Search

Purpose The purpose of the study was the investigation of supernumerary teeth (ST) in the permanent dentition of patients with neurofibromatosis type 1 (NF1). Material and methods The panoramic radiographs of 200 NF1 patients were analysed for ST. The potential impact of certain neurogenic facial tumours on the measured variable was investigated separately. The results were compared to dental findings in panoramic radiographs of 200 age- and sex-matched controls. Results The total number of ST in all individuals was 23 in 12 patients (3% of total population). However, all ST had developed in the group of NF1 patients (6%), (p = 0.0004). ST were particularly common distal to the molar region. Although ST occur in the region of facial plexiform neurofibroma, the numerical aberrations of the dentition are independent of specific type of facial nerve sheath tumour. Conclusion The unusual accumulation of ST in the terminal sections of molar development could be an indicator of preferred points of developmental disorder, in which the genetic predisposition of the patient is involved. Reviewing the results of other NF1 patient collectives is desirable.

BACKGROUND/AIM Neurofibromatosis type 1 (NF1) is a tumor predisposition syndrome. Bone findings make a significant contribution to the clinical diagnosis of NF1. It has been suggested that there are characteristic skeletal features of the NF1 patients' skull that cause a specific 'NF1 facies'. To test this thesis, skull examinations were carried out on NF1 patients. PATIENTS AND METHODS The posteroanterior (PA) cephalograms of 76 patients with NF1 were analyzed using defined measuring points. Patients with confirmed facial plexiform neurofibromas (PNF) were excluded from the study. A special interest of the investigation was the symmetry of the measuring points defined as the distance to the median sagittal plane. RESULTS NF1 patients have a slightly larger distance to the Z-plane than controls at the zygomatic arch and mastoid measurement points (p=0.027 and 0.028, respectively). In contrast, the distances of the juga and antegonion measurement points from the horizontal reference plane are larger in the control group (p=0.002 and 0.480, respectively). The transverse development of the midface at the level of the zygomatic arch showed no differences from the control group (p=0.841). The transverse diameter of the skull at the mastoid and juga measurement points is smaller in the NF1 group compared to the control group (p=0.010 and 0.002, respectively). There is a statistically significant left-right (LR) asymmetry of the distances to the median sagittal plane in favor of the left side in the patient group (p=0.002 to 0.037). However, the numerical deviations from the control group are small overall. CONCLUSION Considering the natural, biological deviations of cephalometric measurements of the individual from idealized geometric norms, the facial skeleton of NF1 patients is symmetrically developed. It is unlikely that the calculated LR asymmetry of the patients has a visible effect. In comparison to cephalometric values of a normal population, no characteristic facial skeleton of the NF1 patient in the PA projection of the skull can be derived from these findings. Clear asymmetries of the facial skeleton should give rise to further diagnosis to clarify the suspicion of facial PNF.

Background Radiological cephalometry is an important diagnostic tool for analyzing the shape and proportions of the skull. Standardized teleradiography of the skull in posterior-anterior (PA) projection provides orientation data on the symmetry and vertical relations of the skull. The comparison of individual findings with normal values places high demands on the selection of a control group. The aim of this study was to characterize a group to be used as a standard for cephalometric comparisons. Patients and methods PA teleradiographs of 23 healthy young adults were analyzed. Distances from reference measuring points to the median sagittal plane and the orbital horizontal plane were made. All individuals showed ideal occlusion. None of the participants had been subjected to orthodontic therapy or craniomaxillofacial surgery. Results The measurement results showed a high degree of lateral symmetry of the skeletal reference points and planes. Comparison of the vertical reference lines confirmed the symmetrical constitution of the facial skeleton. Conclusion The study group is suitable for comparison with the cephalometric evaluations of other study groups.

Background/aim Numerical aberrations of permanent dentition and dystopic tooth eruption are part of the phenotype of the tumor predisposition syndrome neurofibromatosis type 1 (NF1). In these cases, surplus tooth germs usually develop in the alveolar processes of the jaw. This report attests to the dystopic development of a dysplastic supernumerary tooth in NF1 arising outside the jaw. Case report The 8-year-old male patient developed a microdont outside the bone and above the occlusal plane of the retained maxillary right second molar. The supernumerary tooth was completely embedded in oral soft tissue. Hyperplastic oral soft tissue in the molar region and microdont were excised. Specimen of the mucosa surrounding the teeth was interspersed with diffuse and plexiform neurofibroma. The retained upper right first molar emerged spontaneously within a few months after surgery. The upper right second molar did not change position. Conclusion Odontogenesis can take place within tumorous oral mucosa in NF1. Surgical removal of the tumorous mucous membrane facilitates tooth eruption in some cases.

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.

The aim of this study was to measure line segments and areas of sella turcica on lateral cephalograms with respect to the clinical diagnosis of facial phenotype of patients with neurofibromatosis type 1 (NF1). Special attention was given to correlate the measured values with certain tumour types that are typical for this disease. Material and methods: Lateral cephalograms of 194 individuals were investigated. Patients with NF1 were further divided according to the detection and topography of facial plexiform neurofibromas (PNF) taking into account the distribution pattern of the trigeminal nerve. All patients with PNF showed unilateral tumour localisation. Patients without any facial PNF constituted a separate group. Healthy volunteers with ideal occlusion and no history of any intervention in the maxillofacial region served as a control group. The following items were determined on the radiographs: sella entrance, sella width, sella depths, sella diagonal, and sella area. Results: Patients with PNF of the first and second trigeminal nerve branch or affected in all branches showed highly statistically significant enlarged sella tucica measurement values. On the other hand, patients with PNF restricted to one branch only or simultaneously in the second and third branches showed measurement values that were not different to those obtained in NF1 patients devoid of facial PNF. The latter group also showed no difference of sella turcica parameters obtained in the control group. Conclusion: This study provides evidence for the association of a certain NF1 phenotype with distinct skeletal alterations of the skull base, shown here using the example of the representation of the sella turcica in the lateral radiograph. These findings are also relevant in the discussion of NF1 as a disease of bones and in the assessment of brain development in NF1. Both items are discussed in relationship to a facial plexiform neurofibroma. Furthermore, the knowledge of this association of findings provides the clinician with relevant information in the planning of skull base procedures in these patients., Das Ziel dieser Untersuchungen war die Vermessung von Strecken und Flächen der Sella turcica auf seitlichen Fernröntgenbildern unter besonderer Berücksichtigung des fazialen Phänotyps von Patienten, die an einer Neurofibromatose Typ 1 (NF1) erkrankt waren. Besondere Aufmerksamkeit wurde der Korrelation von definierten Tumortypen, die für diese Erkrankung typisch sind, und den kephalometrischen Messwerten gewidmet. Material und Methode: Laterale Kephalogramme von 194 Individuen wurden untersucht. Patienten mit NF1 wurden weiter differenziert nach dem Nachweis und der Topographie fazialer plexiformer Neurofibrome (PNF), wobei das Verteilungsmuster des N. trigeminus im Gesicht als Orientierung diente. Alle Patienten mit PNF hatten eine einseitige Manifestation des Tumors. Patienten ohne faziales PNF stellten eine gesondert analysierte Gruppe dar. Gesunde Probanden mit Idealokklusion und ohne jede Vorgeschichte einer Intervention im kraniomaxillofazialen Bereich dienten als Kontrollgruppe. Die folgenden Messungen wurden durchgeführt: Sella-Eingang, Sella-Weite, Sella-Tiefe, Sella-Diagonale und Sella-Fläche. Ergebnisse: Patienten mit einem PNF des ersten und zweiten oder solche, die in allen drei Ästen des N. trigeminus von diesem Tumor betroffen sind, weisen statistisch signifikant vergrößerte Sella-Messwerte auf. Andererseits sind die Messwerte der Patienten, die nur in einem einzelnen Ast vom PNF betroffen sind oder deren Tumorausbreitung sich auf den 2. und 3. Ast des Nervs beschränkt, von denen der Patienten ohne ein faziales PNF statistisch nicht zu unterscheiden. Die Messwerte dieser beiden Gruppen unterscheiden sich ebenfalls nicht von denen der Kontrollgruppe. Schlussfolgerung: Diese Untersuchung beweist die Assoziation eines bestimmten Ausbreitungstyps des fazialen PNF bei NF1-Patienten mit merklichen skelettalen Veränderungen der Schädelbasis, hier dargestellt anhand der Form der Sella turcica im seitlichen Röntgenbild. Diese Befunde sind auch bedeutsam für die Diskussion der NF1 als Erkrankung des Skelettsystems und für die Einschätzung der Gehirnentwicklung bei NF1, beide in Zusammenhang mit dem Nachweis eines plexiformen Neurofibroms. Weiterhin liefern die Kenntnisse über die hier vorgestellten Befunde dem Kliniker relevante Informationen für die Planung von Schädelbasiseingriffen an Patienten mit dieser Diagnose., GMS Interdisciplinary Plastic and Reconstructive Surgery DGPW; 6:Doc05

Purpose Neurofibromatosis type 1 (NF1) is an autosomal dominant transmitted tumour suppressor syndrome and also a bone disease. Osseous dysplasia affecting the craniofacial region is characteristic of NF1. The aim of this study was to analyse the lateral cephalograms of NF1 patients in comparison to individuals who were not affected by this condition in order to describe the skeletal phenotype of NF1 in more detail. Materials and methods The study comprises the lateral cephalograms of 172 patients with established NF1 diagnoses (female = 85, male = 87). NF1 patients were distinguished by radiological and/or histological findings of the facial region suggestive of plexiform neurofibroma (PNF) or disseminated cutaneous NF (DNF). The analysed radiographs of a collection of 29 healthy volunteers with ideal occlusion served as controls. The focus of this analysis was cephalometrically defined angles. Results Cephalometric analyses of patients with DNF did not differ from those of controls for the vast majority of parameters. However, the measurement results of patients with PNF differed significantly from those of healthy volunteers and patients with DNF. The number of trigeminal nerve branches affected in PNF patients had an effect on the measurement results. Conclusion Lateral cephalograms revealed no significant alteration of the facial skeleton in NF1 patients as compared to controls. Indeed, the stigma of a so-called ‘NF1 facies' cannot be derived from the cephalometric findings presented. Notably, a wide range of deviating readings were recorded for individuals with facial PNF. Clinicians who treat patients with NF1 should be aware of deviations from cephalometric standards on lateral cephalograms in NF1 patients, especially when craniofacial surgical procedures are planned. Some of these findings, particularly asymmetries of the facial skeleton, could be indicators of an associated PNF.

J Oral Pathol Med (2010) 39: 115–120 Background: Podoplanin expression was described in mouse tooth germ and apical bud cells. The aim of this study was to analyse the podoplanin expression of human tooth germ tissues, adult teeth and odontogenic lesions immunohistochemically. Study Design: Nine human tooth germ biopsies and seven healthy permanent teeth extracted for orthodontic reasons were examined. Anti-podoplanin (D2-40) reactivity was investigated immunohistochemically. Five well-defined cystic odontogenic lesions (10 radicular cysts, 10 follicular cysts, three keratocystic odontogenic tumours, five ameloblastomas, and two adenomatoid odontogenic tumours) were analysed simultaneously. Results: Podoplanin expression was detected in the majority of epithelial and ecto-mesenchymal cells of human tooth germ tissues, odontoblasts and superficial dental pulp fibroblasts of permanent teeth. Cystic odontogenic lesions revealed positive reactions predominantly at the invasion front edge within basal epithelial layers. Conclusion: Podoplanin appears to be involved in the orthologic and pathologic processes of the formation of elongated cell extensions and odontoblastic fibers, in the epithelial–mesenchymal transition and local invasion during tooth germ development as well as in both reactive and neoplastic odontogenic cystic lesions.

Aim: The aim of this study was to analyse jaw malformations and tooth displacement in patients with neurofibromatosis type 1 (NF1). Material and Methods: Forty-eight patients were included in the study (male or female 24 each). All fulfilled the current NIH diagnostic criteria for NF1. The age range was 2.5–66 years. The type of neurofibroma was histologically proven in surgically treated patients. Patients with disseminated cutaneous neurofibromata and those with the plexiform type were distinguished. The analysis was based on physical investigation, photographs, panoramic radiographs and dental casts. Results: With the emphasis on alterations of tooth position, deformities of the adjacent bones and malocclusion, the majority of these patients (26) were affected by plexiform neurofibromata. In the other 22 patients with disseminated neurofibromata, malformations of the alveolar ridge were absent and individual oral symptoms were rarely found and were mild, and in all cases were unimpaired. Numerical aberrations and retention of molars was exclusively associated with a trigeminal nerve affected by plexiform neurofibroma. Aplasia of a second lower molar was recognized in four of these plexiform-neurofibroma patients. Conclusion: It is widely accepted that malformations of the facial skeleton are often of genetic origin. However, in this study these malformations were strongly associated with plexiform neurofibromata originating from the trigeminal nerve. Thus, in addition to presently unknown genetic factors, the pattern of skeletal malformation can be caused by tumour invasion and local destruction, e.g. the neuromuscular unit or prenatal development of the plexiform neurofibroma in the inferior alveolar nerve. It is further concluded that epidemiologic studies on the incidence and severity of NF1 in the oral and maxillofacial region have to distinguish between patients with or without plexiform neurofibroma, especially when analysing alterations and deformities of the jaws, teeth and malocclusion. Aplasia of second inferior molars is an additional (dental) finding associated with plexiform neurofibromata in NF1.

Aim: Unfavourable facial growth in patients with cleft lip, alveolus, and palate may occur during puberty. Usually this development is not predictable in a young patient. The aim of the present study was to find an individual growth prediction at an early age that would allow us to decide whether later orthognathic surgery should be included in the treatment plan. Material and Methods: Lateral cephalograms of 41 patients with unilateral clefts of lip, alveolus and palate (uCLAP) with observation intervals of 4 years were computerized, correlations between the variables of the first and second radiograph were calculated and regression equations were established. Results: The skeletal change of the intermaxillary relationship can be explained purely by the lack of midfacial growth. An individual prediction of the angle SNA over a period of 4 years is possible with a correlation coefficient of 0.95. Additional predictions for SNB, Holdaway angle and the index of anterior facial height proportions are demonstrated. Conclusion: The prediction procedure elaborated in this paper facilitates the decision at the age of 12 years already, whether or not orthodontic occlusal treatment has been successfully completed at an early age. The alternative is to limit orthodontic treatment to the simple alignment of the two dental arches independently of their intermaxillary relation, and then to correct the facial skeleton and the dental occlusion simultaneously by combining surgical and orthodontic treatment after the completion of growth.