Logic of medical language 2

What does a medical term mean

Let us ask ourselves what "meaning" means.

The Cambridge Dictionary says that "The meaning of something is what it expresses or represents". As simple as it may seem, the notion of "meaning" is rather generic and vague; there is still no commonly accepted answer to the question 'what does "meaning" mean?' Controversial theories of meaning have been advanced, and each has its advantages and shortcomings.

Traditionally, a term is displayed as a linguistic label meaning an object in a world, concrete or abstract. The term is thought to stand in the language as a representative for that object, e.g. ‘apple’ for the famous fruit. This term ‘apple’ will have the same meaning for the American child, the European adult or the Chinese elder, while the meaning ‘Orofacial Pain’ will have an intention for the neurologist, one for the dentist, and its own essence the unfortunate Mary Poppins.

Such expressions do not derive their meaning from representing something in the world out there, but how they relate to other terms within one’s world or context.

The meaning of pain for Mary Poppins is concerning what it can mean to her, to her conscience, and not about the external world: actually, asking the patient to attribute a numerical value to his pain, say from 0 to 10, makes no sense, has no meaning, because there isn't any internal normalizing reference to one's world or context.
The same is true for the neurologist who will give sense to the term 'pain in the right half face' solely in his/her context based on synapses, axons, ion channels, action potentials, neuropeptides etc.
The dentist will do the same, based on his/her context consisting mainly of teeth, temporomandibular joint, masticatory muscles, occlusion etc.

Concepts should not be neglected when it comes to 'differential diagnosis', because they could be sources of clinical errors. For this reason, we should reflect on the modern philosophy of 'Meaning', which began with Gottlob Frege, as a compound of "extension" and "intention" of a term that expresses a concept.

The concept has its extension (it includes all beings with the same quality) and 'understanding' (a complex of markers referred to the idea). For example, the concept of pain refers to many human beings, but it is more generic (great extension, but little understanding). If we consider the pain in patients who receive, for example, dental implants, in patients with ongoing inflammatory dental pulpitis and patients with neuropathic pain (atypical odontalgia) we'll have:

1. Increases in the mechanical perception threshold and the sensory perception threshold related to C fibres' activation.
2. Somatosensory abnormalities such as allodynia, reduced mechanical perception and impaired pain modulation in patients with atypical odontalgia.
3. No somatosensory alteration after implant insertion, although patients report mild pain in the treated region.

On ‘pain’ in general we can say that it has a wide extension and minimal understanding, but if we consider the type of pain mentioned above, for example in patients who receive dental implants, in patients with ongoing inflammatory dental pulpitis and in patients with neuropathic pain (atypical odontalgia), it becomes evident that the greater the understanding is, the smaller the extension.

The intension of a concept, on the other hand, is a set of aspects that distinguish it from the others. These are the characteristics that differentiate the generic term of "pain", which by articulating the intension of a concept automatically reduces its extension. Obviously, though, various generality scales can descend from a concept depending on which aspect of its intension is articulated. That is why we could conceptually distinguish pain in the TMJ from neuropathic pain.

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We can conveniently say, therefore, that the meaning of a term $\mathrm {S}$ with respect to a particular language $\mathrm {l}$ is an ordered couple, consisting of extension and intension, in a world that we will now call ‘context’.

Precisely with reference to the context we must point out that:

1. In the dental ‘context’, the term pain in the right half face represents a relatively large extension (so that it can be classified in an area that includes the ‘TMDs’) and an intension composed of a series of clinical characteristics perhaps supported by a series of instrumental radiological investigations, EMG, axiographic etc.
2. In the neurological ‘context’, however, the term pain in the right half face represents a relatively wide ‘_nOP’ extension and an intension composed of a series of clinical features, perhaps supported by a series of instrumental radiological investigations, EMG, somatosensory evoked potentials, etc.

This brief but essential argument allows us to ascertain how the linguistic expression of a medical language is vulnerable for a series of reasons; among these, please note semantic incompleteness, as well as how a meaning can be so different in different contexts that the terms ‘_nOP’ or ' TMDs' become ambiguous with these premises.