Recombinant osteoprotegerin effects during orthodontic movement in a rat model

• Published in: European journal of orthodontics Vol. 38; no. 4; pp. 379 - 385
• Main Authors: Fernández-González, Felipe J, Cañigral, Aránzazu, López-Caballo, José L, Brizuela, Aritza, Cobo, Teresa, de Carlos, Félix, Suazo, Iván, Pérez-González, Yurena, Vega, Jose A
• Format: Journal Article
• Language: English
• Published: England 01-08-2016
• Subjects: Animals; Dentistry; Drug Administration Schedule; Drug Evaluation, Preclinical - methods; Male; Maxilla; Molar - drug effects; Molar - metabolism; Osteoclasts - drug effects; Osteogenesis - drug effects; Osteoprotegerin - administration & dosage; Osteoprotegerin - pharmacology; Periodontal Ligament - drug effects; RANK Ligand - metabolism; Rats, Sprague-Dawley; Recombinant Fusion Proteins - administration & dosage; Recombinant Fusion Proteins - pharmacology; Tooth Mobility - physiopathology; Tooth Mobility - prevention & control; Tooth Movement Techniques - methods
• ISSN: 0141-5387; 1460-2210
• DOI: 10.1093/ejo/cjv056

Anchorage is one of the most challenging sides in orthodontics. The use of biological modulators that inhibit osteoclasts could be a solution to address these problems and provide new adjunctive approaches. The aim of this study was to assess the effectiveness of recombinant osteoprotegerin fusion protein (OPG-Fc) in orthodontic anchorage.
Two groups of male Sprague-Dawley rats were utilized. The animals in the experimental group received twice-weekly injections with high dose of OPG-Fc (5.0mg/kg) in mesial and distal mucosa of the first molars, and those in the control group received no drugs. Right first maxillary molars were mesialized using a calibrated nickel-titanium spring connected to an anterior mini-screw. Tooth movement was measured by two blinded observers using scanned and magnified stone casts. Receptor activator of nuclear factor κB (RANK), run-related transcription factor 2 (Runx2), type I collagen, vimentin, matrix metalloproteinases 2 and 9, S100 protein and the putative mechanoproteins acid-sensing ion channel (ASIC2) and transient receptor potential vainilloid 4 (TRPV4) were evaluated using immunohistochemistry.
OPG-Fc group showed an important decreased in mesial molar movement with only 52%, 31%, and 22% of the total mesial molar movement compared with control group at Days 7, 14, and 21, respectively (P < 0.001). RANK ligand and Runx2 positive cells were severely reduced after OPG-Fc treatment. Periodontal ligament architecture, cell arrangement, and immunohistochemical patter for vimentin, type I collagen and the mechanoproteins TRPV4 and ASIC2 were altered by tooth movement and all these parameters altered by the applied treatment.
OPG-Fc effectively inhibits osteoclastogenesis resulting in improved bone quantity and orthodontic anchorage. Based on present results, OPG-Fc could have clinical utility in preventing undesired tooth movements.