Effect of Fabrication Technology on the Accuracy of Surgical Guides for Dental-Implant Surgery.

BACKGROUND: The accuracy of surgical guides is a relevant factor in both surgical safety and prosthetic implications. The impact of widespread fabrication technologies (milling and 3D printing) was investigated. METHODS: Surgical guides manufactured by means of two specific milling and 3D-printing systems were digitized and compared in a 3D analysis with the digital file of the designed guides. The surface mean 3D distance (at the surface where the teeth and mucosa made contact) and the axial and linear deviations of the sleeves' housings were measured by means of a metrological software program. Univariate and multivariate statistical analyses were used to investigate the effects of the fabrication technology, type of support, and arch type on the surgical guides' accuracy. RESULTS: The median deviations of the intaglio surface in contact with the mucosa were significantly (p < 0.001) lower for the milled surgical guides (0.05 mm) than for the 3D-printed guides (-0.07 mm), in comparison with the reference STL file. The generalized estimated equation models showed that the axial deviations of the sleeves' housings (a median of 0.82 degrees for the milling, and 1.37 degrees for the 3D printing) were significantly affected by the fabrication technology (p = 0.011) (the milling exhibited better results), the type of support (p < 0.001), and the combined effect of the fabrication technology and the sleeve-to-crest angle (p = 0.003). The linear deviation (medians of 0.12 mm for the milling and 0.21 mm for the 3D printing) of their center points was significantly affected by the type of support (p = 0.001), with the milling performing slightly better than the 3D printing. CONCLUSIONS: The magnitude of the difference might account for a limited clinical significance.

Three Dimensional Printed Surgical Guides: Effect of Time on Dimensional Stability.

PURPOSE: To analyze, in vitro, the dimensional stability over time of 3D-printed surgical guides. MATERIALS AND METHODS: Ten surgical guides, manufactured by digital light processing 3D-printing technology, were scanned immediately after post-processing and then after 5, 10, 15, and 20 days. The corresponding standard tessellation language (STL) files were used for comparison with the reference CAD project. Mean absolute deviation (MAD) of the intaglio surface, axial, and linear deviations of the sleeves' housings were measured. Generalized estimated equations models (α = 0.05) were used to investigate the effect of time. RESULTS: MAD of the teeth intaglio surface showed less variation (minimum: 0.002, maximum: 0.014 mm) than that of the mucosa (minimum: 0.026, maximum: 0.074 mm). Axial variations of the sleeves' housings on the sagittal (minimum: -0.008°, maximum: -0.577°) and frontal plane (minimum: -0.193°, maximum: 0.525°) changed with similar patterns, but opposite trends (decreasing for the former). Linear deviations of center points of the sleeves' housings had a shifting (minimum: -0.074, maximum: 0.02 mm) pattern with a decreasing tendency. Time after processing had a significant effect, either alone or nested with guides volume, on all outcomes of interest, except for MAD of the mucosa intaglio surface (p < 0.001), which was significantly affected only by the time-volume nested effect (p = 0.012). CONCLUSIONS: Within the limitations of the experimental design, postmanufacturing dimensional variations of surgical guides were statistically significant. Although limited, they are an additional source of variability affecting the overall accuracy of computer-guided surgery. As such, they should be addressed by further research.

Surgical guides for dental implants: Measurement of the accuracy using a freeware metrology software program.

PURPOSE: Manufacturing-related inaccuracies of surgical guides for static computer-aided implant surgery may contribute to the overall potential error in the obtained implant position. Measuring such inaccuracies before surgery may provide quality control assessment and improve the safety and outcomes of guided implant surgery. This technical report demonstrates a workflow to measure the accuracy of a surgical guide (at the intaglio surface and sleeve housing) using a freeware metrology software program. METHODS: The scan of a milled surgical guide was aligned to and compared with its reference computer-aided design model using a freeware metrology software program (GOM Inspect suite; GOM GmbH). The trueness of the internal surface of the surgical guide was measured as an indicator of adaptation to the supporting tissues. Additionally, some features were constructed to extract the plane at the sleeve entrance and sleeve axis and to set a local coordinate system on them. Linear and angular deviations between the planned and obtained sleeve axes were measured using this system. Such measurements, together with additional known data (sleeve offset and the planned implant length), allowed the estimation of linear errors in implant position at both the implant platform and apex by applying common geometric formulas, based on the assumption that all other sources of error in implant position could be effectively controlled during the surgical procedure. CONCLUSIONS: The proposed digital technique is a cost-effective approach for quality control of the inaccuracies of a surgical guide and predicts the related potential error in implant position.

Assessment of tooth displacement during the cast-free digital processing of milled dentures.

STATEMENT OF PROBLEM: Denture tooth displacement may have a significant impact on denture occlusion. This aspect has seldom been investigated, especially for digital denture processing techniques. PURPOSE: The purpose of this clinical study was to evaluate the accuracy of tooth position with milled digital dentures processed without physical casts. MATERIAL AND METHODS: Ten maxillary and 10 mandibular dentures designed from intraoral scans, milled, and processed without physical casts were investigated. The standard tessellation language (STL) files of the digitally designed dentures were compared with the scan of the dentures after processing (milling the denture base, milling teeth in a complete arch, and then bonding teeth into the base). The STL files were superimposed by using a surface-matching software program. After a preliminary alignment, the STL meshes were trimmed and reoriented; then, the final alignment was carried out by using the cameo surface. Six reference points (the mesiobuccal cusp on the most distal molar, the canine cusp, the middle of the incisal edge of the central incisor on both the left and the right side) were selected to measure tooth displacements along the X-, Y-, and Z-axes, corresponding (from the preliminary reorientation) to anteroposterior, mediolateral, and occlusal displacement, respectively. Tooth position accuracy was assessed by using median and interquartile range values. Univariate and multivariate statistical analyses were used to investigate the significance of the extent of displacements, as well as differences among displacement directions, reference teeth, side, and denture arch type (α=.05). RESULTS: Only the median (0.2 mm; interquartile range: 0.27 mm) occlusal displacement was significantly different from zero. A generalized estimated equation model addressing occlusal displacement as a dependent variable showed no significant effect of tooth type, side, or denture arch type, either alone or in combination. CONCLUSIONS: The tooth position of both maxillary and mandibular milled digital dentures processed without physical casts was accurate in the anteroposterior and mediolateral directions. Occlusal displacement seemed to be within the range of clinical acceptability; its consistency throughout the arch allowed optimization or compensation at the design or manufacturing step.

Craniofacial morphology in patients with obstructive sleep apnea: cephalometric evaluation / Morfologia craniofacial em pacientes com apneia obstrutiva do sono: avaliação cefalométrica

Abstract Introduction: Obstructive sleep apnea is characterized by a reduced airflow through the upper airways during sleep. Two forms of obstructive sleep apnea are described: the central form and the obstructive form. The obstructive form is related to many factors, such as the craniofacial morphology. Objective: To evaluate the correlation between the morphology of the cranial base, of the mandible and the maxilla, and obstructive sleep apnea severity. Methods: Eighty-four patients, mean age of 50.4 years old; 73 males and 11 females with obstructive sleep apnea were enrolled in the present study. Patients with high body mass index and comorbidities were excluded. Lateral cephalograms and polysomnography were collected for each patient to evaluate the correlation between craniofacial morphology and obstructive sleep apnea severity. A Spearman's rho correlation test between cephalometric measurements and obstructive sleep apnea indexes was computed. Statistical significance was set at p < 0.05. Results: Patients with a severe obstructive sleep apnea presented a reduction of sagittal growth of both effective mandibular length and cranio-basal length. The mandibular length was the only variable with a statistical correlation with apnea-hypopnea index. Vertical dimension showed a weak correlation with the severity of obstructive sleep apnea. No correlation with maxillary sagittal dimension was shown. Conclusion: Obstructive sleep apnea severity may be correlated to mandibular and cranial base growth. Facial vertical dimension had no correlation with obstructive sleep apnea severity.

Resumo Introdução: A apneia obstrutiva do sono é caracterizada por um fluxo de ar reduzido nas vias aéreas superiores durante o sono. Duas formas de apneia são descritas: a forma central e a forma obstrutiva. A forma obstrutiva tem sido relacionada a vários fatores, como a morfologia craniofacial. Objetivo: Avaliar a correlação entre a morfologia da base do crânio, da mandíbula e da maxila e a gravidade da apneia obstrutiva do sono. Método: Foram incluídos no presente estudo 84 pacientes com apneia obstrutiva do sono, com média de 50,4 anos; 73 homens e 11 mulheres. Pacientes com alto índice de massa corpórea e comorbidades foram excluídos. Foram coletados cefalogramas laterais e polissonografia para cada paciente para avaliar a correlação entre a morfologia craniofacial e a gravidade da apneia. Foi computado o coeficiente de correlação de postos de Spearman (rho) entre medidas cefalométricas e índices de apneia obstrutiva do sono. A significância estatística foi estabelecida em p < 0,05. Resultados: Pacientes com apneia obstrutiva do sono grave apresentaram redução do crescimento sagital do comprimento mandibular efetivo e do comprimento crânio-basal. O comprimento mandibular foi a única variável que apresentou correlação estatística com o índice de apneia-hipopneia. A dimensão vertical mostrou uma fraca correlação com a gravidade da apneia. Não foi demonstrada correlação com a dimensão maxilar sagital. Conclusão: A gravidade da apneia obstrutiva do sono pode estar correlacionada ao crescimento da base mandibular e craniana. A dimensão facial vertical não apresentou correlação com a gravidade da apneia.

Perception of the Role of Food and Dietary Modifications in Patients with Inflammatory Bowel Disease: Impact on Lifestyle.

BACKGROUND: Diet has a relevant role in triggering symptoms in inflammatory bowel disease (IBD) from the patients' perspective, but there is gap the between patients' and doctors' perceptions. Few studies have addressed this topic. The aim of this study was to evaluate food habits and nutrition knowledge in a homogeneous cohort of patients with IBD from southern Italy. METHODS: 167 consecutive patients with IBD were recruited. The survey was based on the administration of a semi-structured questionnaire assessing demographics, disease features, dietary behavior, and food intolerance. RESULTS: The majority of patients did not consider food a cause of their disease. However more than 80% changed their diet after the diagnosis and most report an improvement in symptoms. Spiced and seasoned foods, dairy products, vegetables, and fruit were often avoided. A dairy-free diet was adopted by 33.7%. Food choices were based on self-experience and not on medical counselling. Dietary modifications deeply impact on lifestyle. CONCLUSIONS: Most of the patients with IBD set diet and lifestyle on self-experience and give up many foods. This has an impact on psychosocial functioning and can lead to nutritional deficiencies. High quality studies are warranted to assess evidence-based dietary strategies and develop patient-targeted dietary recommendations.

Effectiveness of Ustekinumab on Crohn's Disease Associated Spondyloarthropathy: Real-World Data from the Sicilian Network for Inflammatory Bowel Diseases (SN-IBD).

BACKGROUND: The effectiveness of Ustekinumab (UST) on Crohn's disease (CD)-associated spondyloarthropathy (SpA) is currently unknown. RESEARCH DESIGN AND METHODS: All consecutive CD patients with active SpA at the initiation of the treatment with UST were extracted from the cohort of the Sicilian Network for Inflammatory Bowel Diseases (SN-IBD). The primary outcome was the articular response at 8 and 24 weeks, defined as the disappearance of objective signs of arthritis (swelling and/or articular stiffness) and resolution of pain. RESULTS: Thirty CD patients with active SpA at the initiation of the treatment with UST were assessed. At 24 weeks, 13 patients (43.3%) had an articular response, including 10/18 patients (55.5%) with peripheral SpA and 3/9 patients (33.3%) with axial and peripheral SpA. No patient with axial SpA experienced an articular response. The drop of mean as Harvey-Bradshaw Index values from baseline to week 24 was higher in patients with articular response compared with non-responders (3.8 ± 2.4 vs. 1.3 ± 2.8, p = 0.02). CONCLUSIONS: Our real-world, multicentre experience showed that UST was able to obtain a response on articular symptoms in nearly half of the patients with CD and active SpA after 24 weeks of treatment.

Effectiveness and safety of vedolizumab in biologically naïve patients: A real-world multi-centre study.

BACKGROUND: Biologically naïve patients with inflammatory bowel disease treated with vedolizumab (VDZ) are largely underrepresented in real-world cohorts. A multi-centre, observational cohort study was performed on the effectiveness and safety of VDZ in biologically naïve subjects with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: Data of consecutive biologically naïve patients with CD and UC treated with VDZ from July 2016 to December 2019 were extracted from the cohort of the Sicilian Network for Inflammatory Bowel Disease. RESULTS: A total of 172 consecutive patients (CD: N = 88; UC: N = 84; median age 66.0 years) were included, with a median follow-up of 58.8 weeks. After 14 weeks, a clinical response was reported in 68.2% of patients with CD and 67.9% of patients with UC treated with VDZ, including 45.5% patients in the CD group and 46.4% patients in the UC group who achieved steroid-free remission. After 52 weeks, a clinical response was reported in 77.4% of CD and in 73.8% of UC patients treated with VDZ, including 59.7% patients in the CD group and 60.7% patients in the UC group who achieved steroid-free remission. CONCLUSIONS: This study demonstrates the effectiveness and safety of VDZ as a first-line biological, particularly among elderly patients.

Swallowing and Temporomandibular Disorders in Adults.

INTRODUCTION: Temporomandibular disease (TMD) etiology is multifactorial and is related to many perpetuating, predisposing, and initiating factors. The daytime parafunctions may have an important role in TMD pathogenesis. The most frequent parafunctions analyzed were the static parafunction (ie, clenching) and the dynamic parafunction (ie, grinding). In the present paper, the authors evaluated the swallowing (an oral function/parafunction) with the surface electromyography in patients with TMD. MATERIALS AND METHODS: Twenty patients with TMD problems (nonhealthy patients, NHP) (mean age: 33 ±â€Š1.994; 8 men and 12 women) and 20 healthy matched subjects (HP) (34.4 ±â€Š2.782; 6 men and 14 women) were selected and examined. On each patient, an 8-channel surface electromyography was done during saliva swallowing. RESULTS: Nonhealthy patients presented higher masseter and temporalis activation (P < 0.05) and an unbalancing of temporalis and submental muscles activation (P < 0.05) than the HP. DISCUSSION: Nonhealthy patients presented a time of swallow higher than HP (P < 0.001). Nonhealthy patients presented a higher muscles activation and time of swallow than HP and a decrease of muscles balancing activation.