ortho talk

Sept. 1, 2000
Remember what Phase I is? How come some orthodontists skip to Phase II? Here`s a reminder about orthodontic principles.

Remember what Phase I is? How come some orthodontists skip to Phase II? Here`s a reminder about orthodontic principles.

Barbara Alexander, RDH

Day after day, hygienists hand patients referrals for orthodontists. The referrals might be to the doctor`s former classmate, another doctor in the building, or just a local doctor with a good reputation. Since hygienists are on the front line in relaying information to patients, shouldn`t we have a better understanding of the recommendations made? Shouldn`t we be aware of the philosophies of the orthodontists who patients are referred to, so that we can assist patients with the decisions regarding orthodontic treatment? Other than handing out referrals for orthodontists and maintaining orthodontic patients at recalls, though, we are really out of the information loop. So "brace" yourself (I could not resist) - here comes a refresher course on orthodontic terms, philosophies, and commonly used appliances.

The timing of orthodontic treatment falls into one of five stages, and the first three classifications below are considered early treatment.

* Deciduous dentition - Entire dentition is deciduous, six months to six years.

* Early mixed dentition - Eruption of the permanent incisors and first molars, six to nine years of age.

* Late mixed dentition - Eruption of all permanent incisors including cuspids and eruption of first molars, nine to 11 years of age.

* Early permanent dentition - All permanent dentition, age 11 to the end of the growing years.

* Mature adult dentition - All permanent dentition after growth has ceased.

Orthodontic philosophies

With treatment dependent on so many factors, orthodontics require some very complex decision-making when deciding on individual treatment plans. However, there is general agreement among orthodontists on the following principles:

* The goal of orthodontics is to correct and stabilize the occlusion while providing a well-proportioned face.

* Patients should be seen by age seven. At that time, they are in early mixed dentition stage. The posterior occlusion is established when the first molars erupt. Occlusion class can be assigned and the severity of the malocclusion can be determined. This gives the orthodontists a window of opportunity for proper treatment planning.

* Severe Class II malocclusion such as severe protrusion and deep bite can benefit from early treatment. If teeth are tipped excessively, they place stress on the alveolar bone and adversely affect the soft tissue.

* Mandibular prognathism is a strong consideration for early treatment. Severe Class III malocclusions may need to be surgically treated in the adult dentition stage.

The timing of treatment is a significant area of disagreement among orthodontists. The two schools of thought about treatment timing are two-phase treatment and one-phase treatment. Two-phase treatment has two stages: Phase I therapy and Phase II therapy. One-phase treatment uses Phase II therapy only.

At this time, no conclusive research dictates when to use one-phase or two-phase treatment. So for now, orthodontists` philosophies are based on their educational background and clinical judgment. Studies show that proper occlusion can be achieved whether a one-phase or two-phase treatment plan is followed. A more detailed description of the two treatment philosophies follows.

One-phase treatment involves only Phase II therapy to balance the underlying skeletal deficiencies and to align the dentition with the use of braces and fixed orthodontic appliances. One-phase treatment can begin at anytime from the dental age of 10 through the adult years. In cases that involve severe dental or skeletal discrepancies, one-phase treatment advocates will use two phases of treatment and start treatment at an earlier dental age.

The advantages of one-phase treatment are that it takes less treatment and offers lower costs to patients. The Phase II therapy resolves most cases, but will require fixed appliance therapy. The primary disadvantage is that the risk of low levels of compliance with oral hygiene and the use of appliances is greatest when one-phase treatment occurs during the teenage years.

Two-phase treatment consists of Phase I therapy, which uses limited fixed and/or nonfixed appliances to balance the underlying skeletal abnormalities, and goes on to Phase II therapy, which uses braces to align the dentition. The thought is that, by using Phase I therapy, the severity of the malocclusion is lessened, providing a simpler case for Phase II therapy. In some mild cases, proponents of two-phase treatment feel that using Phase I therapy can eliminate the need for Phase II therapy.

Two-phase treatment is a more aggressive approach in that treatment starts at an earlier dental age and uses more orthodontic appliances. Studies show that Phase I therapy can correct Class II molar relationships, decrease overjets, and cause posterior maxillary tooth movement.

A primary advantage of phase-two treatment is that it`s considered beneficial for severe Class II malocclusion, and significant skeletal changes occur with the use of nonfixed appliances. In addition, compliance is higher because treatment begins in preadolescence, and it enhances self-esteem at a crucial social time. Phase-two treatment also manages insufficient arch length. Normal growth can be used to correct mild malocclusions before they become severe. The change in skeletal deficiencies results in a decreased amount of treatment time during the second phase of therapy. The appliances used in the first phase eliminate damaging habits such as tongue thrusting.

Opponents argue that dental movements, such as posterior maxillary movements, can relapse. In addition, early treatment can result in damage if the case is misdiagnosed and early treatment is conducted unnecessarily. The total treatment time for two-phase treatment is longer and often is more costly than one-phase treatment. Some argue that Phase I therapy can diminish compliance of a child facing Phase II therapy (orthodontic burnout). Finally, two-phase treatment has no documented long-term benefits.

The stability of the final occlusion in one-phase versus two-phase treatment is being researched. Preliminary data show that there is little difference, if any, in final occlusion outcome between one-phase and two-phase cases. Stability in both forms of treatment can be negatively affected long term by detrimental oral habits (mouth breathing, tongue thrusting) and functional problems (growth, development, and muscle function). These unpredictable factors make studying long-term stability difficult.

Orthodontic appliances

The two types of orthodontic appliances are nonfixed as used in Phase I therapy and fixed as used in Phase II therapy. Nonfixed orthodontic appliances are used primarily by proponents of the two-phase treatment philosophy, but they are also used in severe cases by proponents of the one-phase treatment. Severe cases include those individuals with extreme dental or skeletal discrepancies, such as cross-bites, excessive front-to-back discrepancies, large overjets, and underbites.

The following orthodontic appliances are some of the most commonly used appliances during the dental ages of seven to 10, depending on the individual case.

Y Headgear - Headgear is used in cases of significant protrusion and works in two ways: by inhibiting forward growth of the maxillary jaw, and by moving the molars back to create space for posterior movement of the maxillary anteriors. Headgear uses braces for attachment. Headgear is the counterpart to the lip bumper for the maxillary arch (see lip bumper below).

Y Herbst appliance - The Herbst appliance is fixed with bands or bonding material to both the maxillary and mandibular arches. This appliance is used in cases of excessive protrusion (Class II) and works by moving the maxillary teeth distally and by promoting growth of the mandible (this has not yet been supported by research).

Y Lip bumper - The lip bumper, used on the mandible, can be fixed or removable. This appliance is used in Phase I therapy for cases of significant mandibular crowding. The lip bumper pushes the mandibular molars distally to create space. It is thought to lessen the disruptive forces created by the cheeks and lips (this claim has not yet been supported by research).

Y Lower-lingual holding arch or space maintainer - The lower-lingual holding arch appliance is used to maintain arch length when deciduous teeth are lost prematurely. It is used at the mixed dentition stage.

Y Maxillary expander or rapid palatal expander - The maxillary expander may be fixed or removable. A fixed expander causes skeletal widening of the palate at the midline suture and is used when two or more posterior teeth are in crossbite. A removable expander just tips the teeth involved in the crossbite but does not make skeletal changes. The removable version of the expander is used when there is sufficient width of the palate.

Y Nance appliance - The Nance appliance is fixed onto the maxillary arch and runs across the palate. The purpose of this appliance is to stabilize the molars, preventing them from moving forward.

Y Pendulum appliance and distal jet appliance - Either of these two fixed appliances is used to correct Class II malocclusion. Neither the pendulum nor the distal jet appliances influences growth of the maxillary arch; rather, they work by moving teeth. These appliances are fixed to braces and are used at the beginning of one-phase treatment.

Call the orthodontists that your office refers to and ask to meet them to discuss their philosophies. That way, you can also support your orthodontists with your understanding of their philosophies. Who knows, you may be able to whet your appetite for knowledge with a free lunch!

Barbara Alexander, RDH, practices in Buffalo Grove, Ill. She is also the owner of Day and Night Desktop Writers, a graphic design company which writes and designs brochures, business stationery, dental newsletters, and office manuals. She thanks Dr. Jerry Jarosz, an orthodontist in Buffalo Grove, Ill., for assistance with the article. She may be contacted by e-mail at dayandnight1@ hotmail.com.

Orthodontic terms

The following terms are probably familiar, but, to patients, these terms may as well be a foreign language. Your patients may ask you to explain these terms or to confirm the existence of specific orthodontic problems.

The three angle classifications are:

* Class I malocclusion - Normal first molar relationship, teeth crowded and/or rotated.

* Class II malocclusion - Mandibular first molar distal to maxillary first molar. Relationship of the other teeth to the line of occlusion varies depending upon the individual.

* Class III malocclusion - Mandibular first molar mesial to maxillary first molar. Relationship of the other teeth to the line of occlusion varies depending upon the individual.

General terms in orthodontics include the following:

> Anterior open bite - A vertical gap between the maxillary and mandibular anteriors.

> Bilateral crossbite - The posterior maxillary dentition occlude inside of the mandibular posterior dentition.

> Crossbite - The maxillary dentition are positioned lingually to the mandibular dentition.

> Deep overbite - The maxillary anteriors cover the mandibular anteriors excessively when biting.

> Dental discrepancies - Anterior crossbite, crowding, and ectopic eruption/impactions all fall under this category as opposed to skeletal discrepancies (defined below).

> Eruption guidance - The strategic removal of primary dentition in order to guide the eruption of the permanent dentition.

> Open bite - A vertical gap between the maxillary and mandibular dentition when biting.

> Orthodontics - The dental specialty that prevents and treats malocclusion, considering the growth and development of each individual.

> Overjet - The amount that the maxillary anteriors protrude beyond the mandibular anteriors in a horizontal direction.

> Skeletal discrepancies - Anterior-posterior relationship discrepancies, posterior crossbites, and vertical discrepancies.

The hygienist`s role

While hygienists do not create a treatment plan for their orthodontic patients, we do play an important role in helping patients understand the details of their treatment and its importance to their overall dental health.

Here are some recommendations that you can give your patients or parents.

* Alert them to the fact that unattended orthodontic problems can lead to impairments in speech and chewing, loss or trauma to teeth, and, in some cases, soft tissue and TMJ problems.

* Encourage them to seek a couple of opinions. You must discuss this with your boss. The doctor may only feel comfortable with referring to one orthodontist in the area.

* Suggest that parents ask questions about cost, usual treatment time in cases like theirs or their child`s, the treatment plan, and what will happen at each appointment.

* Recommend that parents listen to their child`s feelings about the orthodontist. A child cannot make such an important decision, but considering their feelings may make for a more compliant patient and a happier dental experience.

* Tell patients to use the orthodontist that they feel the most comfortable with, based on the proposed treatment plan and doctor`s personality.

* Let your patients know that most orthodontists will achieve the proper occlusion in the end.