Post Expansion- Methods of Retention , Dr. Amit Prakash Senior lecturer Department of Orthodontics and Dentofacial Orthopedics Rishi-raj dental college and hospital Bhopal Dr. Piyush Heda Reader Department of Orthodontics and Dentofacial OrthopedicsDarshan dental college and hospital Loyara, Udaipur Dr. Kshitij Gupta Senior lecturerDepartment of Orthodontics and Dentofacial OrthopedicsRishi-raj dental college and hospital Bhopal Dr. Sonali Rai Private practitioner Corresponding address: Dr. Amit PrakashDepartment of Orthodontics and Dentofacial Orthopedics Rishi-raj dental college and hospital, BhopalE-mail address- drprakash24@yahoo.co.in amitprakash30@gmail.com Abstract The reduction of the transverse dimension of the mandible and the maxilla is one of the crowding etiological factors. Therefore, expansion will not only restore the proper dental arch range, but it will also provide additional space for subsequent alignment. Treatment of transverse discrepancies is supposed to promote arch perimeter increase, often allowing overall teeth-crowding correction. Retention is necessary in expansion cases, because teeth that have been moved tend to return to their former positions. There is little agreement as to the reason for this tendency; suggested influences include musculature, apical base transseptal fibers, and bone morphology. In this article we have summarized the different methods. All the methods are effective and it depends on the clinician to use methods depending on case to case. Keywords- Expansion, Stabilization, Retention Introduction Transverse problems are most likely the result of a narrow maxillary arch. The necessary maxillary expansion may be approached either skeletally or dentally, depending on the anatomic basis of the problem. The basis of skeletal maxillary expansion is opening the midpalatal suture by applying heavy forces across the suture. This can produce skeletal changes either rapidly or slowly depending on the age, bone morphology, type of force etc.1-2 Retention of cases of lateral development is important due to the amount of tissue and other structures moved during active therapy. The farther the teeth must be moved laterally, and more rapidly they are moved, the longer should be the period of retention. If a case is widened for a short distance over a clinically long period of time with slow expansion the chance of major relapse is minimal. Slight over expansion is advisable. The amount of retention needed for a given case is dependent on many factors. In estimating the length of time needed for active retention, it is better to overestimate and be sure than to underestimate and suffer possible relapse due to withdrawal of the appliance too soon. As a general rule most cases should remain in active retention at least 6 months. There are different methods to retain the results after achieving an adequate amount of expansion. These are: Soldered or removable TPA(transpalatal arch) (Figure 1) RME appliance itself where holes are sealed up with acrylic and retained (Figure 2) Tying the central cylinders of the expansion screw with small brass separating wire or wire ligature Expanded heavy rectangular wire (0.019X0.025) (Figure 3) Slow expansion can be achieved and retained with quad-helix itself (Figure 4) Removable plate after slow expansion in myofunctional cases (Figure 5) Lingual arch in lower arch or Schwarz plate itself Discussion —need for retention??? When expansion has been completed a 3-6 month period of retention with the appliance is recommended. During this time, bone fills in the space that was created between the left and right halves of the maxilla. Some skeletal relapses begin to occur almost immediately even though the teeth are held in position. The net treatment effect, therefore, is a combination of skeletal and dental expansion. After 3 months of retention, the fixed appliance should be removed but a removable retainer that covers the palate is often needed to further ensure against early relapse. Hicks3 observed that the amount of relapse is related to the method of retention after expansion. With no retention, the relapse can amount to 45% as compared with 10-23% with fixed retention and 22-25% with removable retention. Krebs4 noted that although the dental arch width was maintained during fixed retention, the distance between implants in the infra-zygomatic ridges decreased during the 3 months of fixed retention by an average of 10% to 15%. This relapse continued during retention with removable appliances. After an average period of 15 months, approximately 70% of the infra-zygomatic maxillary width increase was maintained. Figure 1: Retention with soldered TPA Figure 2: Retention with RME itself (holes are filled with acrylic) Figure 3: Retention with expanded heavy wire (0.019X0.025 stainless steel) Figure 4: Retention with Quad-helix itself Figure 5: Retention with removable plates Bibliography Andrew J Haas. Palatal expansion: Just the beginning of dentofacial orthopedics Am J Orthod 57, 3 1970 .219-253 Ascher, C. The removable quad-helix appliance, British Journal of Orthodontics, 12, 40-45. Hicks. Slow maxillary expansion. Am J Orthod Dentofac Orthop; 1978; 73; 134-141. Krebs A. Expansion of the midpalatal suture studied by means of metallic implants. Eur Orthod Soc. Rep 1958; 34:163-71. , http://bit.ly/10nsWEB

Post Expansion- Methods of Retention , Dr. Amit Prakash Senior lecturer Department of Orthodontics and Dentofacial Orthopedics Rishi-raj dental college and hospital Bhopal Dr. Piyush Heda Reader Department of Orthodontics and Dentofacial OrthopedicsDarshan dental college and hospital Loyara, Udaipur Dr. Kshitij Gupta Senior lecturerDepartment of Orthodontics and Dentofacial OrthopedicsRishi-raj dental college and hospital Bhopal Dr. Sonali Rai Private practitioner Corresponding address: Dr. Amit PrakashDepartment of Orthodontics and Dentofacial Orthopedics Rishi-raj dental college and hospital, BhopalE-mail address- drprakash24@yahoo.co.in amitprakash30@gmail.com Abstract The reduction of the transverse dimension of the mandible and the maxilla is one of the crowding etiological factors. Therefore, expansion will not only restore the proper dental arch range, but it will also provide additional space for subsequent alignment. Treatment of transverse discrepancies is supposed to promote arch perimeter increase, often allowing overall teeth-crowding correction. Retention is necessary in expansion cases, because teeth that have been moved tend to return to their former positions. There is little agreement as to the reason for this tendency; suggested influences include musculature, apical base transseptal fibers, and bone morphology. In this article we have summarized the different methods. All the methods are effective and it depends on the clinician to use methods depending on case to case. Keywords- Expansion, Stabilization, Retention Introduction Transverse problems are most likely the result of a narrow maxillary arch. The necessary maxillary expansion may be approached either skeletally or dentally, depending on the anatomic basis of the problem. The basis of skeletal maxillary expansion is opening the midpalatal suture by applying heavy forces across the suture. This can produce skeletal changes either rapidly or slowly depending on the age, bone morphology, type of force etc.1-2 Retention of cases of lateral development is important due to the amount of tissue and other structures moved during active therapy. The farther the teeth must be moved laterally, and more rapidly they are moved, the longer should be the period of retention. If a case is widened for a short distance over a clinically long period of time with slow expansion the chance of major relapse is minimal. Slight over expansion is advisable. The amount of retention needed for a given case is dependent on many factors. In estimating the length of time needed for active retention, it is better to overestimate and be sure than to underestimate and suffer possible relapse due to withdrawal of the appliance too soon. As a general rule most cases should remain in active retention at least 6 months. There are different methods to retain the results after achieving an adequate amount of expansion. These are: Soldered or removable TPA(transpalatal arch) (Figure 1) RME appliance itself where holes are sealed up with acrylic and retained (Figure 2) Tying the central cylinders of the expansion screw with small brass separating wire or wire ligature Expanded heavy rectangular wire (0.019X0.025) (Figure 3) Slow expansion can be achieved and retained with quad-helix itself (Figure 4) Removable plate after slow expansion in myofunctional cases (Figure 5) Lingual arch in lower arch or Schwarz plate itself Discussion —need for retention??? When expansion has been completed a 3-6 month period of retention with the appliance is recommended. During this time, bone fills in the space that was created between the left and right halves of the maxilla. Some skeletal relapses begin to occur almost immediately even though the teeth are held in position. The net treatment effect, therefore, is a combination of skeletal and dental expansion. After 3 months of retention, the fixed appliance should be removed but a removable retainer that covers the palate is often needed to further ensure against early relapse. Hicks3 observed that the amount of relapse is related to the method of retention after expansion. With no retention, the relapse can amount to 45% as compared with 10-23% with fixed retention and 22-25% with removable retention. Krebs4 noted that although the dental arch width was maintained during fixed retention, the distance between implants in the infra-zygomatic ridges decreased during the 3 months of fixed retention by an average of 10% to 15%. This relapse continued during retention with removable appliances. After an average period of 15 months, approximately 70% of the infra-zygomatic maxillary width increase was maintained. Figure 1: Retention with soldered TPA Figure 2: Retention with RME itself (holes are filled with acrylic) Figure 3: Retention with expanded heavy wire (0.019X0.025 stainless steel) Figure 4: Retention with Quad-helix itself Figure 5: Retention with removable plates Bibliography Andrew J Haas. Palatal expansion: Just the beginning of dentofacial orthopedics Am J Orthod 57, 3 1970 .219-253 Ascher, C. The removable quad-helix appliance, British Journal of Orthodontics, 12, 40-45. Hicks. Slow maxillary expansion. Am J Orthod Dentofac Orthop; 1978; 73; 134-141. Krebs A. Expansion of the midpalatal suture studied by means of metallic implants. Eur Orthod Soc. Rep 1958; 34:163-71. , http://bit.ly/10nsWEB , via Dental Teach " Daily Dental Info " http://www.facebook.com/photo.php?fbid=593788470645706&set=a.588953107795909.1073741858.110664842291407&type=1