Removable thermoplastic retainers—a study of wear regimens
Jaderberg S, Feldmann I, Engstrom C. Removable thermoplastic appliances as orthodontic retainers—a prospective study of different wear regimens. Eur J Orthod 2012;34:475-9
Achieving a stable result is a constant concern in orthodontic treatment. Without retention, there is a high risk of the teeth relapsing to their original positions. One option for retention is the removable thermoplastic appliance, or Essix retainer. Full-time Essix wear immediately after removal of the fixed appliance is recommended, but there are various opinions on duration. Recommendations range from 1 week of full-time wear to 3 months of full-time wear. There were 2 experimental groups in this study. One wore the Essix full time for 3 months, and the other for 1 week. The rest of the 6-month observation period was night use only in both groups. Thirty maxillary and 18 mandibular arches were randomly assigned to each group. Inclusion criteria were fixed orthodontic treatment on at least 1 arch, with patients willing to wear removable appliances after treatment. All retainers were fabricated by 1 technician. Little’s irregularity index was recorded for the casts at the beginning of the retention phase and again at 6 months into retention. The most important finding of this study was that there were no differences in the average amount of change in Little’s irregularity index over the 6-month period between the 2 experimental groups. The amount of change in Little’s irregularity index exceeded 1 mm in a few patients in both groups. The researchers attributed this to poor compliance. The patients tolerated the retainers well, with 13% indicating soreness and 22% reporting speech problems. The authors concluded that night-time Essix wear was sufficient to stabilize the treatment results. Future studies with a longer follow-up period are necessary to determine whether these results are stable in the long term.
Reviewed by Matthew Nielsen
Pharmacologic management of osseous condylar resorption
Gunson M, Arnett GW, Milam S. Pathophysiology and pharmacologic control of osseous mandibular condylar resorption. J Oral Maxillofac Surg 2012;70:1918-34
These authors reviewed the relevant literature on condylar resorption and the use of pharmacotherapy to control articular erosions. Understanding known pathogenic mechanisms of condylar resorption and each patient’s susceptibilities provides the clinician with targets for pharmacologic control. Condylar resorption involves a common pathophysiologic pathway culminating in secretion of matrix metalloproteinases and other matrix degrading enzymes by osteoclasts. The cytokines TNF-a, IL-6, and RANKL, specific phospholipid catabolites, and other enzymes or oxidative reactions initiated by free radicals all play biochemical roles in pathogenesis. Various factors have also been linked to increased patient susceptibility to osseous condylar resorption, including female sex hormones, nutritional status, genetic background, oral habits, and iatrogenic compression. Current evidence has shown promise in the management of condylar resorption by using TNF-α inhibitors, tetracyclines, NSAIDs, antioxidants, and dietary modifications. TNF-α inhibitors, the most promising pharmacologic intervention, are currently the only cytokine inhibitors for which temporomandibular joint studies are available. Tetracyclines can be used to inhibit the actions of matrix metalloproteinases by chelating zinc, regulating matrix metalloproteinase gene expression, and binding to the matrix metalloproteinases themselves. Additionally, they can control osteoclast activity via inhibition of cytokines and promoting apoptosis of osteoclasts. NSAIDs provide control of phospholipid metabolism and other beneficial biologic effects. Dietary supplementation with antioxidants might be beneficial in the management of some inflammatory arthritides and osteoarthritis by sequestering free radicals. Additionally, omega-3 fatty acids and vitamin D have been shown to play important roles in controlling inflammation. Other investigations indicate the potential in addressing inflammatory mechanisms with statins and in developing monoclonal antibodies to inhibit RANKL, IL-6, and CD20 protein, and represent areas for future research.
Reviewed by Scott Frey
Pharmacologic management of osseous condylar resorption
Gunson M, Arnett GW, Milam S. Pathophysiology and pharmacologic control of osseous mandibular condylar resorption. J Oral Maxillofac Surg 2012;70:1918-34
These authors reviewed the relevant literature on condylar resorption and the use of pharmacotherapy to control articular erosions. Understanding known pathogenic mechanisms of condylar resorption and each patient’s susceptibilities provides the clinician with targets for pharmacologic control. Condylar resorption involves a common pathophysiologic pathway culminating in secretion of matrix metalloproteinases and other matrix degrading enzymes by osteoclasts. The cytokines TNF-a, IL-6, and RANKL, specific phospholipid catabolites, and other enzymes or oxidative reactions initiated by free radicals all play biochemical roles in pathogenesis. Various factors have also been linked to increased patient susceptibility to osseous condylar resorption, including female sex hormones, nutritional status, genetic background, oral habits, and iatrogenic compression. Current evidence has shown promise in the management of condylar resorption by using TNF-α inhibitors, tetracyclines, NSAIDs, antioxidants, and dietary modifications. TNF-α inhibitors, the most promising pharmacologic intervention, are currently the only cytokine inhibitors for which temporomandibular joint studies are available. Tetracyclines can be used to inhibit the actions of matrix metalloproteinases by chelating zinc, regulating matrix metalloproteinase gene expression, and binding to the matrix metalloproteinases themselves. Additionally, they can control osteoclast activity via inhibition of cytokines and promoting apoptosis of osteoclasts. NSAIDs provide control of phospholipid metabolism and other beneficial biologic effects. Dietary supplementation with antioxidants might be beneficial in the management of some inflammatory arthritides and osteoarthritis by sequestering free radicals. Additionally, omega-3 fatty acids and vitamin D have been shown to play important roles in controlling inflammation. Other investigations indicate the potential in addressing inflammatory mechanisms with statins and in developing monoclonal antibodies to inhibit RANKL, IL-6, and CD20 protein, and represent areas for future research.
Reviewed by Scott Frey
Stay updated, free dental videos. Join our Telegram channel
VIDEdental - Online dental courses
