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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.
Matrix Biol ; 102: 37-69, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34508852

RESUMO

Dysregulation of proteolytic enzymes has huge impact on epidermal homeostasis, which can result in severe pathological conditions such as fibrosis or Netherton syndrome. The metalloprotease meprin ß was found to be upregulated in hyperproliferative skin diseases. AP-1 transcription factor complex has been reported to induce Mep1b expression. Since AP-1 and its subunit fos-related antigen 2 (fra-2) are associated with the onset and progression of psoriasis, we wanted to investigate if this could partially be attributed to increased meprin ß activity. Here, we demonstrate that fra-2 transgenic mice show increased meprin ß expression and proteolytic activity in the epidermis. To avoid influence by other fra-2 regulated genes, we additionally generated a mouse model that enabled tamoxifen-inducible expression of meprin ß under the Krt5-promotor to mimic the pathological condition. Interestingly, induced meprin ß expression in the epidermis resulted in hyperkeratosis, hair loss and mottled pigmentation of the skin. Employing N-terminomics revealed syndecan-1 as a substrate of meprin ß in skin. Shedding of syndecan-1 at the cell surface caused delayed calcium-induced differentiation and impaired adhesion of keratinocytes, which was blocked by the meprin ß inhibitor fetuin-B.

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): 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.

7.
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
8.
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
9.
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
10.
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.

11.
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
12.
Orthod Craniofac Res ; 24(1): 78-86, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32608152

RESUMO

OBJECTIVE: Lateral cephalograms (LC) should be usable to evaluate the vertical bone height of the anterior maxilla for planning the placement of orthodontic mini-implants (OMI). The purpose of this study is to determine the usability of LC for examining the real vertical dimension of the anterior palate. SETTING AND SAMPLE POPULATION: Lateral cephalograms and corresponding cone beam computed tomography (CBCT) scans were employed for examining 30 fresh cadaver heads. MATERIALS & METHODS: The minimum (distance A) and maximum (distance B) vertical palatal bone heights on LCs at the level of first premolars were measured, whereas the corresponding measurements were taken via CBCTs on the median, and 2-, 4- and 6-mm paramedian planes. Additionally, the overall minimum vertical palatal height on CBCT was recorded. RESULTS: Distance A and B on LC were about 8.3 ± 2.5 mm and 9.9 ± 2.5 mm, respectively. The median palatal height on CBCT was significantly higher than both measurements on LC (P < .01). Furthermore, the bone supply on the paramedian planes was similar or higher on CBCT compared to Distance A and similar or less compared to Distance B. The strongest correlation at the level of the premolars was found in the comparison of the maximum vertical palatal height via LC with the vertical palatal height on the median plane via CBCT (r = .84, 95% CI: 0.69-0.92, P < .001). CONCLUSIONS: In order to make the best possible use of the vertical bone supply of the anterior palate and to avoid injuries to the nasal floor, Distance A should be taken into account for planning paramedian OMI placements and distance B for median OMI insertion.


Assuntos
Implantes Dentários , Procedimentos de Ancoragem Ortodôntica , Tomografia Computadorizada de Feixe Cônico , Maxila/diagnóstico por imagem , Palato/diagnóstico por imagem
13.
J Plast Reconstr Aesthet Surg ; 74(4): 740-746, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33189616

RESUMO

The incidence of skin cancer, which often affects the facial skin, has risen worldwide. After resecting such facial lesions, plastic reconstruction is necessary in most cases. The paramedian forehead flap (PFF) and the bilobed flap (BF) are commonly used for nasal reconstruction, but whether patients and physicians are satisfied with the esthetics is undetermined? In this study, scar questionnaires (Manchester Scar Scale, Vancouver Scar Scale, and Patient and Observer Scar Assessment Scale) and optical three-dimensional (3D) imaging were used for subjective and objective evaluation of esthetical outcomes after plastic reconstruction of the nose in 30 patients. The distances between landmarks and changes in volume between the treated and both the mirrored, healthy side of the face as well as an untreated, matched control group were measured using the optical (3D) scans. The questionnaires ascertained whether the patient was content with the esthetical outcome of both flaps. In the opinion of the observer, the esthetical outcome of both flaps was sufficient; only a few of the measured distances differed significantly between the patients and the control group. However, the measured volume differences of the donor site of the flap differed significantly between the PFF group and the control group (p = 0.0078). The BF was used for smaller defects, while the PFF was used for major defects. Besides a greater donor-side morbidity for the PFF, both flaps led to esthetically sufficient results and could be used for the reconstruction of the nose depending on the defect size and localization.


Assuntos
Estética , Testa/cirurgia , Neoplasias Nasais/cirurgia , Rinoplastia/métodos , Retalhos Cirúrgicos/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cicatriz , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
14.
J Periodontol ; 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33258110

RESUMO

BACKGROUND: Because of bisphosphonate medication, dental implantation with a subsequent infection poses a relevant risk factor to suffer from medication-related osteonecrosis of the jaw. This rat study evaluated different implant materials under systemic bisphosphonate delivery using micro-computed tomography (µCT) images. METHODS: Fifty-four rats were randomly allocated into a control group 1, test group 2 with intravenous drug application of zoledronic acid and test group 3 with a subcutaneous application of alendronic acid. After 4 weeks of drug delivery, the first molar on each side of the upper jaw was extracted, and either a zirconia or a titanium implant was immediately inserted. Radiological examinations at four timepoints before the operation, 1 week later, 6 weeks later and after 12 weeks of follow up included µCT measurements of the in vivo peri-implant bone loss. µCT measurements of the ex vivo peri-implant bony structure after 12 weeks follow-up covered the bone mineral density, -volume, -trabecular thickness and -separation. RESULTS: Both test groups showed a significant increase in bone loss over time (P < 0.05). The clinical observations of exposed bone revealed that most cases occurred under alendronic acid delivery. Exposed bone was recorded only in the test groups around both titanium and zirconia implants. Regarding the peri-implant bony structure, no significant differences were found between both materials. CONCLUSIONS: Systemic bisphosphonate delivery led to increased peri-implant bone loss over time after immediate implant insertion. In terms of bone resorption and bone quality parameters, no implant material was superior to the other.

15.
Sci Rep ; 10(1): 20699, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244089

RESUMO

In the context of cleft repair in animal research in rat models, different areas can be used for bone grafting. The aim of the present study was to present the tuberosity of the ischium as a new donor site and to evaluate its quality in relation to an artificial alveolar cleft. Four weeks after creating experimental alveolar clefts in seven Wistar rats, the repair was performed in the now twelve-week-old male animals using bone blocks grafted from the ischial tuberosity. Two days before surgery and two as well as twenty-eight days after surgery, microCT scans were performed, and the grafted bone blocks were analyzed regarding height, width, thickness, and volume. Additionally, bone mineral density (BMD) and bone volume fraction (BV/TV) were measured in the repaired cleft. The mean bone volume of the graft was about 19.77 ± 7.77mm3. Immediately after jaw reconstruction the BMD and BV/TV were about 0.54 ± 0.05 g/cm3 and 54.9 ± 5.07% for the transplant and about 1.13 ± 0.08 g/cm3 and 94.5 ± 3.70%, respectively, for the surrounding bone. Four weeks later the BMD and BV/TV were about 0.57 ± 0.13 g/cm3 and 56.60 ± 13.70% for the transplant and about 11.17 ± 0.07 g/cm3 and 97.50 ± 2.15%, respectively, for the surrounding bone. A hip fracture was found in four of the animals after surgery. The ischial tuberosity offers large bone blocks, which are sufficient for cleft repair in the rat model. However, the bone quality regarding BMD and BV/TV is less compared with the surrounding bone of the alveolar cleft, even after a period of 4 weeks, despite recognizable renovation processes.


Assuntos
Transplante Ósseo/métodos , Fissura Palatina/fisiopatologia , Fissura Palatina/cirurgia , Ísquio/fisiopatologia , Experimentação Animal , Animais , Densidade Óssea/fisiologia , Nádegas/fisiopatologia , Masculino , Ratos , Ratos Wistar , Microtomografia por Raio-X/métodos
16.
Materials (Basel) ; 13(19)2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33007841

RESUMO

AIM: This in vitro study aimed to evaluate the effects of implant designs on primary stability in different bone densities and bony defects. METHODS: Five implant types (tapered-tissue-level, tissue-level, zirconia-tissue-level, bone-level, and BLX implants) were used in this assessment. The implants were inserted into four different artificial bone blocks representing varying bone-density groups: D1, D2, D3, and D4. Aside from the control group, three different types of defects were prepared. Using resonance frequency analysis and torque-in and -out values, the primary stability of each implant was evaluated. RESULTS: With an increased defect size, all implant types presented reduced implant stability values measured by the implant stability quotient (ISQ) values. Loss of stability was the most pronounced around circular defects. Zirconia and bone-level implants showed the highest ISQ values, whereas tissue level titanium implants presented the lowest stability parameters. The implant insertion without any thread cut led to a small improvement in primary implant stability in all bone densities. CONCLUSIONS: Compared with implants with no peri-implant defects, the three-wall and one-wall defect usually did not provide significant loss of primary stability. A significant loss of stability should be expected when inserting implants into circular defects. Implants with a more aggressive thread distance could increase primary stability.

17.
BMC Med Educ ; 20(1): 310, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933499

RESUMO

BACKGROUND: A teaching concept, that takes individual learning and personal belongings into account, is called the "sandwich principle." This didactic method is an educational concept that alternates consecutively between individual and collective learning phases during a course. This study aimed to prove whether the application of the sandwich principle in lectures increases the learning outcome compared with classical lectures. METHODS: All participants (n = 64) were randomly allocated into two groups. One group attended a classical face-to-face lecture and the other attended a lecture that was modified according to the sandwich principle, including activating elements. To compare knowledge gain after the lectures, all the participants had to answer a test comprising40 single-choice questions. In addition, the lectures were evaluated. RESULTS: Students attending the sandwich lecture had significantly better scores in the test than those who attending the classical lecture (p <  0.001). The mean test score of the sandwich group was 63.9% [standard deviation (SD) = 10] points and of the control group 50.2% (SD = 13.7 points). Overall, both the class conditions showed good evaluation results; however, students of the sandwich lecture were more satisfied with the lecture format compared with the other group. CONCLUSION: Our study results confirm the thesis that the application of the sandwich principle in lectures increases the learning outcome compared with classical lectures. Even with a big audience, the sandwich design presents a concept that helps maintain high attention levels and addresses individual learning styles.


Assuntos
Fenda Labial , Estudantes de Medicina , Avaliação Educacional , Humanos , Aprendizagem , Palato , Ensino
18.
Head Face Med ; 16(1): 17, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32741369

RESUMO

BACKGROUND: This study aimed at comparing bracket placement and excess bonding adhesive depending on different indirect bonding (IDB) techniques and bracket geometries. METHODS: Four hundred eighty brackets without hook (WOH) and 360 with hook (WH) were placed on 60 plaster models. Three IDB techniques were tested: polyvinyl-siloxane vacuum-form (PVS-VF), polyvinyl-siloxane putty (PVS-putty), and translucence double-polyvinyl-siloxane (double-PVS). PVS-VF and PVS-putty were combined with chemically, and double-PVS was combined with light cured bonding adhesive. Virtual images of models before and after bracket transfer were generated, and computerized images were compared. Linear, angular deviations, and excess bonding adhesive were measured. RESULTS: Linear differences between the three groups were obtained for PVS-VF (WH: 1.08, SD 0.50 mm; WOH: 0.86, SD 0.25 mm), PVS-putty (WH: 0.73, SD 0.51 mm; WOH: 0.58, SD 0.28 mm), and double-PVS (WH: 0.65, SD 0.45 mm; WOH: 0.59, SD 0.33 mm) (P < 0.001). Hooks affected bracket placement accuracy in PVS-VF (P < 0.001) and PVS-putty (P = 0.029). Angular differences were observed for brackets WOH between the PVS-VF (0.64, SD 0.48°) and double-PVS group (0.92, SD 0.76°) (P < 0.001) and within double-PVS group (WH: 0.66, SD 0.51° vs. WOH: 0.92, SD 0.76°, P < 0.001). Highest amount of excess adhesive was obtained for PVS-putty group (WH: 6.54, SD 5.31 mm 2). CONCLUSIONS: The double-PVS group revealed promising results with respect to transfer accuracy, whereas the PVS-VF group provided least excess bonding adhesive. Basically, hooks lead to lower precision and higher excess bonding adhesive. PVS trays for IDB generate high bracket placement accuracy. PVS-putty is the easiest to handle with and also the cheapest, but leads to large excess bonding adhesive, especially in combination with hooked brackets or tubes.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Cimentos Dentários
19.
Eur J Dent Educ ; 24(4): 695-705, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32558047

RESUMO

INTRODUCTION: Workplace-based assessments are methods that can be applied for assessing competence and performance. One of these methods is the mini-clinical evaluation exercise (mini-CEX). This study was conducted to determine the role of mini-CEX in students' performance assessment on panoramic X-ray reporting at dental radiology course. MATERIALS AND METHODS: A workshop as training for the assessors and the participants was conducted before the primary test. All participants (n = 36) were randomly allocated into six groups. Each group had three seminars in which every student reported a panoramic X-ray. Students were directly observed and rated by an assessor on a modified mini-CEX rating form. Then, a self-assessment of the students and a systematic feedback session were performed. Finally, the students and the assessors were evaluated for the acceptability and satisfaction with this tool. RESULTS: The mean duration of the assessment and the feedback decreased significantly from the first seminar to the third seminar (P < .0001). Comparison of the results of the mini-CEX of all three assessments showed that students displayed a significantly better performance in evaluating the upper jaw and the soft tissue (P < .05). There was no significant improvement for the other aspects of the rating form. Overall, both students and assessors reported a high level of satisfaction in using the mini-CEX rating form. CONCLUSION: Due to the objectivity and transparency of the assessment, the mini-CEX helped to improve the performance on reporting panoramic X-rays. Besides that, the structured feedback had major impact on the improvement. Overall, the assessors and the participants reported a high level of satisfaction using the rating form. Therefore, the mini-CEX may be an effective method for performing workplace-based assessments to evaluate students' performance on reporting panoramic X-rays.


Assuntos
Avaliação Educacional , Radiologia , Competência Clínica , Educação em Odontologia , Humanos , Projetos Piloto
20.
J Craniomaxillofac Surg ; 48(7): 694-699, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32513431

RESUMO

The aim of this study was to evaluate the morphological changes in the face of obese patients during massive weight loss using a more reliable method than two dimensional photographs or tape measures. The faces of 23 patients were recorded prior to and six months after bariatric surgery. Distances between important anatomical landmarks of the face were calculated and the volume of the neck was compared. The distance between the Tragion and Subnasale (132.7 ± 6.804 mm to 131.5 ± 6.866 mm; p = 0.0003), and the distance between Tragion and Stomion became significantly longer 136.0 ± 8.016 mm to 134.3 ± 7.698 mm; p = 0.0031), while distances between the Tragion and Pogonion (150.2 ± 8.216 mm to 148.3 ± 8.383 mm; p < 0.0001), Tragion and Menton (152.3 ± 9.037 mm to 148.9 ± 9.623 mm; p < 0.0001), and Tragion and tip of the nose (144.9 ± 7.273 mm to 144.0 ± 7.416 mm; p = 0.0023) were significantly reduced. The mean volume loss of the neck was 75.218 ± 40.197 ml. No significant correlation was found between total weight loss and cervical volume loss (r = 0.3447; p = 0.1072). The morphological changes of the face after massive weight loss vary in different areas of the face. Patients and their attending physicians must be aware of the face's morphology change after massive weight loss in an extent that does not correlate with the total weight loss of the patient.


Assuntos
Cirurgia Bariátrica , Perda de Peso , Cefalometria , Humanos , Imageamento Tridimensional , Nariz
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