[MUSIC] Welcome. In this segment, we will discuss persistent idiopathic facial pain, or PIFP, a type of neuropathic pain disorder that is often challenging to diagnose. As we have done with previous orofacial pain disorders, we will now review some facts and figures regarding PIFP. Historically, the condition now termed PIFP was known as atypical odontalgia and or atypical facial pain, which is still used by some clinicians. The term atypical was perceived by many to have a negative connotation and therefore, this word is no longer used in the current terminology. The term PIFP is more accurately reflective of the clinical symptoms experienced by patients with this condition. Many consider PIFP to be similar to phantom limb pain and have used the term phantom tooth pain to describe this condition. The general prevalence of PIFP ranges from 0.03% to 1%. Similar to TMDs and trigeminal neuralgia, females are affected by PIFP more than males. Typically, onset is between 40 and 60 years of age. Our discussion now focuses on the clinical signs and symptoms associated with PIFP. As current terminology indicates, the pain experienced by patients with this condition is persistent. Patients often complain that the pain is always present, regardless of most potential modifying factors. This is in contrast to trigeminal neuralgia pain which typically presents as bursts of pain typically of short duration with intermittent pain-free periods. Patients with PIFP also typically have difficulty localizing their pain symptoms. A common scenario in a patient with PIFP is a complaint of toothache-like pain in a tooth or in several teeth or in a general region of the oral cavity or face. The patient often undergoes dental treatment, including root canal therapy and or extraction of the tooth or multiple teeth with perceived pain, with no resolution of symptoms. In fact, many patients experience increased pain and migration of symptoms to other teeth in the region after receiving such dental therapy. Typically, symptoms associated with PIFP may affect both the maxillary and mandibular teeth on the affected side without crossing over to the other side of the oral cavity or face simultaneously. It is not uncommon for PIFP symptoms to resolve on the affected side, and move to the other side of the oral cavity or face. PIFP symptoms typically do not follow a nerve distribution, which is in contrast to trigeminal neuralgia pain. Patients with PIFP symptoms often complain of diffuse radiating pain, especially if the symptoms involve the face. Persistent burning is a common descriptor of pain experienced by patients with PIFP. In my experience, the most common terms used by patients to describe PIFP symptoms are burning, gnawing, or a boring type of pain. Typically, symptoms of PIFP are not affected by most typical modifying factors of orifacial pain. However, stress appears to aggravate symptoms of PIFP. This supports the idea that access to components contribute to PIFP. Onset of PIFP is often idiopathic as the term implies, but can be associated with trauma to the orofacial region. A history of physical trauma to the face, jaws, or oral structures may be elicited in a patient with PIFP. As previously discussed, dental interventions are often sought and completed by patients with PIFP that usually result in no change or worsening of symptoms. PIFP is generally considered a diagnosis of exclusion. Physical exam findings typically reveal an absence of clinical neurologic deficits, most commonly demonstrated by a normal cranial nerve examination. It is imperative to rule out local dental pathology, as well as hard and soft tissue pathology, related to the maxillofacial structures in patients with expected PIFP. Typically, most patients with PIFP will not demonstrate evidence of local or regional maxillofacial pathology, and therefore, PIFP remains a diagnosis of exclusion. Here is a typical example of a panoramic radiograph of a patient with PIFP. Look closely at the posterior teeth in all four quadrants of the mouth. These teeth have received root canal therapy and have been restored with crowns as the patient experienced PIFP symptoms associated with all of these teeth without resolution of symptoms after treatment. In patients with PIFP, it is not uncommon for multiple teeth to have received root canal therapy in attempts by dentists to address the patient's pain complaints. It is important for dental providers to recognize the common signs and symptoms of PIFP in order to avoid unnecessary and irreversible dental treatment. Clinical evaluation of patients with suspected PIFP is similar to what is done for patients with trigeminal neuralgia. The first component of evaluation is to understand patient reported symptoms. We have discussed the signs and symptoms of PIFP that should alert the clinician to this possible diagnosis. A cranial nerve examination should be conducted for any patient with suspected PIFP. It is important to complete this exam in a thorough and systematic manner. Typically, cranial nerve exam findings are normal for patients with PIFP. However, if any abnormal findings are detected on cranial nerve exam, the clinician may include other types of orofacial pain condition conditions in their differential diagnosis. All patients who demonstrate abnormalities in cranial nerve examination should be promptly referred to an appropriate healthcare provider for further evaluation and management. An appropriate physical exam should be conducted for patients with suspected PIFP. Clinicians should complete a thorough extraoral and intraoral examination to rule out any local pathology that may be a source of the patient's pain. If clinicians are appropriately trained to perform an intraoral local anesthetic block, these should be considered for diagnostic purposes in suspected cases of PIFP. These are typically administered as a dental injection with dental anesthetic cartridges typically containing lidocaine with epinephrine. The peripheral nerves thought to be involved are anesthetized and the patient's response should be carefully evaluated. From a diagnostic perspective, if a patient with suspected PIFP receives substantial relief of pain after receiving a local anesthetic injection to the peripheral nerve thought to be involved, it may support a peripheral or local cause of the patient's symptoms rather than a diagnosis of PIFP. However, if the patient does not experience any symptom relief from the peripheral nerve block, then a diagnosis of PIFP is more strongly supported as this condition is considered to be a central disorder rather than a peripheral disorder. Dental imaging, such as periapical and panoramic radiographs, are used to rule out dental sources of pain, as well as local heart tissue pathology affecting the maxillofacial structures that may be a source of pain. Central nervous system imaging may be indicated for evaluating patients with suspected PIFP. The use of MRI and CT are used to rule out soft and or hard tissue pathology, and may be the source of the patient's symptoms, especially if the patient's cranial nerve examination is abnormal, or if the patient reports significant trauma to the skull, face, or jaw. The last part of our discussion will focus on management strategies for PIFP. Perhaps one of the most important strategies for management of this condition is patient validation, as they now know they have a true diagnosis. Patients with PIFP commonly report having consulted with multiple healthcare providers and undergone extensive diagnostic testing without receiving a diagnosis. This can be terribly frustrating for the patient as they suffer from pain on a daily basis with the perception that they have a mysterious condition that can't be treated. This can have a significant detrimental affect on the patient's overall condition by initiating or exacerbating access to components contributing to their pain condition. Very often patients have an overwhelming sense of relief when a healthcare provider who is knowledgeable about PIFP, renders this diagnosis and the therapeutic effect of this alone should not be underestimated. Referral to a Behavior Medicine Specialist may be indicated for PIFP patients, if they require more intensive behavioral therapy. Several types of pharmacologic agents have been used with success for management of PIFP. Tricyclic antidepressants such as amitriptyline and nortriptyline have demonstrated efficacy for management of PIFP. Anticonvulsants used for management of trigeminal neuralgia, such as gabapentin and pregabalin, have shown benefit in managing PIFP. Duloxetine a serotonin norepinephrine reuptake inhibitor, has been beneficial for management of PIFP. Adjunctive therapies for management of this condition include use of analgesics, and or topical lidocaine. All medications must be carefully titrated for maximal benefit and effective dosages differ for each agent in conjunction with individual variability. As stated previously, there is potential for significant side effects and patients using any of these medications must be closely monitored by the appropriate health care provider. This concludes our discussion of PIFP. We have discussed many aspects of orofacial pain throughout this entire segment. In summary, it is important to remember orofacial pain disorders are often complex. They can present with a wide range of symptoms that makes diagnosis challenging. Due to the potential severity of orofacial pain conditions, they often have a profound impact on a patient's quality of life. It is evident from our discussions that patients with orofacial pain conditions require comprehensive evaluation by appropriate healthcare providers. It is recommended to follow an evidence-based approach to management, especially in the context of the biopsychosocial biobehavioral model of disease. Clinicians who manage patients with orofacial pain conditions understand these disorders often evolve with time, and modification of management strategies is often required. Multidisciplinary care is frequently required for patients with orofacial pain conditions in order to successfully manage their conditions. I hope the information presented throughout the entire segment has helped you to gain a better understanding of orofacial pain, to appreciate the factors that influence the pain experience, and has increased your fundamental knowledge of specific orofacial pain disorders.
