Intermaxillary tractions (IMT)
Introduction
They are essential aids for the orthodontist in conducting treatment, hence their frequent use to achieve treatment objectives.
They come in elastic bands of different sizes depending on the desired strength. They are made of latex, rubber or silicone.
- Advantage :
•They can be put on and taken off by the patient himself.
• They do not require cleaning, since they are thrown away after wear.
•They do not require activation by the orthodontist.
- Disadvantages:
• Saliva gradually destroys the elastic which swells and loses its elasticity
• The force exerted is not constant
• They can be put on and taken off by the patient, the patient can attach them incorrectly and cause disruption of the anchoring
• Patient neglect may delay or compromise treatment
- The different types of elastics:
Depending on their direction and their anchoring and application point, we distinguish 3 types of tractions: Antero-posterior tractions, transverse tractions, and vertical tractions.
3-1 Antero-posterior tractions:
They are called class II when they start from the mandibular molar area towards the maxillary anterior sector; and they are called class III when they start from the maxillary molar area towards the mandibular anterior sector.
A – Class II elastics : (TIM class II )
Oblique intermaxillary elastics extending from the lower molar to a device in front of the upper canine.
1-Action on the maxilla:
• The anterior sector undergoes egression
• The upper molar undergoes a slight coronal distortion version
• The maxilla moves back distally
2-Action On the mandible:
• The lower molar undergoes egression with a mesio coronal version
• The mandible undergoes mesial translation,
• The lower incisors tilt vestibularly.
3- On the facial diagram:
• The mandible rotates posteriorly, the chin lowers and moves back,
• The vertical direction of the lower floor of the face is increased.
- Indications for class II elastics:
They are indicated in the case of dental class II of deep-bite skeletal type. That is, when the lower level of the face is normal or diminished.
- Contraindications:
They are contraindicated in all class II cases where the lower level of the face is increased (open-bite case, increased DV).
B – Class III elastics :
They are designed to treat a class III malocclusion, they are oblique going from the lower canine to the upper 1st molar.
- Actions of class III elastics:
1- On the upper arch:
• The upper molar undergoes egression with a mesio coronal version
• The upper incisors tilt vestibularly,
• The upper arch makes a mesial translation.
2- On the lower arch:
• the lower molar makes a distortion version
• the lower incisors make an egression movement with linguoversion
• the lower arch performs a distal movement.
3- On the facial diagram:
• the mandible rotates posteriorly, the chin lowers and moves back
• Increase in vertical dimension.
- Indications for class III elastics:
• Angle Class III
• Dental Class III with skeletal Class III in deep-bite (reduced DV)
- Contraindications:
All class III cases with increased DV.
3-2 Vertical pull-ups: (vertical elastics)
They are applied between the opposing teeth (search for a better occlusion, closing a gap)
A – Anterior vertical elastics:
They are “square” on 2 or 4 upper and lower incisors (v or L), they cause egression (extrusion) of the teeth .
They are indicated in the correction of anterior gaps.
B – Posterior vertical elastics:
Applied between the antagonistic cuspid teeth
3-3 Transverse tractions:
-They can be crossed ” criss-cross “, when they start from the vestibular face of a cuspid tooth towards the lingual face of the antagonist tooth (indicated for a cross occlusion to make the articulation jump).
-They are said to be oblique when they start from a maxillary canine towards the mandibular canine on the opposite side.
They are indicated in the correction of median line deviations.
- Conclusion :
It is important to differentiate between intermaxillary tractions and
Intra maxillary tractions which are horizontal elastics or class I elastics.
These are forces applied between 2 teeth or 2 groups of teeth in the same arch.
The force can be produced by an elastic ligature, or by an elastomer chain (retraction elastic, diastema closure).
Sensitive teeth react to hot, cold or sweet.
Sensitive teeth react to hot, cold or sweet.
Ceramic crowns perfectly imitate the appearance of natural teeth.
Regular dental care reduces the risk of serious problems.
Impacted teeth can cause pain and require intervention.
Antiseptic mouthwashes help reduce plaque.
Fractured teeth can be repaired with modern techniques.
A balanced diet promotes healthy teeth and gums.