title: [Digital panoramic radiography in patients with rigid internal fixations devices after maxillofacial surgery].
abstract: BACKGROUND
  Digital techniques have found promising applications in dental radiology in the recent past, namely with radiovisiography and digital panoramic radiography. These images present some features making them particularly interesting for alveolar bone studies.
  
  
  METHODS
  Digital panoramic radiography with light-emitting phosphors was performed on 16 patients during postoperative follow-up. The patients were previously submitted to multiple maxillofacial osteosynthesis with rigid internal fixation devices (32 miniplates, 12 microplates, 14 screws). Digital images were always observed and printed with analogic-like and Xeroradiographic-like post-processing.
  
  
  RESULTS
  Digital panoramic radiographs yielded clear and effective images of the maxillary and mandibular arches and of surgical osteosynthesis, as demonstrated by a retrospective evaluation performed by three independent observers on a blind basis (score 3: 60.42%), with no major interobserver differences (p = .7286). Xeroradiographic-like images were the most effective in depicting bone structures and osteosynthesis materials, thanks to their better detailing and typically lower overall contrast. Among the drawbacks of the digital technique, reduced cassette size may prevent the full view of the mandibular arch from the symphysis to both condylar regions. The edge effect, which is typical of Xeroradiographic images, may mask useful details within the trabecular bone close to metal implants. This effect was present in some of our cases, but it was seldom disturbing according to our retrospective evaluation (score 3: 53.40%), with good interobserver agreement (p = .1117).
  
  
  CONCLUSIONS
  Digital panoramic radiography proves to be a useful tool to study metal implants after maxillofacial surgery as well as alveolar bone structure. The digital technique markedly reduces the radiation dose to the patient, which is very important for an X-ray examination that must be repeated several times, often in young subjects.
authors.affiliation: Cattedra di Radiologia, Università degli Studi di Milano, Ospedale San Paolo.
authors.forename: R
authors.initials: R
authors.lastname: Nessi
authors.forename: P
authors.initials: P
authors.lastname: Ottolina
authors.forename: F
authors.initials: F
authors.lastname: Lazzerini
authors.forename: A B
authors.initials: AB
authors.lastname: Giannì
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005593:Fracture Fixation, Internal; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D019252:Radiography, Dental, Digital; D011862:Radiography, Panoramic
vernacular_title: L'ortopantomografia digitale nei pazienti portatori di sistemi di fissazione interna rigida maxillo-facciale.