RESUMO
The term neurofibromatosis (NF) is used for a group of genetic disorders that primarily affect the cell growth of neural tissues. Neurofibromatosis type 1 (NF1), also known as von Recklinghausen's disease, is the most common type of NF and accounts for about 90% of all cases. It is one of the most frequent human genetic diseases, with a prevalence of one case in 3,000 births. The expressivity of NF1 is extremely variable, with manifestations ranging from mild lesions to several complications and functional impairment. Oral manifestations can be found in almost 72% of NF1 patients. A case of a NF1 patient with a gingival neurofibroma in the attached gingiva of the lingual aspect of the lower central incisors is presented. The lesion was nodular, with sessile base, non-ulcerated, non-painful, with normal colour and measured 1 cm in diameter. An excisional biopsy of the oral lesion was performed. Histopathological and immunohistochemical analysis confirmed the clinical hypothesis of neurofibroma. Because NF1 is one of the most common genetic diseases and oral manifestations are very common, dentists should be aware of the characteristics of this disease.
Assuntos
Neoplasias Gengivais/patologia , Neurofibromatose 1/patologia , Biópsia , Feminino , Humanos , Imuno-Histoquímica , Incisivo/patologia , Mandíbula , Pessoa de Meia-Idade , Neurofibroma/patologiaRESUMO
BACKGROUND: The hallmark of neurofibromatosis type 1 (NF1) is the development of multiple neurofibromas. Solitary neurofibroma may occur in an individual who does not have NF1, but multiple neurofibromas tend to develop only in those with NF1. It has been suggested that hormones may influence the neurofibromas of patients with NF1. The evidence that hormones may influence the growth of neurofibromas comes mainly from the observation that localised neurofibromas of patients with NF1 commonly grow during puberty and pregnancy. Because growth hormone (GH) concentrations increase during puberty, it is possible that GH influences the growth of these tumours. AIMS: To investigate the presence of GH receptors (GHRs) in neurofibromas. METHODS: By means of immunohistochemistry, the presence of GHRs was investigated in two groups of patients: 16 patients without NF1 with solitary neurofibromas (group A) and 10 patients with NF1 with localised neurofibromas (group B). RESULTS: Six of the 16 patients in group A had neurofibromas that were immunopositive for GHR, whereas nine of the 10 patients in group B were immunopositive. CONCLUSIONS: Most patients with NF1 have localised neurofibromas that express GHR. This suggests that GH may play some role in the development of localised neurofibromas in patients with NF1.
Assuntos
Biomarcadores Tumorais/análise , Neurofibromatose 1/metabolismo , Receptores da Somatotropina/análise , Adolescente , Adulto , Criança , Contraindicações , Feminino , Transtornos do Crescimento/complicações , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento , Humanos , Imuno-Histoquímica/métodos , Masculino , Neurofibroma/química , Neurofibromatose 1/complicaçõesRESUMO
The treatment of through-and-through human periapical lesions by barrier membrane techniques has not been reported in the periodontal literature. However, periodontists frequently perform this treatment. The authors present a case that demonstrates radiopacity after regeneration surgery of a human periapical transosseous mandibular defect, suggesting local bone regeneration. The surgical technique performed in this case was based on the principles of guided bone regeneration using a demineralized freeze-dried bone membrane (DFDBM). The bone membrane acted as an efficient barrier that excluded the nonosteogenic tissue. Radiographic findings demonstrated bone fill after 8 months.
Assuntos
Regeneração Óssea , Regeneração Tecidual Guiada/métodos , Doenças Mandibulares/cirurgia , Substitutos Ósseos/uso terapêutico , Transplante Ósseo , Técnica de Descalcificação , Feminino , Liofilização , Humanos , Doenças Mandibulares/diagnóstico por imagem , Membranas Artificiais , Pessoa de Meia-Idade , Doenças Periapicais/diagnóstico por imagem , Doenças Periapicais/cirurgia , Radiografia , Preservação de TecidoRESUMO
This clinical report presents a restorative option for the partially edentulous maxilla utilizing an implant-retained removable partial denture without retentive clasps. This approach required (1) fewer patient visits and laboratory procedures; (2) the use of minimal number of implants; (3) lower financial obligations; and (4) no sinus elevation surgery. The use of O-ring attachments provided excellent retention and stability. The detachable prosthesis over implants allows easier oral hygiene by the patient and provides superior esthetics and phonetics in cases involving advanced ridge resorption.
Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Encaixe de Precisão de Dentadura , Retenção de Dentadura , Prótese Parcial Removível , Arcada Parcialmente Edêntula/cirurgia , Maxila/cirurgia , Reabsorção Óssea/reabilitação , Dente Suporte , Estética Dentária , Feminino , Humanos , Arcada Parcialmente Edêntula/reabilitação , Doenças Maxilares/reabilitação , Pessoa de Meia-Idade , Higiene Bucal , Fonética , Resultado do TratamentoRESUMO
BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) carrier induces bone for reconstruction of skeletal defects. The rhBMP-2/ACS implant is prepared by administering a rhBMP-2 solution to dry ACS. Once prepared, rhBMP-2/ACS forms a moldable, cohesive, and adhesive implant. However, rhBMP-2/ACS does not have sufficient structural strength to withstand soft tissue compression at specific anatomic sites. To more fully understand the mechanisms that affect bone induction by rhBMP-2/ACS in the presence of soft tissue compression, it would be useful to have a preclinical model that appropriately simulates such circumstances in patients. This pilot study evaluated one such potential model. METHODS: Bilateral, Class III alveolar defects were surgically produced in 4 adult mongrel dogs following extraction of the mandibular fourth premolars and reduction of the alveolar ridge. After an 8-week healing interval, mucoperiosteal flaps were elevated and rhBMP-2/ACS or rhBMP-2/ACS combined with hydroxyapatite (HA) was implanted into contralateral defects. The animals were euthanized at 12 weeks post-augmentation and block biopsies processed for histologic evaluation. RESULTS: Limited augmentation followed implantation of rhBMP-2/ACS (0.7 +/- 0.6 mm). In contrast, sites receiving rhBMP-2/ACS/HA exhibited clinically relevant ridge augmentation (5.5 +/- 1.6 mm). Defects implanted with rhBMP-2/ACS exhibited dense trabeculation within the corpus of the reduced alveolar process. The cortices appeared intact without evidence of expansion into the defect area. Three defects receiving rhBMP-2/ACS/HA exhibited sparse bone trabeculae amidst HA particles, fibrovascular tissue, and marrow. Commonly, the HA particles were encapsulated by fibrous tissue. Some particles were observed in contact with bone. CONCLUSIONS: The results suggests that rhBMP-2/ACS has limited effect alone in this augmentation model of Class III alveolar ridge defects. Inclusion of HA into the rhBMP-2 construct results in clinically relevant augmentation, however, the quality of bone is compromised.
Assuntos
Implantes Absorvíveis , Aumento do Rebordo Alveolar/métodos , Proteínas Morfogenéticas Ósseas/uso terapêutico , Colágeno , Mandíbula/cirurgia , Fator de Crescimento Transformador beta/uso terapêutico , Processo Alveolar/patologia , Alveolectomia , Animais , Dente Pré-Molar/cirurgia , Materiais Biocompatíveis/uso terapêutico , Biópsia , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas/administração & dosagem , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/uso terapêutico , Modelos Animais de Doenças , Cães , Portadores de Fármacos , Durapatita/uso terapêutico , Humanos , Mucosa Bucal/patologia , Projetos Piloto , Pressão , Proteínas Recombinantes , Retalhos Cirúrgicos , Extração Dentária , Fator de Crescimento Transformador beta/administração & dosagem , CicatrizaçãoRESUMO
The immediate placement of a dental implant into a fresh extraction socket has been limited in many instances by the quantity of bone that remains after the extraction. This article presents two clinical cases that demonstrate successful regeneration of alveolar ridges in which there was extensive loss of the buccal plate of bone. This lack of alveolar process impeded the immediate placement of dental implants into fresh extraction sockets. The surgical technique performed in these cases was based on the principles of guided bone regeneration using a demineralized freeze-dried bone membrane. The bone membrane acted as an efficient barrier that excluded the nonosteogenic tissues. Bone formation took place for the placement of endosseous dental implants 8 months after the procedures were initiated. These human clinical cases confirm positive results of previous animal findings.
Assuntos
Perda do Osso Alveolar/cirurgia , Regeneração Óssea , Transplante Ósseo/métodos , Regeneração Tecidual Guiada Periodontal/métodos , Adulto , Liofilização , Humanos , Masculino , Membranas , Pessoa de Meia-Idade , Retalhos Cirúrgicos , Alvéolo Dental/fisiologiaRESUMO
The biologic principle of guided bone regeneration has been successfully used to regenerate alveolar ridges. The objective of this pilot study was to clinically and histologically evaluate the demineralized freeze-dried bone membrane. Four premolar teeth were extracted from two dogs, and the remaining alveolar bone was surgically reduced in width and height to produce Class III ridge defects. After a 2-month healing period, mucoperiosteal flaps were elevated, and demineralized freeze-dried cortical columns were used as space maintainers. Bone membranes were used as barriers. The animals were sacrificed at 3 months and the surgical areas were recovered and processed for histologic evaluation. Results showed ridge augmentation in all sites. Clinically, the augmented areas appeared to have the same hardness as the surrounding bone on the periphery of the experimental site. After elevation of a mucoperiosteal flap, the bone membrane could be seen. Histologically, the bone membrane acted as an efficient barrier, excluding the nonosteogenic tissues. New bone formation underneath the membrane was found in all specimens. This study suggests that a bone membrane in combination with a space maintainer can guide new bone formation to regenerate localized chronic alveolar ridge defects.
Assuntos
Aumento do Rebordo Alveolar , Transplante Ósseo/métodos , Regeneração Tecidual Guiada Periodontal/métodos , Animais , Regeneração Óssea , Técnica de Descalcificação , Cães , Liofilização , Membranas/anatomia & histologia , Projetos PilotoRESUMO
The present study compared two barrier membranes, ePTFE and cellulose, used to treat Class II furcations in mandibular molars. Fifteen patients with no history of systemic diseases and presenting matched pair defects were selected. The following soft tissue measurements were taken at baseline (after the hygienic phase), and 6 months after surgery: gingival recession, probing depth, clinical attachment level, and width of keratinized tissue. At the time of membrane placement, and 6 months later (re-entry), the following hard tissue parameters were recorded: cemento-enamel junction (CEJ) to alveolar crest, CEJ to base of osseous defect, alveolar crest to base of osseous defect, and horizontal defect depth. According to the surgical protocol, the ePTFE membranes were completely covered by the flaps (subgingival placement), whereas the cellulose membranes extended 1 mm coronal to the gingival margin (supragingival placement). Healing was uneventful in all cases and membranes remained in place for 4 weeks. Data were analyzed using the Wilcoxon signed-rank test at the 5% level of significance. No statistically significant differences were found between the ePTFE and cellulose membranes, respectively (in mm): probing depth reduction (2.87+/-1.0 versus 3.27+/-1.1), gain in attachment level (2.53+/-1.2 versus 2.8+/-1.3), defect fill (3.0+/-1.4 versus 4.0+/-2.3), horizontal furcation fill (2.87+/-1.1 versus 2.93+/-1.0), alveolar crest resorption (2.4+/-10 versus 2.73+/-1.2), and intrabony defect fill (0.6+/-1.2 versus 1.27+/-1.7). We conclude that both ePTFE and cellulose membranes are effective, not showing statistical differences in efficacy. A larger study may be necessary to show differences in efficacy and adverse effects.