Page 205 - Demo

Animal experiment: Radiological analysis of the LPM reattachment2037In sheep, the masseteric muscle can be dissected into three distinct layers. The most extensive layer also exerts a protrusive force.(14) This characteristic suggests that the laterotrusive movements seen during the clinical analysis were due to these fibers rather than the LPM. However, the previously discussed evidence negates this argument. When using larger and more complex scaffolds, sufficient blood supply is needed to provide adequate nutrition to the osteogenic cells.(47,48) The outer layer of the periosteum mainly consists of collagen and fibroblasts, but it also contains the highest density of blood vessels and provides vascularization to adjacent bone and muscle.(49) The use of periosteal flaps and free periosteal grafts to provide vascularization and an osteoinductive and conductive environment to bone grafts is not new.(20,50) In 10 out of 13 sheep, a bony connection was formed between the osseous mandible and the enthesis. Important to notice is that the distance from the insertion of the muscle to the bony mandibular margin was much smaller in the TMJR that were placed, compared to the design for human use. This was due to a reduced height of the condylar neck in the implants that were placed. As such it is possible that this boney connection was formed due to the periosteal sleeve still being intact, providing not only the necessary environment for bone formation to occur, but also the necessary vascularity, which might have been absent near the scaffold. Gallardo-Calero et al.(51) found that intramembranous ossification occurs in areas where a bony defect is covered with a vascularized periosteal flap. However, Leucht et al.(52) found that intramembranous ossification occurs when mandibular periosteum is transplanted onto a tibial bony defect. Endochondral ossification occurs when tibial periosteum is transplanted onto a mandibular defect. These findings indicate that the origin of the periosteum affects the repair. Leucht et al.(52) concluded that in craniomaxillofacial and orthopedic surgeries, regardless of the origin of the periosteum, it allows for bone regeneration independent of the type of repair that occurs. Therefore, the preservation of periosteal tissue could be considered to maximize the possibility of bony integration of the enthesis into the scaffold. However, because a soft diet and restriction Nikolas de Meurechy NW.indd 203 05-06-2024 10:14