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OBJECTIVES: This study evaluated the accuracy of deep neural patchworks (DNPs), a deep learning-based segmentation framework, for automated identification of 60 cephalometric landmarks (bone-, soft tissue- and tooth-landmarks) on CT scans. The aim was to determine whether DNP could be used for routine three-dimensional cephalometric analysis in diagnostics and treatment planning in orthognathic surgery and orthodontics. METHODS: Full skull CT scans of 30 adult patients (18 female, 12 male, mean age 35.6 years) were randomly divided into a training and test data set (each n = 15). Clinician A annotated 60 landmarks in all 30 CT scans. Clinician B annotated 60 landmarks in the test data set only. The DNP was trained using spherical segmentations of the adjacent tissue for each landmark. Automated landmark predictions in the separate test data set were created by calculating the center of mass of the predictions. The accuracy of the method was evaluated by comparing these annotations to the manual annotations. RESULTS: The DNP was successfully trained to identify all 60 landmarks. The mean error of our method was 1.94 mm (SD 1.45 mm) compared to a mean error of 1.32 mm (SD 1.08 mm) for manual annotations. The minimum error was found for landmarks ANS 1.11 mm, SN 1.2 mm, and CP_R 1.25 mm. CONCLUSION: The DNP-algorithm was able to accurately identify cephalometric landmarks with mean errors <2 mm. This method could improve the workflow of cephalometric analysis in orthodontics and orthognathic surgery. Low training requirements while still accomplishing high precision make this method particularly promising for clinical use.
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Puntos Anatómicos de Referencia , Cráneo , Adulto , Humanos , Masculino , Femenino , Reproducibilidad de los Resultados , Cefalometría/métodos , Cráneo/diagnóstico por imagen , AlgoritmosRESUMEN
BACKGROUND: Computer Assisted Design and Computer Assisted Manufacturing (CAD/CAM) have revolutionized oncologic surgery of the head and neck. A multitude of benefits of this technique has been described, but there are only few reports of donor site comorbidity following CAD/CAM surgery. METHODS: This study investigated comorbidity of the hip following deep circumflex iliac artery (DCIA) graft raising using CAD/CAM techniques. A cross-sectional examination was performed to determine range of motion, muscle strength and nerve disturbances. Furthermore, correlations between graft volume and skin incision length with postoperative donor site morbidity were assessed using Spearman's rank correlation, linear regression and analysis of variance (ANOVA). RESULTS: Fifteen patients with a mean graft volume of 21.2 ± 5.7 cm3 and a mean incision length of 228.0 ± 30.0 mm were included. Patients reported of noticeable physical limitations in daily life activities (12.3 ± 11.9 weeks) and athletic activities (38.4 ± 40.0 weeks in mean) following surgery. Graft volume significantly correlated with the duration of the use of walking aids (R = 0.57; p = 0.033) and impairment in daily life activities (R = 0.65; p = 0.012). The length of the scar of the donor-site showed a statistically significant association with postoperative iliohypogastric nerve deficits (F = 4.4, p = 0.037). Patients with anaesthaesia of a peripheral cutaneous nerve had a larger mean scar length (280 ± 30.0 mm) than subjects with hypaesthesia (245 ± 10.1 mm) or no complaints (216 ± 27.7 mm). CONCLUSIONS: Despite sophisticated planning options in modern CAD/CAM surgery, comorbidity of the donor site following iliac graft harvesting is still a problem. This study is the first to investigate comorbidity after DCIA graft raising in a patient group treated exclusively with CAD/CAM techniques. The results indicate that a minimal invasive approach in terms of small graft volumes and small skin incisions could help to reduce postoperative symptomatology. Trial registration Retrospectively registered at the German Clinical Trials Register (DRKS-ID: DRKS00029066); registration date: 23/05/2022.
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Cicatriz , Arteria Ilíaca , Humanos , Cicatriz/epidemiología , Cicatriz/etiología , Computadores , Estudios Transversales , Arteria Ilíaca/cirugía , Mandíbula/cirugía , MorbilidadRESUMEN
PURPOSE: Proteasome inhibitors (PI) are the backbone of various treatment regimens in multiple myeloma. We recently described the first in-patient point mutations affecting the 20S subunit PSMB5 underlying PI resistance. Notably, in vivo, the incidence of mutations in PSMB5 and other proteasome encoding genes is too low to explain the development of resistance in most of the affected patients. Thus, additional genetic and epigenetic alterations need to be explored. EXPERIMENTAL DESIGN: We performed DNA methylation profiling by Deep Bisulfite Sequencing in PSMB5, PSMC2, PSMC5, PSMC6, PSMD1, and PSMD5, a subset of proteasome subunits that have hitherto been associated with PI resistance, recruited from our own previous research, the literature, or a meta-analysis on the frequency of somatic mutations. Methylation was followed up on gene expression level and by dual-luciferase reporter assay. The KMS11 cell line served as a model to functionally test the impact of demethylating agents. RESULTS: We identified PSMD5 promoter hypermethylation and subsequent epigenetic gene silencing in 24% of PI refractory patients. Hypermethylation correlated with decreased expression and the regulatory impact of this region was functionally confirmed. In contrast, patients with newly diagnosed multiple myeloma, along with peripheral blood mononuclear cells and CD138+ plasma cells from healthy donors, generally show unmethylated profiles. CONCLUSIONS: Under the selective pressure of PI treatment, multiple myeloma cells acquire methylation of the PSMD5 promoter silencing the PSMD5 gene expression. PSMD5 acts as a key orchestrator of proteasome assembly and its downregulation was described to increase the cell's proteolytic capacity. PSMD5 hypermethylation, therefore, represents a novel mechanism of PI tolerance in multiple myeloma.
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Mieloma Múltiple , Humanos , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Bortezomib , Inhibidores de Proteasoma/farmacología , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Leucocitos Mononucleares/metabolismo , Resistencia a Antineoplásicos/genética , Nucleótidos , Línea Celular TumoralRESUMEN
PURPOSE: Modern virtual implant planning is a time-consuming procedure, requiring a careful assessment of prosthetic and anatomical factors within a three-dimensional dataset. In order to facilitate the planning process and provide additional information, this study examines a statistical shape model (SSM) to compute the course of dental roots based on a surface scan. MATERIAL AND METHODS: Plaster models of orthognathic patients were scanned and superimposed with three-dimensional data of a cone-beam computer tomography (CBCT). Based on the open-source software "R", including the packages Morpho, mesheR, Rvcg and RvtkStatismo, an SSM was generated to estimate the tooth axes. The accuracy of the calculated tooth axes was determined using a leave-one-out cross-validation. The deviation of tooth axis prediction in terms of angle or horizontal shift is described with mean and standard deviation. The planning dataset of an implant surgery patient was additionally analyzed using the SSM. RESULTS: 71 datasets were included in this study. The mean angle between the estimated tooth-axis and the actual tooth-axis was 7.5 ± 4.3° in the upper jaw and 6.7 ± 3.8° in the lower jaw. The horizontal deviation between the tooth axis and estimated axis was 1.3 ± 0.8 mm close to the cementoenamel junction, and 0.7 ± 0.5 mm in the apical third of the root. Results for models with one missing tooth did not differ significantly. In the clinical dataset, the SSM could give a reasonable aid for implant positioning. CONCLUSIONS: With the presented SSM, the approximate course of dental roots can be predicted based on a surface scan. There was no difference in predicting the tooth axis of existent or missing teeth. In clinical context, the estimation of tooth axes of missing teeth could serve as a reference for implant positioning. However, a higher number of training data must be achieved to obtain increasing accuracy.
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Implantes Dentales , Cirugía Asistida por Computador , Diseño Asistido por Computadora , Tomografía Computarizada de Haz Cónico/métodos , Estudios de Factibilidad , Humanos , Imagenología Tridimensional , Mandíbula , Maxilar , Cirugía Asistida por Computador/métodosRESUMEN
PURPOSE: Creating wax-ups of missing teeth for backward planning in implant surgery is a complex and time-consuming process. To facilitate implant-planning procedures, the automatic generation of a virtual wax-up would be useful. In the present study, the reconstruction of missing teeth in partially edentulous patients was performed automatically using newly developed software. The accuracy was investigated in order to test its clinical applicability. MATERIALS AND METHODS: This study presents a new method for creating an automatic virtual wax-up, which could serve as a basic tool in modern implant-planning procedures. First, a statistical shape model (SSM) based on 76 maxillary and mandibular arch scans from dentally healthy individuals was generated. Then, artificially generated tooth gaps were reconstructed. The accuracy of the workflow was evaluated on a separate testing sample of 10 individuals with artificially created tooth gaps given as a median deviation, in millimeters. Scans of three clinical cases with partial edentulism were equally reconstructed using the SSM and compared with the final prosthodontic work. RESULTS: The reconstruction of the artificial tooth gaps could be performed with the following median reconstruction accuracy: gap 21 with 0.15 mm; gap 27 with 0.20 mm; gap 34 with 0.22 mm: gap 36 with 0.22 mm; gaps 12 to 22 with 0.22 mm; gaps 34 to 36 with 0.22 mm. A scenario for an almost edentulous mandible with all teeth missing except teeth 33 and 43 could be reconstructed with a median reconstruction accuracy of 0.37 mm. The median tooth gap deviation of the SSM-based reconstruction in clinical cases differed from the final inserted prosthodontic teeth by 0.49 to 0.86 mm in median. CONCLUSION: A first feasibility of creating virtual wax-ups using an SSM could be shown. Artificially generated tooth gaps could be reconstructed close to the original with the proposed workflow. In the clinical cases, the SSM proposes an anatomical reconstruction, which does not yet consider prosthodontic aspects. To obtain clinical use, contact with antagonist teeth must be considered and more training data must be implemented. However, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined. (Int J Comput Dent 2022;25(4):349-0; doi: 10.3290/j.ijcd.b2599407).
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Implantes Dentales , Boca Edéntula , Humanos , Prostodoncia , Modelos Estadísticos , CoronasRESUMEN
PURPOSE: Postoperative delirium (PD) is a common and severe complication, following extensive surgery and prolonged stays in intensive care units (ICU). The study aimed to estimate the frequency of and identify risk factors for PD in a unified sample of head and neck surgery patients. METHODS: The investigators implemented a retrospective cohort study composing of patients undergoing free flap reconstructive surgery over 1 year. The predictor variables were identified as 146 general and periprocedural parameters. The primary outcome variable was PD (+ or -). Descriptive and bivariate statistics were performed to identify existing correlations between the predictive factors and PD and the P-value was set at .05. A logistic regression model (LRM) was created to adjust for possible confounding factors and reveal possible independent prognostic factors for the onset of PD. RESULTS: Hundred patients (group 1, 18 with PD+, group 2, 82 without PD) undergoing microvascular free flap (65 males, 35 females, mean ageâ¯=â¯65 [range 18 to 84 years]) surgery were recruited. The investigators identified 15 variables that were statistically associated with PD. In the LRM, after adjusting for age, diabetes status, and preoperative TSH, free fibula transplants (FT) as type of surgery was associated with an increased risk for PD (FT, Odds Ratio (OR) 6.3 (1.6 to 25.7, Pâ¯=â¯.01). CONCLUSION: The investigators identified 15 variables associated with an increased risk of developing PD, one of which had a statistically significant association after adjusting for other variables in a LRM. Future research efforts should be devoted to assessing the use of these variables for predicting PD further. Since the use of FT showed to be an independent prognostic parameter for the development of PD in this study, patients receiving FT should get special attention in the first days after surgery to prevent PD and associated complications such as increased mortality and prolonged hospital stays.
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Delirio , Colgajos Tisulares Libres , Neoplasias de Cabeza y Cuello , Procedimientos de Cirugía Plástica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Delirio/epidemiología , Delirio/etiología , Femenino , Neoplasias de Cabeza y Cuello/complicaciones , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Procedimientos de Cirugía Plástica/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Adulto JovenRESUMEN
PURPOSE: The current standard in reconstructing defects of the orbital floor, by using the concept of mirroring, is time-consuming and ignores the natural asymmetry of the skull. By using a statistical shape model (SSM), the reconstruction can be automatized and improved in accuracy. The present study aims to show the possibilities of the virtual reconstruction of artificial defects of the orbital floor using an SSM and its potentials for clinical implementation. METHODS: Based on 131 unaffected CT scans of the midface, an SSM was created which contained the shape variability of the orbital floor. Nineteen midface CT scans, that were not included in the SSM, were manually segmented to establish ground truth (control group). Then artificial defects of larger and smaller sizes were created and reconstructed using SSM (Group I) and the gold standard of mirroring (Group II). Eventually, a comparison to the surface of the manual segmentation (control group) was performed. RESULTS: The proposed method of reconstruction using an SSM leads to more precise reconstruction results, compared with the conventional method of mirroring. Whereas mirroring led to the reconstruction errors of 0.7 mm for small defects and 0.73 mm for large defects, reconstruction using SSM led to deviations of 0.26 mm (small defect) and, respectively, 0.34 mm (large defect). CONCLUSIONS: The presented approach is an effective and accurate method for reconstructing the orbital floor. In connection with modern computer-aided design and manufacturing, individual patient-specific implants could be produced according to SSM-based reconstructions and could replace current methods using manual bending techniques. By acknowledging the natural asymmetry of the human skull, the SSM-based approach achieves higher accuracy in reconstructing injured orbits.
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Órbita , Procedimientos de Cirugía Plástica , Humanos , Modelos Estadísticos , Órbita/diagnóstico por imagen , Órbita/cirugía , Cráneo , Tomografía Computarizada por Rayos X/métodosRESUMEN
The ongoing COVID-19 pandemic has revealed alarming shortages of personal protective equipment for frontline healthcare professionals and the general public. Therefore, a 3D-printable mask frame was developed, and its air seal performance was evaluated and compared. Personalized masks (PM) based on individual face scans (n = 8) and a statistically shaped mask (SSM) based on a standardized facial soft tissue shape computed from 190 face scans were designed. Subsequently, the masks were additively manufactured, and in a second step, the PM and SSM were compared to surgical masks (SM) and FFP2 masks (FFP2) in terms of air seal performance. 3D-printed face models allowed for air leakage evaluation by measuring the pressure inside the mask in sealed and unsealed conditions during a breathing simulation. The PM demonstrated the lowest leak flow (p < 0.01) of inspired or expired unfiltered air of approximately 10.4 ± 16.4%, whereas the SM showed the highest (p < 0.01) leakage with 84.9 ± 7.7%. The FFP2 and SSM had similar values of 34.9 ± 18.5% leakage (p > 0.68). The developed framework allows for the time- and resource-efficient, on-demand, and in-house production of masks. For the best seal performance, an individually personalized mask design might be recommended.
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COVID-19 , Máscaras , Equipo de Protección Personal , Biometría , Diseño de Equipo , Personal de Salud , Humanos , Impresión Tridimensional , Salud PúblicaRESUMEN
OBJECTIVES/HYPOTHESIS: The prevalence of tympanostomy tube surgery (TTS) in patients with a cleft deformity was investigated, in relation to cleft width and cleft type. STUDY DESIGN: Retrospective review of medical health records. METHODS: Retrospective review of medical health records. Seventy-eight patients with non-syndromic cleft deformity of the palate and/or alveolus and lip between 2003 and 2017 were investigated. All available medical documents were analyzed. The study group was divided into subgroups: 1) patients with isolated cleft palate (CP) and patients with a cleft palate with cleft lip and alveolus (CLP). 2) According to Veau's classification (I-IV), further subgroups were defined. Cleft width was measured using plaster cast models. RESULTS: TTS was performed in 55% of the patients (n = 43). Considering Veau's classification, TTS was conducted as follows: Veau I 65.2% (n = 15/23), Veau II 55.0% (n = 11/20), Veau III 47.6% (n = 10/21), and Veau IV 50.0% (n = 7/14). Cleft classifications, maxillary arch width, and absolute/relative cleft width had no statistical impact on TTS occurrence. Although no significant correlation could be found, patients in our study group with CP (Veau I and II) underwent TTS more often (60.5%, n = 26/43) than patients with CPL (Veau III and IV; 48.6%, n = 17/35) during a three-year follow-up. CONCLUSION: None of the cleft characteristics examined had a significant impact on the proportion of patients who received TTS. Nevertheless, patients with lower Veau classification and CP received tympanostomy tubes more often. Therefore, otolaryngologists and pediatricians treating children with cleft palate should maintain a high level of suspicion for chronic middle ear effusion, even in patients with small clefts. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2764-E2769, 2021.
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Encéfalo/anomalías , Labio Leporino/complicaciones , Fisura del Paladar/complicaciones , Ventilación del Oído Medio/estadística & datos numéricos , Otitis Media con Derrame/cirugía , Encéfalo/patología , Estudios de Casos y Controles , Moldes Quirúrgicos/normas , Labio Leporino/clasificación , Labio Leporino/diagnóstico , Labio Leporino/patología , Labio Leporino/cirugía , Fisura del Paladar/clasificación , Fisura del Paladar/diagnóstico , Fisura del Paladar/patología , Fisura del Paladar/cirugía , Arco Dental/anatomía & histología , Femenino , Estudios de Seguimiento , Pérdida Auditiva/diagnóstico , Pérdida Auditiva/etiología , Humanos , Lactante , Masculino , Maxilar/anatomía & histología , Ventilación del Oído Medio/métodos , Otitis Media con Derrame/complicaciones , Otitis Media con Derrame/diagnóstico , Otorrinolaringólogos , Pediatras , Prevalencia , Estudios RetrospectivosRESUMEN
OBJECTIVE: To investigate the effect of lip closure on reduction of cleft palates when no pre-surgical infant orthopedics (PSIO) are used. STUDY DESIGN: Retrospective patient chart-review in our department for Cranio-Maxillofacial Surgery at the University Medical Centre Freiburg, Germany. 19 patients at the age of 5.9 ± 2.1 months with surgical treatment of uni- (UCLP), or bilateral cleft lip and palate (BCLP) without any use of PSIO were included. RESULTS: Early soft tissue correction of the lip leads to an effective reduction of the maxillary arch without any use of PSIO. The presented conventional and digital measurements appeared to be reliable. A successful reduction of the cleft width (UCLP = 3.88 ± 2.42mm, BCLP = 7.33 ± 5.00mm), the width of the alveolar arch (1.91 ± 1.36mm) and the sagittal depth of the alveolar arch (3.07 ± 2.71 mm) could be achieved with the presented workflow. CONCLUSIONS: Cleft reduction was obtainable without PSIO when lip closure after Tennison-Randall was performed.
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Labio Leporino , Fisura del Paladar , Ortopedia , Labio Leporino/cirugía , Fisura del Paladar/cirugía , Arco Dental , Humanos , Lactante , Estudios RetrospectivosRESUMEN
PURPOSE: There is no consensus on the impact of red blood cell (RBC) transfusion on patients with oral squamous cell carcinoma (OSCC). The purpose of this study was to investigate the association between RBC transfusions and overall survival (OS) and tumor-free survival (TFS) after operative treatment of OSCC. METHODS: In this retrospective cohort study, all patients treated with primary surgery between 2003 and 2017 because of OSCC were chart reviewed. The occurrence and amount of RBC transfusions (0; 1-3; >3 units) was correlated with OS and TFS by Kaplan-Meier survival and Cox regression analyses. Demographic, clinical, and pathological parameters were also evaluated in order to identify confounding factors. RESULTS: Of 420 patients (243 [57.9%] male) with a mean age of 62.6 years, 67 (16.0%) received RBC transfusion. There were statistically significant (P < .01) differences in 5-year OS respectively TFS in transfused patients for the Kaplan-Meier survival analysis (0 units = 70.6%; [95% confidence interval {CI}: 65.0-75.4%] respectively 63.2% [95% CI: 57.4-68.4%], 1-3 units = 47.2% [95% CI: 29.4-63.1%] respectively 40.6% [95% CI: 24.6-55.95%] and >3 units = 48.9% [95% CI: 20.9-72.1%] respectively 30.5% [95% CI: 8.9-55.8%]). After multivariate adjustments for demographic, clinical, and pathological parameters, RBC transfusion could not be sustained as a significant prognostic factor in OS respectively TFS (1-3 units: hazard ratio = 1.5 [95% CI: 0.7-3.2] respectively 1.3 [95% CI: 0.7-2.6]; >3 units: hazard ratio = 1.2 [95% CI: 0.5 - 3.0] respectively 1.1 [95% CI: 0.5-2.4]). CONCLUSIONS: Although RBC transfusion was not identified as a significant prognostic parameter in multivariate analysis, a clear trend for shorter OS and TFS for transfused patients in univariate and Kaplan-Meier survival analysis could be shown.
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Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Carcinoma de Células Escamosas/cirugía , Transfusión de Eritrocitos , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/cirugía , Estudios Retrospectivos , Carcinoma de Células Escamosas de Cabeza y CuelloRESUMEN
There is no consensus on the effect of red blood cell (RBC) transfusions on patients with oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the association between RBC administration and the occurrence of distant metastases (M+) after surgical treatment of OSCC. All medical records of patients who underwent primary surgery for OSCC in our department (2003-2019) were analyzed retrospectively (n = 609). Chi and Cox regression models were used to analyze the influence of transfusion on the development of M+, and survival rates. Kaplan-Meier curves were used for graphical presentation. A multitude of patient-specific factors showed a statistical impact in univariate analysis (transfusion, age, gender, diabetes, pT, pN, L, V, Pn, G, UICC, adjuvant therapy, free microvascular transplant, preoperative hemoglobin level). Transfusion status and pN stage were the only variables that showed a significant correlation to M+ in the multivariate Cox model. The hazard ratios for the occurrence of M+ were 2.42 for RBC transfusions and 2.99 for pN+. Administration of RBC transfusions was identified as a significant prognostic parameter for the occurrence of distant metastases after surgical treatment of OSCC. Hence, the administration of RBC transfusions should be considered carefully in the perioperative management.