Dr JT (Koos) Marais

Treating Chronic Orofacial Pain by Root Canal Treatment: Two Case Reports

Introduction

Chronic orofacial pain is a pernicious, debilitating condition affecting millions of people worldwide.

It is often misdiagnosed and over- or under-treated. When over-treated, iatrogenic damage follows and resources are wasted, and when under-treated, patients are denied care. In both instances patients are caused considerable anxiety, adding to the existing, significant emotional stress.

All human pain has an emotional, psychological component and unfortunately in a few cases this component dominates, rendering physicians and surgeons to dismiss some “real” cases, with organic pathology, as of psychosomatic origin.

In some cases the cause of chronic orofacial pain is one or more diseased dental pulps with relatively obscure or unclassical characteristics. In other words the patient experiences symptoms unlike that of a typical toothache or abscess. Often these symptoms are vague, paroxysmal in nature, and sometimes, not always, of relatively low intensity. Radiologically the view is “normal”. In these cases, when the treating practitioner is skilled and or fortunate enough to correctly diagnose the disease, and treat definitively, the chronic orofacial pain will immediately disappear. In this sense it represents the best case scenario for the chronic orofacial pain patient. The treatment of all other chronic orofacial pain patients are considerably more complex and less successful.

There are a myriad of other causes of orofacial pain. All of these must be excluded before the dentist or endodontist embarks on root canal treatment or even a series of treatments. This forces the making of a definitive diagnosis.To make matters extremely difficult, the causes of many cases are simply idiopathic.

 There are a few diagnostic rules to consider:

1. The majority of pain in the orofacial region is caused by dental tissues; these are the dentinal, pulpal and periodontal tissues. Consider the most obvious cause first.

2. It can be notoriously difficult to diagnose dental pain. Examples are cracked roots, incomplete cuspal fractures, resorption and low grade or sub-clinical, peri-radicular preriodontitis.

3. Pain of dental origin can present in tissue distant from the causative site, that is pain can be referred, one form of heterotopic pain. The converse is also true. Disease in other tissues such as the brain, heart and maxillary sinuses, can present as toothache. This is called non-odontogenic toothache.

4. There can be more than one cause for dental pain. When these causes are associated with teeth situated close together, diagnosis becomes even more difficult.

5. Vitality testing of teeth is unreliable because false positive and false negative reactions are quite common.

6. There is no technological silver bullet in the diagnosis of orofacial pain. The only advance in the diagnosis of dental pain since the discovery of radiography has been the introduction of cone beam tomography. Its real value has not been proven yet.

7. There are other organic causes of orofacial pain, including sinusitis, bruxing and other occlusal disturbances, hypoglycemia associated with occlusal disfunction, cardiac ischemia, carcinomas and sarcomas, viral infections such as herpes zoster (shingles), and dry mouth glossitis and stomatitis.

8. There are a number of neuropathological diseases which are extremely difficult to exclude from a differential diagnosis. A well known example is trigeminal neuralgia.

9. There are a small number of cases of psychological pain.

10. A misdiagnosis can cause more harm than the original condition itself, because of subsequent over-treatment or wrong treatment.

Two cases illustrating the dangers and pitfalls of diagnosis and successful treatment of chronic orofacial pain with root canal treatment are presented.

Case1

The patient, a 50 year old lady with a complex medical history of fibromyalgia and rumatoid arthritis was referred for re-treatment of the root canals of the right first maxillary molar (16) (Figure 1).

She volunteered the information that she had been suffering from pain in the orofacial region for fifteen years. She also had to have the contra-lateral tooth, the left maxillary first molar (26) extracted, one year prior to the current consultation, because of unsuccessful root canal treatment. Because of lack of function she was desperate not to lose teeth on the left side. She gave a history of pain upon biting, and sensitivity to extreme temperatures on the right side. 

Examination showed the 16 tender to percussion but with no reaction to hot or cold temperatures. The mandibular first and second molars, (46 and 47), restored with porcelain veneered to metal crown and amalgam, respectively, reacted severely to cold and heat testing. The pain on the 47 lingered markedly.

Radiographic examination (Figures 2 and 3) showed the amalgam restoration on the 47 to be in close relationship to the pulp and a diffuse radiolucency peri-apically to the 46.

A diagnosis of 1. chronic peri-radicular periodontitis predisposed by ineffective endodontic treatment of 16, 2. chronic irreversible pulpitis of 47 due to large restoration and, 3. chronic peri-radicular periodontitis and chronic pulpitis predisposed by the prosthetic crown on 46, was made.

The patient was informed about the condition and advised that conservatively speaking the only treatment possible was re-treatment of the root canals of 16 and root canal treatments of 46 and 47. She was advised that the mesio-buccal root of the 16 would present extreme difficulty and would in all probability require surgical intervention in the form of apicectomy surgery.

The root canals of the 16 were indeed retreated and the apicectomy carried out (Figure 4).  

The root canals of the 46 and 47 were treated (Figures 5 and 6).

At the final appointment the patient confirmed that all pain had disappeared.

Case 2

The patient, a thirty five year old female dentist, presented at the endodontic clinic with the main complaint of severe pain of three month duration in the left maxillary and right mandibular areas, the latter a continuous dull ache, present at the moment of the consultation. She requested root canal treatment of the 47, the tooth adjacent to the fresh extraction wound, because she now believed that tooth to be the main culprit of her condition.

She volunteered the information of an extraction, one week previously, at her request, by a colleague, of the right mandibular third molar tooth (48). Since the extraction the pain in the mandible had worsened. In addition to the pain already mentioned she also experienced tenderness of the right maxillary area, inferior to the nose, thus complaining of pain in three quadrants. She volunteered the information of apical surgery in the maxilla a few years previously.

Extra-oral examination showed tenderness to touch of the soft tissues overlying the anterior maxillary areas. All other structures appeared healthy.

Intra-orally the mucosa overlying the apex of the the right maxillary lateral incisor was slightly red and tender to palpation. The scar tissue of previous surgery was visible in both the areas of the maxillary canines, indicative of a wide flap. The fresh extraction site of the 48 appeared to be healing normally.

The occlusion was compromised due to two absent maxillary and one absent mandibular molar teeth and subsequent drifting and rotation.

The mandibular second right molar (47) was not tender to percussion, but responded briefly to cold testing. The maxillary right lateral incisor (12) reacted severely to hot and cold tests.

Radiographically the 47 appeared normal (Figure 7). 

There was slight evidence of widening of the periodontal ligament space of the 12 (Figure 8).

The maxillary left l canine tooth (23) showed previous, incomplete endodontic treatment with some radiolucency associated with the apex (Figure 9). The maxillary left incisor’s apex appeared flat or square as might be seen after accidental damage by a bur during the previous apical surgery to the 23.

Diagnosis: After careful consideration the 47 was considered to be normal in all respects but subject to referred pain from an acute pulpitis and peri-radicular periodontitis of the 12. This was discussed in detail with the patient, a colleague, as mentioned above. The 23 was diagnosed with peri-radicular periodontitis due to ineffective endodontic treatment and the 22 was thought to be suffering pulpal necrosis due to iatrogenic injury.

Administration of local anaesthesia to the 12 immediately brought relief of the dull ache the patient had been experiencing in the site of the 47, confirming the diagnosis. The root canal of the 12 was accessed, bringing about profuse bleeding for a few minutes, further confirming the diagnosis. The canal was prepared, cleaned and dressed with standard techniques. 

One week later the patient returned as scheduled confirming that she had been pain free on the right side of her face but was still experiencing pain in the left maxilla. After careful consideration and re-examination a diagnosis of recurring peri-radicular periodontitis of the 22 and 23 was made and these teeth were retreated and dressed. 

One week later, as scheduled, the patient reported that all pain had disappeared. Intra-oral examination confirmed the absence of ant signs of disease. The canals were obturated (Figures 10 and 11), the access cavities sealed and the patient dismissed.

Discussion

The patient described as Case 1 had experienced chronic orofacial pain for fifteen years. This was relieved with relatively simple endodontic treatment. This patient’s complex medical history, including fibromyalgia and rumatoid arthritis, might have been a contributing factor to her disease process or it might have been a factor in the decision making process of her treating practitioners. One should be careful to judge patients based upon their medical or even psychological conditions alone. Their orofacial structures should always be examined and viewed independently. Even patients with severe medical disabilities, complicated by the emotional and psychological complexities, can suffer chronic orofacial pain originating from the teeth and associated structures. It has been said before that the role of the endodontist (or dentist) in the managing of these patients is to diagnose and treat correctly, and rule out, not cause, confusion. (Marais, 2008) In this case this tenet eventually held true and the patient made a full recovery from her orofacial pain. 

This patient begs the question of how many patients are being treated for non-odontogenic forms of chronic orofacial pain when in fact the cause is odontogenic in nature.

 What has not been discussed is the patient’s unexpressed scepticism about dental procedures, having lost a tooth one year previously and also the ineffective root canal treatment on the 16, necessitating re-treatment and apicectomy surgery. The profession as a whole should perhaps reflect and consider the establishment of the speciality of endodontics (and orofacial pain) in South Africa, as in the rest of the world.

The patient described as Case 2, herself a dentist, was responsible for the decision to have her mandibular right third molar removed, believing it to be the cause of her chronic pain, of three months standing. This illustrates the complexity of orofacial pain, and the subjective nature of a patient’s experience even further. She then requested me to do a root canal on the adjacent tooth, the 47. Fortunately things turned out as it did. She already suffers from a compromised occlusion. The loss of another tooth may well have been a tipping point. I was able to make the right diagnosis firstly, because I took an independent and objective view. The clinical and radiographic view of the 47 did not fit the image of an irreversible pulpitis, especially in the light of the other sites of tenderness. Had I misdiagnosed, or even worse, simply accepted my colleagues’s diagnosis, I would have been guilty of treating the wrong tooth and leaving her in her condition of pain. The treatment of her 23 was also sub-optimal, with iatrogenic damage, perhaps, to the apex of the 22. 

Although the patient in Case 2 “only” suffered for three months, again the profession should pause and reflect. Has the time for the speciality of endodontics and orofacial pain not come indeed?