Bone structure changes in iliac crest grafts combined with implants.
BACKGROUND
Remodeling of onlay grafts combined with implants to the mandible results in predictable changes in the graft's radiographic density. We studied the relationship between changes in radiographic density and trabecular structure during the first year after onlay grafting with simultaneous implant placement to the mandible.


OBJECTIVE
The aim of this study was to evaluate changes in bone structure after onlay grafting.


METHODS
Standardized extraoral radiographs were taken regularly of 16 mandibular sides. Bone structure was measured using the Carl Zeiss Vision KS 400 3.0 imaging system. The parameters studied were trabecular area and perimeter, cavity area and perimeter, end points, branching points, skeleton length, branch angle and direction, and texture.


RESULTS
No differences were found between measurements ventrally versus dorsally of the implant, nor close to versus away from the implant. Early cortical changes suggest partial resorption and formation of a more complex structure. In the fourth quarter after surgery, progressive resorption is seen in the graft's upper cortex. In the graft's upper spongiosa, most parameters indicate bone formation during the first postoperative year. Loading-induced structure changes could not yet be found.


CONCLUSIONS
The technique can be used to study changes in the architecture of bone grafts. Changes found in the graft's architecture are in accordance with changes in bone density.
Department of Oral & Maxillofacial Surgery, Prosthodontics and Special Dental Care, University Medical Center, Utrecht, The Netherlands. j.w.verhoeven@umcutrecht.nl
Jan Willem
JW
Verhoeven
Jan M
JM
Ruijter
Ronald
R
Koole
Cornelis
C
de Putter
Marco S
MS
Cune
D000368:Aged; D016301:Alveolar Bone Loss / Q000601:surgery*; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000704:Analysis of Variance; D015519:Bone Density; D016723:Bone Remodeling; D016025:Bone Transplantation / Q000502:physiology*; D003758:Dental Implantation, Endosseous; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D011859:Radiography; D018709:Statistics, Nonparametric