Adult orthodontics
1/ INTRODUCTION
Adult demand for orthodontics has grown considerably over the past ten years .
This is mainly due to three factors: health which has become a major concern; aesthetic demand and in particular that concerning the smile; and the appearance of aesthetic devices.
These adult patients cannot be received or treated like young children.
2/ Definitions
An adult (Larousse dictionary) can be defined as any person who has reached the end of their growth and has reached or exceeded 18 years of age, as opposed to an adolescent or a child.
MELSEN : When I say adults, I mean individuals who have completed their growth, and I include older adults with degenerating dentitions.
LANGLADE : The primary factor in defining adult orthodontics is the absence of growth. Certain factors such as periodontal changes, physiological adaptation to an imbalance or psychological behavior can vary enormously from one individual to another.
3- Particularities of adult orthodontics
The treatment of adults differs from that of children by some particularities that it is essential to know in order to carry out our treatment successfully.
These psychological, diagnostic, biological and therapeutic differences make orthodontic treatments for adults specific treatments which require particular attention, not only from the orthodontist, but also from the dental surgeon, the periodontist and even the surgeon, hence the importance of concerted and coherent multidisciplinary treatment .
Adult orthodontics
3-1- Psychological Particularities:
Welcome
It must be different, not only in terms of speech but also in terms of environment. Time must be spent explaining the treatment, at each appointment, before the actual procedure; this allows for a preparation that facilitates the establishment of trust and therefore a certain relaxation that is essential. These patients must be listened to, inquire about their needs, their desires; it is therefore necessary to plan longer treatment sessions than for children.
Decorating a children’s treatment room can be surprising to adults; similarly, using a shared treatment room may not be the best solution. Adults prefer the privacy of a dedicated room; discussion is easier and more discreet in this case.
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Motivation
The motivation of adult patients is different from that of children:
They are much more sensitive to the unsightly appearance of the devices, to the wearing of extraoral devices;
It is difficult to convince the patient that treatment requires time and patience [2]; therefore, it is better not to consider a long treatment duration, which forces us to make compromises.
In terms of hygiene and dietary instructions, the adult patient generally cooperates well.
Pain tolerance is decreased for tissue and biological reasons; thus, the adult is a patient who complains easily
In adults, we frequently find two situations:
• an aesthetic motivation, where the patient comes of his own accord; in this case he is well motivated;
• a functional motivation; he is then referred to us by a colleague (pre-prosthetic need), who has previously informed him. In this case, his motivation is more difficult to obtain.
Explanation. Information. Informed consent
The adult must be informed; before the treatment begins, everything must be explained to him: the treatment plan, the devices, the duration of the treatment, so that he understands the requirements of the therapy and thus cooperates fully.
The adult patient needs to be given precise explanations about what is being done at each appointment, about the progress of the treatment and to be reassured in the choice he has made.
Similarly, since adults are more sensitive to irritation of the mucous membranes and adaptation of functions is slower, the adult patient must be clearly informed of these problems, the risk of pain, irritation and difficulties when carrying out the various functions.
It is also important to clearly explain the constraints and risks associated with orthodontic treatments, particularly root resorption; given the current trend of increasing litigation procedures, it would be interesting for these to appear in the estimate, as the notion of informed consent is important in adults.
3-2-Biological particularities:
Growth
Lack of growth in adults alters treatment plans; thus, adult orthodontic treatments act on the teeth and alveolar processes but have little or no effect on the bony bases
Skeletal discrepancies can only be treated by orthognathic surgery or alveolodental compensations.
Adult orthodontics
Aging of tissues
A / Soft tissues
During aging, soft tissues show significant changes.
The nose sags and widens: its profile becomes convex with age because the bony support of the nasal bone remains stable, while the tip thickens, and falls down and forward
The lips become thinner and the mouth appears more and more pursed. The corners of the lips lower towards the chin. The nasolabial angle becomes more acute.
The stomion lowers. The nasolabial folds become strongly marked.
All these age-related changes must be taken into account during our treatments so as not to aggravate these morphological changes.
B/Superficial and deep periodontium
Changes in the periodontium with age (physiological)
With age, the physiology of the periodontium changes and periodontal disease becomes more common.
Periodontal senescence is not a disease in the true sense. Rather, it is a generally slow and steady periodontal lysis.
Superficial periodontium
Anatomical changes . There is almost always a slight migration of the attachment system, probably due to episodic inflammatory phenomena. At most, in the most favorable cases, it keeps its initial height. In addition, with aging, the papillae retract and the edge of the marginal gingiva becomes blunt. It is necessary to avoid moving a tooth to an area where the attached gingiva is of low height and not very thick.
Histological changes. The superficial periodontium is characterized by progressive tissue disorganization. The possibilities of defense and repair are then more difficult and the healing time increases.
Deep periodontium
Cementum: The formation of cementum at the end of the root is a constant phenomenon that only ends with the disappearance of the tooth, to compensate for physiological wear; therefore, a cementum thickening, a reduction in the desmodontal space and a reduction in the ligament remodeling cell pool appear on the X-ray , which would slow down tooth movement.
Desmodont: It is recognized that with age the structure of the ligament becomes more irregular. There is a decrease in vascularization with arteriosclerosis of the vessels. As the renewal of cells and fibers is more difficult and slower, dental movement is slowed, the retention time is extended, and mobility is increased during treatment.
Alveolar bone. Anatomical changes. In addition to changes in density and bone turnover, there are anatomical changes, with an almost inevitable loss of bone support. Bone atrophies with age and the amount of calcified tissue is reduced. The total amount of bone decreases.
Incidence of periodontal disease pathological change
On the periodontium.
Periodontal disease induces recession of the epithelioconnective attachment system, associated with alveolar bone loss and exposure of cementum.
On the teeth.
Loss of periodontal support and inflammation promote secondary migrations: mesioversions of cuspid teeth, opening of anterior diastemas
Consequences on tooth movement
Histophysiology of dental movement in adults
The main changes related to bone aging in adults are characterized by a decrease in vascularization leading to a reduction in metabolic exchanges and cell supply. All these factors contribute to modifying the activation/resorption/inversion/formation cycle described by Baron
Consequences
Tooth movement is slower in adults. Alveolar remodeling is slower but is in no way an obstacle to tooth movement. This difference is due to the fact that adult bone is less vascularized. Turnover is negatively influenced by the presence of a smaller number of osteoblasts; the cellular exchanges governing resorption and apposition are weaker because the cell population is less intense.
For Stuzmann and Petrovic, the movement is less rapid after 16-17 years, but not more difficult at 50 than at 20-25 years; the difference comes from a more intense hyalinization; after a phase of 3 days, the movement is done at the same speed and with the same amplitude as in children.
Adult orthodontics
The initial tooth movement is slower to appear. Alveolar resorptions are more intense in adults
Stabilization and healing are also slower, therefore retention must be longer .
So-called “at risk” patients
Infective endocarditis
However, some cases of endocarditis have been reported after a visit to the orthodontist.
Bacteremia can be caused by the placement of separators, the adjustment and sealing of rings as well as their removal
The American Heart Association recommends antibiotic prophylaxis at initial bracket placement for patients “at risk for endocarditis.” It is recommended for group A and optional for group B according to the consensus conference. However, it is not necessary before bracket bonding.
Diabetes
As long as blood sugar levels are controlled, there is no contraindication to orthodontic treatment.
In case of imbalance, orthodontic treatment is discussed with the treating physician.
Impact of pharmacological treatments
Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce bone turnover suggesting decreased orthodontic movement.
Steroidal anti-inflammatory drugs; some animal studies suggest that prolonged administration of cortisone or prednisolone appears to increase the rate of orthodontic movement
Bisphosphonates; their main action is to reduce bone resorption by directly inhibiting osteoclastic activity
They have a very long tissue lifespan (with a half-life of up to 10 years)
Treating an adult on bisphosphonates requires assessing the risk of limitation of tooth movement by inhibition of bone remodeling and the risk of maxillomandibular osteonecrosis.
3-3-Diagnostic particularities
Reason for consultation
It is important to ask the patient what he or she expects from the treatment; in fact, we try to respect his or her requests, even if it means making compromises while respecting the objectives of orthodontic treatments.
Background
It is desirable to know heredity and family history: general diseases; dental and periodontal problems.
The patient’s general condition and ongoing medical treatments can influence periodontal health and joint health. Thus, hormonal, psychological or psychiatric problems, heart disease, pregnancy status must be known
Dental and occlusal examination
The intra-arch examination will determine the number and condition of the teeth, and the periodontal environment. It is necessary to note the prosthetic restorations present, the endodontic treatments and the conservative care, the dental extractions replaced or not (in this case note the possible versions and/or egressions), the carious and/or endodontic lesions which must be treated before starting the treatment. The dental examination is supplemented by the information provided by the panoramic radiograph and the long cone retro-alveolar assessment.
After carrying out the dental assessment, a precise occlusal examination must be carried out in the mouth and then on casts of the dental arches mounted on a semi-adaptable articulator in order to highlight dental factors of imbalance in the masticatory system.
Periodontal examination
A complete periodontal assessment is essential before starting any treatment in adults, in order to ensure the absence of ongoing inflammation.
Any periodontal disease must first be eliminated before starting orthodontic treatment.
During the clinical examination, the gingival condition should be noted with the presence of recessions, bleeding, the search for periodontal pockets and dental mobility, and the patient’s level of hygiene.
These examinations, as well as dental plaque control, must be repeated during treatment, which allows precise monitoring of the evolution of the periodontium during therapy.
3-4- biomechanical particularities
Anchoring
In adults, natural anchoring is often diminished:
• the number of teeth present is reduced;
• bone density is lower;
• bone height is decreased;
• periodontal disease, if present, can cause more or less significant mobility.
In the absence of infection, condemned natural teeth can be kept for the duration of treatment to increase anchorage.
Shifting the center of resistance
In adults, the bone level is reduced (periodontitis, aging); as a result, the center of resistance of the teeth is shifted towards the apex. Thus, the force/moment ratio is increased
Thus, for the same activation, we obtain a greater moment if the bone is resorbed and therefore an easier version movement which can create, if not controlled, dehiscences and fenestrations .
Adult orthodontics
Intensity of force
The forces used in adults should be even lighter at the time of initiation of movement to allow for physiological tooth movement. Melsen and Burstone suggest starting treatment with low forces and continuing by increasing the applied force, but what is important is the distribution of force per unit area rather than the force applied to each tooth
Duration of force application
According to Stuzmann and Petrovic, the forces applied in adults should preferably be of the discontinuous type to allow tissue reorganization between each activation.
According to Fontenelle, the use of constant forces ensures a constant distribution of stress and ensures a permanent regime. It is therefore necessary to design mechanical systems that deliver forces as light as possible, while maintaining sufficient intensity so that dental movement is not interrupted.
3-5- Therapeutic particularities
– Discreet device
For psychological reasons, it is preferable to use aesthetic devices:
• segmentation of the arches allows less visible lateral sectors to be treated before focusing on the anterior sectors. This reduces the time spent wearing a visible appliance
• tooth-colored resin or ceramic attachments can be used;
• lingual orthodontics owes its appearance to Fujita and Kurz who use bonded brackets at the linguopalatine area and mushroom-shaped arches
Thermoformed gutters
Duration of treatment
When an adult comes for a consultation, the orthodontist must first and foremost provide a service: the practitioner can be more tolerant regarding the objectives to be achieved, in order to limit the duration of treatment while ensuring functional and aesthetic stability.
Some corrections that are necessary for a child are not always imperative to perform in an adult; thus, a mismatch of the interincisal media can be accepted, the extraction of an incisor is also acceptable to quickly correct a dentomaxillary disharmony, often unimaxillary extractions are performed and result in a therapeutic molar class II, a moderate overbite is tolerated.
Acceleration of orthodontic tooth movement can be achieved by surgical or non-surgical means.
Bonding on non-natural substrates
Modern orthodontics and the treatment of adults leads us to bond brackets to multiple supports: ceramic, amalgam, composite, etc. It is necessary to know and master the bonding protocols adapted to the specificities of these supports.
4- Objectives of adult orthodontics
Improve aesthetics
The practitioner must analyze the aesthetics of the face, smile and teeth. Thus, he will assess the proportions of the face from the front and profile, the balance of the projections and depressions along the profile, the play of the smile, the shape and color of the incisors. The general architecture of the face can only be modified in adults by surgery.
Achieving functional occlusion
Philippe retains two principles:
• respect for occlusal functions: centering, wedging and guiding of the mandible;
• the absence of joint compression.
The physiological occlusion sought in adults is that which corresponds to a harmonious state of mutual tolerance of the different constituents of the masticatory system, accepting some variations in relation to the ideal occlusion. This is a compromise orthodontics.
Ensuring the sustainability of the dental system
One of the fundamental conditions for the implementation of orthodontic treatment in adults is the absence of inflammation. Prior periodontal sanitation is essential: motivation for hygiene, initial therapy, sanitation surgery if necessary and supportive periodontal care throughout the treatment.
Contribute to prosthetic realization
Orthodontics can facilitate the achievement of prosthetic rehabilitations, which are more aesthetic, more functional and more reliable.
Adult orthodontics
5-indication of adult orthodontics
3_1Aesthetics:
- Closure of a medial or lateral incisor diastema
- Ingression of an extruded tooth
- Correction of a pathological version or an unsightly rotation
- Correction of linguoclusion
3_2 Pre-prosthetic or restorative
- Straightening the pillar axis of a bridge
- Opening a space to accommodate a prosthetic tooth
- Closing a space to avoid a cap that is too wide
- Disinclusion
- Correction of an excessive overbite and restoration of a usable prosthetic height
- Rehabilitation of an incisal guide
- The integration of a tooth into a stable and functional occlusion
3_3 Periodontal
Widening of the interdental septum (vertical bone damage)
Correction of an overlap source of food retention and tartar
Egression of pockets and recession
Fixing secondary migrations
3_4 articular; as part of the multidisciplinary treatment of DAM
3_5 surgical
Orthognathic surgery to correct shifts of the bony bases in the 3 spatial directions
6 – Contraindications
- Movements damaging to the periodontium
- The need for major prosthetic restoration
- Anchoring not possible
- Inability to achieve functional occlusion
- Delicate stability after correction
- Insufficient patient motivation.
Adult orthodontics
7- Therapeutic conduct
7.1. Orthodontic treatment alone
Anchoring :
Anchoring is a vital necessity in the case of adults in whom very localized movements are desired for certain teeth and where the remaining dental elements must not be moved under any circumstances. This is why it is essential to avoid any parasitic movement that could disrupt the pre-existing occlusal and functional balance. Anchoring is therefore a major concern and can be ensured by:
Conventional transpalatal bars such as the Nance palatal arch; lingual arch…or absolute skeletal anchors mini plates and mini screws
Anchorage miniscrews are an interesting alternative in adults; they appear particularly indicated when orthodontic anchorage is insufficient, reduced (reduction of periodontal support) or absent (loss of teeth), or when the patient’s compliance with conventional orthodontic treatment is deficient. In addition, the mechanical means of anchorage reinforcement commonly used in children or adolescents are more difficult to integrate into adult treatment. The indications for miniscrews can compensate for the deficiencies of a conventional orthodontic solution without any parasitic manifestation. We are thinking in particular of unitary intrusion movements (passive gression without antagonist) or sectoral (incisive supra-alveolism, tilting of the occlusal plane in the frontal plane).
Devices and processing means
Treatment devices must meet a number of criteria:
– be aesthetic (ceramic attachment, lingual orthodontics);
– be as unobtrusive as possible;
– be effective.
These are most often treatments for DDM and compensation for skeletal shifts which may require extractions, stripping, use of TIM, etc.
Stripping
Interproximal enamel reduction is a technique for removing a controlled amount of interproximal enamel without damaging the tooth.
In orthodontics, this technique is widely used because it allows, by modifying the shape of the interproximal contact point, to perfect the alignment, to treat small anterior crowding (4 mm) and to improve the occlusion, as well as the long-term stability. The advent of non-extraction techniques makes stripping popular and increasingly widespread.
The fundamental principles of stripping. They were stated by Sheridan and Fillion:
- First principle: do not sculpt before fitting the appliance
- Second principle: do not sculpt the teeth in rotation
- Third principle: sculpt molars and premolars as a priority
- Fourth principle: use quality material for reduction and polishing
- Fifth principle: do not sculpt without gingival and even lip protection
Limits of stripping
- Stripping cannot be used on teeth
- having a very low thickness of enamel, little
- interproximal convexity and on patients with
- already sensitive to temperature variations
Extraction
In the absence of infection, condemned natural teeth can be kept for the duration of treatment to increase anchorage.
Extraction of a lower incisor in adult orthodontic treatment is an acceptable compromise
Extract the tooth with the most unfavorable durability value
7.2. Treatment combining orthodontics and periodontology
Initial periodontal therapy
- Patient motivation and hygiene advice
- Non-surgical or therapeutic etiological sanitation
- revaluation
- Complementary surgical therapy (periodontal surgery interventions)
- periodontal maintenance
Adult orthodontics
Supracrestal fibrotomy
The tension of the cementogingival fibers, and less permanently, the desmodontal fibers, can persist for several months, or even more than 1 year after completion of orthodontic treatment, thus becoming the source of an orthodontic relapse that retention does not always prevent.
In order to minimize this risk of recurrence, it was proposed by Edwards to section the cementogingival fibers by a circumferential intrasulcular incision , reaching the bony crest or even the mucogingival line.
This technique was modified by adding vertical interdental incisions
Acceleration of tooth movement
The many studies devoted to corticotomy converge on one point: orthodontic dental movements are faster when associated with corticotomy.
Mucogingival surgery by covering recessions, frenectomy, etc.
Orthodontic extraction
An egression movement is indicated in the face of a vertical lesion that cannot be treated. The dental movement will then allow the bone to be reconstructed, but, of course, will cause an elongation of the clinical crown and will often require endodontic treatment before the restoration of the tooth, or will require the avulsion of the tooth and the placement of an implant at the regenerated site.
Periodontal orthodontics also involves orthodontic extractions which involve eroding the tooth until it is out of its support in order to bring in bone or soft tissue and prepare the implant site.
7.2. Treatment combining orthodontics and prosthesis
Orthodontics performed prior to prosthetic restoration can be simple, often aimed at straightening, mesializing, distalizing, egressing, ingressing a tooth or group of teeth in order to make prosthetic reconstruction possible or to improve its reliability. Orthodontics performed prior to prosthetic restoration can be complex, incorporated into a multidisciplinary treatment plan.
Management of edentulous sites:
Agenesis of the maxillary lateral incisors:
Opening space
It is preferable to preserve or open spaces in patients with molar Class I occlusion without associated abnormality or Class III. Another element to take into consideration is the morphology and shade of the canine.
The use of multi-attachment technique is essential to control in particular the root axes of the contralateral teeth before the installation of a fixed prosthetic reconstruction or an implant most often
Redistribute and optimize prosthetic spaces
During prosthetic rehabilitation, inadequate spaces may be encountered: these edentulous spaces may be too small or too large, which would prevent a functional aesthetic prosthetic solution, in good periodontal conditions and stable in the long term.
Adult orthodontics
Arrangement of prosthetic pillars:
Straightening the pillars
Straightening of mesioverted molars can be performed using various orthodontic techniques.
In both standard Edgewise and Tweed techniques, the distal straightening movement can be achieved by springs, loops, or tip-back information.
In the straight arch technique, the use of super-elastic or shape memory wires allows the straightening of the tooth.
Distribution of pillars
The distribution of the pillars by mesial or distal placement is achieved using fixed techniques. In the case of posterior edentulism, distal placement is a difficult movement to obtain. The development of implant techniques, in particular the use of miniscrews, allows the creation of a posterior anchorage facilitating this movement AND allows a better quality bridge to be produced and should at the same time improve the occlusion relationships.
Recovering misaligned teeth
Misaligned teeth can hinder prosthetic rehabilitation. Rather than extracting them under the name of “strategic extractions ” , their orthodontic recovery can instead be a contribution to the prosthetic treatment plan.
7.4. Surgical-orthodontic treatment
- preparatory orthodontic phase
Pre-surgical orthodontics must meet a certain number of rules:
• decompensation of malocclusions.
• correction of crowding of the arches . This can be achieved by means of extractions , the choice of which is linked to the dental condition and the age of the patient;
• coordination of the arches;
• simulation of the results of the intervention.
- surgical phase
- post-surgical orthodontic finishing phase
After an average bone consolidation time of 2 months, the orthodontist can continue the treatment and perfect the occlusion. This phase can last from 6 to 8 months and will guarantee the stability of the results obtained.
7- restraint
At the end of orthodontic treatment, the retention phase must absolutely be long, ideally for life
Let us emphasize the determining role of the end-of-treatment occlusion on the sustainability of the functional balance in the long term. The quality of the occlusal finishes is essential regardless of the choice of the type of retention or the bonding system.
Restraints can be fixed or removable but fixed devices are generally preferred in adults for reasons of comfort.
The practitioner will therefore be faced with the crucial problem of the number of teeth to include depending on the severity of the periodontal destruction, the degree of mobility, the location of the teeth on the arch
8/ CONCLUSION
Malocclusions in adults can be effectively corrected regardless of the patient’s age, given the quality of the supporting tissues of the teeth, which must be moved, and the force used, which must be gentle and remain within the limits of the natural functional forces of mastication.
The prognosis for these treatments is good with a higher risk of recurrence than in children.
Very precise therapy and perfect clinical judgment on the part of the practitioner usually aided by better cooperation from the patient are necessary and are the key to therapeutic success.