[Significance of periosteum in profile and contour improving osteotomies of the growing skull. Animal experiment studies with the juvenile minipig].
Passive intracranial translocation of plates and screws (PIT effect), which has been described in the literature, is one of the undesirable outcomes in infant craniofacial surgery. Therefore, we investigated the hypothesis of whether epiperiosteal placement of plates and screws causes the periosteum to act as a "limiting membrane", possibly preventing or delaying passive intracranial translocation of hardware. In two different experimental models of the fast-growing skull of juvenile minipigs (16 or 7 weeks old) on one side of the skull a typical, standard galeaperiosteal flap was raised. On the contralateral side, the periosteum was left attached to the bone and after performing the osteotomies, plates and screws were placed on top of the periosteum. This technique showed that the periosteum acts as a "limiting membrane" and prevents early covering of the hardware by appositional bone growth. Thus, plates and screws could easily be identified if removal was intended. In contrast to this, on the subperiosteal side (conventional technique of raising a galeaperiosteal flap), plates and screws were already completely covered by appositional bone formation 8 weeks postoperatively. The posterior bone gaps that resulted from fronto-orbital advancements showed significant delay in reossification when the epiperiosteal technique was used. This may be advantageous for the growth of the skull following fronto-orbital advancements. In contrast, the posterior bone gap showed early reossification when the standard subperiosteal technique was used. Thus, in infant craniofacial surgery, the epiperiosteal technique and placing the plates and screws on top of periosteum seem to have some advantages compared to the standard subperiosteal technique.
Luhr
H G
HG
Abteilung für Mund-, Kiefer- und Gesichtschirurgie, Universitätsklinik, Göttingen.
Merten
H A
HA
Becker
H J
HJ
D000367:Age Factors; D000818:Animals; D001860:Bone Plates; D001863:Bone Screws; D016025:Bone Transplantation / Q000379:methods*; D002508:Cephalometry; D003399:Craniotomy / Q000379:methods*; D016348:Osseointegration / Q000502:physiology; D010521:Periosteum / Q000254:growth & development* / Q000473:pathology; D013552:Swine; D013556:Swine, Miniature