Category Archives: Facial Neuropathology

EVALUATION OF OROFACIAL PAIN PATIENT

Evaluation of the dental patient who presents with jaw or  face pain of nonodontogenic origin is an important skill for the dentist to master. Obtaining an accurate history is the most important component of information gathering.For chronic headache disorders and many neuropathic disorders, such as TN, pre-TN, and other cranial neural–
.glas, as well as burning mouth syndrome~:generally no abnormality is found on physical examination; therefore  the clinician must rely on the verbal history to arrive at anaccurate diagnosis. Chronic headache disorders based on symptom description are presented in Table 29-3.
The pain history should include the chid complaint,  including the current description of pain quality (e.g.,aching! throbbing, burning, shocklike, paroxysmal, or some combination), intensity, when it occurs, how long
it lasts, if it changes in character over time, precipitating factors, and alleviating factors, The history of the present illness should include date of onset, circumstances surrounding onset, how the pain evolved over time, diagnostic tests undertaken, diagnoses rendered, what treatments were instituted in the _past, and the response to those treatments. Finally, a comprehensive medral and dental history should be taken. Most commonly a short differential diagnostic list can be made at this time.

BOX 29-3

Differential Diagnoses of Common Headaches

Differential Diagnoses of Common Headaches
‘.
Migraine _Cluster ——T-en-s-io-n——–
Onset —- A-cu-te-o-r ch-ronic ——- Acu-te – — — –Ac-u-te– —
Location. Localized Unila!~~1 (40%) Unilateral –
Associated Weight loss, polymyalgia, Nausea, vomiting, Rhinorrhea,
symptoms rheumatica, fever, photophobia, lacrimation of
decreased vision, jaw phonophobia ipsilateral side
claudi ion
Temporal Arteritis
Chronic – _—“”__ ••• _ 0.-
.–9lobal, unil~-:.r~~_
Multisomatic
complaints (?)
Pain character Severe throbbing over Throbbing
— – —– area affected
Durati.9n______-“rol0r:!.ged
_P!:i.9rHX (=)
Diagnostic test ESR(+)
PE Tender temporal arteries,
myalgias, fever
Sharp stabbing Aching
-“-3…:..0_m’-‘-in_-2-“–h-‘.0_-u:-‘Drs~y _
(+) (.±L _
None-history None-history
Unilateral, rhinorrhea, (-)
lacrimation, partial
Horner’s
_______ Prolonged
(+)
None-history
Nausea, vomiting,
photophobia,
phonophobia

 

physical examination will attempt to narrow this list to obtain a working diagnosis. The physical evaluation should Include all aspects of the
normal de ntal evaluation, including vital signs determina- -, tion, intraoral examination with oral cancer screening, and head and neck examination with an evaluation of the temporal and carotid arteries, lymph nodes, skin, head, and neck, as well as myofascial and temporomandibular joint (TMJ) examination. In addition, a cranial nerve screening examinati<J1_ should be performed. It is understood that most dentists would not include all aspects of the formal neurologic examination, such as fundoscopic examination and testing of ability to smell, in this screening. See Box
29-10 for cranial screening evaluation. This latter exarnina- .tion is frequently an attempt to detect areas of hyperesthesia or hyperalgesia, allodynia, a trigger zone for TN, or an area of decreased sensation. In addition, it is important to define whether the pain follows normal neuroanat mic boundaries and, if so, to define these areas. Diagnostic anesthetic testing, usually with a vasoconstrictor-free solution,
is appropricllte to help define whether a suspected neuropathic pain condition has a significant peripheral component perpetuating pain. .
When a peripheral component occurs, local anest esia may arrest the pain for the duration of anesthesia. Most  commonly local anesthesia is applied to increasingly largerneuroa natomic regions. For instance, with a pain in
the region of the mandibular canine, topical anesthesia in the anterior mandibular gingiva is applied. If pain is  not arrested, the response to infiltration anesthesja is assessed. If no response is seen, a mental block (sparing  he lingual nerve) is attempted and, finally, inferior alveolar
and lingual nerve block anesthesia is undertaken if pain has not yet been alleviated. At each test any alter- J:i,m in pain response i< .,,,,,:01
. Imaging is appropriate for many disorders to rule out . all odontogenic, sinus, or bony pathology, The orthopan to graph is helpful when supported by selected dental periapical

Indomethacin-Responsive Headaches

A number of head pains respond primarily ‘or exclusively to the NSAID, indomethacin. One of these headaches, chronic paroxysmal hemicrania, is similar In presentation to cluster headache, although the attacks are short
lived (lasting several minutes) and occur manytimes per day. Unlike clust-er headaches, women are more often affected than men: Again toothache may be the initial presentation. Exertional headaches, as in we-ightlifting or during intercourse, may also produce intense, rapidonset headache’ responsive to indomethacin, Hypnic headache, waking the patient from sleep generally within 2 to 4 hours of sleep onset and lasting 15 minutes to 3 hours, is frequently indomethacin responsive, buthypnic headache is not accompanied by symptoms of parasympathetic overactivity.

Cluster Headache

Cluster headache is an overwhelmingly unilateral head pain typically centered around the eye and temporal regions. The pain is’ intense, frequently described as a stabbing sensation (i.e., as if an ice pick was being driven into the eye). Some component of parasympathetic overactivity
is present (commonly lacrimation, conjunctival injection, ptosis, or rhinorrhea). Headaches last 15 to 180 minutes and may occur once or multiple times per day, commonly with’ precise regularity (e.g., awakening the patient at the same time night after night), The headaches occur in “clusters” such that they may be present for some months and then remit’ for several months or even, years. Alcohol ingestion consistently triggers
headache but only during cluster episodes. As opposed to ‘most other chronic headaches, men are much more-like- Iy to suffer from cluster headache than women (Box 29-8). IHS criteria are listed in Box 29-9. Treatment, as in migraine, is either; preventive or symptomatic. Preventive
treatment is accomplished with verapamil, lithium salts, anticonvulsants, corticosteroids, and certain ergot com- ,pounds, Symptomatic treatment is with “triptans,” ergots, and analgesics. Oxygen inhalation at 7 to “to
min may be an effective abortive treatment.

BOX 28-9

Common Cluster Headache Features

Sex: Mainly male
Frequency: Up to 8 per day
Quality: Throbbing/stabbing
Intensity: Severe

BOX 29-9

IHS Criteria for Cluster Headache

A. Severe unilateral orbital, supraorbital, or temporal
pain (or a combination) lasting 15 to 180 minutes
(Note: Frequently in posterior maxillary dentoalveolar
region as well) –
B. At least one of the following on the headache side:
• Conjunctival injection
• Facial sweating
-. Lacrimation
• Miosis
• Nasal congestion
• Ptosis
• Rhinorrhea
• Eyelid edema
C. No evidence of organic disease

Dentists must be aware that frequently cluster headache produces pain in the posterior maxilla, mimicking severe dentoalveolar pain in the posterior maxillary teeth. The pain is frequently stabbing and intense,although background aching may occur. Unnecessary dental therapy is, unfortunately, common. Common features can distinguish a toothache secondary to cluster headache from a toothache produced by a dental problem  Rapid emergence and discontinuation of symptoms unlike typical toothache  Toothache precipitated by alcohol ingestion .

Tension-Type Headache

The majority of patients who report to the physician with a chief complaint of headache will be diagnosed with tension-type headache, The’ name can be misleading ecause “muscle tension” or “tension from stress” is not
always present, either alone or in combination. Tensiont}pe headache is common in the general population, and most people will experience at least one tension-type headache at some point. ,Chronic tension-type headache is more common in woman. than men. The headache is generally bilateral. It is , frequently bitemporal qr frontal-temporal in distribution, Patients commonly describe their pain as though their head is “in a vice” or a “squeezing hatband” is around their head. Headache can occur with or without “pericranial muscle tenderness” (i.e., tenderness to palpation of the,
masticatory and occipital muscles). To be defined as chronic tenslon-type headache, symptoms must be ‘present greater than 1S days per month. The IHS criteria for tension- type headache are listed in Box 29-7. Treatment of
tension-type headache is commonly with tricyclic or other antidepressants. When tension-type headache OCC in migraineurs, migraine treatments are usually beneficial. Psychosocial factors am often a contributing factor
influencing tension-type headache. In this situation cognitive- behavioral and other psychologic therapies are frequently beneficial.

Neuropathic Facial Pains Presenting as Toothache

Glossary of Pain Terms

Allodynia Pain caused by a stimulus that does
not normally’ provoke pain
Absence of pain in response to
stimulation that would normally be
painful
Absence of all sensation
, ‘Pain caused by loss of sensory input
into the central nervous system
(eNS)
Unpleasant abnormal sensation,
whether spontaneous or evoked
(Note: Dysesthesia includes’paresthesia
but not vice versa.) ,
Increased sensitivity to noxious
stimulation
Increased sensitivity to all stimulation,
‘excluding special senses (Note: When
the sensation is painful, the terms
allodynia and hyperalgesiamay be
appropriate.)
Diminished sensitivity to noxious
stimulation
Diminished sensitivity to all
stimulation, excluding the special
senses (Note: When the sensation is
pain, the terms hypaplgesia and anal-
~esia may be cpptoptiote.)
Pain in the distribution of a nerve or
nerve)
Disturbance of function or pathologic
change in a nerve
Abnormal sensation, whether
spontaneous or evoked
Analgesia
Anesthesia
Deafferentation
pain
Dysesthesia
Hyperalgesia
Hyperesthesia
Hypoalqesia
Hypoesthesia
Neuralgia
Neuropathy
Paresthesia

Although this could refer to any neuropathic pain o trizerninal nerve origin, l:\’ or “tic douloureux” u.e. pamn.l ~i”, 11;1 ~jl{‘(ifjc inclusion criteria, Occurring most Irequently In patients over Si) yl:iIi~ of age (incidence I): 100,000; female-to-male 1 atlo 1.6: 1,O}, l:\’ usually  presents with sharp, electric shocklike pain in theface or mouth, The pain is intense, Iasrlng for brief periods of seconds to 1 minute, after which there is a rcfractory
period during which the pain cannot be reinitiated for a period of time, At times, a background aching or burning pain is present. Usually a “trigger zone” is present where mechanical stimuli such as soft touch may
provoke an attack, Firm pressure to the region is genuallv not (l~ provocative. Common cutaneous trigger ZOIlC~ include the corner of the lips; cheek, ala of the no-c. or !:I:’:rJI hrovv, :\ny intraoral sill’ may also be_a  rigger WIll’ for T;\, including the teeth, gingi\’,l(‘, or longu , ‘I rigger zones in both the \’2 and \’3 distrihut ions are 111O\t (,01 11111on, after which they oc CUI alone (and iri dvcn-asmg order of incidencvr in the \ ,{, \’2, .md \’1 divtrihutinns. The pain ofT” illuvt ratcs ail Important
dlst inction 01 m.mv ncurop.u h

NEUROPATHIC FACIAL PAINS

Neuropathic pains arise from an injured pain transmission or modulation system, Surgical intervention or trauma is frequently the cause, For example, trauma to the infraorbital region may lead to numbness or pain in the . distribution of the infraorbital nerve. In oral and maxillofacial surgery, extraction of mandibular third molars carries a slight but measurable risk of nerve damage to the mandibular or lingual nerves. In the majority of these
cases, damage leads to paresthesia, an abnormal sensatic in the dermatome of the affected nerve. Typically, tLis sensation is one of mild numbness or tingling, Loss I sensation may occur’ when the nerve is transected. III a subset “f cases dysesthesia. an’ abnormal. unpleasant  result it is often described as a burning or sharp electric shocklike sensation, In tact, \\’Ill’:l a patient ‘ complains of bum ill),: or ~h,HP shocklike pain in the face
or mouth, p.un of neurop.ttluc origm should be included in thc.differcntlal diagnOSiS. It should he appreciated that the oral 1110Stcommon site ot amputation, if one recognizes amputations to include the teeth and the dental pulp (i.c. cndodontlcstS ill phantom limb pain  after extremity amputation, “phantom” scn-ations can’
also arise, albeit more rarely, alter dental and pulpal trauma or extraction. ‘europathic pains mav also give rise to the sensation of tooth pain, wluch often I~ J diagnostic dilemma for the dentist. II i customary to refer patients for management of these dhorliers to dentists focusing
on orofucial pain diagnosi .or to the patient’s personal physiclan .or a neurologist.

CLASSIFICATION OF OROFACIAL PAINS

Numerous classification systems exist for orofacial pain conditions. At the most basic level, it is appropriate to classify orofacial pains as primarily somatic, neuropathic, or psychologic in or.igin. SOli/atic pain arises from musculoskeletal or visceral structures interpreted through an intact pain transmission and modulation system. Common orofacial exampres
of musculoskeletal pains are temporomandibular disorders or periodontal pain. Examples of visceral orofacial pains would include salivary gland pain and pain caused by dental pulpitis, the tooth pulp behaving like a visceral
structure. Neuropathic pain arises from damage or alteration to the pain pathways, most commonly a peripheral – nerve injury from surgery or trauma. Other causes may involve G\S injurv as in thalamic ~~roke.
.Orofacial pairls ~t’true ps)’clw/ugic oriSill are so rare as not to be included in the differential diagnosis of orofacial pain for the general practitioner. Although psychologic influences frequently _modify the patient’s perception of pain intensity and their response to pain, an actual pain symptom generated by intrapsychic disturbance (e.g., conversion disorder, psychotic delusion! is exceedingly rare  paragraph.

 

C’HAPTER OUTLINE

BASICS OF PAIN NEURQPHYSIOLOGY
CLASSIFICATION OF OROFACIAL PAINS
NEUROPATHIC FACIAL PAINS
Neuropathic Facial Pains Presenting as Toothache
Trigeminal Neuralgia ‘
Pretrigeminal Neuralgia
Odontalgia Secondary to Deafferentation (Atypical
Odontalgia)
Other Neuropathic Fadill Pains
Postherpetic Neuralgia
Neuroma

Burning Mouth Syndrome
Other Cranial Neuralgias
CHRONIC HEADACHE •
Migraine
Tension-Type Headache
Cluster Headache ‘
OTHER CHRONIC HEAl) PAINS OF DENTAL INTEREST
Temporal Arteritis (Giant Cell Arteritis)
Indomethacin-Responsive Headaches
EVALUATION OF OROFACIAL PAIN’PATIENT
The dentist is frequently called upon to diagnose pain in the oral and’ maxillofacial region, Although pain in the mouth is most frequently of
odontogenic origin, many facta! ‘pains arise from other sources, The dlvcrsity of structures in the head and neck region . muscle membranes intracranial blood vessels) (In make arriving at In accurate diagnosis quite challenging. hellotoothache symptoms may occur in a halthy tooth secondarv to referred pain or a damaged pain-transmission system.