45.) Class III – Anomalies Types-Etiology-Effects-Diagnosis-Prognosis
Within the group of class III- anomalies there are types, clearly can be differentiated.
But they also have some aspects in common. This is the reason why Blimer in this respect was speaking about, “ Progener Formenkreis”, which mean circle of prognathic forms.
According to the different types there are correspondingly different etiological factors causing those types. For the sever mandibular prognathism, for instance, heredity is the primary etiological factor.
Size and location of the tong might be another one. In progenic force bit more less accident occlusal interferences of antagonistic teeth are the causing factor. In other cases, such as maxillary retrognathism we find instead of over development of the mandible a growth deficit of the maxilla causing the anterior crossbit.
There are several factors which can be blamed for this deficit, cleft lip and plate is one of them.
The essence of these type is, that the mandibular apical base during the development has gained dominance over the maxillary apical base.the apical base relationship is shift to a reverse ratio.
This group of anomalies, which can be characterize by the dominance of the mandible, have functional as well as esthetic effects.
As the masticatory function depends on the type of occlusion, it is understandable, that and anterior crossbite leads to a wrong occlusal guidance and most have influence on the chewing mechanism, the function loading of certain of teeth as well as of the temporomandibular joint. Thus the masticatory can be impaired caused by profile characteristics of the
Class III- anomaly.
Within the diagnosis the differentiation of types has to be stressed.
This is reached by anamnestic data, clinical investigation, particularly with regard of soft tissues function, habits, parafunctions and the breathing mechanism, and most important cephalometrics. Special attention has to be paid to criteria, which differentiate the degree of severity of the anomaly, and variables having predicting power of both growth intensity and direction.
These criteria are also relevant for the prognosis, which is one of the most important factors for treatment planning in those cases.
Esthetic and psychological aspects in patients with sever class III – anomalies
In an own study the esthetic effect of different types of profiles has been investigated.
Class III – profiles on the average are felt as less beautiful
compared to class I – profiles – this was a significant difference – but they are not significantly worse than class II – profiles. Inspite of this, class III – patients are rated as more unlikable compared to class II.
The type of profile has been found to have a specific expressional meaning in terms of dominance and aggressivity. This result has to be explained from biological sources, leading back to dynamic expressional jaw movements and their specific meaning in the animal world as well as with humans being. Artists, like painters know about this effects and used it repeatedly, as will be show by examples.
From another study we know about the social problems of patients with sever class III – anomalies. People with disfiguring anomalies have less chances for social contacts, particularly for closer and more intimate relationship.
As they feel or fear a handicap they develop a worse selfesteem and run according to a mechanism of self-fulfilling prophecy more and more into trouble.
That means, many of our patients with severe disfiguring anomalies suffer psychologically from their appearance.
Orthodontists and other professionals dealing with such patients have to keep this aspects in mind and, besides providing an excellent orthodontic and surgical treatment, have to take care of the patients´ psychological situation by showing understanding and giving support. The treatment demand of those patients is fully justified.
Treatment approach for class III – anomalies
Initially the general and the specific treatment objective will be considered.
Then an overview will be given about the appliances, which could be used in class III – cases. Depending of the phase of treatment and the concerning philosophy of orthodontic schools removable plates, different types of functional orthopedic appliances, including Fränkel´s function regulator, double plates and of course fixed multibracket appliances are said to be effective in the treatment of class III – cases, whereas the chin cap and the Delair´s appliance, the face mask, are deemed as complimentary means. The value of these appliances of class III – therapy will be indicate from the own point of view.
The indication of extractions and the rules, which should be kept in mind regarding class III – cases, is dealt with in other chapter, accomplished by considerations about the benefit, which could be expected from additional myofunctional therapy in certain cases.
This will be followed by considerations about the treatment time. We try to answer the question, which developmental phase is most suitable to start an orthodontic therapy in such cases.
Particularly the concept of early treatment will be questioned.
The main time for beginning a treatment is the late mixed and the early permanent dentition. Examples for early as well as for regular treatment will be demonstrated.
This will be followed by a chapter dealing with class III – therapy in adolescent and adults. Here orthognatic surgery, or better the combine treatment is on the forefront. Methods of treatment planning, surgical producer and specific problems will be dealt with. The conservative orthodontic treatment in adults and its indication is another subject within this chapter. This will be show by case reports too.
Finally questions about stability and retention will be asked and answered.
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