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OBJECTIVES: The preclinical study aimed to establish a standardized preclinical model to investigate osseous graft consolidation in defect configurations of limited regenerative capacity. MATERIAL AND METHODS: Critical size defects (CSD) were prepared and titanium tubes inserted for defect separation from local bone in the forehead area of 18 pigs. Defects were filled with demineralized bovine bone mineral (DBBM) or served as empty controls and were covered with a resorbable collagen membrane (CM) or left untreated. Six randomly selected pigs were sacrificed after 4, 8 and 12 weeks. Specimens were histologically and histomorphometrically analysed focusing on newly formed bone (NFB), demineralized bovine bone mineral (DBBM) and soft tissue (ST) proportions. RESULTS: Four weeks after defect preparation, no statistically significant difference concerning NFB quantity could be detected within the groups. Defects covered with the CM showed lower amounts of DBBM. After 6 and 12 weeks, defects augmented with DBBM in combination with a CM (8 weeks: 43.12 ± 4.31; 12 weeks: 43.05 ± 3.01) showed a statistically significant higher NFB rate compared to empty control defects covered with 8 weeks: 7.66 ± 0.59; 12 weeks or without a CM; 8 weeks: 8.62 ± 2.66; 12 weeks: 18.40 ± 2.40. CM application showed no significant impact on osseous defect regeneration or soft tissue formation. Superior NFB could be detected for basal aspect for several evaluation time points. CONCLUSIONS: The modification of CSD with titanium tubes represents a suitable model to imitate a one-wall defect regeneration situation. CLINICAL RELEVANCE: The established model represents a promising method to evaluate graft consolidation in one-wall defect configuration.
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Regeneração Óssea , Substitutos Ósseos , Minerais/uso terapêutico , Crânio/lesões , Animais , Bovinos , Colágeno , Testa , Suínos , TitânioRESUMO
Leukoplakia is a potential precursor of oral as well as laryngeal squamous cell carcinoma. Risk assessment of malignant transformation based on the grade of dysplasia of leukoplakia often does not lead to reliable results. However, oral squamous cell carcinoma, laryngeal squamous cell carcinoma, and leukoplakia express single or multiple members of the melanoma-associated antigens A (MAGE-A) family, while MAGE-A are absent in healthy mucosal tissue. The present study aimed at determining if there is an association between the expression of MAGE-A in leukoplakia and malignant transformation to oral or laryngeal squamous cell carcinoma. Paraffin-embedded tissues of 205 oral and laryngeal leukoplakia, 90 corresponding tumors, and 40 healthy oral mucosal samples were included in the study. The grade of dysplasia of the leukoplakia samples was determined histopathologically. The leukoplakia samples were divided into lesions that transformed to oral and laryngeal squamous cell carcinoma (n = 91) and lesions that did not (n = 114) during a 5 years follow-up. The expression of MAGE-A3/6 and MAGE-A4 was analyzed by real-time RT-PCR. The expression of MAGE-A 1-4, 6, and 12 was determined by immunohistochemistry. A total of 59.3% of the transforming leukoplakia expressed at least one of the examined antigens as opposed to an expression rate of 3.5% of all non-transforming leukoplakia. There was no MAGE-A expression in healthy oral mucosa. The risk of malignant transformation was statistically significantly associated with MAGE-A expression in immunohistochemistry (p < 0.001) and real-time RT-PCR (MAGE-A3/6, p = 0.001; MAGE-A4, p = 0.002) analyses. There was no significant association between MAGE-A expression and the grade of dysplasia ("low-grade", D0/D1; "high-grade", D2/D3) in immunohistochemistry (p = 0.412) and real-time RT-PCR (MAGE-A3/6, p = 0.667; MAGE-A4, p = 0.756). It seems that the analysis of the MAGE-A expression profile may support the identification of leukoplakia at risk for malignant transformation. Therefore, efforts should be made to establish this analysis as a routine procedure in addition to conventional histopathology.
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Antígenos de Neoplasias/análise , Biomarcadores Tumorais/análise , Transformação Celular Neoplásica/imunologia , Neoplasias Laríngeas/imunologia , Leucoplasia Oral/imunologia , Proteínas de Neoplasias/análise , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Adulto , Idoso , Antígenos de Neoplasias/genética , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/patologia , Leucoplasia Oral/genética , Leucoplasia Oral/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Proteínas de Neoplasias/genética , Medição de Risco , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Fatores de TempoRESUMO
The following note was inadvertently omitted from the published paper: This work was performed in (partial) fulfillment of the requirements for the first author's obtaining the degree Dr. med. dent.
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OBJECTIVES: This study aimed to identify anatomical areas where resections of oral squamous cell carcinomas (OSCC) are significantly associated with close or positive margins. MATERIALS AND METHODS: This retrospective study included 330 patients with a primary OSCC from 2010 to 2015. Patient and tumour data were categorised into three groups by R-status (R0 [clear], ≥ 5 mm, 185 patients [56.06%]; R1 [positive], < 1 mm, 24 patients [7.27%]; and R0 [close], 1-5 mm, 121 patients [36.67%]). RESULTS: Areas where resections were significantly associated with close or positive margins were the hard palate (p < 0.001), buccal mucosa (p = 0.03), floor of the mouth (p = 0.004), lower alveolar ridge (p = 0.01), retromolar triangle (p = 0.005), and dorsal tongue (p = 0.02). CONCLUSIONS: Anatomical areas were identified in the oral cavity where it is challenging to resect OSCCs with an adequate safety margin. CLINICAL RELEVANCE: These results may enable surgeons to achieve a postulated safe distance during tumour resection, leading to a survival benefit for patients.
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Carcinoma de Células Escamosas/cirurgia , Margens de Excisão , Neoplasias Bucais/cirurgia , Pontos de Referência Anatômicos , Carcinoma de Células Escamosas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Gradação de Tumores , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
For full-arch reconstruction of an atrophied cleft maxilla with missing premaxilla, a prefabricated microvascular free bony flap is a relevant option. A fibula flap was prefabricated in a cleft patient who received six dental implants and an epithelial layer. Six weeks later, maxillary reconstruction was performed. The inpatient period could be confined to 2 weeks. A fixed provisional prosthesis was delivered after an additional 2 weeks. A prefabricated flap allows for the reduction of the interval without a dental prosthesis to only a few weeks, even when a complex full-arch reconstruction of the maxilla is required.
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Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Fíbula/transplante , Mastigação , Procedimentos de Cirurgia Plástica , Implantes Dentários , Humanos , Masculino , Maxila , Pessoa de Meia-Idade , Palato , Retalhos Cirúrgicos/transplanteRESUMO
The protection of sensitive structures (e.g., nerves) from iatrogenic damage is of major importance when performing laser surgical procedures. Especially in the head and neck area both function and esthetics can be affected to a great extent. Despite its many benefits, the surgical utilization of a laser is therefore still limited to superficial tissue ablation. A remote feedback system which guides the laser in a tissue-specific way would provide a remedy. In this context, it has been shown that nerval structures can be specifically recognized by their optical diffuse reflectance spectra both before and after laser ablation. However, for a translation of these findings to the actual laser ablation process, a nerve protection within the laser pulse is of utmost significance. Thus, it was the aim of the study to evaluate, if the process of Er:YAG laser surgery--which comes with spray water cooling, angulation of the probe (60°) and optical process emissions--interferes with optical tissue differentiation. For the first time, no stable conditions but the ongoing process of laser tissue ablation was examined. Therefore, six different tissue types (nerve, skin, muscle, fat, cortical and cancellous bone) were acquired from 15 pig heads. Measurements were performed during Er:YAG laser ablation. Diffuse reflectance spectra (4500, wavelength range: 350-650 nm) where acquired. Principal component analysis (PCA) and quadratic discriminant analysis (QDA) were calculated for classification purposes. The clinical highly relevant differentiation between nerve and bone was performed correctly with an AUC of 95.3% (cortial bone) respectively 92.4% (cancellous bone). The identification of nerve tissue against the biological very similar fat tissue yielded good results with an AUC value of 83.4% (sensitivity: 72.3%, specificity: of 82.3%). This clearly demonstrates that nerve identification by diffuse reflectance spectroscopy works reliably in the ongoing process of laser ablation in spite of the laser beam, spray water cooling and the tissue alterations entailed by tissue laser ablation. This is an essential step towards a clinical utilization.
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Tecido Conjuntivo/inervação , Nervo Facial/patologia , Nervo Facial/cirurgia , Terapia a Laser , Animais , Tecido Conjuntivo/patologia , Tecido Conjuntivo/cirurgia , Ossos Faciais/inervação , Ossos Faciais/patologia , Músculos Faciais/inervação , Músculos Faciais/patologia , Músculos Faciais/cirurgia , Terapia a Laser/efeitos adversos , Terapia a Laser/instrumentação , Terapia a Laser/métodos , Lasers de Estado Sólido , Fenômenos Ópticos , Procedimentos Cirúrgicos Bucais/efeitos adversos , Procedimentos Cirúrgicos Bucais/métodos , Sensibilidade e Especificidade , Pele/inervação , Pele/patologia , SuínosRESUMO
BACKGROUND: The Oral Squamous Cell Carcinoma (OSCC) frequently metastasizes lymphogenously. Haematogenous dissemination is less common. This report describes a rare case of a metastatic OSCC of the floor of the mouth to the patients' left upper arm. To our knowledge this is the first of such case described in the literature. CASE PRESENTATION: Twelve months after R0 tumor resection surgery, including microvascular reconstruction of the lower jaw followed by adjuvant radiotherapy, the patient was admitted for osteosynthesis plates removal. During clinical examination a tumor located at his left upper arm was detected. According to the patient the tumor has demonstrated rapid growth. Macroscopic appearance and conventional imaging led to the differential diagnosis of an abscess. MR-imaging could not differentiate between a tumor of soft tissue origin and a metastasis. A biopsy was taken and the pathological examination confirmed the diagnosis of an OSCC metastasis. The postoperative interdisciplinary tumor board recommended radiation therapy. CONCLUSION: Due to the fact that patients with regional lymph node metastases have a higher probability to develop distant metastasis a more detailed screening might be considered--especially when hemangiosis carcinomatosa was histologically or macroscopically found.
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Carcinoma de Células Escamosas/secundário , Soalho Bucal/patologia , Neoplasias Bucais/patologia , Neoplasias de Tecidos Moles/secundário , Extremidade Superior/patologia , Abscesso/diagnóstico , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Diagnóstico Diferencial , Seguimentos , Humanos , Masculino , Neoplasias Mandibulares/patologia , Neoplasias Mandibulares/cirurgia , Pessoa de Meia-Idade , Soalho Bucal/cirurgia , Neoplasias Bucais/cirurgia , Esvaziamento Cervical , Invasividade Neoplásica , Radioterapia Adjuvante/métodos , Radioterapia de Intensidade Modulada/métodos , Dermatopatias Infecciosas/diagnósticoRESUMO
OBJECTIVES: Piezoelectric surgery (PS) is meant to be a gentle osteotomy method. The aim of this study was to compare piezosurgical vs. conventional drilling methods for implant site preparation (ISP) - focusing on load-dependent thermal effect on hard tissue and the expenditure of ISP time. MATERIALS AND METHODS: Three hundred and sixty ISP were performed on ex vivo pig heads using piezosurgery, spiral burs (SB) and trephine burs (TB). The load applied was increased from 0 to 1000 g in 100-g intervals. Temperature within the bone was measured with a thermocouple, and duration was recorded with a stop watch. Thermal effects were histomorphometrically analysed. Twelve ISPs per technique were performed at the lateral wall of the maxillary sinus. RESULTS: PS yields the highest mean temperatures (48.6 ± 3.4°C) and thermal effects (200.7 ± 44.4 µm), both at 900-1000 g. Duration is reduced with a plus of load and significantly longer in either case for PS (P < 0.05). There is a correlation of the applied load with all other examined factors for PS and TB. Temperature and histological effects decrease for SB beyond 500 g. CONCLUSIONS: PS yields significantly higher temperatures and thermal tissue alterations on load levels higher than 500 g and is significantly slower for ISP compared to SB and TB. For ISP with PS, a maximum load of 400 g should be maintained.
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Seio Maxilar/cirurgia , Procedimentos Cirúrgicos Pré-Protéticos Bucais , Piezocirurgia , Animais , Implantação Dentária Endóssea , Implantes Dentários , Temperatura Alta , Técnicas In Vitro , Duração da Cirurgia , SuínosRESUMO
Facial nerve function may be hampered by iatrogenic damage during head and neck laser surgery procedures. Optical techniques can serve as a basis for feedback-controlled tissue-specific laser surgery on the jaw bone and the parotid gland. In order to preserve nerve tissue during laser surgery, the alteration of optical tissue properties through laser-tissue interactions have to be taken into account. It was the aim of this study to evaluate the viability of optical tissue differentiation through diffuse reflectance spectroscopy after exposure to laser light as a basis for a feedback system for tissue-specific laser surgery. Spectra of diffuse reflectance (wavelength, 350-650 nm) of nerves, salivary glands, and cortical and cancellous bone of the midfacial region (ex vivo domestic pig heads) were acquired before/after Er:YAG laser (wavelength, 2.94 µm) ablation (each 16,800 spectra). Principal component analysis was computed followed by quadratic discriminant analysis. The tissue classification performance as well as area under the curve (AUC) sensitivity and specificity for tissue differentiation was assessed before and after laser-tissue exposure. A high classification performance was observed before laser ablation (total error, 7.74%). Nerve tissue was differentiated from bone and salivary glands with results greater than 0.96 in AUC, sensitivity and specificity. After laser exposure, a total classification error of 18.61% was observed. The differentiation of nerve tissue was reduced with an AUC of >0.94, sensitivity of >0.95, and specificity >0.87. Er:YAG laser ablation only slightly reduces the differentiation performance through diffuse reflectance in the investigated tissue types. The results show the general viability of diffuse reflectance spectroscopy in identifying neural structures in the vicinity of salivary glands and bone as a basis for nerve preservation during feedback-controlled laser surgery.
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Cabeça/cirurgia , Terapia a Laser/métodos , Lasers de Estado Sólido , Pescoço/cirurgia , Nervo Óptico/cirurgia , Animais , Área Sob a Curva , Análise de Componente Principal , Análise Espectral , Sus scrofaRESUMO
OBJECTIVES: The present case series evaluates the success rate of osteotomy and primary wound closure in patients with bisphosphonate-associated osteonecrosis of the jaw (BRONJ). MATERIALS AND METHODS: Eighty patients suffering from BRONJ were included in the study. All patients received intravenous bisphosphonate therapy and underwent osteotomy and primary wound closure according to a standardised protocol. After discharge, the patients were reviewed on a regular basis over an average time period of 20 months. RESULTS: During follow-up in 11 patients, a recurrence of BRONJ occurred in the former operation field. Seventeen patients died due to their underlying disease. The success rate of osteotomy and primary wound closure in the treatment of BRONJ was calculated at 84.2 % 20 months after surgery. The results showed non-significant difference concerning the outcome of surgery in the different clinical stages of BRONJ. CONCLUSIONS: In accordance with previous studies, stage-independent osteotomy and primary wound closure combined with antibiotics shall be deemed a viable treatment option in patients suffering from BRONJ. CLINICAL RELEVANCE: With a high success rate, osteotomy in combination with primary wound closure seems to be a viable alternative to more conservative protocols in the treatment of BRONJ.
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Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/cirurgia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
The current prospective study aimed at assessing skeletal stability and complications arising from transantral maxillary distraction adopted for advancements of less than 12 mm in patients with cleft lip, alveolus, and palate malformations.The recruited patients with cleft lip, alveolus, and palate were followed up for 12 months. Lateral skull radiographs were obtained before surgery (T0), at the end of the activation period of the distractors (T1), and after completion of the follow-up interval (T2). Length and height of the maxilla were assessed at the different points of time. The relapse rate of maxillary advancement was calculated. Complications such as infections, distractor breakage and loosening, nonunions, and the need for reoperation were documented.Seven patients were included in this study (mean [SD] age, 19.5 [2.6] y). The length of the maxilla significantly increased by 6.4 ± 1.1 mm at T1 (P = 0.018) but showed a significant relapse by 7.5% at T2 (P = 0.018). As a complication, a case of infection of the cheek occurred during the consolidation period, which could be treated conservatively. In an additional patient, there was a loosening of a distractor at the end of the distraction period, which required reoperation with conventional fixation of the maxilla in the intended position. At the time of removal of the distractors and the conventional osteosynthesis plates, no cases of nonunion could be identified.It seems that the low horizontal relapse rate of transantral maxillary distraction in patients with cleft lip and palate outweighs the possible complications of this procedure in cases of limited distances of advancement of less than 12 mm.
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Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Osteogênese por Distração/métodos , Complicações Pós-Operatórias/cirurgia , Adolescente , Cefalometria , Fenda Labial/diagnóstico por imagem , Fissura Palatina/diagnóstico por imagem , Feminino , Humanos , Masculino , Maxila/diagnóstico por imagem , Maxila/cirurgia , Osteotomia de Le Fort/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Estudos Prospectivos , Radiografia , Reoperação , Adulto JovemRESUMO
This report describes a complex, surgical, and prosthodontic hemimaxillary rehabilitation with a prefabricated vascularized free fibula graft. The treatment was based on 3-dimensional skull and fibula models but avoided software-based virtual planning of the reconstructive procedure or the implant positions. Cast-based surgical guides were used for implant placement during prefabrication of the fibula graft and for the positioning of the prefabricated graft in the maxilla during the reconstructive procedure. This procedure allowed the definitive prosthesis to be attached to the implants of the reconstructed maxilla during the inpatient period.
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Transplante Ósseo/métodos , Implantação Dentária Endóssea/instrumentação , Retalhos de Tecido Biológico/transplante , Maxila/lesões , Planejamento de Assistência ao Paciente , Procedimentos de Cirurgia Plástica/instrumentação , Placas Ósseas , Parafusos Ósseos , Implantação Dentária Endóssea/métodos , Prótese Dentária Fixada por Implante , Revestimento de Dentadura , Prótese Parcial , Fíbula/cirurgia , Humanos , Imageamento Tridimensional/métodos , Masculino , Maxila/cirurgia , Modelos Anatômicos , Impressão Tridimensional , Procedimentos de Cirurgia Plástica/métodos , Transplante de Pele/métodos , Tomografia Computadorizada por Raios X/métodos , Sítio Doador de Transplante/cirurgia , Adulto JovemRESUMO
OBJECTIVE: Human papillomavirus (HPV) is strongly associated with cervical cancer and possibly with some oropharyngeal cancers. However, the relation between oral and cervical HPV infection is not fully understood. This study evaluates the prevalence rate and type-concordance of HPVs in these areas. METHODS: HPV DNA typing was performed in saliva and cervical specimens of 43 sexually active women, with the use of general consensus PCR and nested PCR (NPCR) tests. RESULTS: The prevalence rate of HPV DNA in cervical and saliva samples was 51.2% and 11.6% with general PCR, and 60.5% and 44.2% with NPCR, respectively. The probability of HPV DNA detection with general PCR in saliva was about 8 times lower compared to the cervix (P<0.001, OR: 0.13, 95% CI: 0.04-0.37), but showed no difference when the more sensitive NPCR method was applied (P=0.139, OR: 0.52, 95% CI: 0.22-1.21). The distribution of HPV variants according to their oncogenic potential revealed no statistically significant difference, regardless to the PCR method used for both sites. All general PCR HPV DNA positive saliva specimens belonged to women with cytology findings (n=5). These women had also 8.5 times higher risk for presenting with positive HPV detection in saliva with the NPCR method (P=0.009, OR=8.50, 95% CI: 1.74-39.70). CONCLUSIONS: Women with genital HPV infection are at higher risk for asymptomatic oral HPV infection. Prophylactic HPV-vaccination may reduce the burden of HPV-related diseases in both cervix and oropharynx.
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Alphapapillomavirus/isolamento & purificação , Infecções Assintomáticas/epidemiologia , Testes de DNA para Papilomavírus Humano , Infecções por Papillomavirus/epidemiologia , Saliva/virologia , Esfregaço Vaginal , Adulto , Alphapapillomavirus/genética , Estudos de Coortes , DNA Viral , Feminino , Grécia/epidemiologia , Testes de DNA para Papilomavírus Humano/métodos , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Reação em Cadeia da Polimerase , Comportamento SexualRESUMO
Ameloblastoma is a histologically benign, locally aggressive tumor arising from the odontogenic ectoderm. It accounts for 1% of all oral tumors and for 9% to 11% of all odontogenic tumors. In up to 96.6%, the tumor can be found in the mandible, predominantly in the molar region. High recurrence rates of up to 90% have been described with conservative treatment. Recurrences most often occur after 2 to 5 years. After radical resection, significantly lower recurrence rates have been reported, sometimes as low as 3.6%. As a consequence, when recurrence rate is the main concern, there is a tendency to prefer radical resection of the ameloblastoma. Microvascular segmental reconstruction of the mandible that uses an intraoral anastomosis technique has not been described in the current literature. Therefore, the present study aimed at extending the armamentarium of bony microvascular reconstruction in cases of segmental mandibulectomy by describing an intraoral microvascular anastomosing technique.
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Ameloblastoma/cirurgia , Anastomose Cirúrgica/métodos , Retalhos de Tecido Biológico/transplante , Neoplasias Mandibulares/cirurgia , Reconstrução Mandibular/métodos , Microcirurgia/métodos , Placas Ósseas , Transplante Ósseo/métodos , Desenho Assistido por Computador , Implantação Dentária Endóssea/métodos , Prótese Dentária Fixada por Implante , Seguimentos , Retalhos de Tecido Biológico/irrigação sanguínea , Humanos , Masculino , Microvasos/cirurgia , Planejamento de Assistência ao Paciente , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
Cases of immediate bony microvascular reconstruction following segmental mandibulectomy in children are hard to find in the current literature. Moreover, microvascular segmental mandibular reconstruction that adopts an intraoral anastomosis technique has not been described so far. Therefore, the present clinical report aims at extending the armamentarium of bony microvascular reconstruction in pediatric cases of segmental mandibulectomy by highlighting an intraoral microvascular anastomosing technique.A 6-year-old boy, who suffered from an ameloblastoma of the mural type in the mandible, received a radical segmental mandibular resection because of the high recurrence rate of this tumor entity. Immediate reconstruction was carried out with a fibular double-barrel graft. Microvascular anastomoses were performed in an end-to-end fashion with the facial artery and vein as recipient vessels. The postoperative course was uneventful. There was no impairment of speech, deglutition, mastication, and facial nerve function. The facial appearance remained unobtrusive. On removal of the reconstruction plate 3 months after the reconstruction procedure, bleeding from the reconstructed mandibular segment indicated vascularization of the graft.It seems that segmental mandibulectomy and simultaneous microvascular bony reconstruction do not necessarily lead to impaired function as far as speech, deglutition, and mastication are concerned. Instead, the intraoral anastomosis technique allows waiving extraoral skin incisions and subsequent scarring, leaving the facial appearance unchanged and unobtrusive. Especially, the potential risk of stigmatization of the patient is avoided. Therefore, decision making in the choice of 1 or the other reconstruction option following segmental mandibulectomy should always consider the adoption of an intraoral anastomosing technique.
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Ameloblastoma/cirurgia , Anastomose Cirúrgica/métodos , Retalhos de Tecido Biológico/transplante , Neoplasias Mandibulares/cirurgia , Reconstrução Mandibular/métodos , Microcirurgia/métodos , Autoenxertos/transplante , Transplante Ósseo/métodos , Criança , Deglutição/fisiologia , Estética , Seguimentos , Humanos , Masculino , Osteotomia Mandibular/métodos , Mastigação/fisiologia , Fala/fisiologiaRESUMO
Laser surgery provides a number of advantages over conventional surgery. However, it implies large risks for sensitive tissue structures due to its characteristic non-tissue-specific ablation. The present study investigates the discrimination of nine different ex vivo tissue types by using uncorrected (raw) autofluorescence spectra for the development of a remote feedback control system for tissue-selective laser surgery. Autofluorescence spectra (excitation wavelength 377 ± 50 nm) were measured from nine different ex vivo tissue types, obtained from 15 domestic pig cadavers. For data analysis, a wavelength range between 450 nm and 650 nm was investigated. Principal Component Analysis (PCA) and Quadratic Discriminant Analysis (QDA) were used to discriminate the tissue types. ROC analysis showed that PCA, followed by QDA, could differentiate all investigated tissue types with AUC results between 1.00 and 0.97. Sensitivity reached values between 93% and 100% and specificity values between 94% and 100%. This ex vivo study shows a high differentiation potential for physiological tissue types when performing autofluorescence spectroscopy followed by PCA and QDA. The uncorrected autofluorescence spectra are suitable for reliable tissue discrimination and have a high potential to meet the challenges necessary for an optical feedback system for tissue-specific laser surgery.
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Algoritmos , Terapia a Laser/métodos , Reconhecimento Automatizado de Padrão/métodos , Espectrometria de Fluorescência/métodos , Cirurgia Assistida por Computador/métodos , Análise Serial de Tecidos/métodos , Animais , Projetos Piloto , SuínosRESUMO
OBJECTIVES: The present prospective study aimed at objectively evaluating the relevance of a single horizontal Y-V vermilion plasty including orbicularis oris muscle repair for secondary correction of whistling deformities in unilateral as well as bilateral cleft lip cases. STUDY DESIGN: Ten patients were included in the study (mean age 20.2 ± 6.2 years). The size of the whistling defects was determined on photographs before and 12 months after surgery. Additional surgical procedures like columella lengthening and rhinoplasty were documented. RESULTS: Seven minor and 3 moderate whistling defects were corrected. In 7 patients additional procedures were carried out. The data of the 12 months follow-up showed that the whistling defect was significantly reduced in size (p < 0005). In 7 out of 10 patients the result of surgery was rated "good" and in 3 patients "moderate". CONCLUSIONS: The present prospective study is the first one to show on an objective basis that the presented technique allows reducing whistling deformities significantly with good overall results in the majority of the cases. Moreover, the technique can be combined with other corrective procedures like columella lengthening without problems. As a consequence, it is a relevant and universal surgical technique for the correction of whistling defects.
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Fenda Labial/cirurgia , Músculos Faciais/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Adolescente , Adulto , Criança , Fenda Labial/patologia , Humanos , Masculino , Estudos Prospectivos , Adulto JovemRESUMO
BACKGROUND: Optical diffuse reflectance can remotely differentiate various bio tissues. To implement this technique in an optical feedback system to guide laser surgery in a tissue-specific way, the alteration of optical tissue properties by laser ablation has to be taken into account. It was the aim of this study to evaluate the general feasibility of optical soft tissue differentiation by diffuse reflectance spectroscopy under the influence of laser ablation, comparing the tissue differentiation results before and after laser intervention. METHODS: A total of 70 ex vivo tissue samples (5 tissue types) were taken from 14 bisected pig heads. Diffuse reflectance spectra were recorded before and after Er:YAG-laser ablation. The spectra were analyzed and differentiated using principal component analysis (PCA), followed by linear discriminant analysis (LDA). To assess the potential of tissue differentiation, area under the curve (AUC), sensitivity and specificity was computed for each pair of tissue types before and after laser ablation, and compared to each other. RESULTS: Optical tissue differentiation showed good results before laser exposure (total classification error 13.51%). However, the tissue pair nerve and fat yielded lower AUC results of only 0.75. After laser ablation slightly reduced differentiation results were found with a total classification error of 16.83%. The tissue pair nerve and fat showed enhanced differentiation (AUC: 0.85). Laser ablation reduced the sensitivity in 50% and specificity in 80% of the cases of tissue pair comparison. The sensitivity of nerve-fat differentiation was enhanced by 35%. CONCLUSIONS: The observed results show the general feasibility of tissue differentiation by diffuse reflectance spectroscopy even under conditions of tissue alteration by laser ablation. The contrast enhancement for the differentiation between nerve and fat tissue after ablation is assumed to be due to laser removal of the surrounding lipid-rich nerve sheath. The results create the basis for a guidance system to control laser ablation in a tissue-specific way.
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Diferenciação Celular , Tecido Conjuntivo/cirurgia , Terapia a Laser , Animais , Análise Discriminante , Análise de Componente Principal , SuínosRESUMO
The study aimed at checking if MAGE-A expression in oral leukoplakia (OLP) lesions is related to malignant transformation. The 48 samples of OLP that transformed to oral squamous cell carcinoma (OSCC) (group 1) and 50 samples of OLP that did not transform to OSCC (group 2) were included in the study. The expression of MAGE-A was restricted to group 1. The correlation between malignant transformation and MAGE-A occurrence in OLP was statistically significant (p < .0001). Detection of MAGE-A may allow identifying OLP with a high risk of malignant transformation giving a view to a new approach to prevention of oral cancer.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Leucoplasia Oral/patologia , Antígenos Específicos de Melanoma/análise , Neoplasias Bucais/metabolismo , Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mucosa Bucal/metabolismo , Mucosa Bucal/patologia , Neoplasias Bucais/patologiaRESUMO
BACKGROUND: Advances in healthcare such as virtual dental implant planning have the capacity to result in greater accuracy, speed, and efficiencies leading to improvement in patient care. It has been suggested that the acceptance of new technology is influenced by a variety of factors including individual differences, social and situational influences, user beliefs, and user attitudes. Despite the large volume of work in this area, only limited research has been conducted in the field of dental education. Therefore, the present study aimed at assessing the acceptance of virtual dental implant planning software by undergraduate students. METHODS: Forty-three third-year dental students of the University of Erlangen-Nuremberg, Germany, were included in the study. They filled in a questionnaire based on a combination of the technology acceptance model and the theory of planned behavior (C-TAM-TPB). Cronbach's α, Pearson product moment correlation coefficients, and squared multiple correlations (R2) were calculated. RESULTS: Cronbach's α exceeded .7 for all constructs. Pearson correlations were significant for the pairs perceived usefulness/behavioral intention, perceived usefulness/attitude, and attitude/behavioral intention. Perceived ease of use explained .09% of the variance of perceived usefulness (R2 = .09). Perceived ease of use and perceived usefulness accounted for 31% of the variance of attitude (R2 = .31). Perceived usefulness, attitude, subjective norm, and perceived behavioral control explain 37% of the variance of behavioral intention (R2 = .37). CONCLUSIONS: Virtual dental implant planning software seems to be accepted by dental students especially because of its usefulness and the students' attitude towards this technology. On the other hand, perceived ease of use does not play a major role. As a consequence, the implementation of virtual dental implant planning software in a dental undergraduate curriculum should be supported by highlighting the usefulness by the supervisors, who should also strengthen the attitude of the students towards this technology.