Oct. 9 (Tue.), 2001

4. Principles and objectives of early treatment

At the Sendai Class III Symposium, the following principles of long-term occlusal management were proposed as part of a comprehensive approach to Class III treatment:
1. Deal with abnormal changes in individual growth.
2. Manage the risk of developing facial asymmetry, TMD, etc.
3. Clarify goals of treatment and case management at each stage of development.
4. Perform treatment at an appropriate time to maximize efficiency.
5. Provide patient-oriented care with short treatment time and long-term management.
6. Employ an interdisciplinary approach including orthognathic surgery.

The following objectives of Phase I treatment were also established:
1. Evaluate oral hygiene status and institute caries prevention measures accordingly.
2. Eliminate functional mandibular displacement and stabilize the mandibular position.
3. Correct three-dimensional disharmony of jaw relationship as much as possible.
4. Correct midline deviation and maintain the correction.
5. Establish a correct incisor relationship to obtain anterior guidance in the permanent dentition.
6. Obtain equal posterior stops on all posterior teeth and Class I molar relationship.
7. Obtain adequate spaces for eruption of buccal teeth.
8. Improve the functional environment by correcting habits, low tongue position, mouth breathing, lip incompetence, etc.

In addition, the following approach to Phase I treatment was recommended.
1. Use non-extraction therapy as much as possible.
2. A facial mask is often used in combination with a partial multi-bracket appliance.
3. Avoid excessive lingual tipping of the lower incisors in correcting anterior crossbite.
4. Finish treatment in the shortest time possible (about 1 year) and avoid unpredictable treatment.
5. Assess caries risk to prevent the development of new caries lesions.
6. Improve functional environment as needed.

This is a nice summary of Class III treatment, though the underlined parts are questionable in actual clinical practice.
The following orthodontic appliances were recommended for correcting incisor relationship in Phase I treatment:
1. Lingual arch
2. Functional appliance
3. Partial multi-bracket appliance
4. Chin cup
5. Facial mask or protractor

In addition, the following auxiliary appliances were recommended:
1. Lateral expansion appliance of (1) rapid type or (2) slow type
2. Class III elastics
3. Sliding plate
4. Incisal guide plane

It was also proposed that the following points be considered in Phase I treatment:
1. Select a mechanics that is efficient in correcting incisor relationship.
2. Avoid excessive lingual tipping of the lower incisors.
3. Try to correct lateral mandibular displacement (skeletal asymmetry), if mild to moderate, as much as possible.

By what criteria can the anteroposterior jaw relationship and lateral mandibular displacement be evaluated? It may be difficult to assess these accurately prior to treatment in some cases. Not only individual differences but also familial and social environments must be taken into consideration.
The difficulties and problems encountered in making these assessments will be discussed later, but these recommendations constitute an excellent summary of the principles of long-term occlusal management and approach to Class III treatment.

Now the model (flow chart) of Class III treatment presented at the Sendai Class III Symposium will be reviewed.