A. Literature on Retention
B. Scientific Compliance Peer Reviewed Literature
C. Scientific Compliance Presentations
1.George W. Hahn, D.D.S, F.A.C.D.; Retention – The Stepchild of Orthodontia; Angle Orthodontist; June 1943; Volume XIV, Nos. 1-2; Pages 3-12.
Since the introduction of the pin and tube appliance by Dr. Angle in 1908, which was introduced primarily as a working retainer, the mechanics of orthodontic treatment have been subject to constant scrutiny, revision and improvement. Etiology and diagnosis as well have progressed far beyond the concepts of the earlier students. So great have these changes been that the present day methods of treatment and diagnosis would be scarcely recognizable by such men as Kingsley, Farrar, Guilford, or their contemporaries. During this time, retention has made but one change of note. The transition from the use of mechanical devices which were designed to hold the teeth immovable in their new positions to those which permit “freedom of movement in every direction save that toward which the teeth tend to return.” This is a complete reversal from the earlier teachings as indicated by a quotation from a paper read before the Ninth International Medical Congress in 1887 by Dr. Angle – “A retaining appliance should hold the teeth so firmly that there will be no movement to disturb or in any way interfere with the new bone formation. Absolute rest is essential to the most speedy and satisfactory results.”
The newer concept of retention was evolved the hard way, that is by clinical evidence, the result of trial and error, and in all clinical evidence in the history of orthodontia this one basic fact stands out: “That irrespective of the length of time a tooth is held in its new position by any means whatsoever, it will upon release seek a position where it is in balance with the forces that act upon the denture – whether these forces are for good or evil is immaterial, the greatest of these forces is the force of occlusion.” Mershon once said “You can move teeth to where you think they belong – Nature will move them to where they will best adapt themselves to the rest of the organism.”
No matter how, when, or where teeth are moved during treatment, the basic principles of retention are the same and can be stated very briefly. “To antagonize the movement of the teeth in the direction of their tendencies, and to allow the teeth freedom of movement in every direction save that toward which they tend to return.” (Angle)
2. Graziella Airoldi, DSc,a Guido Riva, BSc, MSc,b Maria Vanelli, BSc,c Vittorio Filippi,d and Giovanna Garattini, MDe; Oral environment temperature changes induced by cold/hot liquid intake; American Journal of Orthodontics and Dentofacial Orthopedics; July 1997; Volume 112, No. 1; Pages 58-63.
The use of NiTi shape memory alloys, introduced into orthodontics because of their ability to develop light continuous forces that prove more effective than heavy intermittent forces in the teeth movement, requires the mastering of the functional properties of NiTi wires. More specifically, the recovery force acting on the teeth is a sensitive function of temperature: knowledge of oral temperature modifications is therefore required to understand the stress state modification felt during orthodontic therapy. The temperature modifications induced by cold or hot drink intake in the oral cavity were investigated by using arch wires, fixed to removable Hawley retainers, similar to those currently used in orthodontic practice, by means of six temperature sensors placed in correspondence with specific teeth. Similarly, the temperature changes were detected on a metallic frame, fixed onto the palatal zone to a Hawley retainer, where a palatal expander was placed to correct unilateral or bilateral crossbites in deciduous or in early mixed dentition. The maximum temperature change was observed in the interincisor area: The temperature modification on other teeth depends on the modality of drink intake, with the highest temperature variations being detected in the palatal zone. Hence modifications in the stress state during orthodontic therapy with NiTi wires are to be expected. (Am J Orthod Dentofac Orthop 1997;112:58-63.)
3. Rachel J. Moore, Jeffrey T. F. Watts, James A. A. Hood and David J. Burritt; Intra-oral temperature variation over 24 hours; European Journal of Orthodontics 21; 1999; Pages 249-261.
The study aimed to investigate temperature variation at archwire sites adjacent to the maxillary right central incisor and first premolar, its correlation with ambient temperature, and the influence of inter-racial variation. Twenty young adult male subjects were randomly selected (13 Asian, seven Caucasian). Thermocouples were attached to the labial archwire component of custom-made orthodontic retainers at the two intra-oral sites. A third thermocouple measured ambient temperature. A data-logger recorded temperatures at 5-second intervals over a 24-hour period. Temperatures ranged from 5.6 to 58.5°C at the incisor and from 7.9 to 54°C at the premolar, with medians of 34.9°C and 35.6°C, respectively. Ambient temperature correlated poorly with the intra-oral temperatures. The Asian and Caucasian groups had significantly different temperature distributions. On average during the 24-hour period, temperatures at the incisor site were in the range of 33-37°C for 79 percent of the time, below it for 20 percent, and above it for only 1 percent of the time. Corresponding figures for the premolar site were 92, 6, and 2 percent. At both archwire sites, the most frequent temperatures were in the range of 35-36°C. The data presented demonstrate that the temperature at sites on an archwire in situ varies considerable over a 24 hour period and that racial differences may exist. This information should be considered during the manufacture and use of temperature-sensitive orthodontic materials, in particular nickel-titanium archwires and springs.
4. Elizabeth K. Lyons and Douglas S. Ramsay; A Self-Regulation Model of Patient Compliance in Orthodontics: Implications for the Design of a Headgear Monitor; Seminars in Orthodontics; December 2000; Volume 6, Number 4; Pages 224-230.
When patients are asked to follow a therapeutic regimen, they are being given a target or goal and their task is to control or regulate their behavior to meet that objective. Unfortunately, patients often fail to meet the expectations set forth by the clinical recommendation. The present model suggests that the principles governing the self-regulation of behavior may help explain poor compliance with therapeutic regimens. The component parts of a self-regulation model are reviewed in the context of orthodontic treatment. The importance of providing patients with accurate feedback about their degree of compliance with a regimen is discussed. Finally, the technological application of these principles is illustrated in the design of a system for monitoring orthodontic headgear use.
5. D. L. Destang and W. J. S. Kerr; Maxillary retention: is longer better?; European Journal of Orthodontics 25; 2003; Volume 25; Pages 65-69.
Two different maxillary retention regimes were compared to ascertain if differences in post-treatment relapse existed. The patient pool was derived from subjects being treated at two orthodontic departments in the west of Scotland. Group 1 (20 patients) followed a 6 month regime using removable upper Hawley retainers for a period of 3 months full time and 3 months nights only. Group 2 (18 patients) followed a 1 year regime of 6 months full time and 6 months nights only.
The results revealed that maxillary incisor alignment, as determined by Little’s irregularity index, had relapsed by an average of 50 percent of the end of retention value 3 months out of retention in Group 1 but only 23 percent in Group 2. Although the actual mean values for relapse were 0.77 and 0.23 mm, respectively, seven subjects in Group 1 showed relapse of more that 3 mm as compared with only one in Group 2. This suggests that retaining a case for 1 year rather than 6 months is clinically beneficial.
B. Scientific Compliance Peer Reviewed Literature
1. Marc B. Ackerman, DMD; Morgan S McRae, MSICS; William H Longley, B.A.; Clinical Decisions Based on Tangible Data: A Technology Driven Paradigm Shift in Orthodontic Retention (In Press)
Abstract: The difficulty in assessing compliance on a case by case basis in orthodontic retention has been the discrepancy between what the patient self-reports about retainer usage and what the orthodontist actually finds upon clinical examination. In some cases, clinical examination confirms the patient’s self-reported usage; however in other cases it is unclear as to whether or not it was the patient or retainer at fault for the observed relapse. Scientific Compliance has invented, patented, and produced a SMART Retainer environmental microsensor that is easily incorporated into many different types of removable orthodontic appliances. The technology behind the SMART Retainer environmental microsensor is only possible due to recent reductions in electronic component sizes and power requirements. When an orthodontist or staff member places a retainer with an integrated SMART Retainer environmental microsensor onto the proprietary USB-powered SMART Reader, within a few seconds a wireless communication link is established and all the information recorded since the last read-session is automatically downloaded, decrypted, further analyzed using proprietary algorithms for trends and use patterns, and presented to the user via easy to understand charts. The orthodontist can in turn discuss actual retainer usage versus prescribed retainer usage with the patient and/or their parent and make data driven recommendations about future retention.
C. Scientific Compliance Presentations
1. March 5-8, 2008; Atlanta, Ga.; North Atlantic Component of the Edward H. Angle Society of Orthodontists; Monitoring Compliance During Orthodontic Retention; Marc B. Ackerman, DMD
2. April 3, 2008; Paris, France; American Dental Study Club of
Paris; Marc B. Ackerman, DMD3. May 18, 2008; Denver, Colorado; American Association of Orthodontists Annual Session; Marc B. Ackerman, DMD
"Measuring Compliance During Orthodontic Retention: The Intelligent Retainer"
Download May 18th Presentation