Trismus is defined as difficulty in opening the mouth due to a muscle spasm resulting from a disturbance in the trigeminal nerve, however it can also refer to limited mouth opening of any cause. Another definition of trismus is simply a limitation of movement. Historically and commonly, the term "lock jaw" was sometimes used as a synonym for both trismus and tetanus.

Normal mouth-opening ranges from 35 to 45 mm. Males usually have slightly greater mouth opening than females. (40–60 mm, average of 35 mm). The Normal Lateral movement is 8-12mm, and normal protrusive movement is approximately 10mm. Some have distinguished mild trismus as 20–30 mm interincisal opening, moderate as 10–20 mm and severe as less than 10 mm.

Trismus is derived from the Irish word "trismos" meaning "a scream; a grinding, rasping or gnashing"

Trismus, also called lockjaw, is reduced opening of the jaws (limited jaw range of motion). It may be caused by spasm of the muscles of mastication or a variety of other causes. Temporary trismus occurs much more frequently than permanent trismus. It is known to interfere with eating, speaking, and maintaining proper oral hygiene. This interference, specifically with the patient's ability to swallow properly, results in an increased risk of aspiration. In some instances, trismus presents with altered facial appearance. The condition may be distressing and painful for the patient. Examination and treatments requiring access to the oral cavity can be limited, or in some cases impossible, due to the nature of the condition itself.

Pain originating from the muscles of mastication as a result of abnormal muscular function or hyperactivity. The muscular pain is frequently, but not always, associated with daytime clenching or nocturnal bruxism.

Sometimes TMD pain can radiate or be referred from its cause (i.e. the TMJ or the muscles of mastication) and be felt as headaches, earache or toothache.

Due to the proximity of the ear to the temporomandibular joint, TMJ pain can often be confused with ear pain. The pain may be referred in around half of all patients and experienced as otalgia (earache). Conversely, TMD is an important possible cause of secondary otalgia. Treatment of TMD may then significantly reduce symptoms of otalgia and tinnitus, as well as atypical facial pain. Despite some of these findings, some researchers question whether TMJD therapy can reduce symptoms in the ear, and there is currently an ongoing debate to settle the controversy.

Fever, sore throat, odynophagia (painful swallowing), swelling in neck.

Anterior space abscess can cause trismus (spasm of jaw muscle) and hard mass formation along the angle of the mandible, with medial bulging of the tonsil and lateral pharyngeal wall. Posterior space abscess causes swelling in posterior pharyngeal wall. Trismus (spasm of jaw muscle) is minimal. Posterior abscess may involve structures within the carotid sheath, causing rigors, high fever, bacteremia, neurologic deficit, massive haemorrhage caused by carotid artery rupture.

Pericoronitis may also be chronic or recurrent, with repeated episodes of acute pericoronitis occurring periodically. Chronic pericoronitis may cause few if any symptoms, but some signs are usually visible when the mouth is examined.

The signs and symptoms of pericoronitis depend upon the severity, and are variable:

- Pain, which gets worse as the condition develops and becomes severe. The pain may be throbbing and radiate to the ear, throat, temporomandibular joint, posterior submandibular region and floor of the mouth. There may also be pain when biting. Sometimes the pain disturbs sleep.

- Tenderness, erythema (redness) and Edema (swelling) of the tissues around the involved tooth, which is usually partially erupted into the mouth. The operculum is characteristically very painful when pressure is applied.

- Halitosis resulting from the bacteria putrefaction of proteins in this environment releasing malodorous volatile sulfur compounds.

- Bad taste in the mouth from exudation of pus.

- Intra-oral halitosis.

- Formation of pus, which can be seen exuding from beneath the operculum (i.e. a pericoronal abscess), especially when pressure is applied to the operculum.

- Signs of trauma on the operculum, such as indentations of the cusps of the upper teeth, or ulceration. Rarely, the soft tissue around the crown of the involved tooth may show a similar appearance to necrotizing ulcerative gingivitis.

- Trismus (difficulty opening the mouth). resulting from inflammation/infection of the muscles of mastication.

- Dysphagia (difficulty swallowing).

- Cervical lymphadenitis (inflammation and swelling of the lymph nodes in the neck), especially of the submandibular nodes.

- Facial swelling, and rubor, often of the cheek that overlies the angle of the jaw.

- Pyrexia (fever).

- Leukocytosis (increased white blood cell count).

- Malaise (general feeling of being unwell).

- Loss of appetite.

- The radiographic appearance of the local bone can become more radiopaque in chronic pericoronitis.

The signs and symptoms depend upon the type of OM, and may include:

- Pain, which is severe, throbbing and deep seated.

- Initially fistula are not present.

- No dental pain, but headache or other facial pain, as in the descriptive former term "neuralgia-inducing" (cavitational osteonecrosis).

- Fibromyalgia.

- Chronic fatigue syndrome.

- Swelling. External swelling is initially due to inflammatory edema with accompanying erythema (redness), heat and tenderness, and then later may be due to sub-periosteal pus accumulation. Eventually, subperiosteal bone formation may give a firm swelling.

- Trismus (difficulty opening the mouth), which may be present in some cases and is caused by edema in the muscles.

- Dysphagia (difficulty swallowing), which may be present in some cases and is caused by edema in the muscles.

- Cervical lymphadenitis (swelling of the lymph nodes in the neck).

- Aesthesia or paresthesia (altered sensation such as numbness or pins and needles) in the distribution of the mental nerve.

- Fever which may be present in the acute phase and is high and intermittent

- Malaise (general feeling of being unwell) which may be present in the acute phase

- Anorexia (loss of appetite).

- Leukocytosis (elevated numbers of white blood cells) which may be present in the acute phase

- Elevated erythrocyte sedimentation rate and C reactive protein are sometimes present.

- An obvious cause in the mouth (usually) such as a decayed tooth.

- Teeth that are tender to percussion, which may develop as the condition progresses

- Loosening of teeth, which may develop as the condition progresses.

- Pus may later be visible, which exudes from around the necks of teeth, from an open socket, or from other sites within the mouth or on the skin over the involved bone.

- Fetid odor.

Unlike acute OM in the long bones, acute OM in the jaws gives only a moderate systemic reaction and the person remains surprisingly well. Acute OM of the jaws may give a similar appearance to a typical odontogenic infection, but cellulitis does not tend to spread from the periosteal envelope of the involved bone. If the infection is not controlled, the process becomes chronic and systemic symptoms are usually present, including draining fistulas, loosening of teeth and sequestra formation. Untreated chronic osteomyelitis tends to feature occasional acute exacerbations.

Unlike tonsillitis, which is more common in the children, PTA has a more even age spread, from children to adults. Symptoms start appearing two to eight days before the formation of an abscess. A progressively severe sore throat on one side and pain during swallowing (odynophagia) usually are the earliest symptoms. As the abscess develops, persistent pain in the peritonsillar area, fever, a general sense of feeling unwell, headache and a distortion of vowels informally known as "hot potato voice" may appear. Neck pain associated with tender, swollen lymph nodes, referred ear pain and foul breath are also common. While these signs may be present in tonsillitis itself, a PTA should be specifically considered if there is limited ability to open the mouth (trismus).

Physical signs of a peritonsillar abscess include redness and swelling in the tonsillar area of the affected side and swelling of the jugulodigastric lymph nodes. The uvula may be displaced towards the unaffected side.

In the initial phase of the disease, the mucosa feels leathery with palpable fibrotic bands. In the advanced stage the oral mucosa loses its resiliency and becomes blanched and stiff. The disease is believed to begin in the posterior part of the oral cavity and gradually spread outward.

Other features of the disease include:

- Xerostomia

- Recurrent ulceration

- Pain in the ear or deafness

- Nasal intonation of voice

- Restriction of the movement of the soft palate

- A budlike shrunken uvula

- Thinning and stiffening of the lips

- Pigmentation of the oral mucosa

- Dryness of the mouth and burning sensation

- Decreased mouth opening and tongue protrusion

Oromandibular Symptoms

- difficulty opening the mouth (trismus)

- clenching or grinding of the teeth (bruxism)

- spasms of jaw opening

- sideways deviation or protrusion of the jaw

- lip tightening and pursing

- drawing back (retraction) of the corners of the mouth

- deviation or protrusion of the tongue.

- jaw pain

- difficulties eating and drinking

- difficulties speaking (dysarthria)

Blepharospasm symptoms

- the first symptom to appear is an increased rate of blinking

- uncontrollable squinting/closing of eyes

- light sensitivity (photophobia)

- squinting/eyes closing during speech

- uncontrollable eyes closing shut (rare instances completely causing blindness)

In addition, in some patients, the dystonic spasms may sometimes be provoked by certain activities, such as talking, chewing, or biting. Particular activities or sensory tricks may sometimes temporarily alleviate OMD symptoms, including chewing gum, talking, placing a toothpick in the mouth, lightly touching the lips or chin, or applying pressure beneath the chin.

Most people with bruxism will experience no pain. The presence or degree of pain does not necessarily correlate with the severity of grinding or clenching. The pain in the muscles of mastication caused by bruxism can be likened to muscle pain after exercise. The pain may be felt over the angle of the jaw (masseter) or in the temple (temporalis), and may be described as a headache or an aching jaw. Most (but not all) bruxism includes clenching force provided by masseter and temporalis muscle groups; but some bruxers clench and grind front teeth only, which involves minimal action of the masseter and temporalis muscles. The temporomandibular joints themselves may also become painful, which is usually felt just in front of the ear, or inside the ear itself. Clicking of the jaw joint may also develop. The forces exerted on the teeth are more than the periodontal ligament is biologically designed to handle, and so inflammation may result. A tooth may become sore to bite on, and further, tooth wear may reduce the insulating width of enamel and dentin that protects the pulp of the tooth and result in hypersensitivity, e.g. to cold stimuli.

The relationship of bruxism with temporomandibular joint dysfunction (TMD, or temporomandibular pain dysfunction syndrome) is debated. Many suggest that sleep bruxism can be a causative or contributory factor to pain symptoms in TMD. Indeed, the symptoms of TMD overlap with those of bruxism. Others suggest that there is no strong association between TMD and bruxism. A systematic review investigating the possible relationship concluded that when self-reported bruxism is used to diagnose bruxism, there is a positive association with TMD pain, and when stricter diagnostic criteria for bruxism are used, the association with TMD symptoms is much lower. In severe, chronic cases, bruxism can lead to myofascial pain and arthritis of the temporomandibular joints.

The main symptoms involve involuntary blinking and chin thrusting. Some patients may experience excessive tongue protrusion, squinting, light sensitivity, muddled speech, or uncontrollable contraction of the platysma muscle. Some Meige's patients also have "laryngeal dystonia" (spasms of the larynx). Blepharospasm may lead to embarrassment in social situations, and oromandibular dystonia can affect speech, making it difficult to carry on the simplest conversations. This can cause difficulty in both personal and professional contexts, and in some cases may cause patients to withdraw from social situations.

The condition tends to affect women more frequently than men.

Most people who brux are unaware of the problem, either because there are no symptoms, or because the symptoms are not understood to be associated with a clenching and grinding problem. The symptoms of sleep bruxism are usually most intense immediately after waking, and then slowly abate, and the symptoms of a grinding habit which occurs mainly while awake tend to worsen through the day, and may not be present on waking. Bruxism may cause a variety of signs and symptoms, including:

- Excessive tooth wear, particularly attrition, which flattens the occlusal (biting) surface, but also possibly other types of tooth wear such as abfraction, where notches form around the neck of the teeth at the gumline.

- Tooth fractures, and repeated failure of dental restorations (fillings, crowns, etc.).

- Hypersensitive teeth, (e.g. dental pain when drinking a cold liquid) caused by wearing away of the thickness of insulating layers of dentin and enamel around the dental pulp.

- Inflammation of the periodontal ligament of teeth, which may make them sore to bite on, and possibly also a degree of loosening of the teeth.

- A grinding or tapping noise during sleep, sometimes detected by a partner or a parent. This noise can be surprisingly loud and unpleasant, and can wake a sleeping partner. Noises are rarely associated with awake bruxism.

- Other parafunctional activity which may occur together with bruxism: cheek biting (which may manifest as morsicatio buccarum and/or linea alba), and/or lip biting.

- A burning sensation on the tongue (see: glossodynia), possibly related to a coexistent "tongue thrusting" parafunctional activity.

- Indentations of the teeth in the tongue ("crenated tongue" or "scalloped tongue").

- Hypertrophy of the muscles of mastication (increase in the size of the muscles that move the jaw), particularly the masseter muscle.

- Tenderness, pain or fatigue of the muscles of mastication, which may get worse during chewing or other jaw movement.

- Trismus (restricted mouth opening).

- Pain or tenderness of the temporomandibular joints, which may manifest as preauricular pain (in front of the ear), or pain referred to the ear (otalgia).

- Clicking of the temporomandibular joints.

- Headaches, particularly pain in the temples, caused by muscle pain associated with the temporalis muscle.

Bruxism is usually detected because of the effects of the process (most commonly tooth wear and pain), rather than the process itself. The large forces that can be generated during bruxism can have detrimental effects on the components of masticatory system, namely the teeth, the periodontium and the articulation of the mandible with the skull (the temporomandibular joints). The muscles of mastication that act to move the jaw can also be affected since they are being utilized over and above of normal function.

The classification is similar to the classification of OM generally, according to the length of time the inflammation has been present and whether there is suppuration (the formation of pus). "Acute osteomyelitis" is loosely defined as OM which has been present for less than one month and "chronic osteomyelitis" is the term used for when the condition lasts for more than one month. Suppurative osteomyelitis of the jaws is uncommon in developed regions, and more common in developing countries. In Europe and the United States, most cases follow dental infections or mandibular fractures. There have been many reported cases occurring in Africa which are coexistent with acute necrotizing ulcerative gingivitis or cancrum oris.

In the pre-antibiotic era, acute OM of the jaws was more extensive. Massive, diffuse infections commonly involved the whole side of the mandible, or the whole of one side and the opposite side as far as the mental foramen. Localized osteomyelitis tended to be described as either "vertical", where a short segment of the body of the mandible from the alveolar crest to the lower border was involved, and "alveolar", where a segment of alveolar bone down to the level of the inferior alveolar canal would sequestrate, including the sockets of several teeth. Treatment with antibiotics has significantly altered the natural history of OM of the jaws. Today, however, the condition is often a hidden infection, due in part to not being visible on most dental X-rays. In addition, some schools of dentistry do not recognize "silent" OM of the jaws—occurrence of the condition without visually obvious manifestations—in their curriculum. In addition, as circulation is intrinsically diminished in jawbones, antibiotics are frequently ineffective.

Non-dental causes of toothache are much less common as compared with dental causes. In a toothache of neurovascular origin, pain is reported in the teeth in conjunction with a migraine. Local and distant structures (such as ear, brain, carotid artery, or heart) can also refer pain to the teeth. Other non-dental causes of toothache include myofascial pain (muscle pain) and angina pectoris (which classically refers pain to the lower jaw). Very rarely, toothache can be psychogenic in origin.

Disorders of the maxillary sinus can be referred to the upper back teeth. The posterior, middle and anterior superior alveolar nerves are all closely associated with the lining of the sinus. The bone between the floor of the maxillary sinus and the roots of the upper back teeth is very thin, and frequently the apices of these teeth disrupt the contour of the sinus floor. Consequently, acute or chronic maxillary sinusitis can be perceived as maxillary toothache, and neoplasms of the sinus (such as adenoid cystic carcinoma) can cause similarly perceived toothache if malignant invasion of the superior alveolar nerves occurs. Classically, sinusitis pain increases upon Valsalva maneuvers or tilting the head forward.

Painful conditions which do not originate from the teeth or their supporting structures may affect the oral mucosa of the gums and be interpreted by the individual as toothache. Examples include neoplasms of the gingival or alveolar mucosa (usually squamous cell carcinoma), conditions which cause gingivostomatitis and desquamative gingivitis. Various conditions may involve the alveolar bone, and cause non-odontogenic toothache, such as Burkitt's lymphoma, infarcts in the jaws caused by sickle cell disease, and osteomyelitis. Various conditions of the trigeminal nerve can masquerade as toothache, including trigeminal zoster (maxillary or mandibular division), trigeminal neuralgia, cluster headache, and trigeminal neuropathies. Very rarely, a brain tumor might cause toothache. Another chronic facial pain syndrome which can mimic toothache is temporomandibular disorder (temporomandibular joint pain-dysfunction syndrome), which is very common. Toothache which has no identifiable dental or medical cause is often termed atypical odontalgia, which, in turn, is usually considered a type of atypical facial pain (or persistent idiopathic facial pain). Atypical odontalgia may give very unusual symptoms, such as pain which migrates from one tooth to another and which crosses anatomical boundaries (such as from the left teeth to the right teeth).

Establishing a diagnosis of nondental toothache is initially done by careful questioning about the site, nature, aggravating and relieving factors, and referral of the pain, then ruling out any dental causes. There are no specific treatments for nondental pain (each treatment is directed at the cause of the pain, rather than the toothache itself), but a dentist can assist in offering potential sources of the pain and direct the patient to appropriate care. The most critical nondental source is the radiation of angina pectoris into the lower teeth and the potential need for urgent cardiac care.

Toothache, also known as dental pain, is pain in the teeth and/or their supporting structures, caused by dental diseases or pain referred to the teeth by non-dental diseases.

Common causes include inflammation of the pulp, usually in response to tooth decay, dental trauma, or other factors, dentin hypersensitivity (short, sharp pain, usually associated with exposed root surfaces), apical periodontitis (inflammation of the periodontal ligament and alveolar bone around the root apex), dental abscesses (localized collections of pus, such as apical abscess, pericoronal abscess, and periodontal abscess), alveolar osteitis ("dry socket", a possible complication of tooth extraction, with loss of the blood clot and exposure of bone), acute necrotizing ulcerative gingivitis (a gum infection, also called "trenchmouth"), temporomandibular disorder and others.

Pulpitis is classified as reversible when the pain is mild to moderate and lasts for a short time after a stimulus (for instance, cold or sweet); or irreversible when the pain is severe, spontaneous, and lasts a long time after a stimulus. Left untreated, pulpitis may become irreversible, then progress to pulp necrosis (death of the pulp) and apical periodontitis. Abscesses usually cause throbbing pain. The apical abscess usually occurs after pulp necrosis, the pericoronal abscess is usually associated with acute pericoronitis of a lower wisdom tooth, and periodontal abscesses usually represent a complication of chronic periodontitis (gum disease). Much less commonly, non-dental conditions can cause toothache, such as maxillary sinusitis, which can cause pain in the upper back teeth, or angina pectoris, which can cause pain in the lower teeth.

Toothache is the most common type of orofacial pain and, when severe, it is considered a dental emergency, since there may be a significant impact on sleep, eating, and other daily activities. It is one of the most common reasons for emergency dental appointments. Correct diagnosis can sometimes be challenging. The treatment of a toothache depends upon the exact cause, and may involve a filling, root canal treatment, extraction, drainage of pus, or other remedial action. The relief of toothache is considered one of the main responsibilities of dentists. In 2013, 223 million cases of tooth pain occurred as a result of dental caries in permanent teeth and 53 million cases occurred in baby teeth. Historically, the demand for treatment of toothache is thought to have led to the emergence of dental surgery as the first specialty of medicine.

Masticatory muscle myositis (MMM) is an inflammatory disease in dogs affecting the muscles of mastication (chewing). It is also known as atrophic myositis or eosinophilic myositis. MMM is the most common inflammatory myopathy in dogs. The disease mainly affects large breed dogs. German Shepherd Dogs and Cavalier King Charles Spaniels may be predisposed. There is a similar disease of the eye muscles found in Golden Retrievers. Symptoms of acute MMM include swelling of the jaw muscles, drooling, and pain on opening the mouth. Ophthalmic signs may include third eyelid protrusion, red eyes, and exophthalmos (protruding eyeballs). In chronic MMM there is atrophy of the jaw muscles, and scarring of the masticatory muscles due to fibrosis may result in inability to open the mouth (trismus). The affected muscles include the temporalis, masseter, and pterygoid muscles. The disease is usually bilateral.

MMM is caused by the presence of 2M fibers in the muscles of the jaw. 2M fibers are not found elsewhere in the body. The immune system recognizes these proteins as foreign to the body and attacks them, resulting in inflammation. Diagnosis of MMM is through either biopsy of the temporalis or masseter muscles or the 2M antibody assay, in which blood serum of the possible MMM-dog is reacted with temporalis tissue of a normal dog, or both. False negatives by the 2M antibody assay may be obtained if MMM is end-stage with destruction of type 2M fibers and marked fibrosis. Treatment is usually with corticosteroids such as prednisone, often with decreasing doses for up to 4–6 months, and in the case of trismus, manual opening of the mouth under anesthesia. Feeding very soft or liquid food during this time is usually necessary. The ultimate degree of recovery of jaw function and muscle mass will depend upon the extent of damage to the muscle tissue. Recurrence of MMM may occur. Misdiagnosis of MMM as a retroorbital abscess based on physical examination and finding of trismus leads to inappropriate treatment with antibiotics, which will not impede the progress of MMM.

Peritonsillar abscess (PTA), also known as a quinsy, is pus due to an infection behind the tonsil. Symptoms include fever, throat pain, trouble opening the mouth, and a change to the voice. Pain is usually worse on one side. Complications may include blockage of the airway or aspiration pneumonitis.

They are typically due to infection by a number of types of bacteria. Often it follows streptococcal pharyngitis. They do not typically occur in those who have had a tonsillectomy. Diagnosis is usually based on the symptoms. Medical imaging may be done to rule out complications.

Treatment is by removing the pus, antibiotics, sufficient fluids, and pain medication. Steroids may also be useful. Admission to hospital is generally not needed. In the United States about 3 per 10,000 people per year are affected. Young adults are most commonly affected.

Oral submucous fibrosis (OSMF or OSF) is a chronic, complex, premalignant (1% transformation risk) condition of the oral cavity, characterized by juxta-epithelial inflammatory reaction and progressive fibrosis of the submucosal tissues (the lamina propria and deeper connective tissues). As the disease progresses, the jaws become rigid to the point that the person is unable to open the mouth. The condition is remotely linked to oral cancers and is associated with areca nut or betel quid chewing, a habit similar to tobacco chewing, is practiced predominantly in Southeast Asia and India, dating back thousands of years.

Pericoronitis is an infection of the soft tissue that covers the crown of an impacted tooth and is usually caused by the normal oral microbiota. For most people there exists a balance between the host defenses and the oral micriobiota but if the host defenses are compromised like during minor illness such as influenza or an upper respiratory tract infection, pericoronitis results. Another common cause is entrapment of food beneath the gum flap (also called an operculum). Pericoronitis can present as a mild infection or severe infection. In its mildest form it is just a localized tissue swelling and soreness whereas in severe forms the swelling is slightly larger even sometimes creating trismus (difficulty opening the mouth).

Occasionally, an impacted tooth causes sufficient pressure on the roots of adjacent teeth causing it to resorb.

An impacted tooth occupies space that is usually filled with bone. This weakens that area of bone and renders the jaw more susceptible to fracture.

When impacted teeth are retained completely within the alveolar process, the associated follicular sac is also retained along with it. Though in most persons the dental follicle maintains its original size sometimes it may undergo cystic degeneration and become a dentigerous cyst or a keratocyst.

This type of classification is based on the amount of impacted tooth that is covered with the mandibular ramus. It is known as the Pell and Gregory classification, classes 1, 2, and 3.

By far, the two most common symptoms described are pain and the feeling that teeth no longer correctly meet (traumatic malocclusion, or disocclusion). The teeth are very sensitive to pressure (proprioception), so even a small change in the location of the teeth will generate this sensation. People will also be very sensitive to touching the area of the jaw that is broken, or in the case of condylar fracture the area just in front of the tragus of the ear.

Other symptoms may include loose teeth (teeth on either side of the fracture will feel loose because the fracture is mobile), numbness (because the inferior alveolar nerve runs along the jaw and can be compressed by a fracture) and trismus (difficulty opening the mouth).

Outside the mouth, signs of swelling, bruising and deformity can all be seen. Condylar fractures are deep, so it is rare to see significant swelling although, the trauma can cause fracture of the bone on the anterior aspect of the external auditory meatus so bruising or bleeding can sometimes be seen in the ear canal. Mouth opening can be diminished (less than 3 cm). There can be numbness or altered sensation (anesthesia/paraesthesia in the chin and lower lip (the distribution of the mental nerve).

Intraorally, if the fracture occurs in the tooth bearing area, a step may seen between the teeth on either side of the fracture or a space can be seen (often mistaken for a lost tooth) and bleeding from the gingiva in the area. There can be an open bite where the lower teeth, no longer meet the upper teeth. In the case of a unilateral condylar fracture the back teeth on the side of the fracture will meet and the open bite will get progressively greater towards the other side of the mouth.

Sometimes bruising will develop in the floor of the mouth (sublingual eccymosis) and the fracture can be moved by moving either side of the fracture segment up and down. For fractures that occur in the non-tooth bearing area (condyle, ramus, and sometimes the angle) an open bite is an important clinical feature since little else, other than swelling, may be apparent.

On physical exam, the fracture appears as a loss of cheek projection with increased width of the face. In most cases, there is loss of sensation in the cheek and upper lip due to infraorbital nerve injury. Facial bruising, periorbital ecchymosis, soft tissue gas, swelling, trismus, altered mastication, diplopia, and ophthalmoplegia are other indirect features of the injury. The zygomatic arch usually fractures at its weakest point, 1.5 cm behind the zygomaticotemporal suture.