Jaw protruder muscles and condylar cartilage growth in the rat

摘要: Many studies have explored the role of protrusive musculature in promoting growth at condylar cartilage and overall lengthening lower jaw, with emphasis on lateral pterygoid muscle (LPM). The largely anteroposterior orientation superficial part masseter (SM) rat suggests that it may also function as a protruder jaw. Accordingly, is possible action SM play regulation To examine this hypothesis, bilateral resection portion was performed male Sprague-Dawley rats 26 days age. At 5 after surgery, [ 3 H]-thymidine incorporation increased ( F = 6.93, p ≤ 0.01) myectomy group relative to surgical control unoperated groups. However, by 20 surgery no differences were present. sacrifice interval, jaw dimensions relating areas attachment, well ramus height, significantly reduced group, but length (mental foramen condyle) unaffected. In contrast, myotomy LPM resulted significant decrease mitotic activity 4 surgery. This present, not more pronounced, animals subjected both myotomy. Hence, or these two muscles, each orientation, produces opposite effects proliferative cartilage.