Non odontogenic tooth ache

Pain is perfect misery, the worst of evils and excessive, overturns all patience –John Milton, Paradise Lost

Pain is not a simple sensation but rather a complex neurobehavioral event involving at least two components.

First is an individual’s discernment or perception of the stimulation of specialized nerve endings designed to transmit information concerning potential or actual tissue damage (nociception).

Second is the individual’s reaction to this perceived sensation (pain behavior). This is any behavior, physical or emotional, that follows pain perception.

Pain pathway

Odontogenic pain

Odontogenic pain is generally derived from either one of

two structures associated with the tooth: pulpal or

periodontal tissue.

Pulpitis is the most common cause of odontogenic pain

As a visceral organ, pain of the dental pulp is

characterized by deep, dull, aching pain that may be

difficult to localize

It may present as intermittent or continuous, moderate or

severe, sharp or dull, localized or diffuse and may be

affected by the time of day or position of the body

Odontogenic pain

Periodontal pain is more readily localized and identifiable because of proprioceptors located within the periodontal ligament.

Therefore, periodontal pain will follow the characteristics of pain of musculoskeletal origin.

The periodontal receptors are able to accurately localize the pain whether they are lateral or apical to the tooth

Non odontogenic pain

The cardinal warning symptoms of nonodontogenic toothache are as follows

spontaneous multiple toothaches

inadequate local dental cause for the pain

stimulating, burning, nonpulsatile toothaches

constant, unremitting, nonvariable toothaches

persistent, recurrent toothaches

local anesthetic blocking of the offending tooth does not

eliminate the pain

failure of the toothache to respond to reasonable dental therapy.

Clinical characteristics of a non odontogenic tooth ache

The extent of pain may vary from very mild and intermittent pain to severe, sharp, and continuous

Pains that are felt in the tooth do not always originate from dental structures

In ‘primary’ pain, the site and source of pain are coincidental and in the same location

Pain with different sites and sources of pain, known as heterotopic pains, can be diagnostically challenging

Heterotopic Pain

Central pain Projected pain Referred pain

Constant nociceptive

input from deep structures

Central pain is simply pain derived from the central nervous system (CNS) resulting in pain perceived peripherally

An example of central pain is an intracranial tumor as this will not usually cause pain in the CNS because of the brain’s insensitivity to pain but rather it is felt peripherally

Projected pain is pain felt in the peripheral distribution of the same nerve that mediated the primary nociceptive input. An example of projected pain is pain felt in the dermatomal distribution in post-herpetic neuralgia

Referred pain is spontaneous heterotopic pain felt at a site of pain with separate innervation to the primary source of pain

Pain referred from the sternocleidomastoid muscle to the temporomandibular joint is an example of referred pain

CNS pain – intracranial tumour

Projected pain in post herpetic neuralgia

Referred pain in TMJ disorder

Referred pain theories

Pain arising from deep tissues, muscles, ligaments, joints, and viscera is often perceived at a site distant from the actual nociceptive source.

Convergence-projection theory: This is the most popular theory. Primary afferent nociceptors from both visceral and cutaneous neurons often converge onto the same second-order pain transmission neuron in the spinal cord.

The brain, having more awareness of cutaneous than of visceral structures through past experience, interprets the pain as coming from the regions subserved by the cutaneous afferent fibers

Convergence-facilitation theory: This theory is similar to the convergence-projection theory, except that the nociceptive input from the deeper structures causes the resting activity of the second-order pain transmission neuron in the spinal cord to increase or be “facilitated.”

The resting activity is normally created by impulses from the cutaneous afferents.

“Facilitation” from the deeper nociceptive impulses causes the pain to be perceived in the area that creates the normal, resting background activity.

This theory tries to incorporate the clinical observation that blocking sensory input from the reference area, with either local anesthetic or cold, can sometimes reduce the perceived pain

Making a diagnosis of non odontogenic tooth ache

Careful and exhaustive history Physical examination Diagnostic studies Pulp testing Nerve blocks Radiographs Blood tests Appropriate referrals

Myofacial Tooth Ache

The myofascial toothache is described as non-pulsatile and aching pain and occurs more continuously than pulpal pain

Patients are unable to accurately locate the source of the pain

Pain tends to be associated with extended muscle use and exacerbated with emotional stressors, rather than direct provocation of the affected tooth

Palpation of the trigger point is able to reproduce the toothache, even modulate the pain by increasing or eliminating it altogether

Alleviation of the toothache is often achieved when local anesthetic is administered to the strained muscle (source of pain) rather than the tooth (site of pain)

Management

Warm or cold compresses Muscle stretching Massage, and a restful sleep may alleviate both

the muscle and tooth pain. Elimination of the trigger point and pain of the

muscle should be the aim of the treatment rather than the tooth itself

Ear pain

Ear pain is typically seen with disorders such as otitis media, otitis externa, and mastoiditis and may be associated with headache

The ear is innervated by cranial nerves V, VII, VIII, IX, X, and XI

Therefore, pain can be referred to the ear from inflammatory or neoplastic disease of the teeth, tonsils, larynx, nasopharynx, thyroid, TMJ, and cervical spine, as well as from inflammation or tumors in the posterior fossa of the brain

Patients with otitis externa (inflammation of the external auditory canal) may present themselves to the dentist first because this pain is aggravated by swallowing

The dentist must carefully examine the dentition for

pulpal disease and the oropharyngeal mucosa for

inflammation to rule out referred ear pain from oral or

dental sources.

Myofascial TrPs (trigger points) in the lateral and

medial pterygoid muscles frequently refer pain to the

ear as well.

Cardiac tooth ache

Cardiac ischemia more commonly presents with substernal pain and radiation to the left shoulder and arm

When cardiac pain presents in the orofacial region commonly affected areas include pain(s) in the neck, throat, ear, teeth, mandible and headache

The mechanism of cardiac pain likely involves multiple nociceptive mediators with bradykinin being the most important, evoking a sympathoexcitatory reflex and inducing a sympathetic response of the heart

Pain may be episodic, lasting from minutes to hours, and varies in intensity, although almost invariably is precipitated by exertional activities and alleviated with rest

Cardiac nociceptive input travels into CNS

Ascends to higher centers for processing in region of convergence

Adjacent nociceptors are activated

Misinterpreted in cortex – unintentional pain input

Heterotopic pain

Angina pectoris- referred pain areas

These symptoms may radiate upward from the epigastrium to the mandible the left more frequently than the right.

The pain of angina pectoris is often felt in the left arm or the jaw, and diaphragmatic pain is often perceived in the shoulder or neck

Sinus tooth ache

Since the roots of the maxillary dentition are in intimate contact with, and often protruding into, the sinus cavity, it is comprehensible that the dentition could be a potential source of sinus inflammation and infection.

Patients may present with facial pain and pressure in the maxillary posterior region.

constant but rather mild pain in a number of posterior maxillary teeth on one side is almost pathognomonic

Other symptoms such as headache, halitosis, fatigue, cough, nasal discharge/drainage or congestion and ear pain may be more identifiable as being associated with sinus disease

Sinus pain can also present as a continuous dull ache or diffuse lingering pain in the maxillary teeth with sensitivity to percussion, mastication, and/or temperature

Sinus and parasinus pain

. The pain, mild but deep and nonpulsating, radiates out of this area onto the face, upward toward the temple, and forward toward the nose. A referred frontal headache and cutaneous hyperalgesia along the side of the face and scalp may also be present

Pain may be elicited by palpation of the infraorbital regions or maneuvering the head to below the levels of the knees, initiating gravitational shifting of fluid in the sinus

The absence of an offending tooth or gingival inflammation upon intraoral examination may further lead to the conclusion that there is sinus inflammation or infection.

The sinuses may appear cloudy, opacified, and congested on the panoramic radiograph.

Most cases of acute sinusitis are of viral origin and require nasal decongestants, a therapy targeted at reducing the soft tissue edema to allow drainage of the sinus through the ostium into the middle meatus of the nasal cavity

The canaliculi of the teeth often open toward the sinus, and pulpal nerves may be in direct contact with the inflamed mucoperiosteum of the sinus lining. Their direct irritation may cause dental symptoms.

Thyroid Pain

The typical symptom picture includes pain over at least one lobe of the thyroid gland or pain radiating up the sides of the neck and into the lower jaws, ears, or occiput. Swallowing may aggravate the symptoms.

The thyroid gland may be visibly enlarged and will be tender to palpation with nodularity . If thyroiditis or other thyroid disease is suspected, referral to the patient’s physician should be made for a complete medical workup.

Neurovascular tooth ache

Headache may also present as a variant involving the orofacial region mimicking toothache

Two primary headache types that may present as toothache are migraine and trigeminal autonomic cephalalgia

Migraines are typically unilateral, moderate to severe pains of pulsatile and throbbing quality that are often disabling

Migraine is often accompanied by nausea, vomiting, phonophobia and/or photophobia and may present with (20%) or without aura

Trigeminal autonomic cephalalgias (TACs) are a collective term that refers to a group of headaches characterized by unilateral head and/or face pain with accompanying autonomic features

The most common sites are either around and behind the eye radiating to the forehead and temple or around and behind the eye radiating infraorbitally into the maxilla and occasionally into the teeth, rarely to the lower jaw and neck.

Neuropathic Tooth Ache

Neuropathic pain refers to a pain that originates from abnormalities in the neural structures and not from the tissues that are innervated by those neural structures

There are two types of neuropathic pains that can be felt in teeth: episodic and continuous

Episodic neuropathic pain is characterized by sudden volleys of electric-like pain referred to as neuralgia. The most typical example of this type of pain is trigeminal neuralgia

The clinical presentation of an episodic neuropathic toothache is a severe, shooting, electric-like pain that lasts only a few seconds

The pain is not altered by intraoral thermal stimuli

The most common branch of the trigeminal nerve involved is the mandibular followed by the maxillary and least involved is the ophthalmic

With trigeminal neuralgia there is often a trigger zone that, when lightly stimulated, provokes the severe paroxysmal pain.

Anesthetic blocking of the trigger zone will completely eliminate the toothache and paroxysmal episodes during the period of anesthesia.

Patients with trigeminal neuralgia frequently receive endodontic treatment for their dental pain

Trp

Atypical facial pain

Continuous neuropathic pains are pain disorders that have their origin in neural structures and are expressed as constant, ongoing and unremitting pain

Continuous neuropathic pains that can be felt in teeth have been referred to as atypical odontalgia or sometimes phantom toothache

Patients with continuous neuropathic toothache often report a history of trauma or ineffective dental treatment in the area

It is not unusual for patients with continuous neuropathic toothache to have received multiple endodontic treatments or extractions for their dental pain

The following characteristics of continuous neuropathic toothache can be used to differentiate it from odontogenic pain:

a) diffuse pain b) pain not always restricted to a tooth (e.g., the area may be

edentulous) c) pain that is almost always continuous d) a pain quality often described as a dull, aching, throbbing, or

burning e) pain that may or may not be relieved by a diagnostic intraoral

local anesthetic block f) pain that often lasts more than 4 months g) pain not altered by intraoral thermal stimuli

The molars are most commonly involved, followed by premolars

Atypical facial pain

The vast majority of patients present themselves with unilateral pain

Onset of the pain may coincide with the dental treatment

A more probable cause of atypical odontalgia is deafferentation (partial or total loss of the afferent nerve supply or sensory input) with or without sympathetic involvement

The current treatment of choice is the use of tricyclic antidepressant agents such as amitriptyline or imipramine.

If the pain has a burning quality, the addition of a phenothiazine, such as trifluoperazine, may be helpful

Neoplastic Tooth Ache

Primary squamous cell carcinoma (SCC) of the oral mucosa may present with pain and sensory disturbances that mimic toothache symptoms particularly when located on the gingiva, vestibule or floor of mouth.

Nasopharyngeal cancers may present with signs and symptoms that have been confused with, and treated as, temporomandibular disorders parotid gland lesions ,and odontogenic infections with trismus

Systemic cancers such as lymphoma and leukemia may have intraoral manifestations that mimic toothache like symptoms

Orofacial pain has also been reported in patients with distant non-metastasized cancers, most commonly from the lungs

Orofacial pain may be associated with metastatic malignancies and when metastatic orofacial tumors occur, they affect the jaw bones more often than the oral soft tissues

squamous cell carcinoma

Pyschogenic Pain

Psychogenic pain is pain that is associated with psychologic factors in the absence of any physiologic cause.

Pain descriptors are often diffuse, vague, and difficult to localize

Pain may be sharp, stabbing, intense, and sensitive to temperature changes, all of which are similar to pain symptoms of odontogenic origin

The pain is inconsistent with normal patterns of physiologic pain and presents without any identifiable pathologic cause

Patients should be referred to a psychiatrist or psychologist for further management.

Quality of pain summary