Evaluation of bone volume following bone grafting in patients with unilateral clefts of lip, alveolus and palate using a CT-guided three-dimensional navigation system.
OBJECTIVE
In cleft patients the eruption of the permanent canine depends very much on the amount of bone available following bone grafting. The purpose of this study was to evaluate the initial defect in alveolar clefts and the volume of bone bridging found in unilateral clefts which had undergone bone grafting.


METHODS
To determine the fate of the bone graft in cleft palate patients a three-dimensional CT-based Navigation System (Zeiss, Aalen, Germany) was used. CT scans of 16 patients with unilateral clefts were taken immediately preoperatively and 1 year postoperatively. The patients underwent surgery between the age of 9 and 14 years using iliac crest bone grafts. The data was transferred to the work station of the navigation system. Using the STN software, the defect at the alveolar clefts and volume of the bone grafts were determined in each case. Three-dimensional models were created showing the amount of bone immediately preoperatively and 1 year postoperatively.


RESULTS
The size of the cleft defect did not correlate with the success rate of the alveolar bone grafting. The form of the transplant remained almost constant when the permanent canine erupted spontaneously into the graft. In cases of absence of the permanent tooth or when the permanent canine required orthodontic treatment, significant bone loss could be observed in the buccopalatal direction.


CONCLUSIONS
Three-dimensional reconstruction of bone grafts using a navigation system enables a valuable objective assessment of graft volume. Bone formation can be assessed in all three dimensions showing a high grade of resorption in patients lacking physiological load.
Feichtinger
Matthias
M
Department of Oral and Maxillofacial Surgery, University Hospital of Graz, Austria, Europe. matthias.feichtinger@meduni-graz.at
Mossböck
Rudolf
R
Kärcher
Hans
H
D000293:Adolescent; D000539:Alveolar Process / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D016025:Bone Transplantation / Q000000981:diagnostic imaging / Q000379:methods*; D002648:Child; D002971:Cleft Lip / Q000601:surgery*; D002972:Cleft Palate / Q000000981:diagnostic imaging / Q000601:surgery*; D003481:Cuspid; D005260:Female; D006801:Humans; D007085:Ilium / Q000637:transplantation; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007180:Incisor; D008297:Male; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D014078:Tooth Eruption / Q000502:physiology; D016896:Treatment Outcome