Neurofibromatosis type 1 (NF1) is one of the most common inherited syndromes. The literature on craniofacial alterations associated with NF1 has been limited and partially contradictory. This review is based on literature search and the results of the clinical study “Craniofacial and Oral Alterations and Speech in patients with Neurofibromatosis 1”, carried out at the University of Turku and Turku University Hospital, Finland in 2006-2012. By the end of 2012, a total of 110 NF1 patients, 54 female and 56 male patients, were examined. A part of our results confirms pre-existing understanding, a part is contradictory to previous considerations based mainly on case reports, and some are entirely novel. Specifically, our results confirmed that enlargement the mandibular canal is the most common abnormality of the mandible in patients with NF1. It should be noted, however, that this finding does not require treatment. Caries was not a major problem. In fact, it was less frequent in NF1 patients compared to reference population. These findings abrogate some previous perceptions. Novel findings of our project include periapical cemental dysplasia in females; short jaws, a finding which usually does not affect bite; and immunohistological analysis of oral mucosal abnormalities. Pioneering study on speech showed that various deviations were very common: As many as 94% of the participants showed some alterations. To conclude, the awareness of craniofacial alterations common in NF1would help avoiding unnecessary and even harmful involvement, e.g. of periapical cemental dysplasia or enlarged mandibular canal which do not require treatment.

/pdf/craniofacial-and-oral-alterations-in-patients-with-tea3gqqukx.pdf

Craniofacial and oral alterations in patients with Neurofibromatosis 1

Neurofibromatosis 1 (NF1) presents a wide range of clinical manifestations, including bone alterations. Studies that seek to understand cellular and molecular mechanisms underlying NF1 orthopedic problems are of great importance to better understand the pathogenesis and the development of new therapies. Dental pulp stem cells (DPSCs) are being used as an in vitro model for several diseases and appear as a suitable model for NF1. The aim of this study was to evaluate in vitro chondrogenic differentiation of DPSCs from individuals with NF1 using two-dimensional (2D) and three-dimensional (3D) cultures. To fulfill the criteria of the International Society for Cellular Therapy, DPSCs were characterized by surface antigen expression and by their multipotentiality, being induced to differentiate towards adipogenic, osteogenic, and chondrogenic lineages in 2D cultures. Both DPSCs from individuals with NF1 (NF1 DPSCs) and control cultures were positive for CD90, CD105, CD146 and negative for CD13, CD14, CD45 and CD271, and successfully differentiated after the protocols. Chondrogenic differentiation was evaluated in 2D and in 3D (pellet) cultures, which were further evaluated by optical microscopy and transmission electron microscopy (TEM). 2D cultures showed greater extracellular matrix deposition in NF1 DPSCs comparing with controls during chondrogenic differentiation. In semithin sections, control pellets hadhomogenous-sized intra and extracelullar matrix vesicles, whereas NF1 cultures had matrix vesicles of different sizes. TEM analysis showed higher amount of collagen fibers in NF1 cultures compared with control cultures. NF1 DPSCs presented increased extracellular matrix deposition during chondrogenic differentiation, which could be related to skeletal changes in individuals with NF1.

/pdf/increased-extracellular-matrix-deposition-during-4kel51avp5.pdf

Increased extracellular matrix deposition during chondrogenic differentiation of dental pulp stem cells from individuals with neurofibromatosis type 1: an in vitro 2D and 3D study

Neurofibromatosis type (NF1) is an autosomal dominant inherited tumor-suppressor gene syndrome of significant phenotypic variability with probable complete penetrance of the disease. Skeletal malformations of the skull belong to the phenotype of NF1. In the skull, defects of the calvaria and the sphenoid bone are diagnostically groundbreaking findings in NF1. Malformations of the facial skull are usually diagnosed in patients with NF1 in a topographical context with a plexiform neurofibroma (PNF). This report describes the rare occurrence of slowly advancing, unilateral destruction of proportions of the mandible in NF1, with the affected bone segment completely surrounded by a PNF. A malignant process was ruled out as a cause of partial organ loss. Various hypotheses on the pathogenesis of the rare finding are presented.

/pdf/unilateral-creeping-destruction-of-deformed-mandibular-ramus-48p9pqc6d1.pdf

Unilateral Creeping Destruction of Deformed Mandibular Ramus and Angle Associated with Extensive Facial Plexiform Neurofibroma in Neurofibromatosis Type 1: A Case Report with Analysis of the Literature for Diagnosing Osteolytic Events of the Mandible in Tumor-suppressor Gene Syndrome.

Osseous manifestations of neurofibromatosis 1 (NF-1) occur in a minority of the affected subjects but may be because of significant clinical impairment Typically, they involve the long bones, commonly the tibia and the fibula, the vertebrae, and the sphenoid wing The pathogenesis of NF-1 focal osseous lesions and its possible relationships with other osseous NF-1 anomalies leading to short stature are still unknown, though it is likely that they depend on a common mechanism acting in a specific subgroup of NF-1 patients Indeed, NF-1 gene product, neurofibromin, is expressed in all the cells that participate to bone growth: osteoblasts, osteoclasts, chondrocytes, fibroblasts, and vascular endothelial cells Absent or low content of neurofibromin may be responsible for the osseous manifestations associated to NF-1 Among the focal NF-1 osseous anomalies, the agenesis of the sphenoid wing is of a particular interest to the neurosurgeon because of its progressive course that can be counteracted only by a surgical intervention The sphenoid wing agenesis is regarded as a dysplasia, which is a primary bone pathology However, its clinical progression is related to a variety of causes, commonly the development of an intraorbital plexiform neurofibroma or the extracranial protrusion of temporal lobe parenchyma and its coverings Thus, the cranial bone defect resulting by the primary bone dysplasia is progressively accentuated by the orbit remodeling caused by the necessity of accommodating the mass effect exerted by the growing tumor or the progression of the herniated intracranial content The aim of this paper is to review the neurosurgical and craniofacial surgical modalities to prevent the further progression of the disease by "reconstructing" the normal relationship of the orbit and the skull

Craniofacial bone alterations in patients with neurofibromatosis type 1

The aim of the study was to summarize literature data on oral and maxillofacial manifestations of neurofibromatosis I (NFI) and to analyze clinical case in with dentist had the leading role in proper diagnosis of the disease. Literature review showed main oral alterations in NFI to be: neurofibroma formation seen in 8-14% of children and adolescents, dysplastic «orthodontic» phenotype with shortened mandible, maxilla and sphenoid bones; radiologic signs including alveolar nerve canal and mental foramen widening in almost one third of patients; lesions of cranial nerves (mainly trigeminal, facial and glossopharyngeal), with non-specific paralysis clinic. These symptoms, however, develop gradually throughout the life and may be evident only in late adolescents. The most pathagnomic sigh is cafe-au-lait spots as they present in 95% of children at birth. The described clinical case demonstrates the difficulties in diagnostic of NFI in children in the absence of mutilating plexiform neurofibromas. The disease provoked significant functional disorders in maxillofacial area which resulted not only in lower quality of life but also mimicked iatrogenic complications of routine dental treatment.

Maxillofacial manifestations in children and adolescents with neurofibromatosis 1

BACKGROUND Oral manifestations are common in neurofibromatosis 1 (NF1), and include jaws and teeth alterations. Our aim was to investigate the craniomaxillofacial morphology of Brazilian children, adolescents and adults with NF1 using cone beam computed tomography. MATERIAL AND METHODS This study was conducted with 36 Brazilian individuals with NF1 with ages ranging from 4 to 75. The participants were submitted to anamnesis, extra and intraoral exam and cephalometric analysis using cone beam computed tomography. Height of the NF1 individuals was compared to the length of jaws and skull base. The results of the cephalometric measurements of the NF1 group were compared with a control group paired by age, gender and skin color. RESULTS Individuals with NF1 had lower maxillary length (p<0.0001), lower mandibular length (p<0.0001), lower skull base length (p<0.0001). In children and adolescents, the mandible was more posteriorly positioned (p=0.01), when compared with the control group. There was no association between jaws and skull base length with the height of the individuals with NF1. CONCLUSIONS Brazilian children, adolescents and adults with NF1 have short mandible, maxilla and skull base. Moreover, children and adolescents present mandibular retrusion.

/pdf/craniomaxillofacial-morphology-alterations-in-children-3c0b60sl3s.pdf

Craniomaxillofacial morphology alterations in children, adolescents and adults with neurofibromatosis 1: A cone beam computed tomography analysis of a Brazilian sample.

Raquel-Richelieu-de Andrade Pontes

Papers

Craniomaxillofacial morphology alterations in children, adolescents and adults with neurofibromatosis 1: A cone beam computed tomography analysis of a Brazilian sample.