Treatment of Class II Malocclusion

Treatment of Class II Malocclusion

Introduction :

Class II malocclusions represent the most frequently encountered dento-skeletal anomaly in dento-facial orthopedic consultations. The prevalence of class II in the European population is 30% to 40% (Kelly and Mc Lain cited by Mac Namara).

The reality of class II covers a great architectural complexity, with a multiplicity of clinical forms, and above all with a functional and muscular balance which is always disturbed.

1. Prevention:

• Breastfeeding: at least 6 months to have a beneficial effect on growth.

 Orthostatic suckling works much more oral musculature as the infant falls asleep and the onset of sleep is a period when mitoses are more numerous (PETROVIC)

• Good skull development: adopting a correct sleeping position
• Food:
• Ventilation and the airway 
• Preservation of baby teeth: 

2. The interception:

” The earlier the treatment, the more the face adapts to your concept; the later the treatment, the more your concept must adapt to the face.” ” (C. Gugino).

 Our interceptive approach consists of eliminating any blockage (lock) which, acting on the alveolo-dental structures or on the bony bases, hinders the normal course of growth of the masticatory system.

There are mechanical locks ( in all three spatial directions) and functional locks.

1.  Mechanical locks:
2. In the transverse direction

 Maxillary “V” unlocking:

 Free the mandible from all occlusal constraints by reshaping the maxilla (guide arch), by correction of molar rotation and by anterior and/or posterior maxillary expansion; 

2. VERTICAL DIRECTION:

Overcclusion can lock the mandible anteriorly.

Unlock: RICKETTS Ingression Base Bow

2. Functional locks  :

A functional lock is understood to mean any disturbed functional matrix (oral ventilation, atypical swallowing, dysfunction of the orofacial musculature and posture) which can compromise the normal course of growth.

•  Ventilation: HINZ mouth shields
• Swallowing: trainer position, ELN
• Defective perioral musculature (lip bumper)
• Para functions gentle psychological approach 

3. Class II therapeutic means:
4. orthopedic means:

 1.1. MAXILLARY RESPONSIBILITY:

Extra-oral forces (EOF):

• On gutter

In stable mixed dentition, extraoral orthopedic forces applied 12 out of 24 hours, preferably on groups of teeth, by means of plates, or better resin splints, covering all the teeth. 

• On rings:

This appliance consists of a face bow inserted into tubes welded to bands sealed on the molars; the force should be gradually increased during the first week to a force of at least 500 grams on each side.

The direction of the force can be modified depending on the facial typology

1.2. MANDIBULAR RESPONSIBILITY:

• The Activator:

• Promote condylar growth and reposition the mandible forward and downward;

• Slow down maxillary growth;

• Slow down incisor extrusion by encouraging that of the molars;

• Cause a vestibular version of the lower incisors.

• BALTERS’ Bionator (1950) 

It is a rigid monobloc, providing bimaxillary blocking and comprising a palatal loop allowing lingual stimulation, and vestibular arches ensuring the distance of the musculature.

Role: Enlarge the oral space and normalize functions.

• Bring the incisors end to end.

Obtain mandibular lengthening.

• Obtain tongue re-education.

• Herbst connecting rod:

This is a double-ended connecting rod:

• In mixed dentition by two resin gutters 

• In permanent teeth: by upper and lower aligners or multi-bracket devices.

• Fränkel function regulator: 

This device, as its name suggests, normalizes and re-educates the activity of the perioral and jugal muscles.

If it is built in propulsion, as suggested by McNamara, it will have an effect on skeletal growth (activator action). indicated for meso- or brachyfacial typology with strong disruption of functional matrices 

• Twin-Block

An orthopedic and functional appliance consisting of four resin blocks, two on each arch, William Clark’s Twin-Block (1982) corrects Class II malocclusions by transmitting muscular forces to the occlusal surfaces of the teeth, forcing the mandible to move forward to accomplish the closing movement, which teaches it to take this new position and increases its strength.

• Jasper Jumpers 

It is a removable orthodontic appliance, which redirects the pressures of the facial and masticatory muscles towards the teeth and their periodontium to achieve dental alignment and an improvement in occlusal relationships. It is similar to the Herbst but easier to use.

 1.3 . Mixed responsibility:

• FEB combined with an activator:

Compared to the activator alone, it allows for better control of the vertical direction.

• On average, after treatment, skeletal class II relationships are corrected and profile convexity is greatly improved 
• DAC (Distal Active Concept)

The goal of DAC therapy is to achieve a skeletal effect on mandibular growth in mixed dentition or adolescent dentition.

 This orthopedic effect is comparable to the effects obtained by growth activators. 

Used in mixed dentition it gives dento-skeletal effects.

2.  Orthodontic means:

• Distalization is considered in cases of maxillary molars in mesioposition following premature loss of the temporary molars, or proximal caries of these,
• In addition, cases of maxillary crowding of the anterior or middle region, materialized by ectopic or retained canines or premolars
• Maxillary molar distalization is not the best means of correcting skeletal Class II (retromandibulia) and severe mandibular crowding requiring bimaxillary extractions.
• Finally, it should be avoided for hyperdivergent patients because it will tend to open the occlusion.
• It is done using different devices: distal jet, pendulum, etc.

4. The treatment itself:
5. Class II division 1 
   1. Class II division 1, long face:

• In temporary dentition:  normalization of functions and suppression of parafunctions 
• In mixed dentition: 

• Do not treat in mixed dentition if PM extractions are planned due to concomitant DDM.
• The “position trainer”: is used around 6-8 years old; it helps re-educate the tongue and guide the eruption of permanent teeth.
• A Frankel function regulator, 
• A FEB on gutter with low traction and plan the extraction of 18 and 28 
• In permanent dentition: 

• You should never back down. 
• Absolutely prohibit propellants and activators, and cervical FEBs on molar rings,
• Avoiding Class II TIMs
• Extractions are most often necessary

So we can conclude that the treatment of CLII division 1 long face, includes:

less frequent early sequences; significant emphasis is placed on the treatment of functional disorders; procedures involving extractions of permanent teeth.

1.2. Class II division 1 short face

• In temporary dentition: There is often an overbite and the mandible is locked.
•  In mixed dentition: This is the prime time for treatment

• Promaxillie: A FEB on a splint with medium or high traction
• Retromandibular joint: Activator, different types of propellers: herbst connecting rods, twin block, jasper jumper….
• Mixed shapes : FEB on medium or high traction monobloc.

 DAC (Distal Active Concept): mixed dentition is the ideal time for its use; correction of the misalignments can be observed in 10 weeks

• Permanent dentition:

Orthodontic treatment will be undertaken during the development of adolescent teeth:

• If the ant-post shift is not very marked : extractions will be avoided or limited to wisdom teeth; the use of CL II elastics   will be preferred.
• Distalization of the upper  molars
• DAC in mixed cases
• If the offset is significant:

Extract 14 and 24 and use FEB on rings with cervical traction

1.3. Average face:

Are the least complex, the therapeutic approach will depend on the position of the lower incisors:

• If they are placed too far forward, the therapeutic procedures are similar to those used for the long face type.
• And if they are set back , we prefer intermaxillary tractions and activators, inspired by the treatments proposed in cases of short face. 

Surgery:

• Wassmud 

This segmental osteotomy allows the mobilization of the incisor-canine group in all three spatial directions. 

• To allow its surgical retreat, the preparation involves the extraction of the first two premolars. It is possible to ingress it without modifying the vertical facial type. 
• Mandible advancement : associated or not with a segmental osteotomy, this is the most frequent case, add a disjunction if the width of the maxillary arch is insufficient 
• Retention is the preventive treatment of post-orthodontic relapse, it is necessary to distinguish between retention of dental movements and retention of orthopedic treatments, the latter is most often carried out using the same device that was used to carry out the treatment and its duration will vary depending on whether the child’s growth is favorable or not. 

2. Class II division 2

• Temporary dentition:

Prevent the appearance of visible incisor overbite from 4 to 5 years of age if one of the ascendants has a characteristic class II division 2, using a removable maxillary plate, with a resin extension located on the anterior crest, as soon as the temporary central incisors fall out.

• Mixed dentition: the upper incisors must be intruded first, using a Ricketts base arch 

Note: Before using the basic intrusion arch, you must wait until the apices of the incisors are formed before undertaking the intrusion.

Promaxillary: 

• FEB on high traction aligners after correction of overbite and incisor LV 

Retromandibulia: 

• Activator which will correct the supracclusion by molar egression and vestibuloversion of the incisors.

Mixed forms:

• Activator with addition of high traction FEB
• DAC but not in cases with a significant gummy smile
• In permanent dentition:

• Incisor intrusion involves the use of multi-bracket appliances 
• Extractions are avoided as far as possible as long as there is no DDM
• Using CL II TIMs

If the correction of the anteroposterior shift remains insufficient or in the case of DDM, extractions will be planned long after the growth peak, if this proves possible. 

Surgical treatment:

• In adulthood, an orthodontic-surgical solution is sometimes necessary.
• It will consist of transforming by orthodontic  means a class II, division 2 into class II, division 1 (by vestibulo-tilting the upper incisors) and planning a segmental osteotomy in the maxilla and/or the mandible,
• Genioplasty is well indicated, because it reduces the overly prominent symphysis, 

Treatment of Class II Malocclusion

Contention

If the Class II report is not very recurrent here, the overbite on the other hand is very recurrent.

• Balancing in propulsion by grinding the incisal edges and reestablishing a correct angle of attack.

Conclusion

The goal of each practitioner is to transform Class II malocclusions into Class I as early as possible and reduce the multi-bracket phase to a simple short-term dental alignment, with minimal use of intra-or extra-oral auxiliaries…

Treatment of Class II Malocclusion

Untreated cavities can damage the pulp.
Orthodontics aligns teeth and jaws.
Implants replace missing teeth permanently.
Dental floss removes debris between teeth.
A visit to the dentist every 6 months is recommended.
Fixed bridges replace one or more missing teeth.
 

Treatment of Class II Malocclusion