Class II treatment
Plan :
Introduction
1- prevention
2- interception
3- orthopedic treatment
3-1 maxillary responsibility
3-2 Mandibular responsibility
4- orthodontic treatment
4-1 without extraction
4-2 with extraction
5- surgical treatment
Conclusion
Introduction
Interest of the question:
- Frequency: Class 2 is the most frequent orthodontic anomaly, 3/4 of the cases in an orthodontic population are Class II malocclusions according to BASSIGNY.
- Significant aesthetic damage with visible incisors for class 2/1 with risk of fracture of the latter, receding chin, convex skin profile in class 2/1 cases and concave in class 2/2 cases, marked furrows, absence of stomion, etc.
- Disturbed functions, breathing, chewing, swallowing, phonation…
- Prevention
- Sleeping positions: avoid the ventral position which promotes mouth breathing and the persistence of neonatal retromandibulia
- oral hygiene (care and avoidance
early extraction of milk molars)
- feeding: the effectiveness of breastfeeding is no longer in doubt given the importance of the muscular activity it involves. With the appearance of teeth, chewing must be effective (avoid a soft diet and introduce increasingly hard foods to trigger “mandibular strike” (PLANAS)
- Interception
- Elimination of thumb or object sucking tics.
- Rehabilitation of functions and bad postures (lingual posture, breathing, swallowing, chewing and phonation)
- Removing occlusion locks: overbite and transverse deficit
- Orthopedic treatment
It aims to correct the size and position of the jaws between themselves and with the base of the skull, before the growth peak.
3.1 Maxillary responsibility:
FEB which can be on molar rings or on a gutter. It is a removable device comprising:
- A pericranial support
- External elastic traction
- A facebow: with two external branches and two internal branches, the latter will fit into the molar tubes of the rings or embedded in the resin if it is on a gutter
Effect of extraoral forces:
- This type of device allows significant slowing of the sagittal growth of the maxilla.
- It allows to control the orientation of the maxilla and the occlusal plane thanks to the orientation of the external branches.
High traction:
- The support is parietal, the direction of traction is higher than the occlusal plane, in this case, the vertical component is equal to the distal component
– Intrusion of molars
– Anterior rotation of the mandible
– Increased anchoring
– In the case of class II open bite
Low traction:
The support is cervical at the level of the neck.
Merrifield places it at the level of the 3rd or 4th cervical vertebra.
The support is located lower than the occlusal plane and has two components: a vertical one which is equal to half of the distal component.
– Egression of molars
– Distal movement of molars
– Increased molar anchorage
– Indicated in the case of class II deep bite
Horizontal traction:
The support is occipital, its action is in the extension of the occlusal plane, the vertical component is negligible / the distal component.
– Distal action
– indicated in Class II normobite
— increases molar anchorage
3.2 Mandibular responsibility:
Activator
removable device using intrinsic forces (oro-facial muscles) to correct skeletal class II by mandibular propulsion, it is a functional orthopedic device
There are 3 main families of activators:
- Rigid monobloc activators
- Elastic activators
- Stop activators
We cite the Andressen activator, the most popular. It is part of the rigid activators, it consists of:
– Of an upper palatine plate with:
- vestibular arch
- 2 Adams hooks
– And a resin lingual plate that covers the lower incisors.
– The two plates are connected by a bilateral resin interposition which covers the occlusal faces of the lateral sectors
Effects:
- Growth and advancement of the mandible
- Slowed jaw growth
- Increase in DV by posterior rotation of the mandible
- Palatoversion of the upper incisors and vestibuloversion of the lower incisors
Indication: class II with deep bite or normo bite mandibular responsibility
Port: 12 to 14 hours per day
Contraindication: Associated DDM and posterior rotation of the mandible
DAC (distal active concept) therapy has proven its effectiveness and appears to be an alternative to functional activators.
It offers the advantage of being able to combine orthopedic action with orthodontic action, this is particularly interesting in the following cases:
This device includes:
- Wedges on the mandibular 1st molars to unlock mandibular growth
- Intermaxillary tractions to propel the mandible
- NITI springs between incisors and 1st molar to distalize or stabilize the upper 1st molar.
3.3 Mixed responsibility:
Association of activator and extra-oral forces
- Back from point A
- facilitates forward mandibular growth.
- a decrease in profile convexity.
- Maxillary growth rotation, following the orientation of the external branches: (anterior rotation for a low orientation, no rotation for an average orientation, posterior rotation for a high orientation.
- Orthodontic treatment
It is called compensation, after the growth peak the orthopedic correction of the position of the jaws is no longer possible.
Orthodontic treatment can be done with or without tooth extraction
The choice will be made based on the following factors
- Convexity of the profile
- Single or double maxilla DDM
- The height of the lower floor
- Importance of the shift
Without extraction:
The TIMs are stretched from the upper canine to the lower molar.
Indicated in class II cases with low offset, without increase in the lower floor, without DDM, profile not too convex
With extraction
Single-jaw extraction 14/24 or 15/25
Bimaxillary extraction 14/24 and 34/44 or 15/25 and 35/45
Principle:
- If the offset is significant = 14/24 extraction
- If the offset is not significant = extraction 15/25
- If single-maxillary extraction = end-of-treatment molar ratio of class 2 type
- If DDM in the mandibular arch = bimaxillary extraction
5. Surgical treatment
It aims to correct the position and/or size of the jaws using osteotomies after the end of growth (from 18 years old) when:
- the anomaly is significant or
- The child consulted late
- Orthopedic therapy has failed
The agreement between the orthodontist and the surgeon is essential because it is the realization of a good orthodontic preparation which allows a quality surgery and therefore an excellent occlusal finish, a guarantee of stability.
Thus the orthodontist plays an important role before, during and after surgery.
Class II treatment
Pre-surgical orthodontics:
- Decompensate malocclusions, in other words make them worse initially,
- Correct the clutter of the arches
- Ensure good coaptation of the arches;
- The results of the intervention are simulated on casts to visualize any inadequacies in the orthodontic preparation, particularly in terms of the transverse direction, the intercanine distance and the posterior torques.
Intraoperative orthodontics:
-During the intervention, the role of the orthodontist will be to remove or modify the arches used by the surgeon to achieve interarch blocking during the intervention.
Orthodontic finishing:
– After an average time of bone consolidation (around 2 months), the orthodontist can continue treatment in order to perfect the static and dynamic occlusal results.
Two main categories of surgery are possible:
- Segmental osteotomies which move a group of teeth within an arch
- Total osteotomies which move the entire arch.
5.1 Isolated promaxillary:
By Wassmund:
– Segmental osteotomy allows the mobilization of the incisor-canine group in the three directions of space. To allow its surgical retraction, the preparation involves the extraction of the first two premolars (intraoperatively).
– This surgery is accompanied by a recession of the upper lip and the A-point area.
Lefort 1:
– Total maxillary osteotomy allows the movement of the arch in the 3 directions of space. The retraction of the maxillary arch can be accompanied by a lowering with the placement of a bone graft and sometimes a disjunction.
5.2 Isolated retromandibulia:
– Most frequently, it is corrected by total transramal osteotomy which allows a displacement in the three directions of the space of the mandible (advancement, retraction, elevation and lowering) called Obwegeser osteotomy, it is carried out thanks to a cleavage in the thickness of the ramus. The osteotomized fragments are held in place using screwed titanium plates.
– a Koële segmental osteotomy which allows the correction of an excess of anterior coverage due to the egression of the mandibular incisors. It includes a posterior osteotomy line passing between the canine and the first premolar.
– It is sometimes necessary to add a disjunction if the width of the maxillary arch is insufficient.
Class II/2:
They are treated as class II/1 short face, once the upper incisors have been vestibuloversed. A genioplasty is welcome and reduces the overly prominent symphysis and restores height to the chin thanks to a graft placed under the basilar edge.
Conclusion
Faced with a class II skeletal discrepancy and when the indication arises, orthopedic treatment is the ideal therapeutic approach because it allows action on the bony bases, normalizing growth to ensure harmonious development of the stomatognathic system.
But this is not always the case, in patients at the end of growth, the practitioner must resolve this discrepancy by achieving an orthodontic compromise sometimes requiring extractions.
Surgical treatment is reserved for adults at the end of growth and facing severe discrepancies with significant aesthetic damage.
Class II treatment
Wisdom teeth may need to be extracted if they are too small.
Sealing the grooves protects children’s molars from cavities.
Bad breath can be linked to dental or gum problems.
Bad breath can be linked to dental or gum problems.
Dental veneers improve the appearance of stained or damaged teeth.
Regular scaling prevents the build-up of plaque.
Sensitive teeth can be treated with specific toothpastes.
Early consultation helps detect dental problems in time.