Chapter 6

Diagnosis and Classification

6.1 Introduction

In orthodontics, much confusion exits over the concept of diagnosis and classification. In this chapter, both these subjects are defined and elaborated on, but first the procedures involved in the diagnosis are discussed. The formulation of the diagnosis and the use of the Angle Classification are also viewed.

6.2 Diagnostic procedures

In Chapter 5 a survey was presented on the quantity of data that may be obtained from the different methods of investigation. In the ambit of this book all the relevant details—within limits—that can be determined under each heading were described and enlarged upon. However, the amount of information that may be actually obtained from an individual patient is limited, because by no means all possible abnormalities occur together. Nonetheless, the examination of each patient provides so much information that these data must be arranged in such a way that an overall picture emerges.

The integrated assessment of data obtained from various modes of enquiry has been referred to in the facial analysis (5.2.1) and the Apical Area Analysis (5.5), and a comparable method of integrated assessment also needs to be employed for other information collected. Equally, different methods of enquiry can lead to important separate findings that, when combined and integrated, will have a greater value because they make a particular picture more comprehensible or provide extra information. For example, a radiograph of the mandible can reveal much information about the internal structures, and the dental cast will give details of external aspects such as a spatial proportion in the mandibular dental arch. Alternatively, by palpation, a great deal of the surroundings of the jaw may be studied. However, none of these sources will provide, on its own, such a good picture of the situation that may be obtained if the data is combined and integrated from all the sources used. It can therefore be said that a correct synthesis of the results of all analyses leads to such a description of the anomaly that adequate access to the process of treatment planning is provided.

It is not always easy to correctly evaluate and integrate individual items of data. One should recognize significant combinations, taking in what is efficacious, rejecting what is surplus and seeing which information is still lacking. This can lead to further study of the collected data and/or to more investigation. As experience grows, more of the accompanying cognitive processes will run easily, because more often the correct line to take through all the data will be readily found. Without practice one cannot learn, for instance, or to keep an eye open for all necessary combinations that should be investigated, or to assess the information more specifically so as to verify conjectures that are emerging. Theoretically, these activities eventually lead to the formulation of a diagnosis.

An orthodontic diagnosis is, by its very nature, descriptive. In the diagnosis the different aspects that can be recognized in anomaly are integrated and appraised according to their relative importance. For the formulation of a diagnosis, a particular systematic terminology is followed. In addition to morphological aspects, anomalous functional matters are included.

6.3 The concept “Orthodontic diagnosis”

As stated in Chapter 2, an orthodontic anomaly is almost never a pathological condition, but an unharmonious combination of variables that can be distinguished in the face and dentition, which in themselves may not fall outside normal distribution. “Malocclusion” is a much used term for an orthodontic anomaly which only conveys that the occlusion is incorrect; there is no talk of a sick occlusion or a disease of the occlusion.307 Pathological conditions seldom play a part, as the average orthodontic patient is not sick, has no pain and does not usually suffer physical or mental discomfort. Of course this does not apply to congenital facial anomalies such as clefts, nor to the consequences of trauma to the head and dentition.

The concept of diagnosis therefore means something different in orthodontics, than it does in general medicine and dentistry. Furthermore, few orthodontic anomalies have a specific cause and, if recognized, its removal does not automatically result in a cure. Even the type of therapy employed may have little connection with the cause.

A good diagnosis is important because through it a foundation is laid for deciding whether or not to treat and, if so, what the preferable method is and when it should be initiated.

Good diagnosis calls for a fully developed power of observation and an analytical mind, with experience playing a large part. Most mistakes in orthodontics are not due to a lack of technical skill in executing the treatment, but rather to making an incorrect or incomplete diagnosis on the basis of which inappropriate therapy was undertaken.

In an orthodontic diagnosis, norms and values handled by the dentist are important; some are objective, others subjective. This particularly applies to aesthetic judgements regarding the face and teeth as much latitude has to be left for the patient and his parents to make their own decisions. For example, particular features may be characteristic in a family who do not regard them as disturbing, while the same features appearing in another family/>