Special Considerations in Orthodontics
“The direction in which education starts a person will determine his future life.”
Although debate surrounds the question of which factors influence the stability of orthodontic results, there is one factor for which there is no debate: periodontal health. Periodontal research has shown us that plaque control is the most essential element in maintaining the health of the teeth throughout one’s lifetime. Without healthy teeth, long-term stability is not a realistic goal
Theoretically, teeth and periodontal tissues will last a lifetime if the tissues are periodontally plaque free, regardless of the patient’s occlusion or function. Although deep bite malocclusion and bruxism can cause dental attrition and eventually soft tissue recession, regardless of the high quality of the finished occlusion, there will be no long-term health of the teeth if the patient does not have good oral hygiene (Fig 3-1). If a person has perfectly straight teeth but horrible plaque control, early periodontitis, gingival inflammation, gingival recession (from poor brushing techniques), periodontal bone loss, and eventual tooth loss are inevitable.
Therefore, one of the greatest opportunities afforded the orthodontist is to educate the patient regarding excellent oral hygiene and to reinforce this education during each routine visit. If good oral hygiene habits can be instilled at a young age during orthodontic treatment, then lifelong dental health is a real possibility.
Potential periodontal problems during orthodontic treatment
The most common periodontal problem that develops during orthodontic treatment is gingivitis. This condition is the result of a buildup of plaque and calculus that forms because of the patient’s inability to keep his or her teeth clean while orthodontic appliances are present. The acid-etching technique used in bonding can also cause irritation of the gingival tissue if proper care is not taken. A longstanding gingivitis can develop into soft tissue hyperplasia while the patient is wearing the orthodontic appliances. Other iatrogenic causes of periodontal problems could include the improper fitting of bands around the teeth, excessive cement not being cleaned properly, and elastic wear causing pressure on the tissue. Periodontal abscesses can form as a result of poorly fitting appliances or unclean areas surrounding them. As the teeth are moved during orthodontic treatment, occlusal trauma can occur that may result in periodontal disorders. As treatment continues, progressive periodontitis can develop, resulting in lost gingival attachment. This is a result of the tissue inflammation not being controlled. Improper orthodontic therapy can also be a factor. If the forces are too great or the movement is too rapid, permanent periodontal problems can develop.
One of the hidden scars of orthodontic treatment is root resorption (Fig 3-2). Although much research has been done on this phenomenon, there is still uncertainty about what actually causes this condition.
With all these potential problems arising during orthodontic treatment, the forces instigating dental movement should be as gentle as possible.
Orthodontic correction of periodontal problems
Periodontal considerations that may be improved or corrected by orthodontic therapy include the following:
- Paralleling of abutment teeth
- Uprighting of a mesially inclined tooth with an associated mesial defect and decreasing or eliminating its probing depth
- Moving a tooth into an osseous defect, possibly eliminating the defect or decreasing its size
- Establishing a more favorable distribution about the arch of existing abutments
- Establishing proper root proximity
- Establishing a cusp-to-fossa or groove relationship and alignment of occlusal forces in the long axis of the teeth
- Creating a proper occlusal plane, incisal guidance, and anterior disocclusion
- Forcibly extruding teeth that are fractured at or below the gingival margin to establish a proper biologic width and permit placement of a crown or to correct or decrease an associated infrabony defect
Possibly the greatest periodontal benefit the patient receives from a well-treated orthodontic result is the potential for improved maintenance of the periodontium. When the teeth are positioned properly, the patient has a much better opportunity to keep his or her teeth plaque free. With proper tooth alignment and embrasure space comes improved gingival morphology. Therefore, the patient can develop a much better technique for keeping the plaque controlled. A good occlusion will also allow the dental hygienist, generalist, and periodontist to be more effective in plaque removal and root instrumentation during the patient’s recall visits.
Continued maintenance therapy is essential for the adult orthodontic/periodontic patient so that normal tissue health can be restored and maintained throughout the patient’s life. Any restorative or prosthetic treatment should be performed after orthodontic treatment is completed. Approximately 6 months after orthodontic treatment, an occlusal equilibration may need to be performed. Most adult periodontal patients are required to continue some form of retention for an indefinite period.
Ultimate success in orthodontic treatment is defined by teeth that are attractive and healthy throughout the remainder of the patient’s life. Our goal is for the patient to have healthy teeth when 95 or even 100 years old. This can only be accomplished if the orthodontist places the teeth in the best possible relationships that can be achieved and the patient maintains proper oral hygiene. Daily oral hygiene procedures such as brushing and flossing to keep the teeth plaque free and routine visits to the dentist and periodontist for prophylaxis are critical to enable the patient to maintain optimum dental health throughout his or her life. It is a lofty goal, to be sure, but with the modern therapeutic procedures that are available today, I believe lifelong dental health is a realistic goal.
Temporomandibular Joint Considerations
One of the least understood areas in the human body is the temporomandibular joint (TMJ). I have much admiration for those clinicians who specialize in temporomandibular joint disorder (TMD). Malocclusion can be a factor in TMD, so the orthodontist must understand the problem and have the expertise to diagnose and improve the situation.
A large number of adult patients who present for orthodontic treatment also suffer from some form of TMD. The prevalence has been estimated at anywhere from 10% to 80%. Regardless of the actual statistic, the large number of patients with TMD cannot be ignored.
For many years, TMJ dysfunctions were a medical no man’s land. Physicians knew very little about them, and dentists knew only slightly more. In the last 5 to 10 years, dentistry has taken on the challenge of learning more about this most complicated joint in the human body.
The multitude of theories surrounding TMJ dysfunction, including mostly unfounded claims that orthodontics causes TMD, the need for a multidisciplinary approach to treatment, the myriad of TMD symptoms, and fear of legal actions have produced nightmares for almost every practicing orthodontist at some time or another. However, with the percentage of adult patients with TMD increasing in nearly every orthodontic practice, it is incumbent upon the clinician to learn as much about TMJ therapy as possible.
First of all, the determination is made prior to treatment whether the patient’s joints are functioning normally. Normal function is defined according to five properties:
- No sounds during condylar movement
- Proper condylar range of motion
- Absence of pain
- Proper neuromuscular function
- Condyle/fossa in centric relation
The first four properties can be discerned fairly easily through a proper examination, but the problem of centric relation is far more difficult. The differences among various expert opinions of what centric relation is can be very confusing. Some clinicians argue that centric relation is the most posterior-superior position of the condyle in the fossa whereas others think the condyle should be centered in the fossa against the eminence or even down and forward along the eminence. However, if the patient does not have a dual bite or slide, has condyles that are relatively well centered in the fossa (according to laminographs), and displays the first four properties, orthodontic treatment can be initiated with cautious optimism.
But if the patient complains of any of the following symptoms, joint integrity should be questioned:
- Category I: Headache, toothache, migraine, eye pain, or vertigo
- Category II: Restricted head or jaw movement, clicking or popping of joint, or TMJ pain
- Category III: Facial muscle tension or soreness, stiff shoulder, or backache
There are at least four causes of TMJ dysfunction:
- Trauma to the joint
- Emotional factors, including stress
- Repetitive overloading of the joint
The first three causes are usually beyond the province of orthodontics. Some pain relief can be provided, but a permanent solution includes treatment involving other medical specialties. However, repetitive overloading can often be reduced or eliminated through orthodontics. Generally, this problem is accompanied by occlusal factors such as grinding, clenching, missing teeth, and malocclusion. Providing an excellent occlusion will certainly mitigate this problem.
Because the orthodontist alone cannot alleviate most TMJ problems, a team of medical specialists often must be assembled. General dentists, periodontists, oral surgeons, orthopedists, physical therapists, psychologists, psychiatrists, and ear, nose, and throat specialists have all played a role at one time or another in the treatment of TMJ patients in our office.
A confusing aspect of TMJ therapy is the classification of joint problems. TMDs can be divided into at least eight categories:
- Myofascial pain dysfunction
- Degenerative joint disease
- Internal derangements (disc displacements)
- Loss of posterior occlusal support
- Chronic mandibular hypermobility
- Dental interferences
- Traumatic joint disturbances
- Spontaneous dislocation
Many of these disorders will require at least one other specialist in addition to the orthodontist to solve the problem. Therefore, the patient must be properly classified by the orthodontist before referral to the proper specialist or the composition of the correct multidisciplinary team. The orthodontist’s responsibility to the patient is to provide the best result possible even when the patient is undergoing treatment that is not provided by the orthodontist.
One of the most valuable diagnostic tools for TMD is an accurate and detailed clinical history of the problem and the patient in general. In addition to the normal diagnostic records, tomograms (laminographs) are taken on every patient who exhibits any symptoms of TMD. The tomogram should be used only as a tool and not as the only definitive diagnostic medium. It must be used in conjunction with the clinical history and other tests to arrive at a diagnosis.
Another critical factor in diagnosis is the clinical observation regarding the crepitus or clicking of the joint when opening. An early opening click indicates that the disc has been anteriorly displaced. In most of these cases, an anterior repositioning splint may be used to reposition or recapture the disc. If accompanied by a late closing click, the condyle stops with the disc until the teeth are almost in centric occlusion before the disc pops forward; the treatment success rate for this type of problem is encouraging. A late opening click or early closing click indicates that splint therapy to reposition the disc may be of limited value and other treatment modalities will need to be considered. As their costs decrease, computed axial tomography (CAT) scans and nuclear magnetic resonance imaging (NMRI) will be used more commonly in the future to show hard and soft tissue relationships of the joints.