Orthodontics-periodontics interrelations

Orthodontics-periodontics interrelations:

1. Introduction :

Orthodontics and periodontology have recognized in recent years a remarkable development and improvement, and the common point that connects them is the periodontium. 

Orthodontics allows the movement of teeth with their supporting tissues under certain conditions while the second (periodontology) helps to clean up and treat the environment.

• Reciprocal report 

Periodontal treatment controls inflammation and prevents reinfection. This is where orthodontic therapy comes in, which, through the bile of the dental movements caused, allows an anatomical and occlusal-functional framework favorable to periodontal maintenance to be reestablished.

• Synergy of action

This is a synergy of action between orthodontics and periodontics which also ensures aesthetics. 

2. Reminder :

1. Histology of the periodontium
2. Periodontal disease (definition and etiology)
3. Physiology of the periodontium:
4. Dental movement actors: 

• The tooth: its root morphology determines the speed of movement.
• The desmodont 
• Alveolar bone: bone density plays an important role in movement (spongy bone or compact bone). It will also intervene through its cells: osteoblasts, osteoclasts and osteocytes.

2. Tissue remodeling in a healthy periodontium during orthodontic treatment:

• Changes in soft tissues (superficial periodontium):

-The gums: if there is not rigorous hygiene, one can have gingivitis.

-Epithelial attachment: there may be migration due to the sinking of orthodontic rings.

– Desmodont: in adults, turnover decreases, fibroblasts and collagen fibers decrease immediately, so it will be necessary to control the orthodontic forces which must be light.

• Bone and cement remodeling (deep periodontium):

-Alveolar bone: osteoblastic and osteoplastic activity allows remodeling, so there will be induced dental movement.

– Cementum: capable of being shaped under the effect of orthodontic forces.

Orthodontics-periodontics interrelations

3. Tissue remodeling in a weakened periodontium during orthodontic treatment:

• In the absence of bacterial plaque, orthodontic treatment does not cause gingivitis.
• In the presence of bacterial plaque, gingivitis and periodontitis will occur, especially if version and intrusion movements are performed.
• A weakened but healthy periodontium: orthodontic treatment is possible with light forces but without gingival inflammation.
• Relapse is not related to per or post-orthodontic surgical periodontal treatment: retention is essential.

4. Histophysiology of dental movement:

• The actors of dental movement: tooth, alveolar bone and desmodont.
• Physiological tooth movement: 

-It is always mesial.

-Bone remodeling is the mechanism by which bone tissue is constantly renewed (apposition resorption).

-Factors inducing physiological migration: facial growth, mesial force of the DDS, trans-septal fibers, and muscular and occlusal forces.

• Induced tooth movement: 

– Immediate mechanical effect: 

The hydro-pneumatic capacity of the desmodont.

Elastic deformation of the alveolar bone and tooth.

As soon as a force is applied, there is an immediate displacement with the fibers under pressure on one side and they are under tension on the other side concomitantly.

As soon as the force stops, we have a return to normal more or less quickly.

    – Short-term biological effect:

Fibers under pressure: 

Stunning phase: this is the hyaline zone, so there is movement after stopping the movement.

Bone remodeling phase: direct resorption and indirect resorption.

Fibers in tension:

Desmodontal widening: if the force decreases, there will be immediate apposition; if the force increases, there will be an osteoblastic hyper reaction followed by bone apposition.

-Long-term biological effect:

After this initial period, there will be a phase of cellular adaptation, during which the rate of bone remodeling increases.

     -The force required for tooth movement:

Effective intermittent forces, if resting phases less than the latency time of cell differentiation.

     -How to produce these forces:

Use springs with a reduced load-to-flex ratio.

Small diameter wires.

Leveling loops.

• Induced dental movement (version, egression, ingression… see course).

Orthodontics-periodontics interrelations

3. The Orthodontics Periodontics interrelationship: 
4. General conditions:

• Periodontal sanitation is necessary.
• Control of inflammation.
• The use of light forces.

2. Contribution of periodontics to orthodontics:
3. Healthy periodontium:

• Before treatment: 

-Hygiene: strengthen motivation.

-Surgeries: increase the height of attached gum…

• During and at the end of treatment:

-Correction of gingival defects in the extraction site (gingival invaginations) => papillectomy

-Fibrotomy.

-Corticotomy.

-Creation of an implant anchor.

-flap for included tooth.

-Freinectomy.

-Occlusal adjustment (selective grinding).

2. Weakened periodontium:

If orthodontic forces are applied to a weakened, unhealthy periodontium, bone resorption (lysis) will be accelerated.

• In case of gingivitis: we will carry out scaling and treat the gingival inflammation to be able to start orthodontic treatment.
• In case of periodontitis: it is necessary to stabilize the periodontitis to begin oethodontic treatment.

3. Significant indentation.
4. Contribution of orthodontics to periodontics:
5. Choosing the timing of orthodontic treatment:

• In the presence of periodontal disease: after periodontal treatment of periodontopathy.
• In case of recession: periodontium is healthy, we start with orthodontic treatment to reduce the recession then we do recession surgery.

2. The role of orthodontic treatment:

• Direct action (on superficial and deep periodontium: 

-Displacement of the epithelial attachment and bone with the tooth (Version, egression, etc.)

– Orthodontics and guided bone regeneration (GBR): when there is bone lysis, a specialist in periodontology will make a displaced flap, detach it, curettage it and put in place a filling material (bone of bovine, porcine origin, etc.) inducing bone regeneration. The orthodontic egression movement allows the regeneration of the crestal bone volume and optimizes a GBR technique. 

• Indirect action: preventive action by preventing the worsening of periodontal disease and its establishment

-Restoration of dental alignment: 

*Hygiene 

*Repositioning the tooth in the bone: the tooth must be surrounded by sufficient bone thickness so that it can be moved away from the cortices as much as possible. E.g. the gression movement + root displacement gives a satisfactory bone foundation.

*Repositioning of the alveolar-dental complex: the tooth and its alveolar bone must be placed in the Château dental corridor; this repositioning will avoid excessive muscular pressure and recessions.

*Absence of root proximities: the fineness of the septa and the root proximities, their correction, gives a favorable mucogingival environment.

– Restoration of a balanced occlusal function (compromise or convenience occlusion) 

– Restoration of a balanced neuromuscular function: the tooth and the alveolar bone compensate for the skeletal discrepancy (Ex. sometimes we have a skeletal class III but it is too late to act on the bone, so we place the dental arches in class I, i.e. move the lower teeth back and vestibulate the upper teeth). In this case (treatment by alveolar compensation), the alveolar bone is not supported by the basal bone, so the muscle force is not balanced. This is the same case as atypical swallowing => mouth breathing => gingival inflammation, so orthodontic treatment (functional therapy) is required.

-Improvement of prosthetic restorations: orthodontics plays an important role in facilitating the creation of prosthetics which will be less iatrogenic, a distal movement of a tooth in an endentation can allow the creation of a fixed prosthesis which was impossible before.

Orthodontics-periodontics interrelations

4. Iatrogenic effect of orthodontic treatment and therapeutic attitude:
5. Anatomical:

1. Root resorption
2. Root bend
3. Periodontal disease
4. Bone lysis
5. Ankylosis
6. Technical (therapeutic) nature:

1. Periodontal aggression by rings, brackets, composite, etc. 
2. Anchor disruption  :

• Imbalance between intrinsic and extrinsic forces
• Mobility
• Modified root crown ratio
• Coronal, gingival, pulpal lesions…

5. Maintaining ortho-periodontal results (never start with ODF, Paro prime):

When we have bone lysis with pockets larger than 3mm => directly surgery of the pockets, even if we have bone lysis but the pockets are smaller than 3mm it is acceptable. 

1. Ortho-periodontal retention:
2. Indications: 

• Durability of ortho-periodontal results.
• The Paro and ortho objectives must promote tissue reorganization by ensuring a harmonious distribution of occlusal forces.

2. The contraindications  :

• Poor control of bacterial plaque and patient non-cooperation
• Susceptibility to caries
• Aesthetic problem in the presence of a significant diastema

3. The objectives: 

• Bond teeth together to prevent recurrence of tooth migration and maintain orthodontic results.
• Respect interdental spaces and embrasures
• This restraint should not hinder the control of bacterial plaque.
• Provide the patient with functional and masticatory comfort

4. Principles: The splint or support (glued wire) ensures distribution of forces and reduces constraints:

• The occlusal context: inter-arch occlusal contact influences the type of retention (if there is an overbite, using glued wire is difficult) 
• The value of the teeth contained: the intrinsic value depends on the coronal morphology and its translucency; the extrinsic value by the mobility

5. Restraint devices:

• The direct method: has the advantage that it is performed in a single session. The support splints are made using a glued Ellman metal grid, fiber composite (polyethylene fibers), Kevlar fibers, preformed rigid metal wire
• The indirect method: requires enamel preparation, use justified by precision:

– Cast-bonded splint: it is a metal structure encompassing the buccal and proximal face of the supporting teeth and can replace one or more teeth, helps reduce dental mutilation; it is a long-term retention

-Fiber composite splint: better impregnation of the fiber with composite, this increases resistance.

– Retention bridge: allows missing teeth to be replaced and at the same time contains teeth that have undergone ortho-periodontal treatment .

2. periodontal maintenance: 

• Patient control of bacterial plaque
• Implementation of periodontal care by the practitioner.

Orthodontics-periodontics interrelations

6. Conclusion : 

Orthodontics plays a very important role in periodontal treatment, this requires: 

• Perfect cooperation and great motivation from the patient.
• Close collaboration in the management of the treatment plan between orthodontics and periodontics for a maintained, healthy and inflammation-free periodontium.
• Adaptation of orthodontic treatment according to periodontal changes related to age and periodontal disease (by light forces).

Knowledge and understanding of the physiological and biomechanical rules allow the various movements to be carried out with maximum efficiency and the different use between healthy periodontium and weakened periodontium.

Dental crowns are used to restore the shape and function of a damaged tooth.
Bruxism, or teeth grinding, can cause premature wear and often requires wearing a retainer at night.
Dental abscesses are painful infections that require prompt treatment to avoid complications. Gum grafting is a surgical procedure that can treat gum recession. Dentists use composite materials for fillings because they match the natural color of the teeth.
A diet high in sugar increases the risk of developing tooth decay.
Pediatric dental care is essential to establish good hygiene habits from an early age.
 

Orthodontics-periodontics interrelations