Jaw malformations plus displacement and numerical aberrations of teeth in neurofibromatosis type 1: a descriptive analysis of 48 patients based on panoramic radiographs and oral findings.
OBJECTIVE
The aim of this study was to analyse jaw malformations and tooth displacement in patients with neurofibromatosis type 1 (NF1).


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.


CONCLUSIONS
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.
Friedrich
Reinhard E
RE
Department of Oral and Maxillofacial Surgery, Eppendorf University Hospital, Hamburg, Germany. rfriedri@uke.uni-hamburg.de
Giese
Manfred
M
Schmelzle
Rainer
R
Mautner
Victor-Felix
VF
Scheuer
Hanna A
HA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000848:Anodontia / Q000000981:diagnostic imaging / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003390:Cranial Nerve Neoplasms / Q000150:complications; D005260:Female; D006801:Humans; D007569:Jaw Abnormalities / Q000000981:diagnostic imaging* / Q000209:etiology; D007573:Jaw Neoplasms / Q000145:classification / Q000000981:diagnostic imaging; D008297:Male; D008310:Malocclusion / Q000000981:diagnostic imaging / Q000209:etiology; D008340:Mandibular Nerve / Q000473:pathology; D008875:Middle Aged; D003765:Models, Dental; D008963:Molar / Q000002:abnormalities; D009361:Neoplasm Invasiveness; D018318:Neurofibroma, Plexiform / Q000145:classification; D009456:Neurofibromatosis 1 / Q000145:classification / Q000150:complications*; D010781:Photography; D010808:Physical Examination; D011862:Radiography, Panoramic; D014071:Tooth Abnormalities / Q000000981:diagnostic imaging* / Q000209:etiology; D020433:Trigeminal Nerve Diseases / Q000150:complications