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1.
BMC Med Educ ; 21(1): 466, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470635

RESUMO

BACKGROUND: In dentistry, the reporting of panoramic radiographs is particularly challenging, as many structures are depicted in one image and pathologies need to be identified completely. To enhance the learning process for these interpretations, the advantages of the increasingly popular education method of mobile learning could be used. Therefore, this study aimed to determine the effectiveness of learning to report panoramic radiographs using an application (app) on a mobile device. METHODS: The existing e-learning programme 'PantoDict' was further developed into a mobile app with a new training section. Participants of a dental radiology course were divided into two groups, one of which additionally had the chance to practise reporting panoramic radiographs using the app. A test to assess the knowledge gained was conducted at the end of the semester; the course and the app were also evaluated. RESULTS: The group that used the app showed significantly better results in the test than the control group (p < 0.05). Although the app group approved a high satisfaction using the app as an additional supplement to the course, this did not result in a higher overall satisfaction with the course. Further, these students observed that the traditional face-to-face seminar could not be replaced by the app. CONCLUSION: By using the PantoDict app, students were offered better training options for writing reports on panoramic radiographs, which resulted in significantly better test results than the results of the control group. Therefore, the mobile app is a useful supplement to classical education formats within the context of a blended learning approach.


Assuntos
Aprendizagem , Aplicativos Móveis , Educação em Odontologia , Humanos , Radiografia Panorâmica , Estudantes , Redação
2.
Ann Anat ; 239: 151834, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34547412

RESUMO

BACKGROUND: Harvesting vascularized bone grafts with computer-assisted surgery represents the gold standard for mandibular reconstruction. However, current augmented reality (AR) approaches are limited to invasive marker fixation. This trial compared a markerless AR-guided real-time navigation with virtually planned and 3D printed cutting guides for harvesting iliac crest grafts. MATERIAL AND METHODS: Two commonly used iliac crest transplant configurations were virtually planned on 10 cadaver hips. Transplant harvest was performed with AR guidance and cutting guide technology. The harvested transplants were digitalized using cone beam CT. Deviations of angulation, distance and volume between the executed and planned osteotomies were measured. RESULTS: Both AR and cutting guides accurately rendered the virtually planned transplant volume. However, the cumulative osteotomy plane angulation differed significantly (p = 0.018) between AR (14.99 ± 11.69°) and the cutting guides (8.49 ± 5.42°). The cumulative osteotomy plane distance showed that AR-guided navigation had lower accuracy (2.65 ± 3.32 mm) than the cutting guides (1.47 ± 1.36 mm), although without significant difference. CONCLUSION: This study demonstrated the clinical usability of markerless AR-guided navigation for harvesting iliac crest grafts. Further improvement of accuracy rates might bring clinical implementation closer to reality.

3.
Medicina (Kaunas) ; 57(8)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34440965

RESUMO

Background and objectives: In oral and maxillofacial operations, the iliac crest is a commonly used donor site from which to harvest bone for augmentation prior to dental implantation or for reconstruction of jaw defects caused by trauma or pathological lesions. In an aging society, the proportion of elderly patients undergoing iliac crest bone grafting for oral augmentation is growing. Although postoperative morbidity is usually moderate to low, the age and health of the patient should be considered as risk factors for complications and delayed mobilization after the operation. The aim of this retrospective study was to evaluate the postoperative morbidity and complications in elderly patients after the harvesting of iliac crest bone grafts for oral surgery. Material and Methods: Data were collected from a total of 486 patients (aged 7-85) who had a surgical procedure that included the harvesting of iliac crest bone grafts for intraoral transplantation. All patients were operated on between 2005 and 2021 in the Department for Oral and Maxillofacial Surgery of the University Hospital in Aachen, Germany. As parameters for postoperative morbidity and complications, gait disturbances, hypesthesia of cutaneous nerves, incision hernias, iliac crest fractures, delayed wound healing, and unfavorable scar formation at the donor site were all evaluated. Results: The study was performed with 485 patients due to the exclusion of one patient as the only one from whom grafts were taken from both sides. When younger and older patients were compared, neither gait disturbances (p = 0.420), nor hernias (p = 0.239), nor fractures (p = 0.239), nor hypesthesia (p = 0.297), nor wound healing delay (p = 0.294), nor scar problems (p = 0.586) were significantly different. However, the volume of the graft was significantly correlated with the duration of the hospital stay (ρ = 0.30; p < 0.01) but not with gait disturbances (ρ = 0.60; p = 0.597). Additionally, when controlling for age (p = 0.841), sex (p = 0.031), ASA class (p = 0.699), preexisting orthopedic handicaps (p = 0.9828), and the volume of the bone graft (p = 0.770), only male sex was associated with the likelihood of suffering gait disturbances (p = 0.031). Conclusions: In conclusion, harvesting bone grafts from the anterior iliac crest for intraoral augmentation is a safe procedure for both young and elderly patients. Although there is some postoperative morbidity, such as gait disturbances, hypesthesia, scar formation, or delayed wound healing at the donor site, rates for these minor complications are low and mostly of short duration. Major complications, such as fractures or incision hernias, are very rare. However, in our study, the volume of the bone graft was associated with a longer stay in hospital, and this should be considered in the planning of iliac crest bone graft procedures.


Assuntos
Ílio , Coleta de Tecidos e Órgãos , Idoso , Transplante Ósseo , Humanos , Masculino , Morbidade , Dor Pós-Operatória , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos
4.
Int J Med Robot ; : e2318, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34328700

RESUMO

BACKGROUND: Defects of the facial skeleton often require complex reconstruction with vascularized grafts. This trial elucidated the usability, visual perception and accuracy of a markerless augmented reality (AR)-guided navigation for harvesting iliac crest transplants. METHODS: Random CT scans were used to virtually plan two common transplant configurations on 10 iliac crest models, each printed four times. The transplants were harvested using projected AR and cutting guides. The duration and accuracies of the angulation, distance and volume between the planned and executed osteotomies were measured. RESULTS: AR was characterized by the efficient use of time and accurate rendition of preoperatively planned geometries. However, vertical osteotomies and complex anatomical settings displayed significant inferiority of AR guidance compared to cutting guides. CONCLUSIONS: This study demonstrated the usability of a markerless AR setup for harvesting iliac crest transplants. The visual perception and accuracy of the AR-guided osteotomies constituted remaining weaknesses against cutting guide technology.

5.
Sci Rep ; 11(1): 13598, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193930

RESUMO

Conventional anastomoses with interrupted sutures are challenging and inevitably associated with trauma to the vessel walls. The goal of this study was to evaluate a novel alternative adhesive-based suture-free anastomosis technique that uses an intraluminal stent. Overall, 120 porcine coronary vessels were analyzed in an ex vivo model and were examined for their mechanical (n = 20 per cohort) and hydrostatic strength (n = 20 per cohort). Anastomoses were made using the novel VIVO adhesive with an additional intraluminal nitinol stent and was compared to interrupted suture anastomosis and to native vessels. Sutureless anastomoses withstood pressures 299 ± 4.47 [mmHg] comparable to native vessels. They were performed significantly faster 553.8 ± 82.44 [sec] (p ≤ 0.001) and withstood significantly higher pressures (p ≤ 0.001) than sutured anastomoses. We demonstrate that the adhesive-based anastomosis can also resist unphysiologically high longitudinal tensile forces with a mean of 1.33 [N]. Within the limitations of an in vitro study adhesive-based suture-free anastomosis technique has the biomechanical potential to offer a seamless alternative to sutured anastomosis because of its stability, and faster handling. In vivo animal studies are needed to validate outcomes and confirm safety.

6.
Sci Rep ; 11(1): 13586, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193933

RESUMO

To minimize the postoperative risks posed by grafting autologous transplants for cleft repair, efforts are being made to improve grafting materials for use as potential alternatives. The aim of this study was to compare the bone graft quality of different bone substitutes including the gold standard autografts during the healing processes after cleft repair in the context of orthodontic treatment. In 21 Wistar rats, a complete, continuity-interrupting cleft was created. After 4 weeks, cleft repair was performed using autografts from the hips' ischial tuberosity, human xenografts, or synthetic bone substitutes [beta-tricalcium phosphate (ß-TCP)/hydroxyapatite (HA)]. After another 4 weeks, the first molar movement was initiated in the reconstructed jaw for 8 weeks. The bone remodeling was analyzed in vivo using micro-computed tomography (bone mineral density and bone volume fraction) and histology (new bone formation). All the grafting materials were statistically different in bone morphology, which changed during the treatment period. The ß-TCP/HA substitute demonstrated less resorption compared to the autologous and xenogeneic/human bone, and the autografts led to a stronger reaction in the surrounding bone. Histologically, the highest level of new bone formation was found in the human xenografts, and the lowest was found in the ß-TCP/HA substitute. The differences between the two bone groups and the synthetic materials were statistically significant. Autografts were confirmed to be the gold standard in cleft repair with regard to graft integration. However, parts of the human xenograft seemed comparable to the autografts. Thus, this substitute could perhaps be used as an alternative after additional tissue-engineered modification.

7.
Ann Anat ; 238: 151782, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34144156

RESUMO

BACKGROUND: Sutured anastomosis remains the gold standard in microvascular surgery. The procedure is not free of complications and is a time-consuming operation requiring a high level of experience. The aim of this study was to develop new methods for a stable, faster, and safer anastomosis using a novel biodegradable adhesive, VIVO, and a custom-made microvascular stent. METHODS: The VIVO medical adhesive was used for a total of 30 anastomoses in rats in the right carotid artery: 15 anastomoses were performed with a temporary intraluminal catheter, VIVO, and reduced sutures (VIVO + TC). A further 15 anastomoses were performed with nitinol stents, VIVO, and reduced sutures (VIVO + SM). Sutured anastomoses served as controls (C) and were performed on the left carotid arteries of the 30 rats. Operation and bleeding times were assessed, and patency was evaluated by Doppler flowmetry and indocyanine green (ICG) angiography. Subsequently, the anastomoses were evaluated histopathological. RESULTS: The overall patency was recorded as 100% in all groups. No thrombosis or circulatory disturbance was found. Compared to C and VIVO + SM, VIVO + TC proved to be significantly less traumatic, less demanding, and time-saving. The sealing properties of VIVO lead to shorter bleeding times and less oozing. In contrast, VIVO + SM proved to be the most technically demanding and time-consuming procedure. CONCLUSION: The success of a microvascular sutured anastomosis is determined by a short ischemic interval. Compared to sutured anastomosis, VIVO + TC showed ease of use as well as shorter time taken for anastomosis, less trauma, and lower blood loss. More long-term studies on the functions, biological interactions, and survival rates of glue-based anastomoses need to be initiated.

8.
J Wound Care ; 30(6): 492-496, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34121430

RESUMO

OBJECTIVE: Stevens-Johnson syndrome (SJS) and its more severe counterpart, toxic epidermal necrolysis (TEN), are skin hypersensitivity reactions defined by epidermal blistering and necrosis. The exact pathophysiology of SJS/TEN is yet to be deciphered, but a number of risk factors have been identified including adverse drug reactions. The diagnosis of SJS/TEN is made on a clinical basis, and treatment consists of supportive care and occasionally immunosuppressants, such as cyclosporin, high-dose intravenous immunoglobulins and/or corticosteroids. Mortality rates can reach 20-25% in adults but are reduced with early intervention. To identify optimal treatment regimens, to better understand the patient cohort affected, and to help identify key risk factors for mortality, we report our experience with the treatment and management of SJS/TEN patients. METHODS: A retrospective review of consecutive patients with SJS and/or TEN admitted to a single burns centre in Germany, between 2008 and 2018, was conducted. The primary outcomes of demographics, clinical course, treatment and patient-reported outcomes were recorded and compared with a control group of patients with burns without a diagnosis of SJS/TEN. RESULTS: A total of 23 patients with SJS/TEN met the inclusion criteria: 17 (74%) with TEN; four (17%) with SJS/TEN overlap; and two (9%) with SJS. Of the patients, 14 (61%) were female and nine (39%) were male. Patient age ranged from 32-78 years (mean: 52 years). A matched cohort of 23 patients with burns served as the control group. All patients received standard of care with a multidisciplinary team. Compared with the control group, SJS/TEN patients had higher mortality rates (n=6, 26% versus n=8, 35%, respectively). The average age of death was 69 years in SJS/TEN patients versus 63 years in control group patients. Age and SCORTEN scores were significant predictors of mortality. CONCLUSIONS: SJS and TEN are rare but extreme reactions of the skin and mucosa, associated with high disease mortality rates. This 10-year single-centre retrospective review contributes to the bank of information for reviews evaluating the management of SJS/TEN patients.


Assuntos
Corticosteroides/uso terapêutico , Queimaduras/terapia , Imunoglobulinas Intravenosas/uso terapêutico , Imunossupressores/uso terapêutico , Síndrome de Stevens-Johnson/tratamento farmacológico , Cicatrização , Adulto , Idoso , Unidades de Queimados , Queimaduras/mortalidade , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome de Stevens-Johnson/mortalidade , Resultado do Tratamento
9.
J Craniofac Surg ; 32(6): 2082-2086, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33935144

RESUMO

ABSTRACT: Facial fractures comprise a substantial part of traumatology. Due to aging of the population, over the last 20 years, there has been a pattern of redistribution of these fractures with a higher incidence at an older age. The aim of this study was to retrospectively analyze the epidemiology, pattern, and surgical management of facial fractures in geriatric patients presenting at a single tertiary trauma center.This study included patients aged ≥70 years who presented with facial bone fractures between 2008 and 2017 and were treated with surgical interventions. Parameters such as age, sex, American Society of Anesthesiologists classification, Glasgow Coma Scale score, fracture type, fracture mechanism, concomitant injuries, duration of hospitalization, and postoperative complications were evaluated.A total of 300 patients were included: 118 men (39.3%) and 182 women (60.7%). The mean age was 78.8 years. An orbital floor fracture was the most common injury (35.1%). The most common cause of fracture was a fall at home (67%). A total of 113 patients (37.7%) had 162 concomitant injuries, 35 patients (11.7%) suffered from polytrauma, and 7 patients developed postoperative complications. The average length of stay was 1.67 days in the intensive care unit and 5.50 days in the standard ward. Polytrauma, pre-existing medical conditions, and oral anticoagulation had a significant impact on the duration of hospitalization.Facial fractures are common in combination with other injuries. Women are more often affected than men, and falling at home is the most common cause of facial injuries. Postoperative complications are rare.


Assuntos
Traumatismos Faciais , Fraturas Cranianas , Idoso , Ossos Faciais/cirurgia , Traumatismos Faciais/epidemiologia , Traumatismos Faciais/cirurgia , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Estudos Retrospectivos , Fraturas Cranianas/epidemiologia , Fraturas Cranianas/cirurgia
10.
Eur J Vasc Endovasc Surg ; 62(2): 276-283, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34053840

RESUMO

OBJECTIVE: The impact of stent design on venous patency is not well studied. The purpose of this study was to investigate the effect of stent material burden on endothelial coverage of stented venous segments, which may contribute to vessel healing and patency. METHODS: Segmented self expanding bare nitinol stents (18 × 50 mm) comprising 5 mm long attached metallic rings separated by 2, 5, or 8 mm gaps were implanted in the inferior vena cava (IVC) of 10 sheep. These stents were designed and manufactured for the purposes of this study. At six, 12, and 24 weeks after implantation the animals were euthanised and the stented vessels harvested for histomorphometric analysis. Three sections from the metallic part as well as the gaps between the struts were reviewed for quantification of endothelialisation after six, 12, and 24 weeks. The intimal thickness over and between the stent struts was measured. The endothelialisation score (graded from 1 for complete luminal endothelialisation to 5 for absence of endothelial cells) was determined. RESULTS: All stents were successfully deployed and all 10 sheep survived until the time of harvesting. Macroscopic inspection after 24 weeks showed only partial endothelialisation over stents with 2 mm and 5 mm skipped segments, whereas the stents with 8 mm skipped segments were totally incorporated into the vein wall. After 24 weeks, the mean (SD) neointimal thicknesses over stent struts with 2 mm, 5 mm, and 8 mm skipped segments were 254.0 (51.6), 182.2 (98.1), and 194.6 (101.1) µm, respectively. Comparison of endothelialisation scores of stents over time showed statistically significantly better endothelialisation over stents with 8 mm gaps after 12 and 24 weeks. CONCLUSION: Stent designs providing structural support to veins with larger gaps between the scaffold material appear to lead to faster and more complete endothelialisation as well as a thinner intimal layer.


Assuntos
Endotélio/fisiopatologia , Neointima/patologia , Desenho de Prótese , Stents , Ligas , Animais , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Ovinos , Veia Cava Inferior
11.
Sci Rep ; 11(1): 9805, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963203

RESUMO

After craniofacial trauma, symptoms like swelling and pain occur. Cooling reduces these symptoms but the optimal cooling temperature for a maximum benefit without adverse effects is unclear. 30 participants were cooled at 10 °C, 15 °C, 20 °C, 25 °C and 30 °C for 30 min. Before cooling and at 15, 30, 45 and 60 min after cooling, the skin blood flow, oxygen saturation (SO) and haemoglobin concentration (Hb) were measured by laser Doppler spectrophotometry at 2 mm and 8 mm depth. The skin temperature was measured, and the participant's satisfaction was marked on a visual analogue scale. There were significant differences between males and females in the blood flow, SO and Hb (p < 0.0001). After cooling, the blood flow, SO and Hb was reduced. The measured values rose slightly above the initial values 60 min after cooling. Depending on the cooling temperature the decrease in blood flow, SO and Hb was significantly different. Both sexes were most comfortable with a 25 °C cooling temperature and satisfaction decreased with lower temperatures. Significant differences for the satisfaction between both sexes were measured (10 °C: p < 0.0001, 15 °C: p < 0.0001, 20 °C: p = 0.0168, 25 °C: p = 0.0293). After 60 min, the males and females exhibited mild skin hyperthermia. The optimal cooling temperatures their physiological effects and their perception for females and males were different. For females, around 20 °C is an optimal cooling temperature. For males, it is around 15-20 °C.

12.
J Craniofac Surg ; 32(6): e594-e598, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34054091

RESUMO

ABSTRACT: A split thickness skin graft (STSG) or a full thickness skin graft (FTSG) are commonly used for donor site closure after raising a radial forearm flap. The aesthetic outcome of the donor site is frequently not satisfying for the patient. This study evaluated the aesthetic outcome of the donor site of a radial forearm flap covered with an STSG or FTSG using an objective measurement method. The forearms of 30 patients (15 FTSG, 15 STSG) were scanned with an optical three-dimensional scanner. The surface of the forearm at the skin transplant was cut out and filled by an automatic hole-filling algorithm. The mean surface deviation between the original and the filled forearm was acquired. This method was validated with a control group of 15 volunteers. A questionnaire investigating aesthetical and healing satisfaction, postoperative pain and scarring was filled in by the patients. The mean surface difference in the STSG group was 0.9907 ±â€Š0.3120 and 0.6177 ±â€Š0.2245 mm in the FTSG group. The difference in the surface deviation between STSG and FTSG groups was significant (P = 0.0009). Correlations between the surface deviation and the subjective aesthetical satisfaction of the patient were not significant. In the questionnaires no significant differences between STSG and FTSG group were measured. Both FTSGs and STSGs resulted in good aesthetical outcomes after closure of a radial forearm flap donor site. Scanning the radial forearm flap donor site with an optical three-dimensional scanner supplied an objective, fast, and reliable measuring method of aesthetical outcomes.


Assuntos
Antebraço , Procedimentos Cirúrgicos Reconstrutivos , Estética Dentária , Antebraço/cirurgia , Humanos , Transplante de Pele , Retalhos Cirúrgicos
13.
Head Face Med ; 17(1): 13, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33853633

RESUMO

BACKGROUND: Orthognathic surgery can be carried out using isolated mandibular or maxillary movement and bimaxillary procedures. In cases of moderate skeletal malocclusion, camouflage treatment by premolar extraction is another treatment option. All these surgical procedures can have a different impact on the soft tissue profile. METHODS: The changes in the soft tissue profile of 187 patients (Class II: 53, Class III: 134) were investigated. The treatment approaches were differentiated as follows: Class II: mandible advancement (MnA), bimaxillary surgery (MxS/MnA), upper extraction (UpEX), or Class III: maxillary advancement (MxA), mandible setback (MnS), bimaxillary surgery (MxA/MnS), and lower extraction (LowEX) as well as the extent of skeletal deviation (moderate Wits appraisal: - 7 mm to 7 mm, pronounced: Wits <- 7 mm, > 7 mm, respectively). This resulted in five groups for Class II treatment and seven groups for Class III treatment. RESULTS: In the Class II patients, a statistically significant difference (p ≤ 0.05) between UpEX and moderate MnA was found for facial profile (N'-Prn-Pog'), soft tissue profile (N'-Sn-Pog'), and mentolabial angle (Pog'-B'-Li). In the Class III patients, a statistically significant differences (p ≤ 0.05) occurred between LowEX and moderate MxA for facial profile (N'-Prn-Pog'), soft tissue profile (N'-Sn-Pog'), upper and lower lip distacne to esthetic line (Ls/Li-E-line), and lower lip length (Sto-Gn'). Only isolated significant differences (p < 0.05) were recognized between the moderate surgical Class II and III treatments as well between the pronounced Class III surgeries. No statistical differences were noticed between moderate and pronounced orthognathic surgery. CONCLUSIONS: When surgery is required, the influence of orthognathic surgical techniques on the profile seems to be less significant. However, it must be carefully considered if orthognathic or camouflage treatment should be done in moderate malocclusions as a moderate mandibular advancement in Class II therapy will straighten the soft tissue profile much more by increasing the facial and soft tissue profile angle and reducing the mentolabial angle than camouflage treatment. In contrast, moderate maxillary advancement in Class III therapy led to a significantly more convex facial and soft tissue profile by decreasing distances of the lips to the E-Line as well as the lower lip length.


Assuntos
Má Oclusão Classe III de Angle , Procedimentos Cirúrgicos Ortognáticos , Cefalometria , Estética Dentária , Humanos , Má Oclusão Classe III de Angle/diagnóstico por imagem , Má Oclusão Classe III de Angle/cirurgia , Mandíbula , Resultado do Tratamento
14.
Sensors (Basel) ; 21(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33803030

RESUMO

Reliable object tracking that is based on video data constitutes an important challenge in diverse areas, including, among others, assisted surgery. Particle filtering offers a state-of-the-art technology for this challenge. Becaise a particle filter is based on a probabilistic model, it provides explicit likelihood values; in theory, the question of whether an object is reliably tracked can be addressed based on these values, provided that the estimates are correct. In this contribution, we investigate the question of whether these likelihood values are suitable for deciding whether the tracked object has been lost. An immediate strategy uses a simple threshold value to reject settings with a likelihood that is too small. We show in an application from the medical domain-object tracking in assisted surgery in the domain of Robotic Osteotomies-that this simple threshold strategy does not provide a reliable reject option for object tracking, in particular if different settings are considered. However, it is possible to develop reliable and flexible machine learning models that predict a reject based on diverse quantities that are computed by the particle filter. Modeling the task in the form of a regression enables a flexible handling of different demands on the tracking accuracy; modeling the challenge as an ensemble of classification tasks yet surpasses the results, while offering the same flexibility.


Assuntos
Algoritmos
15.
Ann Anat ; 236: 151713, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33675947

RESUMO

BACKGROUND: The aim of the present investigation was to develop a new cleft model in rats that allows alveolar cleft repair and subsequent tooth movement. METHODS: A complete continuity-interrupting alveolar cleft was performed on the left-side maxillae of 33 rats through ultrasonic surgery. The clefts were filled with bone wax, and microCT scans were done to analyze the cleft size. After four weeks, the cleft repair was completed using autologous, xenogeneic (human), or synthetic bone substitute. After an additional four weeks, the orthodontic tooth movement was initiated. RESULTS: Fourteen rats died during the research, and the study design was constantly adapted accordingly. The main reasons for death included breathing problems during or immediately after the experimental activities (eight animals), followed by two deaths due to circulatory failures. In the remaining 19 animals, the average cleft size was about 2.70 ± 0.46 × 2.01 ± 0.25 × 1.18 ± 0.20 mm, and the mean velocity of orthodontic tooth movement after seven days was between 0.21 ± 0.08 mm in the autologous group and 0.50 ± 0.54 mm in the xenogeneic group. After 56 days, the mean values ranged between 0.67 ± 0.27 mm in the autologous group and 0.82 ± 0.72 mm in the synthetic group. CONCLUSIONS: Surgical interventions in the oral cavity of rats requires a stronger anesthesia and lead to increased risk of coolant and coagulated blood aspiration. The new alveolar cleft model in rats allows for subsequent orthodontic tooth movement after cleft repair, but only in the mesial root of the first molar.

16.
BMC Med Educ ; 21(1): 137, 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33639906

RESUMO

BACKGROUND: Local anaesthesia plays a key role in many aspects of a dentist's work. The required skills to perform anaesthesia successfully are acquired at university. To take advantage of the possibilities for new teaching formats, a blended learning concept for the local anaesthesia course was developed. The aim of the study was to compare the effectiveness of face-to-face, blended and e-learning in teaching in local anaesthesia by assessing students' knowledge gain, performance of practical skills and satisfaction with the course. METHODS: All participants (n = 37) were randomly allocated into three groups. After acquiring the theoretical background in the blended learning, e-learning or lecture groups, a test to assess knowledge gain was performed. The performance of the practical skills was assessed in a small-group seminar. Student attitudes were evaluated with a questionnaire. RESULTS: The blended group showed significantly better results (mean = 17, SD =1.5) in theoretical knowledge gain than the other two groups (e-learning group: mean = 14.7, SD = 2.2; lecture group: mean = 14.8, SD =2.3). When comparing the results of the clinical skills assessment, there was no significant difference among all three groups (p > 0.017). The participants confirmed a high overall satisfaction with the course, in particular with the blended learning approach. CONCLUSION: This study indicates that blended learning improves the learning outcome for theoretical knowledge in teaching local anaesthesia more than either face-to-face learning or e-learning alone. Furthermore, the blended learning approach is highly appreciated by the students. For acquiring practical skills, this study shows that blended learning is as effective as other teaching methods.


Assuntos
Anestesia Local , Competência Clínica , Instrução por Computador , Educação em Odontologia/métodos , Estudantes/psicologia , Adulto , Feminino , Humanos , Masculino , Distribuição Aleatória , Adulto Jovem
17.
Clin Oral Investig ; 25(1): 345-353, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32691298

RESUMO

OBJECTIVES: The aim of this randomized observer-blinded split-mouth-study is to objectively assess the influence of a rubber drain on postoperative swelling using 3D face scans as measurement method and additionally evaluate pain, trismus and complications after the osteotomy of lower third molars. MATERIAL AND METHODS: Seventy-two patients with symmetrically impacted lower wisdom teeth were recruited. Before the operation, patients rated pain using the visual analogue scale, the interincisal distance was measured, and 3D face scans were taken with an optical scanner. Each patient underwent two procedures which were at least 30 days apart. On one side, a rubber drain was inserted randomly before closure, the contralateral control side was closed without drainage. On the third and tenth postoperative day, face scans to quantify the swelling, pain evaluation and trismus measurements were performed. Due to loss of follow-up, 32 patients were excluded which resulted in 40 out of 72 patients remaining in the study. RESULTS: There was no statistical difference in using a drain on swelling and trismus on the third and tenth day (p > 0.05). Pain was slightly worse on the third day on the treatment side, but the difference was not significant (p > 0.05). We observed no differences in the number of wound infections. CONCLUSIONS: The insertion of a rubber drain does not have any influence on swelling, pain or trismus and has no impact on the number of wound infections. CLINICAL RELEVANCE: The use of a rubber drain cannot be recommended as no reduction of postoperative discomfort was detected.


Assuntos
Drenagem/métodos , Dente Serotino , Dente Impactado , Edema/etiologia , Edema/prevenção & controle , Humanos , Mandíbula/cirurgia , Dente Serotino/diagnóstico por imagem , Dente Serotino/cirurgia , Boca , Dor Pós-Operatória/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Extração Dentária/efeitos adversos , Dente Impactado/cirurgia , Trismo/etiologia , Trismo/prevenção & controle
18.
Ann Anat ; 234: 151655, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33278578

RESUMO

BACKGROUND: Bone resorption of the jaw leads to challenging implant placement. Frequently, augmentation of the jaw is necessary. Is calvarian split bone an alternative to other extraoral donor sites and what volume of bone is harvestable? The aim was to evaluate the spatial distribution and the total amount of harvestable calvarian split bone. MATERIAL AND METHODS: Computerized tomographies of 600 patients were divided into four groups (male and female: ≤45 years and >45 years). The skull was segmented and cut into the harvestable compartments (Os frontale, Ossa parietalia). The volume and thickness of the harvestable bone were calculated. RESULTS: The overall harvestable bone was 110.644 ± 25.429 cm³. The bone from the Os frontale was significantly less than harvestable bone from the Os parietale (p < 0.001). More bone could be harvested from the right Os parietale. In younger males, significantly more bone could be harvested than in females (females ≤45 years: p = 0.001; females >45 years: p = 0.003). A weak negative correlation existed between the participants' age and the harvestable bone volume of the left Os parietale (r = -0.087; p = 0.033). The thickness of the harvestable bone from the Ossa parietalia is greater in females than in males. CONCLUSION: A great amount of calvarian bone can be harvested to augment the jaw. Surgeons must acknowledge that more bone is harvestable from males than females while the female bone is thicker. Calculating the volume leads to accurate results of the available bone.

19.
Clin Oral Investig ; 25(1): 265-273, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32500401

RESUMO

OBJECTIVES: The purpose of this pilot porcine cadaver study was to evaluate the feasible temperature thresholds, which affect osteocyte viability and bone matrix in a preclinical setup, assessing the potential of thermal necrosis for implant removal for further in vivo investigations. MATERIALS AND METHODS: After implant bed preparation in the upper and lower jaw, temperature effects on the bone were determined, using two tempering pistons with integrated thermocouples. To evaluate threshold temperature and time intervals leading to bone necrosis, one piston generated warm temperatures at 49 to 56 °C for 10 s and the other generated cold temperatures at 5 to 1 °C for 30 s. Effects were assessed by a semi-quantitative, histomorphometrical scoring system, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). RESULTS: The bone matrix was significantly degenerated starting at 51 °C for 10 s and 5 °C for 30 s. The osteocyte condition indicated significant bone damage beginning at cold temperatures of 2 °C. Temperature inputs starting at 53 °C led to decalcification and swollen mitochondria, which lost the structure of their inner cristae. CONCLUSIONS: This study identified temperatures and durations, in both heat and cold, so that the number of samples may be kept low in further studies regarding temperature-induced bone necrosis. Levels of 51 °C for 10 s and 5 °C for 30 s have presented significant matrix degeneration. CLINICAL RELEVANCE: Temperature thresholds, potentially leading to thermo-explantation of dental implants and other osseointegrated devices, were identified.


Assuntos
Implantes Dentários , Animais , Temperatura Alta , Necrose , Projetos Piloto , Suínos , Temperatura
20.
Clin Oral Investig ; 25(3): 1299-1306, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32613434

RESUMO

OBJECTIVES: The aim of this study was to evaluate the accuracy of fully guided orthodontic mini-implant (OMI) placements supported by tooth- (TBGs) or gingiva-borne silicone guides (GBGs) based on virtually superimposed lateral cephalograms on virtual plaster models. MATERIALS AND METHODS: Lateral cephalograms and corresponding plaster models were virtually superimposed for the planning of OMI positions; fully guided TBGs and GBGs were fabricated (each, n = 10). A total of 40 OMIs were inserted in a paramedian position into the palate of 20 human cadavers. Postoperative cone-beam computer tomographies (CBCTs) were carried out, and an accuracy evaluation was performed by comparing preoperative planning models and postoperative CBCTs. Deviations of the axis, tip, centre of the shoulder and vertical position of each of the implants were evaluated. Furthermore, the transfer accuracy measured by postoperative CBCT scans were compared with the accuracy determined using an intraoral scanner. RESULTS: A significant deviation between TBGs (2.81° SD 2.69) and GBGs (6.22° SD 4.26) regarding implant angulation was evaluated (p = 0.005). Implant tip and implant shoulder deviations revealed no statistical differences between the guides. Accuracy values of oral scans regarding vertical deviations were significantly more inaccurate when compared with CBCTs (p < 0.001). CONCLUSIONS: The accuracy of an OMI position can be significantly increased by using a guide extension over the teeth. Vertical implant positions presented the lowest deviations. Postoperative oral scans and CBCTs represent diverging accuracy measurements when compared with virtual planning. CLINICAL RELEVANCE: Users must keep in mind that despite virtual planning deviations, inaccuracies of a few millimetres may occur.


Assuntos
Implantes Dentários , Procedimentos de Ancoragem Ortodôntica , Cirurgia Assistida por Computador , Cadáver , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Humanos , Imageamento Tridimensional , Planejamento de Assistência ao Paciente
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