Retention & relapce in orthodontics

1. PREPARED BY
DR. WESAM GOUDA
PhD IN ORTHODONTICS
PROFESSOR IN ORTHODONTIC
DEPARATMENT
FACULTY OF DENTAL MEDICINE
ALAZHR UNIVERSITY
RETENTION & RELAPCE

2. RETENTION
Defined by Moyers as “Maintaining newly moved teeth in
position long enough to aid in stabilizing their correction”.
Defined as loss of any correction achieved
by orthodontic treatment
Relapse

3. PRE-TREATMENT
POST-TREATMENT
RETENTION

4. PRE-ORTHO AFTER SERIAL EXT. POST-TREAMENT
POST-RETENTION
RELAPSE

5. Why is retention necessary?
Retention is necessary for 3 main reasons
1. The gingival and periodontal tissues are affected by
orthodontic tooth movement and require time for
reorganization when the appliances are removed.
2. The teeth may be in an inherently unstable position
after the treatment,so that soft tissue pressures
constantly produce a relapse tendancy.
3. Changes produced by growth may alter the
orthodontic treatment.

6. If teeth are not in an inherently unstable position and if there is no
further growth, retention still s vitally important until gingival and
periodontal organization is complete.
NB. Retention cannot be abandoned until growth is essentially
completed.

7. Common relapse problems include:
a.The appearance of crowding and rotation.
b. b. The appearance of reappearance of spaces after full space
closure particularly in extraction sites.
c. A tendency for the return of Class II molar relationship with
consequent over-jet appearance after reduction of Class II div. 1
malocclusions

8. Etiology of relapse:
1- Persistence of the cause: as oral habits ( thumb sucking, nail
biting, tongue thrust, abnormal swallowing. ,,, etc.
2. Tooth position: the teeth should be present at the area of functional
tolerance at the end of orthodontic treatment.
3. Soft tissue:
There are three soft tissue entities that may influence the stability of the tooth
in its new position :
a. The superalveolar (gingival group of fibers)
b. The periodontal ligament.
c. The muscles. As tongue and buccinator

9. 4. Bone:
The alveolar bone surrounding a repositioned tooth is a functional tissue
which generally responds to force.
There is no evidence to suggest that bone will produce forces which may
reposition teeth. Accordingly alveolar bone is probably not a causative factor
in relapse.
5. Growth:
Growth can be an important factor in retention-relapse because the active
phase of treatment of many patients is completed while facial growth is still in
progress. If a patient is in the retention phase of treatment during the last stages
of facial growth, some changes inskeletodental relationship may occur.

10. Finishing criteria:-
1. Proper axial inclination with artistic positioning of the incisors.
2. Good buccal intercuspation.
3. Good arch alignment.
4. Good overbite and over-jet, accompanied by a good cephalometric interincisal angle.
5. Good root paralleling, especially at extraction sites.
6. Good arch form.
7. Reasonably flat occlusal plane.
8. Corrections of rotations.
9. Continuity of tooth contacts.
10.Unhindered functional movements.
Finishing and retention

11. TYPES OF
RETENTION
1-Natural or no retention as in
a. Anterior cross bite
b. Serial extraction
c. Blocked out or highly placed canines in class I ext. cases
d. Posterior cross bite in patient having steep cusps

12. 2- Limited or short-term retention
As in:
a. Class I non ext. cases
b. Deep bite
c. Class I, class II div. 1&2
cases treated by ext.

13. 3- Prolonged or permanent
retention
As in :
a. Midline diastema
b. Severe rotation
c. Patient with abnormal musculature or
tongue habits
d. Arch expantion without good occlusion

14. Retention appliances

15. After completion of tooth movement, the bone trabeculae are reoriented again in the
direction of the axis of the root of the tooth.
This takes six month to complete. The bone is found to be more responsive to the influence
of pressure where the occlusion will not hold the tooth in position; therefore, it is necessary
that after active orthodontic tooth movement, the tooth should be retained in position by
means of a retention appliance to prevent its relapse.

16. Retention appliances should be made simple as possible as the young patient is
usually anxious by this time, to abandon orthodontic appliances.
As a measure for retention, muscle exercises may be used either alone or in
conjunction with appliance.
It should be abandoning gradually and under supervision by having the patient
progressively reduce the number of hours it is worn every day.

17. Retention appliances may be either removable or fixed. Occasionally, it is
possible to use as a retainer the appliance which has actively corrected the
malocclusion by rendering the appliance passive (as in cases of screws) so that
it exerts no further pressure, or by substituting an appliance of simpler design
which will hold the teeth in their correct position.
A retaining appliance should be simple, efficient and should not interfere with
the proper cleansing of the teeth and care of the soft tissue of the mouth by the
patient.

18. HAWLEY RETAINER FOR
UPPER AND LOWER
ARCHES
REMOVABLE
RETAINERS

19. The activator:
It can be used to maintain the relationship of the dental in any plane i.e.
anteroposterior , vertically and transversely. It can also provide strong inter-
maxillary anchorage to prevent unfavorable movement of the teeth and aids the
reestablishment of muscle behavior.

20. CLEAR
RETAINERS

21. FIXED RETAINERS
BAND AND SPRU
RETAINER
BONDED LOWER RETAINER

22. BANDED CANINE TO CANINE RETAINER

23. The duration of retention:
The period varies greatly in different cases, varying from few weeks
to a year or longer, when we feel that the recently moved teeth of
modified arches have been harmonized in function with all the forces
to which they are subjected the appliances may be removed and the
case should be kept under close observation.