analysis was the most serious injury. Variables, such as sex, circumstances of the injury, the mechanism that caused the injury, medical certificate of incapacity to work, among others were related to the injury recovery time, measured in days. The Kruskal Wallis (K-W) ANOVA and a multivariate analysis using the ordinal regression model were applied. RESULTS: In the multivariate analysis, the factors most associated with longer recovery time were the extent of joint damage (CR95%:1.47-5.94,p = 0.0001) and bone damage (CR95%:2.92-7.42,p < 0.001). In terms of circumstances of the injury, traffic accidents (CR95%:1.03-2.96,p < 0.001), medical-legal impairments (CR95%:0.34-2.19,p = 0.007), and complications of the primary injury (CR95%: 1.18-2.57,p < 0.001) had the greatest impact on recovery time. Others factors that significantly impacted injury recovery time are surgical treatments (IC95%: 0.33-3.26,p = 0.0164) and delayed treatment (CR95%:1.41-4.72,p < 0.001). A direct correlation (significant and moderately strong) was found between the recovery time of the injury and the days of incapacity for work (r = 0.802, p < 0.001). CONCLUSION: This prospective analysis determined which variables were most strongly related to the medical-legal assessment of non-fatal injuries and the recovery time of said injuries. Further studies aimed at improving the strategies to help individuals complete the legal process are required.

Relation between Reactive Surface Sites and Precursor Choice for Area-Selective Atomic Layer Deposition Using Small Molecule Inhibitors.

Implementation of vapor/phase dosing of small molecule inhibitors (SMIs) in advanced atomic layer deposition (ALD) cycles is currently being considered for bottom-up fabrication by area-selective ALD. When SMIs are used, it can be challenging to completely block precursor adsorption due to the inhibitor size and the relatively short vapor/phase exposures. Two strategies for precursor blocking are explored: (i) physically covering precursor adsorption sites, i.e., steric shielding, and (ii) eliminating precursor adsorption sites from the surface, i.e., chemical passivation. In this work, it is determined whether steric shielding is enough for effective precursor blocking during area-selective ALD or whether chemical passivation is required as well. At the same time, we address why some ALD precursors are more difficult to block than others. To this end, the blocking of the Al precursor molecules trimethylaluminum (TMA), dimethylaluminum isopropoxide (DMAI), and tris(dimethylamino)aluminum (TDMAA) was studied by using acetylacetone (Hacac) as inhibitor. It was found that DMAI and TDMAA are more easily blocked than TMA because they adsorb on the same surface sites as Hacac, while TMA is also reactive with other surface sites. This work shows that chemical passivation plays a crucial role for precursor blocking in concert with steric shielding. Moreover, the reactivity of the precursor with the surface groups on the non-growth area dictates the effectiveness of blocking precursor adsorption.

Biotypic classification of facial profiles using discrete cosine transforms on lateral radiographs.

OBJECTIVE: The aim of the study was to use discrete cosine transforms to graph soft tissue curves in lateral cephalometric radiographs and, with the obtained mathematical values, to group these curves by both traditional biotypes and cluster systems, in order to evaluate discriminatory capacity in terms of accuracy. DESIGN: A sample of 625 lateral radiographs of adult patients (319 women and 306 men) was classified by facial biotype based on the ANB angle and mandibular plane angle. The curves of the facial profile were digitized with 50 equidistant points and discrete cosine transform was applied to analyze these curves mathematically for the determination of the accuracy of the classification of traditional biotypes. Phylogram cluster analysis was then performed for hierarchical grouping and accuracy was determined through cross-validation. RESULTS: Grouping by biotype was performed for men and women separately. Although significant, accuracy did not surpass 71.4%. In the groups by clusters, significant results were achieved when performing four analyses for men and two for women. The best accuracy regarding classification power and qualitative distinction was 89.5% for men and 94% for women. CONCLUSIONS: Discrete cosine transforms using a cluster system had greater discriminatory capacity in terms of accuracy compared to traditional grouping considering the ANB angle and mandibular plane angle. This exploration can be useful for the creation of a soft-tissue facial reconstruction software for the Latin American population.

Shape differences among symmetrically shaped skeletal growth patterns in a panoramic view: a Fourier analysis.

The objective of this study was to apply elliptic Fourier analysis (EFA) to find shape differences among skeletal growth patterns in both radiographic and tomographic panoramic views, controlling for asymmetry. Lateral and panoramic images were obtained from 350 patients. After screening patients with asymmetric linear and angular values and natural asymmetric hemimandibular shape, 240 patients were included in the study: 48 with tomographic information and 192 with radiographic information. The images were classified according to the mandibular plane angle and the ANB angle. Mandibular contours were digitized on the panoramic images and EFA was performed with 20 harmonics, filtering rotation, translation and size properties. As there were no differences between radiographic and tomographic panoramic mandibular contours and normal distribution was found in all groups, MANOVA was conducted to determine differences using a Hotelling's p-values with Bonferroni correction and an XY graph tool was applied to visualize these differences graphically. A 95% confidence level was used. Significative differences were found among hypodivergent, normodivergent, and hyperdivergent patterns in Class I, II, and III (p < 0.05), located mainly in the symphyseal region. The results of this study suggest that EFA is a useful tool to mathematically analyze mandibular contours and their morphological differences given by facial biotypes. This method could improve the precision of the mandibular prediction models.

Incidence of condylar resorption after bimaxillary, Lefort I, and mandibular surgery: an overview.

The aim of the present overview was to evaluate the outcomes of systematic reviews to determine the incidence of condylar resorption in patients submitted to orthognathic surgery and analyze whether the risk of developing this condition is related to a specific type of surgery. Searches were conducted in the PubMed/MEDLINE, Embase, and Cochrane electronic databases for systematic reviews with quantitative data on condylar resorption due to any type of orthognathic surgery for dentoskeletal deformities published up to May 25, 2019. The AMSTAR 2 and Glenny tools were applied for the quality appraisal. Five systematic reviews were included for analysis. Only one article was considered to have high quality. Among a total of 5128 patients, 12.32% developed condylar resorption. From those patients, 70.1% had double jaw surgery, 23.4% had mandibular surgery alone, and in 6.5% a Lefort I technique was used. Based on these findings, bimaxillary surgery could be considered a risk factor for condylar resorption. However, these results should be interpreted with caution, since other factors, such as pre-operative skeletal deformities, type of movement, and type of fixation, can contribute to the development of this condition. Further studies should consider reporting main cephalometric data, temporomandibular diagnosis, hormonal levels, and tomographic measures before and after the surgery at least every 6 months during the firsts two years to identify accurately risk factors for condylar resorption.

On the self-assembly of a highly selective benzothiazole-based TIM inhibitor in aqueous solution.

Benzothiazole is a common scaffold on which many bioactive structures, including protein inhibitors and biosensors, are based. The potential self-aggregation of such molecules to form nanoparticles is relevant for a number of practical applications. 3-(2-Benzothiazolylthio)-propanesulfonic acid (BTS) has been reported as a powerful and selective inhibitor of triosephosphate isomerase from Trypanosoma cruzi, the parasite that causes the Chagas' disease. Electrical conductivity, sound velocity, density, and nuclear magnetic resonance experiments as a function of temperature and of NaCl concentration have been performed in the present work to provide a comprehensive physicochemical description of this compound in aqueous solution. Molecular dynamics simulations of the same system were also performed to characterize the structure and dynamic behavior of the corresponding aggregates at several concentrations of BTS.

Efficacy of proportional versus high condylectomy in active condylar hyperplasia - A systematic review.

OBJECTIVE: To perform a systematic literature review to test the efficacy of proportional condylectomy versus high condylectomy in patients with active condylar hyperplasia, in terms of avoiding secondary surgeries. METHOD: Following a search of Medline (Pubmed), Embase, Scopus, Web of Science and Cochrane databases, ten studies were included for qualitative analysis, and two studies were included for meta-analysis. Quality assessment was performed using the Newcastle-Ottawa scale for cohort studies and the 18-item modified Delphi technique for case series. RESULTS: 259 patients were included in the qualitative analysis, with a weighted arithmetic mean age of 20.4 years, and a female:male ratio of 2:1. Meta-analysis was carried out for 52 patients, and it was found that proportional condylectomy reduced the need for secondary surgery (p = 0.0003). Although this evidence had limitations, excised bone on proportional condylectomy was superior when compared with excised bone on high condylectomy, re-establishing the occlusal plane, resulting in fewer asymmetries, and therefore reducing the need for further surgery. CONCLUSIONS: This systematic review showed a tendency for proportional condylectomies to avoid additional surgeries; however, more comparative studies are necessary.

Evaluation of natural mandibular shape asymmetry: an approach by using elliptical Fourier analysis.

OBJECTIVES: The purpose of this study was to demonstrate that asymmetry is a natural occurring phenomenon in the mandibular shape by using elliptical Fourier analysis. METHODS: 164 digital orthopantomographs from Colombian patients of both sexes aged 18 to 25 years were collected. Curves from left and right hemimandible were digitized. An elliptical Fourier analysis was performed with 20 harmonics. In the general sexual dimorphism a principal component analysis (PCA) and a hotelling T2 from the multivariate warp space were employed. Exploratory analysis of general asymmetry and sexual dimorphism by side was made with a Procrustes Fit. A non-parametric multivariate analysis of variance (MANOVA) was applied to assess differentiation of skeletal classes of each hemimandible, and a Procrustes analysis of variance (ANOVA) was applied to search any relation between skeletal class and side in both sexes. RESULTS: Significant values were found in general asymmetry, general sexual dimorphism, in dimorphism by side (p < 0.0001), asymmetry by sex, and differences between Class I, II, and III (p < 0.005). However, a relation of skeletal classes and side was not found. CONCLUSIONS: The mandibular asymmetry by shape is present in all patients and should not be articulated exclusively to pathological processes, therefore, along with sexual dimorphism and differences between skeletal classes must be taken into account for improving mandibular prediction systems.

Use of automated learning techniques for predicting mandibular morphology in skeletal class I, II and III.

BACKGROUND: The prediction of the mandibular bone morphology in facial reconstruction for forensic purposes is usually performed considering a straight profile corresponding to skeletal class I, with application of linear and parametric analysis which limit the search for relationships between mandibular and craniomaxillary variables. OBJECTIVE: To predict the mandibular morphology through craniomaxillary variables on lateral radiographs in patients with skeletal class I, II and III, using automated learning techniques, such as Artificial Neural Networks and Support Vector Regression. MATERIALS AND METHODS: 229 standardized lateral radiographs from Colombian patients of both sexes aged 18-25 years were collected. Coordinates of craniofacial landmarks were used to create mandibular and craniomaxillary variables. Mandibular measurements were selected to be predicted from 5 sets of craniomaxillary variables or input characteristics by using automated learning techniques, and they were evaluated through a correlation coefficient by a ridge regression between the real value and the predicted value. RESULTS: Coefficients from 0.84 until 0.99 were obtained with Artificial Neural Networks in the 17 mandibular measures, and two coefficients above 0.7 were obtained with the Support Vector Regression. CONCLUSION: The craniomaxillary variables used, showed a high predictability ability of the selected mandibular variables, this may be the key to facial reconstruction from specific craniomaxillary measures in the three skeletal classifications.

Shape differences among symmetrically shaped skeletal growth patterns in a panoramic view: a Fourier analysis

Abstract The objective of this study was to apply elliptic Fourier analysis (EFA) to find shape differences among skeletal growth patterns in both radiographic and tomographic panoramic views, controlling for asymmetry. Lateral and panoramic images were obtained from 350 patients. After screening patients with asymmetric linear and angular values and natural asymmetric hemimandibular shape, 240 patients were included in the study: 48 with tomographic information and 192 with radiographic information. The images were classified according to the mandibular plane angle and the ANB angle. Mandibular contours were digitized on the panoramic images and EFA was performed with 20 harmonics, filtering rotation, translation and size properties. As there were no differences between radiographic and tomographic panoramic mandibular contours and normal distribution was found in all groups, MANOVA was conducted to determine differences using a Hotelling's p-values with Bonferroni correction and an XY graph tool was applied to visualize these differences graphically. A 95% confidence level was used. Significative differences were found among hypodivergent, normodivergent, and hyperdivergent patterns in Class I, II, and III (p < 0.05), located mainly in the symphyseal region. The results of this study suggest that EFA is a useful tool to mathematically analyze mandibular contours and their morphological differences given by facial biotypes. This method could improve the precision of the mandibular prediction models.

An automatic method for skeletal patterns classification using craniomaxillary variables on a Colombian population.

BACKGROUND: The mandibular bone is an important part of the forensic facial reconstruction and it has the possibility of getting lost in skeletonized remains; for this reason, it is necessary to facilitate the identification process simulating the mandibular position only through craniomaxillary measures, for this task, different modeling techniques have been performed, but they only contemplate a straight facial profile that belong to skeletal pattern Class I, but the 24.5% corresponding to the Colombian skeletal patterns Class II and III are not taking into account, besides, craniofacial measures do not follow a parametric trend or a normal distribution. OBJECTIVE: The aim of this study was to employ an automatic non-parametric method as the Support Vector Machines to classify skeletal patterns through craniomaxillary variables, in order to simulate the natural mandibular position on a contemporary Colombian sample. MATERIALS AND METHODS: Lateral cephalograms (229) of Colombian young adults of both sexes were collected. Landmark coordinates protocols were used to create craniomaxillary variables. A Support Vector Machine with a linear kernel classifier model was trained on a subset of the available data and evaluated over the remaining samples. The weights of the model were used to select the 10 best variables for classification accuracy. RESULTS: An accuracy of 74.51% was obtained, defined by Pr-A-N, N-Pr-A, A-N-Pr, A-Te-Pr, A-Pr-Rhi, Rhi-A-Pr, Pr-A-Te, Te-Pr-A, Zm-A-Pr and PNS-A-Pr angles. The Class Precision and the Class Recall showed a correct distinction of the Class II from the Class III and vice versa. CONCLUSIONS: Support Vector Machines created an important model of classification of skeletal patterns using craniomaxillary variables that are not commonly used in the literature and could be applicable to the 24.5% of the contemporary Colombian sample.

Incidence of condylar resorption after bimaxillary, Lefort I, and mandibular surgery: an overview

Abstract The aim of the present overview was to evaluate the outcomes of systematic reviews to determine the incidence of condylar resorption in patients submitted to orthognathic surgery and analyze whether the risk of developing this condition is related to a specific type of surgery. Searches were conducted in the PubMed/MEDLINE, Embase, and Cochrane electronic databases for systematic reviews with quantitative data on condylar resorption due to any type of orthognathic surgery for dentoskeletal deformities published up to May 25, 2019. The AMSTAR 2 and Glenny tools were applied for the quality appraisal. Five systematic reviews were included for analysis. Only one article was considered to have high quality. Among a total of 5128 patients, 12.32% developed condylar resorption. From those patients, 70.1% had double jaw surgery, 23.4% had mandibular surgery alone, and in 6.5% a Lefort I technique was used. Based on these findings, bimaxillary surgery could be considered a risk factor for condylar resorption. However, these results should be interpreted with caution, since other factors, such as pre-operative skeletal deformities, type of movement, and type of fixation, can contribute to the development of this condition. Further studies should consider reporting main cephalometric data, temporomandibular diagnosis, hormonal levels, and tomographic measures before and after the surgery at least every 6 months during the firsts two years to identify accurately risk factors for condylar resorption.