Bone repair in mandibular body osteotomy after using 2.0 miniplate system--histological and histometric analysis in dogs.
The objective of this study was to evaluate the bone repair along a mandibular body osteotomy after using a 2.0 miniplate system. Nine adult mongrel dogs were subjected to unilateral continuous defect through an osteotomy between the mandibular 3rd and 4th premolars. Two four-hole miniplates were placed in accordance with the Arbeitgeimeinschaft für Osteosynthesefragen Manual. Miniplates adapted to the alveolar processes were fixed monocortically with 6.0-mm-length titanium alloy self-tapping screws, whereas miniplates placed near the mandible bases were fixed bicortically. At 2, 6 and 12 weeks, three dogs were sacrificed per period, and the osteotomy sites were removed, divided into three thirds (Tension Third, TT; Intermediary Third, IT; Compression Third, CT) and prepared for conventional and polarized light microscopy. At 6 weeks, while the CT repaired faster and showed bone union by woven bone formation, the TT and IT exhibited a ligament-like fibrous connective tissue inserted in, and connecting, newly formed woven bone overlying the parent lamellar bone edges. At 12 weeks, bone repair took place at all thirds. Histometrically, proportions of newly formed bone did not alter at TT, IT and CT, whereas significantly enhanced bone formation was observed for the 12-week group, irrespective of the third. The results demonstrated that although the method used to stabilize the mandibular osteotomy allowed bone repair to occur, differences in the dynamics of bone healing may take place along the osteotomy site, depending on the action of tension and compression forces generated by masticatory muscles.
Sverzut
Cássio Edvard
CE
Department of Oral and Maxillofacial Surgery and Periodontology, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. cesve@forp.usp.br
Lucas
Marina Amaral
MA
Sverzut
Alexander Tadeu
AT
Trivellato
Alexandre Elias
AE
Beloti
Marcio Mateus
MM
Rosa
Adalberto Luiz
AL
de Oliveira
Paulo Tambasco
PT
D000818:Animals; D001860:Bone Plates; D001861:Bone Regeneration; D002454:Cell Differentiation; D019902:Chondrocytes / Q000473:pathology; D003238:Connective Tissue / Q000473:pathology; D004285:Dogs; D008297:Male; D008334:Mandible / Q000473:pathology / Q000502:physiology / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D011184:Postoperative Period; D013314:Stress, Mechanical