Recidivism and restraint
Introduction :
Faced with the major problem of orthodontics, relapse, which arouses the interest of practitioners, several authors emphasize the importance of systematic and rigorous control by establishing a retention phase which always follows the active phase of treatment,
Château, highlights its impact by saying that a treatment is only worth it to the extent that its result is lasting; if it is not lasting, it is harmful.
However, our knowledge of the factors of post-orthodontic imbalance remains insufficient, for this reason a whole arsenal of devices is available to us to maintain our results.
I. Recurrence:
- Definition:
This is the reappearance of an anomaly after its correction either partially or totally immediately after the removal of the device or later
- Etiologies:
- Genetic factors:
- Facial typology: in case of a short face, the recurrence of the overbite is very frequent and in case of a long face, we notice a recurrence of dental gaps
- Growth: (direction and intensity) the practitioner must know if the growth is in the direction of the treatment or in the direction of the anomaly, in the latter case, recurrence is certain, according to J Philippe: “we do not know of any means of containment that can effectively oppose unfavorable skeletal growth”
- Dental morphology:
*Tooth size: plays a role in the recurrence of DDM or DDD
*Shape of teeth: e.g. crowns of incisors, round roots turn more easily, number of roots reduces risk of relapse
*Occlusal and proximal morphology: the height and good cusp engagement increase stability, absence of proximal contact points can lead to recurrence of malpositions
– Tension of the desmodental fibers: the intraseptal and supracrestal fibers play a role in tissue reorganization; early orthodontic treatment allows for better adaptation of these fibers and therefore less relapse.
– The muscle factor:
* Anatomy and lingual posture: e.g.: true macro or microglossia, short lingual frenulum, low and forward position of the tongue lead to the recurrence of Cl III, lower proalveolism, upper endognathia
* Anatomy and lip posture:
– Lip position e.g.: absence of stomion (recurrence of laproalveolism), lower lip completely covers the upper incisors (recurrence of Cl II division two)
– Lip tone: ex hypertonicity (recurrence of retroalveolitis)
– Insertion of the frenulum: recurrence of diastemas
- Functional or acquired factors:
- Dysfunctions:
- Atypical swallowing: recurrence of gaping bites, proalveoli
- Mouth breathing: influences lingual posture, arch development and mandibular growth (recurrence of pro inf and Cl III)
- Disturbed phonation: recurrence of anterior or lateral infraclusion
- Parafunctions:
- Thumb sucking: recurrence of open bites, pro or biproalveoli
- Lip sucking: recurrence of upper or lower retroalveoli
- Interposition of an object: infraclusion at the level of the affected teeth
- Human factor:
- Age: related to growth
- Patient cooperation: wearing the device, duration of wearing, efforts to suppress tics and distorting habits
- General diseases: hormonal, bone, vitamin deficiencies
- Iatrogenic factors:
- Diagnostic error: neglecting the etiological diagnosis
- Wrong choice of treatment plan
- Poor processing finish
- Poorly adapted contention
- Post-therapeutic factors:
- Evolution of wisdom teeth: mesial eruptive forces
- Late growth: residual mandibular growth (unfavorable for Cl III)
- Recurrence depending on the anomalies:
- Dentoalveolar anomalies:
- Intra-arch anomalies:
- Diastemas: causes: hypertrophic or poorly inserted lingual or labial frenulum.
- Rotations: this is the most recurrent dental movement, causes: stretching of the desmodental fibers.
- Lower incisor crowding: causes: DDS thrust, change in arch shape, centripedal muscle forces, post-therapeutic position of teeth, treatment modalities (extraction or not).
- Inter-arch anomalies:
- Pro or retroalveolus sup or inf: recurrence depending on the persistence of the etiology (imbalance of the Château corridor)
- Supraclusion: very recurrent anomaly, causes: hypertonicity of the facial muscles, direction of anterior mandibular growth.
- Infreclusion: recurrence depending on the persistence of dysfunctions
- Endoalveolus: causes: persistence of the low position of the tongue, significant changes in the shape of the arch and modification of the intercanine width, hypertonicity of the perioral musculature.
- Skeletal anomalies:
- Cl II1: treatment stability is achieved by late growth of the mandible
- Cl II2: very recurrent anomaly due to overbite
- Cl III: highly recurrent anomalies, causes: hereditary character, volume and lingual position, late growth of the mandible
- Skeletal hyper and hypodivergence: causes: therapeutic changes in the vertical direction, ant or post insertion of the masseter muscle, posterior rotation of the mandible
- Transverse anomalies: cases treated by disjunction are more stable
4. Factors preventing recidivism:
- Growth forecast: it is to predict the rate and direction of future growth, plays an important role in treatment stability
- Compliance with intra-arch occlusal criteria:
- Root parallelism at the end of treatment
- Ideal arch form and interproximal contact points
- Right occlusal plane
- Compliance with inter-arch occlusal criteria:
- Static: Cl I canine and molar, meshing and coverage respected.
- Dynamics: coincidence between RC and PIM, absence of interference during lateral or propulsion movements
- Overcorrection.
- Other preventive measures:
- Fibrotomy: avoiding recurrence of rotations
- Cononoplasty: put composite at the cingulum level (lift the supra)
- Reduction of the inter-incisal angle: reduces the risk of recurrence of the supra
- Freinectomy: reduces the recurrence of diastemas
- Glossoplasty: reduces recurrence of alveolar anomalies and Cl III
II. Contention:
- Definition:
Retention corresponds to the final therapeutic phase of an orthodontic treatment; it is also the whole process and the devices intended to maintain or perfect the results obtained and avoid the recurrence of anomalies.
It occurs at the end of active treatment when the objectives sought by the practitioner have been achieved.
- The goals of restraint:
- Stabilize teeth during tissue reorganization
- Promote the establishment of a good occlusion, and maintain the teeth in their corrected position during occlusal grinding.
- Prevention of recidivism
- Counteract the effect of unfavorable residual growth going in the opposite direction.
- Maintains correction of a skeletal offset
- Maintains conditions favorable to good function
- The terms of the restraint:
- Time of restraint:
The time interval between the removal of the active device and the fitting of the retention device varies according to the authors:
- One week later to observe the stability of the corrections, for BERCH and BURSTONE
- THEUVNEY and HOLDAWAY, the same day
- REITAN, if strict retention of the teeth is desirable, it must be put in place immediately after stopping the active appliance because the recurrence of rotation is clear two hours after removal of the active force.
- Type of restraint
Natural contention:
This in the following cases:
- An anterior crossbite provided that sufficient coverage has been established
- Posterior crossbite in cases of palatal disjunction after good intercuspation
- Palatal retention or inclusion of the upper canines
Active restraint:
In these cases, restraint is an integral part of active treatment.
EX: Class II or Class III cases treated with TIM maintained during the retention period and placed on plates.
Fixed or removable contention:
For BRODIE, the condition must be fixed
However, a removable retainer requires the patient’s cooperation, which a fixed retainer does not, and helps to maintain good hygiene and suspend the retainer during meals.
- Duration of restraint:
The desirable retention time varies according to the authors and the anomalies treated:
IZARD and CHATEAU recommend wearing the device day and night, then a few weeks later only at night.
THEUVNEY, stops the restraint after one year
SCHUDY, until the end of the growth and evolution of DDS
Depending on the anomalies treated:
-for a class I with DDM: one year
– for a class II: two years
-for class III; until the end of growth
4. Restraint devices:
Removable unimaxillary devices:
HAWLEY plate
This is the most commonly used retention device, consisting of a resin palatal plate with a vestibular band passing behind the molars, it must be thin, and must fit on the lingual surfaces of the teeth.
Thermoformed gutters
They are made from a thermoformed plastic sheet about 1 mm thick. The gutters cover all sides of the dental arches. The gutters have 2 advantages:
- They are compact and transparent, so they are well accepted;
- They provide containment in all 3 directions of space.
Their main disadvantage is that they interfere with occlusion and therefore disrupt it.
Recidivism and restraint
Removable bimaxillary devices
The “tooth positioner”
Made of natural rubber, very flexible and very resistant, the device is built on a mounting of the patient’s teeth , placed in perfect alignment and in perfect intercuspidation, the device envelops the two arches.
The activator
It must be worn perfectly regularly because, if the slightest dental movement occurs, the device can no longer be put back in place.
For this reason, the activator remains difficult to accept for long-term retention.
Unimaxillary fixed devices
Metal wires
A polished wire with a round section, 0.7 mm in diameter, is glued from 43 to 33.
This wire should be stiff and easy to clean. Each end of the segment should end with a coil, to improve retention
Glued grids
Cut from a metal mesh, sometimes plastic, between the meshes of which glue passes, glued grids are more often used in periodontics.
Cast glued splints
They combine the maximum of qualities, and are particularly indicated when periodontological reasons are added to orthodontic reasons to make a very long-term retention desired.
Bimaxillary fixed devices
The cingulate stops
These are small masses of composite placed on the cingula of the incisors and often the maxillary canines, intended to prevent the recurrence of the overbite.
Class III elastic holders
This device is intended to provide containment for Class III treatments. It can be added to a mandibular bonded wire.
Recidivism and restraint
Conclusion
The restraint, like the treatment, must be specifically adapted to each case, thus the type of restraint must be chosen according to its own characteristics, the particularities of each case and each type of treatment, and according to the possible recurrence.
Regarding the duration of retention of restraint devices, the tendency being to extend this duration as much as possible, the aspects of information and informed consent of the patient, as well as the responsibility of the practitioner, must not be neglected under any circumstances.
Recidivism and restraint
Deep cavities may require root canal treatment.
Interdental brushes effectively clean between teeth.
Misaligned teeth can cause chewing problems.
Untreated dental infections can spread to other parts of the body.
Whitening trays are used for gradual results.
Cracked teeth can be repaired with composite resins.
Proper hydration helps maintain a healthy mouth.