Three steps to diagnosis

An orofacial pain evaluation should consist of the following steps:

• History taking
• Physical examination
• Diagnostic testing as needed

History

The most important step in the diagnostic process is history taking, which leads the clinician to develop an initial differential diagnosis. By talking to the patient and collecting the right information, the provider narrows down the list of all the possible conditions to a few more likely ones. For example, knowing the patient’s age and gender already provides a good pointer towards conditions that may be more or less frequent in that group. 

Signs and symptoms teach us about the underlying condition and its nature. When preparing for a medical appointment, be ready to answer many questions about the characteristics of the pain and the context in which it presents. Your answers probably hold the most valuable diagnostic information. A clinician is not only interested in what you are saying, but also how you are saying it. For patients seeking care for pain, the pain itself will be called the chief complaint and the details of its history are often referred to by providers as history of present illness, including:

• Location: Where is the pain felt? Is it always in the same place? Is it in a small spot or does it affect a broader region? Is there a spreading or movement component to it? Is it easily localized or is it more diffuse? Does it feel superficial, on the surface of the skin, or deep “in the bone”?
• Onset: When did it first start and in which circumstances? Were there any initiating factors? Was it a sudden or gradual onset?
• Progression: Has it changed since the onset? Is it getting better, worse or staying the same? Is it always the same when it occurs, or does it change?
• Frequency: Is it constant or intermittent? How often does it occur?
• Duration: How long does the pain go on?
• Timing: Is there a time of the day when it is usually worse? Does it present at the same time each day? Are there periods of remission, times when you feel nothing?
• Quality: What does the pain feel like? Which words could be used to describe it? Is it sharp, dull, throbbing, shooting, electric shock-like, burning? Is there an emotional component?
• Intensity: Is it mild, moderate or severe? How would it be rated on a scale of 0 to 10, being 0 no pain and 10 the worst pain possible?
• Interference: Does it disrupt sleep? Does it affect the ability to perform daily activities?
• Aggravating/Alleviating factors: What makes it better and what makes it worse? Is it affected by physical activity, light, noises, jaw movements, body position, temperature, touch, sneezing/coughing? Does it respond to over-the counter analgesics or other medications?
• Associated features: Are there other signs or symptoms present before, during or after the pain? Are there any appearance changes, for instance redness, swelling, tearing or sweating? Is it predictable? Can you feel or sense it coming on? Are there other changes in vision, movements, sensation?
• Prior treatments/tests: Were other providers consulted? What therapies have been tried and what were the results? Are there any prior imaging, labs? If so, what were their findings? What medications have you taken, at what dose, for how long, and what were the effects? It is clear that the pain itself is where most of the attention of the patient will tend to focus; however, it is important to think of the whole person and the conditions in which the problem is presenting. The history can also uncover contributing factors that can help to understand the origin of the pain as well as to guide the therapy. Fundamental pieces of the puzzle are also frequently found “thinking outside of the box”.
• Medical history: Are there any other medical conditions? How are they being addressed? Are there any medications, vitamins or supplements being taken? At what doses and for how long have they been taken? Has there been any trauma? Are there any other pains throughout the body?
• Family history: Are there other cases of similar problems in the family? Are there any cases of auto-immune disorders, cancer, pain disorders?
• Habits: What are your health habits: exercise, diet, water, tobacco, caffeine?
• Oral parafunctional habits: do you have issues with teeth clenching or grinding, biting objects such as fingernails, lips, cheeks, gum chewing, etc.?
• Sleep: What is the typical sleeping routine? How many hours? Is it restorative? Is there difficulty falling or staying asleep? What is your typical sleeping position?
• Psychosocial history: What is the patient’s occupation, marital status, family dynamics? What is the level of psychosocial stress? Does the patient have a support system, coping strategies? Are there diagnoses of anxiety, depression or other mood disorders and how are they being addressed? Have there been traumatic life events? 

Physical exam

After the history taking, the clinician should have generated a mental list of the possible conditions that could be going on. The physical examination will serve to confirm or refute such hypotheses and guide the process of diagnosis. The trained professional may be able to gather further information beyond what is volunteered by the patient, starting from general appearance, affect, posture, gait, speech, and non-verbal communication.

One of the major goals of the physical exam is to duplicate the chief complaint, as to better understand its origin and response to stimuli. For instance, dental pain is expected to be elicited or changed in a predictable manner by application of cold to the surface of the tooth; therefore a dentist uses a cold test and interprets the response to be normal or altered. To further illustrate this concept, in order to render the diagnosis of temporomandibular disorders (TMD), there should be a positive finding of pain or tenderness or range of motion of the involved muscles and/or temporomandibular joints (TMJ) on exam.

Since pain is a very personal and subjective experience, even during the exam, part of the findings will be subjective and dependent on the patient’s reports. If pain is provoked, it is crucial to discuss how the provoked pain is the same or different than what is typically experienced. The exam maneuvers may provoke pain; however, the clinician will be particularly interested in the facial pain you typically experience.

A head and neck exam should include visual inspection and palpation of masticatory and cervical muscles, TMJs, face, thyroid gland lymph nodes, teeth, mouth, and oropharyngeal mucosa. Changes in symmetry, shape, size, consistency, color, and texture should be noted. Range of motion of the head and neck should be evaluated for limitations and coordination, as well as associated pain or noises.

Cranial nerve screening evaluation is also valuable to evaluate motor and sensory functions of the major nerves supplying the face and neck. The teeth and supporting tissues should also be inspected for signs of disease, attrition, fractures, and occlusion.

Imaging and other diagnostic tools

No tests or exams are able to objectively confirm the source or even the presence of pain. In most cases, comprehensive history and examination will reach a diagnosis; however, there are clinical findings that require further investigation of the causes of specific signs or symptoms, especially to rule out disease or pathology underlying these features. For instance, neuralgia-type pains or neurologic deficits require brain imaging to rule out intracranial processes that could be causing the symptoms.

In a few conditions, diagnostic imaging can be used to confirm a clinical diagnosis, but in order to avoid unnecessary costs, exposure to procedure risks, and delay of therapy, it should only be ordered if the results will determine treatment recommendations. For example, in a typical case of TMD, the prognosis with conservative treatment is usually very good, and the clinical evaluation can assess with a reasonable degree of confidence that the condition is present. With computer tomography (CT), the diagnosis could be confirmed and graded in severity. The initial treatment strategy would be the same as if no imaging was done, but the patient would have been exposed to a dose of ionizing radiation and there would be associated costs to the healthcare system.

It is also important to keep in mind that no test is perfect and a certain degree of false positives (test indicates disease being present when it is not there) and/or false negatives (test indicates disease not present when it is there) is expected. The practical conclusion is that tests ordered without indication can generate misleading and meaningless results. Treatment based on the imaging findings alone is not adequate.

The response to treatment is also sometimes diagnostic. Based on the disease mechanism, there are specific drugs that seem to work so well that a significant response tells much about what is going on. It is the case of carbamazepine for trigeminal neuralgia. The rates of improvement in those cases are so high that it makes a diagnosis very unlikely if there is no significant response to the medication.

Another type of test that would have diagnostic and potential therapeutic benefit is nerve blocks, which help to locate the source of the pain and may provide relief as well. In the future, other tests may be developed to diagnose pain conditions.

Final considerations

Once all the information is collected, your doctor will develop a list of diagnoses that are the most likely reasons for your pain. Oftentimes there is a single diagnosis, one that fits the information that you are presenting. Sometimes the information is not clear, or the doctor is unsure, so a list of possible diagnoses or a general diagnostic category is given. This list or general category is reviewed and revised accordingly as your doctor obtains more information about you over time as your symptoms change and how you respond to initial treatments.

While the goal is to obtain the correct diagnosis right away, it can be a process occurring over a couple visits for more rare conditions. Arriving at an accurate diagnosis is a very important step to getting appropriate treatment.