J Oral Maxillofac Surg58:12-14, 2000, Suppl 2

Pain Management in the MultiplyOperated Temporomandibular

Joint PatientPeter Quinn, DMD, MD*

The International Association for the Study of Paindefines pain as “an unpleasant sensory and emotionalexperience associated with actual or potential tissuedamage or described in terms of such damage.”1 Oneof the most difficult challenges facing oral and maxil-lofacial surgeons in evaluating multiply operatedpatients, aside from considering reconstructive op-tions, is ascertaining appropriate pain managementfor these patients.

Nociceptive, Neuropathic, andSympathetic Pain

The multiply operated patient generally manifestsboth nociceptive and neuropathic pain.2,3 Nocicep-tive pain is the more classic pain, which is mediatedby discrete nerve pathways. Several steps are involvedin nociception, including transduction, during whichnociceptors in the peripheral tissue convert noxiousstimuli into electrochemical impulses. These stimuliare then transmitted to the spinal cord and centralnervous system (CNS) where they can be modulatedby a number of endogenous analgesic substances (eg,endorphins). Finally, the painful stimuli can be mod-ulated by the patient’s perception.

In contrast, neuropathic pain has no discrete neu-ropathways or neurotransmitters. Neuropathic painresults from injury to neurostructures within the pe-ripheral nervous system or CNS; injury to these nervesgenerates spontaneous action potentials, which resultin the perception of pain. The innervation to thetemporomandibular joint (TMJ) and associated mus-culature is both motor and sensory (Table 1), andchronic “neural barrage” from “overload” in the TMJcan actually generate cellular changes in the CNS.

Neurons in this activated nociceptive pathway arestimulated to synthesize peptides that evoke recep-tive field expansion and promote interneuronal inter-action that further heightens the pain experience.The “dynamic” status of the stimulated neuropath-ways leading to these changes is referred to as neu-roplasticity.

In addition, many multiply operated TMJ patientshave also developed sympathetically maintained painthat can be generated either peripherally or centrally,and that is characterized by autonomic dysregulation.There is now evidence that under the influence ofsome neurotropins, such as nerve growth factor, sym-pathetic neuronal sprouts appear at dorsal root gan-glia supplying damaged or irritated nerves.4 Any con-dition that then promotes enhanced sympathetic tone(eg, stress or hypoglycemia) could increase pain viathis mechanism. This sympathetically maintained painhas been referred to as reflex sympathetic dystrophy,causalgia, or complex regional pain syndrome.5 In theTMJ patient, the sensation is most often manifested asa burning pain or tactile allodynia in the preauricularregion. A stellate ganglia block can be both diagnosticand therapeutic when considering a component ofsympathetically maintained pain.

Preoperative, Intraoperative, andPostoperative Pain Management

Preoperative and IntraoperativeIn the preoperative state, it is critical to have a

baseline assessment of the patient’s current pain leveland medication needs. To assess the efficacy of ther-apy, it is useful to have some objective measurementof pain (ie, a visual analog scale with ratings of 1 to10) that the patient can repeat periodically to allowthe surgeon to evaluate responses to therapy.

The most important aspect of inpatient pain man-agement is the concept of preemptive analgesia. Re-cent studies suggest that the neurons that are stimu-lated by noxious stimuli to generate a “neuroplasticresponse” do so by inducing gene transcription,which results in the peptide formation previouslydiscussed. If some of these noxious stimuli could beblocked intraoperatively, then theoretically such “pre-emptive” analgesic techniques might reduce post-

*Chairman, Department of Oral & Maxillofacial Surgery, School

of Dental Medicine, University of Pennsylvania, Philadelphia, PA.

Address correspondence and reprint requests to Dr Quinn: De-

partment of Oral & Maxillofacial Surgery, School of Dental Medi-

cine, 5 White Building, University of Pennsylvania, 3400 Spruce St,

Philadelphia, PA 19104; e-mail: pdquinn@mail.med.upenn.edu

© 2000 American Association of Oral and Maxillofacial Surgeons

0278-2391/00/5810-2005$3.00/0

doi:10.1053/joms.2000.17879

12

surgical pain and perhaps reduce the possibility ofchronic pain in the multiply operated TMJ patient.6

Evidence from animal studies3 has suggested thatthe neuroplastic response can be modified or pre-vented by the following: 1) neuroblockade with localanesthetics, 2) administration of opioids, or 3) admin-istration of N-methyl-D-aspartate receptor antagonists(eg, ketamine HCl, dextrophan).

To disrupt the neuroplastic response, the agent hasto be administered before the noxious surgical stim-ulus. Therefore, use of large amounts of postoperativenarcotic analgesic agents may have a less beneficialeffect than the use of preemptive analgesic tech-niques. Of note, although inhalation general anesthe-sia induces a marked degree of CNS depression, itdoes not protect the CNS adequately from these nox-ious surgical stimuli.

PostoperativeThe mainstay of postoperative pain management is

the use of long-acting opioids given on a regularschedule.7 Dosing on an as-needed basis should beavoided when possible. During the immediate post-operative period, one should, at times, continue withneuroblockade using a long-acting local anestheticsuch as bupivacaine. After the use of intraoperativefentanyl, the most common management strategy isuse of a morphine pump (eg, 1 to 2 mg/h baseline,with 1 mg on demand every 7 to 15 minutes). Afterthe patients are able to ingest fluids orally, especiallythose who have had a presurgical history of opioiduse, opioid dosing is usually continued with one ofthe longer-acting drugs such as morphine sulfate oroxycodone. Transnasal administration of an opioidsuch as butorphanol tartrate (Stadol NS; Bristol-MyersSquibb, New York, NY) may prove useful in postsur-gical TMJ patients who have difficulty ingesting oralmedication. A gradual reduction in the baselineamount of the long-acting narcotic is usually at-tempted, with doses of short-acting drugs for “break-through” pain over a 4- to 6-week period.

In addition to the use of opioids, drug therapy forchronic pain can involve the use of tricyclic antide-pressants, nonopioid analgesics, and gamma-aminobu-tyric acid-ergic drugs such as gabapentin. Evidencesuggests that tricyclic antidepressants can have a ben-eficial effect on neuropathic pain in the multiply op-erated patient.8 The tricyclic drugs with mixed sero-tonin and norepinephrine reuptake inhibition (eg,amitriptyline) appear to be most effective for this typeof pain. For patients who report an inadequate re-sponse with the opioids, gabapentin can be used inaddition to a tricyclic drug. Gabapentin also appearsto have the ability to reduce pain associated withsome neuropathic states, including pain that appearsto be maintained sympathetically. Finally, nonopioidanalgesics, such as nonsteroidal anti-inflammatorydrugs, have not been very effective in the multiplyoperated patient.

Alloplastic Prostheses

Indications for this procedure are based on the factthat, theoretically, an alloplastic joint prosthesis af-fords the following advantages:

1. Lack of donor site morbidity2. Reduced intraoperative surgical time3. A potential for decreased hospitalization4. Immediate functional ability without the need

for prolonged maxillomandibular fixation5. Ability to maintain a stable occlusion postsurgi-

cally because of the lack of dimensional changein the implant, as opposed to potential remod-eling with an autogenous graft

6. Opportunity to manipulate the prosthesis designto discourage heterotopic bone formation

7. Opportunity to correct retrognathia and aper-tognathia simultaneously with rigid supportfrom a bilateral alloplastic prostheses

The relative contraindications for alloplastic replace-ment at this time are:

1. Allergy to the prosthetic materials2. Chronic infection3. Skeletal immaturity4. Systemic disease associated with increased sus-

ceptibility to infection.

Postoperatively, there is no period of maxilloman-dibular fixation and immediate function of the joint isencouraged. Postsurgical jaw motion is encouragedbecause evidence suggests that early mobilization canreduce postsurgical pain levels.9,10 However, in ourexperience, it appears that there may be a negativecorrelation between the total number of previous

Table 1. INNERVATION OF THETEMPOROMANDIBULAR JOINT ANDASSOCIATED MUSCULATURE

Trigeminal Nerve

Motor Sensory

Mylohyoid BuccalAnterior digastric Inferior alveolarMasseter AuriculotemporalPosterior deep temporalAnterior deep temporalMedial pterygoidLateral pterygoid

PETER QUINN 13

surgeries and the overall pain reduction; that is, pa-tients who have had more surgeries tend to reportless pain reduction after joint replacement than thosewho have had fewer surgeries.

Conclusion

It is important to have “reasonable expectations” intreating the multiply operated TMJ patient. It shouldbe stressed to patients preoperatively that some of thepain they are experiencing may be secondary to“nerve damage” and chronic pain pathways, and thusthis pain is unlikely to be ameliorated by furthersurgical intervention. If the patient has an adequaterange of motion (greater than 30 mm preoperatively)without dislocation or locking, great caution shouldbe exercised in considering alloplastic joint replace-ment when the only complaint is pain.11 Because thatpain may be neuropathic (with a large component ofcentrally mediated pain), alloplastic joint replacementof peripheral tissues may not always address thesepain symptoms adequately. A postoperative interin-cisal opening of 30 to 34 mm, with a reduction ofapproximately 60% to 70% of the preoperative painlevel and the ability to eat a diet that is approximately75% of normal, are achievable goals with properplacement of an alloplastic total joint implant. How-ever, it must be noted again that patients who seekmechanical improvement tend to do better than thosepatients who are seeking surgery for relief of pain

alone. For TMJ patients whose primary complaint ispain, all nonsurgical interventions should be ex-hausted before the consideration of alloplastic jointreplacement.

References1. Merskey H, Bogduk N (eds): Classification of Chronic Pain:

Descriptions of Chronic Pain Syndromes and Definitions ofPain Terms (ed 2). Seattle, WA, IASP Press, 1994

2. Cesare P, McNaughton P: Peripheral pain mechanisms. CurrOpin Neurobiol 7:493, 1997

3. Ferrante FM: The pharmacologic management of chronic or-thopedic pain. U Penn Orthop J 11:73, 1998

4. Ramer MS, Kawaja MD, Henderson JT, et al: Glial overexpres-sion of NGF enhances neuropathic pain and adrenergic sprout-ing into DRG following chronic sciatic constriction in mice.Neurosci Lett 251:53, 1998

5. Kinnman E, Levine JD: Sensory and sympathetic contributionsto nerve injury-induced sensory abnormalities in the rat. Neu-roscience 64:751, 1995

6. Milam SB: Chronic temporomandibular joint arthralgia. OralMaxillofac Surg Clin North Am 12:5, 2000

7. Zenz M, Strumpf M, Tryba M: Long-term oral opioid therapy inpatients with chronic nonmalignant pain. J Pain SymptomManage 7:69, 1992

8. Arner S, Meyerson BA: Lack of analgesic effect of opioids onneuropathic and idiopathic forms of pain. Pain 33:11, 1988

9. Israel HA, Syrop SB: The important role of motion in therehabilitation of patients with mandibular hypomobility: A re-view of the literature. Cranio 15:74, 1997

10. McCarty WL Jr, Darnell MW: Rehabilitation of the temporoman-dibular joint through the application of motion. Cranio 11:298,1993

11. Mercuri LG: Alloplastic temporomandibular joint reconstruc-tion. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 85:631,1998

14 PAIN MANAGEMENT—TMJ SURGERY