Because the adaptability of a system is primarily a genetic factor and decreases with increasing age, the most effective therapeutic measures are those aimed at the reduction of the harmful influences.
2 Fundamentals of the etiology of symptoms in the masticatory system
Every biological system is subjected to harmful influences of varying severity. The ones listed here represent only a selection of those which the dentist can demonstrate simply and repeatedly. These influences are assimilated by the system through progressive adaptation (connective-tissue reactions) or compensation (muscular reactions). As long as a system remains in this state, the patient will report no history of symptoms or functional disturbances. Only when the damaging factors exceed a certain threshold does regressive adaptation, or decompensation, accompanied by destructive morphologic changes and/or pain begin. By the time a patient comes to the dental office with symptoms, not only must severe influences already be present, but the mechanisms for adaptation and compensation must already be exhausted.
3 Equilibrium between influences and adaptation/compensation
A healthy biological system can be compared with a balanced set of one side are countered by the individual’s capacity for adaptation and compensation. The adaptive and compensatory mechanisms are genetically determined and therefore remain relatively constant, except for a gradual decline with age. For this reason, the equilibrium can only be disturbed by change on the side of the influences.
Progressive/Regressive Adaptation and Compensation/Decompensation
The patient population of a dental or orthodontic practice can be divided into three groups:
• “Green” group: The masticatory structures are either physiological or have undergone complete progressive adaptation. These patients have no history of problems, nor do they experience symptoms during the specific clinical examination.
• “Yellow” group: These patients have compensated functional disturbances and no history of problems. However, symptoms can be repeatedly provoked by specific manipulation techniques.
• “Red” group: Patients with complaints whose symptoms can be repeatedly provoked through specific examination methods suffer from a decompensated or regressively adapted functional disturbance.
In young patients, adaptation is based upon growth, modeling, and remodeling (Hinton and Carlson 1997). Modeling (= progressive adaptation) is the shaping of tissues by apposition and results in a net increase of mass. Remodeling (= regressive adaptation) is usually accompanied by a net decrease of mass. In adults adaptation depends primarily upon remodeling processes (de Bont et at. 1992).
4 Functional status of biological systems
A functional analysis should always be carried out before any dental restorative or orthodontic treatment is initiated. The patient’s most urgent needs are determined by which group of the patient population he/she is classified under. For patients with complaints (red group) a functional analysis should be performed to arrive at a specific diagnosis and to determine whether or not treatment h indicated and possible, and if so whether it should be cause-related or symptomatic. All other patients (green and yellow groups) have no history of complaints. If during a specific functional analysis with passive manual examination techniques, compensated symptoms can be repeatedly provoked in an otherwise symptom-free patient, the patient is classified in the yellow (caution!) group. Identification of these “yellow” patients is extremely important because of the therapeutic and legal implications. They make up between 10% and 30% of the patients in an orthodontic practice. Patients with compensated functional disturbances are also of special interest because tooth movement or repositioning of the mandible is always accompanied by stresses which increase the harmful influences on the system.
When faced with a compensated functional disturbance, the clinician has three basic options:
1. Referral of the patient because of the complexity of the problem.
2. Dental treatment without provoking decompensation. Here the dentist must be aware of the loading vector acting upon the system.
3. Treatment directed at the cause with subsequent definitive dental treatment monitored through on going functional analysis.
Functional Diagnostic Examination Procedures...
Besides a thorough case history, a modem treatment-oriented functional diagnostic concept is composed of three parts:
• Examination to determine the extent of destruction of the different structures of the masticatory system. This part determines conclusively whether or not there is a loading vector (= overloading of one or more structures in a specific direction).
• Treatment-oriented examination to reveal any structural adaptations (= progressive adaptations). Here thought must be given to distinguishing between progressive adaptation in the loaded structures and adaptation of the surrounding structures. As a rule, the former are desirable and require no treatment, whereas adaptations in the surrounding structures usually result in an increase of the load and restriction of movement. Adaptations of surrounding structures are always oriented in the direction of the loading vector and therefore impede treatment. Within the framework of an interdisciplinary treatment, it is the duty of the physical therapist to eliminate any adaptive conditions in the surrounding structures through manual therapy and measures to increase mobility. Without a permanent modification of habitual functional patterns, physical therapy will not be successful.
5 Schematic representation of the treatment-directed examination sequence
To establish a function-based, problem-oriented treatment plan, it is first absolutely necessary to gather specific information in a rigidly defined sequence. Our current concept has been tested and validated by more than 10 years of clinical experience. The three elements at its core are the reproducible determinations of destruction (= loading vector), structural compensations (= adaptations) and etiological factors (= influences). The first two elements require the examination techniques of manual functional analysis. At this time there is no practical alternative available to test for loading vectors and evidence of adaptations in the masticatory system. Because of their multiplicity and variety of origins, the influences can be only partially clarified within a dental practice. For this the dentist has at his/her disposal the techniques of clinical occlusal analysis and instrumented functional analysis (in the articulator). In functional diagnostics the latter serves only as a test of the inclusive information without knowledge of the individual loading vectors that may be present.
...and their Therapeutic Consequences
• The third part of the examination process seeks to identify all possible harmful influences, and for the dentist this is the most important part. It deals especially with finding evidence for causal relationships between any loading vector and the occlusion. The findings provide information as to whether or not the static and dynamic occlusions are contributing to the overloading of affected structures. In the discussion of whether treatment should be solely dental or interdisciplinary there are two basic points to consider: On the one hand, isolated treatment of the masticatory system also affects the structures that allow movement (Lotzmannetal. 1989. Gole 1993), while on the other hand, treatment of the movement apparatus may also resolve problems in the masticatory system (Makofsky