Periosteum response to static forces stimulates cortical drifting: A new orthopedic target

• Published in: Journal of the world federation of orthodontists 2024-12, Vol.13 (6), p.293-302
• Main Authors: Alikhani, Mani, Alikhani, Mona, Sangsuwon, Chinapa, Oliveira, Serafim P., Abdullah, Fanar, Teixeira, Cristina C.
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Animals; Bone formation; Cortical Bone; Cortical Drifting; Expansion; Inflammation; Male; Maxilla; Mechanical stimulation; Microscopy, Fluorescence; Osteoblasts; Osteoclasts; Osteogenesis - physiology; Palatal Expansion Technique; Periosteal stimulation; Periosteum; Rats; Rats, Sprague-Dawley; Static Forces; Stress, Mechanical; X-Ray Microtomography
• ISSN: 2212-4438; 2212-4438
• DOI: 10.1016/j.ejwf.2024.07.003

•Static forces induce a transient inflammatory reaction in the periosteum followed by activation of osteoclasts, and later of osteoblasts that restore the cortical bone.•Activation of osteoclasts in the periosteum occurred independent of the magnitude of tooth movement.•Bone formation in the cortical bone after static forces is a delayed phenomenon, and therefore, clinicians should refrain from disturbing the process with any procedures that can affect the periosteum.•Resorption of cortical bone and rebuilding of its surface resulted in lateral movement of the cortical bone in space, referred to as cortical drifting.•Periosteal stimulation can be used by clinicians to induce cortical drifting and reshaping the alveolar cortical plate. The mechanism of cortical bone adaptation to static forces is not well understood. This is an important process because static forces are applied to the cortical bone in response to the growth of soft tissues and during Orthodontic and Orthopedic corrections. The aim of this study was to investigate the cortical bone response to expanding forces applied to the maxilla. Overall, 375 adult Sprague-Dawley rats were divided into three groups: 1) static force group, 2) static force plus stimulation group, and 3) sham group. In addition to static force across the maxilla, some animals were exposed to anti-inflammatory medication. Samples were collected at different time points and evaluated by micro-computed tomography, fluorescence microscopy, immunohistochemistry, and gene and protein analyses. The application of expansion forces to the maxilla increased inflammation in the periosteum and activated osteoclasts on the surface of the cortical plate. This activation was independent of the magnitude of tooth movement but followed the pattern of skeletal displacement. Bone formation on the surface of the cortical plate occurred at a later stage and resulted in the relocation of the cortical boundary of the maxilla and cortical drifting. This study demonstrates that cortical bone adaptation to static forces originates from the periosteum, and it is an inflammatory-based phenomenon that can be manipulated by the clinician. Our findings support a new theory for cortical adaptation to static forces and an innovative clinical approach to promote cortical drifting through periosteal stimulation. Being able to control cortical drift can have a significant impact on clinical orthodontic and dentofacial orthopedics by allowing corrections of s