Bone Sarcoma and Subtypes - Sarcoma Alliance Sarcoma Alliance guidance education support Bone Sarcoma and Subtypes The second group of sarcoma is bone sarcomas or bone cancer. There are three types of bone sarcoma: osteosarcoma; Ewing’s sarcoma; and chondrosarcoma. Bone sarcomas very rare with approximately 2,890 new cases diagnosed in the United States each year, and approximately 1,410 deaths. The incidence is slightly higher in males than females and no race has a higher incidence than another, although, Ewings sarcoma is more among Americans of European descent. Bone sarcomas are very likely to be diagnosed in children; and due to the rarity and severity of bone cancer, a bone cancer specialist such as a pediatric oncologist or an orthopedic oncologist should be consulted in the treatment of the disease. Bones consist of three types of tissue: compact tissue (the hard outer portion of the bone), cancellous tissue (spongy tissue inside the bone containing the bone marrow), and subchondral tissue (the smooth bone tissue of the joints). Cartilage surrounds the subchondral tissue to form a cushion around the joints.

Bone tumors can be benign (non-cancerous) or malignant (cancerous). Benign bone tumors are rarely life threatening and do not spread within the body; however, they can grow and compress healthy bone tissue. Cancer that develops in the bone is called primary bone cancer. It is differentiated by secondary bone cancer which spreads to the bone from another part of the body. Primary bone cancer is rare with approximately 2,500 new cases diagnosed each year in the United States (this figure includes bone cancer which is not sarcoma). The most common type of primary bone cancer is osteosarcoma. Because it occurs in growing bones, it is most often found in children. Another type of primary bone cancer is chondrosarcoma which is found in the cartilage. This cancer occurs more often in adults. Ewing’s sarcoma can occur as either a bone sarcoma or a soft tissue sarcoma depending upon the original location in the tumor. Scientists are uncertain what causes bone cancer however they have been able to identify some factors which may put a person at risk. Children and young adults who have had undergone radiation therapy or chemotherapy for other diseases are at increased risk for bone cancer.

Additionally, adults with Paget’s disease which is a disease characterized by abnormal growth of new bone cells have an increased risk of osteosarcoma. There are also some hereditary conditions which can increase the risk of bone cancer. Symptoms of bone cancer can vary depending on the size and location of the tumor. Pain is the most common symptom. Tumors arising in or around the joints often cause swelling and tenderness. Tumors can also weaken the bones thus causing fractures. Some other symptoms can be weight loss, fatigue and or anemia. The first step in diagnosing primary bone cancer is a complete medical history and physical examination performed by a physician. The doctor may order a blood test to determine the level of an enzyme called alkaline phosphatase. Approximately 55% of patients with primary bone cancer will have elevated levels of alkaline phosphatase. However, it isn’t a completely reliable indicator for bone cancer since growing bones in children will cause the enzyme to be elevated. X-rays are also used to locate a tumor. If an x-ray suggests a tumor is present than a doctor may require further testing such as a CT scan, Magnetic Resonance Imaging (MRI), or an angiogram.

Finally, a biopsy must be performed to determine if cancer is present. A biopsy is a procedure used to remove sample tissue from the tumor. A surgeon, usually an orthopedic oncologist, performs the procedure using a needle or making an incision. During a needle biopsy the surgeon makes a small hole in the bone and removes sample tissue with a small instrument. During an incisional biopsy, the surgeon cuts into the tumor and removes sample tissue. A Pathologist (a doctor specializing in identifying disease) then studies the cells and tissues under a microscope to determine whether the tumor is cancerous. The treatment of bone cancer depends on the size, location, type and stage of the cancer. Chemotherapy with surgery is often the primary treatment. While amputation of a limb is sometimes necessary, using chemotherapy either before or after surgery has allowed physicians to save the limb and improve survival in many cases. Radiation may be used in Ewing’s sarcoma is surgery is not feasible or in certain select cases of metastatic disease. New and more effective treatments are being developed in clinical trials at many hospitals and cancer centers in the United States.

Ewing’s Sarcoma Ewing’s sarcoma is actually several types of sarcomas known as the Ewings Family of Tumors. In the U.S., there are approximately 250 cases diagnosed a year, generally in children and young adults under the age of 30. It can be found in any bone, but is most common in the bones of the lower body such as the pelvis, tibia (shin), fibula (shin), and femur (thigh). Ewing’s sarcoma is often associated with a chromosomal translocation between genes EWS and FLI1 on chromosomes 22 and 11. Although Ewings is classified as a bone cancer, the type of cells it originates in is not completely known, which is why as mentioned above, occasionally Ewing’s sarcoma may occur in soft tissues, Peripheral Primitive Neuroectodermal Tumor (peripheral PNET) is a rare tumor that has the same translocation, and is now considered to be identical to Ewings. The Ewings Family of Tumors (EFT) includes Ewing’s sarcoma of bone, extraosseous Ewings, and peripheral PNET.

It is not known what causes the tumor, although it is more likely to occur in people of European descent. It is an aggressive cancer and is treated with a combination of surgery, radiation, and chemotherapy, with a good outcome for many cases. Chondrosarcoma Chondrosarcoma is a cancer that develops from the cells that produce cartilage . A little less than one-third of bone sarcomas are chondrosarcomas. While the disease can affect people of any age, unlike most other forms of skeletal system cancer, it is more common among older people than among children. Also unlike the other bone cancers chondrosarcoma is more often found in the spine and pelvis than in legs or arms. Surgery is the most common treatment for chondrosarcoma, sometimes with radiation or chemotherapy as well. Osteosarcoma (Osteogenic Sarcoma) Osteosarcoma is a malignant (cancerous) bone tumor that occurs predominantly in adolescents and young adults. It accounts for approximately 5% of the tumors in childhood. the bones most frequently involved are the large bones of the upper arm (humerus) and the leg (femur and tibia).

In children and adolescents, 80% of these tumors arise from the bones around the knee. It is slightly more common in males than females. It is the most common primary malignant bone tumor with the exception of myeloma. Although osteosarcoma is a common malignant bone tumor, it is still rare with less than 1,000 new cases each year in the United States. Due to its rarity, it is imperative that patients with proven or suspected osteosarcoma have an initial evaluation by an orthopedic oncologist familiar with the management of this disease. This evaluation should be done prior to the initial biopsy, since an inappropriately performed biopsy may jeopardize a limb-sparing procedure. Osteosarcoma occurs in adolescents at the time they are most rapidly growing in their most rapidly growing bones; therefore, it is suspected that rapid bone growth may play a role in the development of osteosarcoma. Additionally, some evidence suggests that chronic bone injury can increase the risk for osteosarcoma. When osteosarcoma occurs in adults over age 40 it is usually associated with a pre-existing condition such as Paget’s disease.

The initial symptoms include pain, often in and around the knee, especially in tumors on the tibia or femur. The pain typically worsens over time and is not related to the time of day. Swelling and tenderness typically occur late in the course of osteogenic sarcoma, followed by a large soft tissue mass appearing. A screening of serum alkaline phosphatase levels may be done. These levels are high in approximately 45-50% of patients with osteosarcoma; therefore it cannot be used alone to diagnose the disease. Osteosarcoma must be diagnosed by biopsy. Because the disease commonly spreads (metastasizes) to other parts of the body, especially the lungs, chest x-rays, lung tomograms, CT scans of the chest , and an x-ray skeletal survey or bone scan may be done before treatment. This process is called staging. There are three groups used to describe the extent of the disease: Localized – the cancer cells have not spread beyond the bone or nearby tissue. Metastatic – the cancer cells have spread from the bone where the cancer began to other parts of the body (commonly the lungs, however it can spread to other bone).

Recurrent – the cancer has come back after it has been treated. It may come back to the original site of the tumor or another part of the body. Surgery is the primary method of treatment. This can be either an amputation or limb-sparing procedure. A limb-sparing procedure is when a surgeon removes the tumor and a block of surrounding tissues to ensure clean (cancer free) margins around the tumor. The surgeon then reconstructs the limb using prosthetic devices, bone grafts or other reconstructive techniques. These procedures are highly specialized and are usually performed by an orthopedic oncologist. In general 70-90% of osteosarcomas of the limb can be treated by a limb-sparing procedure and do not require amputation; therefore, before undergoing an amputation, it is recommended that the patient seek the advice of an orthopedic oncologist. Surgery is usually followed by a course of chemotherapy using one or more anti-cancer drugs. Some clinical trials have shown that adjuvant chemotherapy ( chemotherapy given when no clear evidence of cancer can be found i.e. after the tumor is removed) may be helpful in preventing the relapse or recurrence of the disease.

Other trials suggest that there is no difference in outcome between pre-operative chemotherapy or adjuvant chemotherapy. Parosteal osteosarcoma Parosteal osteosarcoma is a low grade tumor that arises on the surface of the bone. It rarely penetrates the center of the bone and rarely becomes a highly malignant osteosarcoma. It accounts for approximately 4% of all osteosarcomas and is slightly more common in females than males. It is different than classic osteosarcoma in that it typically arises in adults between the ages of 20 and 40. It has a better prognosis than classic osteosarcoma with an overall survival rate of 75% to 85%. It has a very slow rate of metastases (spreading). Parosteal osteosarcoma is most commonly found on the femur, behind the knee (72% of all cases). It usually presents itself with minimal pain and tenderness and in its typical location behind the knee there may be some restriction in movement of the knee joint. Surgery with wide margins is the standard treatment for parosteal osteosarcoma, either by amputation or limb-sparing surgery.

Because they are located at the end of the bone, are typically low grade, and lack local invasiveness, they are often amenable to limb-sparing procedures. Grade III parosteal lesions usually require chemotherapy because of the risk of metastases. Periosteal osteosarcoma Like parosteal osteosarcoma, periosteal osteosarcoma is an uncommon tumor arising on the surface of the bone, most commonly the tibia. It is a high grade tumor composed of malignant cartilage. It occurs in a younger age group and is even more common among females than males than parosteal osteosarcoma. Because periosteal osteosarcoma is more likely to metastasize than the parosteal, some oncologists treat this tumor more aggressively with combination therapy such as surgery and chemotherapy. Multifocal Sclerosing osteosarcoma Multifocal sclerosing osteosarcoma is an extremely rare form of osteosarcoma. It tends to occur in children less than 10 years old and represents less than 3% of all primary osteosarcomas. It is an aggressive tumor which presents as a single painful tumor, much like other types of osteosarcoma.

However further tests looking for metastases reveal tumor in virtually all of the skeleton. Since all the bones of the body are involved surgery is usually not an option, except to relieve pain. Aggressive chemotherapy can lead to a remission; however, multiple tumors eventually progress and mortality approaches 100%. Osteosarcoma of the Jaw and Skull Osteosarcoma of the craniofacial bones are relatively rare and represent less than 10% of all osteosarcomas. They typically occur in patients between the ages of 20 and 40 and have the same occurrence rate between males and females. The bones most commonly affected are the mandible (jaw bone) and the maxilla (cheek bone). Because they are located in the head and neck, they tend to be diagnosed earlier and can remain localized for longer periods of time; however, they are more difficult to remove surgically and therefore local recurrence is common. Treatment of malignant osteosarcoma in the skull bones is similar of classic osteosarcoma. It should include preoperative chemotherapy. This is extremely important due to the limited margins available for surgical excision.

Osteosarcoma in Paget’s Disease Paget’s disease affects approximately 3% of the population over the age of 60. It is characterized by abnormal growth of new bone cells leading to multiple bone deformities. Approximately 1% of patients with Paget’s disease develop primary bone sarcoma. The tumors usually arise in the pelvis, femur, or humerus. They typically are large and very destructive making surgery difficult. At the time of diagnosis, the cancer has often metastasized to the lungs. Amputation is sometimes necessary. Patients with suspected osteosarcoma arising in Paget’s disease should receive a bone scan and x-ray of all identified tumors. Additionally, a CT scan of the chest should be done to rule out metastases to the lungs. Treatment is the same as fully malignant osteosarcoma arising in a younger population. Patients with preoperative chemotherapy, radical surgery of the tumor, followed by post-operative chemotherapy have the best prognosis. Tumors arising in the skull and spine are sometimes inoperable. In this instance patients are typically given chemotherapy and radiation therapy to control and shrink the tumor. Great care must be taken during chemotherapy treatments since many older patients have impaired kidney function.

Post-irradiation Osteosarcoma (Radiation Induced) Radiation Induced Osteosarcoma is a rare form of osteosarcoma which occurs in people who have undergone radiation therapy treatments for other diseases. The average length of time before these tumors appear is 10 years following radiation. The younger the patient is at the time of radiation, the higher the risk of osteosarcoma. Additionally, evidence suggest that patients who receive higher doses of radiation are at a higher risk of developing osteosarcoma than patients who receive lower doses of radiation. Post-irradiation osteosarcomas are most commonly located in the spine, pelvis, hips and shoulders. People with retinoblastoma, a malignant tumor of the eye, are at a higher risk of developing post-irradiation osteosarcoma due to a defect in the RB gene. Symptoms of postirradiation osteosarcoma are painful swelling in and around the area of radiation. A biopsy must be performed in order to diagnose the disease. Once the diagnosis is made, staging of the tumor is done using bone scan, CT scan or MRI. Additionally a CT scan of the lungs should be done to rule out metastases to the lungs.

The treatment of postirradaition sarcoma is similar to classic osteosarcoma. It usually included preoperative chemotherapy, surgery and followed by postoperative chemotherapy. Surgery can be difficult when tumors are in and around the spine and therefore preoperative chemotherapy to shrink the tumor is crucial. Due to this challenge, the prognosis for postirradiation osteosarcoma is worse than that for classic osteosarcoma. Mandible | Radiology Reference Article | Radiopaedia.org A.Prof Frank Gaillard ◉ et al. The mandible consists of a curved, horizontal portion, the body, and two perpendicular portions, the rami, which unite with the ends of the body nearly at right angles (angle of the jaw). It articulates with both temporal bones at the mandibular fossa at the temporomandibular joints (TMJ) .

Osteology Body The body of the mandible is curved, somewhat like a horseshoe, and two surface and two borders: external surface midline ridge indicating the symphysis mental foramen : inferior to second premolar tooth, midway between the superior and inferior borders; allows for the passage of the mental vessels and mental nerve internal surface fossae for the submental and submandibular salivary glands superior (or alveolar) border wider behind than in front hollowed for reception of teeth (normally 16) inferior border rounded, longer than the superior border and thicker in front than behind groove for the facial artery may be present at the point it joins the ramus of the mandible Ramus The ramus is quadrilateral in shape, and has two surfaces, four borders, and two processes and one canal: external (or lateral) surface flat; gives attachement to the masseter muscle inner (or medial) surface mandibular foramen: inferior alveolar vessels and nerve pass into lingula mandible: prominent, sharp ridge in front of the mandibular foramen; gives attachment to the sphenomandibular ligament lower border thick, straight and continuous with the inferior border of the body of the mandible

 posterior border thick, smooth, rounded and covered by the parotid gland angle of the mandible is at its junction of the posterior border and the body anterior border thin above and thicker below; continuous with the oblique line upper border thin consists of the coronoid process anteriorly and the condylar process posterior separated by the mandibular notch The mandibular canal runs obliquely downward and forward in the ramus, and then horizontally forward in the body, where it is placed under the alveoli and communicates with them by small openings.

On arriving at the incisor teeth, it turns back to communicate with the mental foramen, giving off two small canals which run to the cavities containing the incisor teeth. It contains the inferior alveolar vessels and nerve, from which branches are distributed to the teeth via the incisive nerve . Coronoid Process thin, triangular eminence from the upper border of the ramus of the mandible separated from the condylar process posteriorly by the mandibular notch temporalis muscle inserts into its medial and lateral surfaces masseter muscle also inserts into its lateral surface Condylar Process thicker than the coronoid process consists of two portions: condyle and neck articular surface for articulation with the articular disk of the temporomandibular joint (TMJ) convex from before backward and from side to side, and extends farther on the posterior than on the anterior surface condylar neck is flattened from front to back; lateral pterygoid muscle inserts into it Blood supply rectus capitis posterior major muscle rectus capitis posterior minor muscle obliquus captifs superior muscle References Gray's Anatomy 20th Edition What is the Mandible? (with pictures) What is the Mandible?

Last Modified Date: 16 December 2016 Copyright Protected: Top 10 amazing movie makeup transformations In human anatomy , the mandible is the lower jawbone, providing structure to the chin and support for the lower teeth. Another name for the mandible bone is the inferior maxillary bone. It is a U-shaped bone which extends from one ear down to the chin and back up to the ear on the other side of the head. Vertical extensions of the mandible form left and right joints with the main portion of the skull, the cranium, to form the jawbone joints. The name for these joints is the tempero mandibular joints. In mandible anatomy, names are given to various parts of the jawbone. The main names for the different parts of the mandible are the body, the condoyle, the coronoid process , and the ascending ramus. The body is the middle part of the bone that forms a U-shape and holds the lower teeth. The condoyles are the rounded projections at both sides of the upper back part of the bone. These round pieces of bone fit into the joint with the cranium on each side of the head, slightly lower than the ear.

Together with the cranium sockets and the associated muscle tissue, the condoyles form the jawbone joints. Ad The coronoid process is a piece of bone that protrudes upwards from the mandible at the back of the teeth. There are two coronoid processes, one at each side of the jaw. The muscles that are used for chewing are attached to the coronoid processes and they then attach to the cranium. The ascending ramus is the name for the portion of bone that joins the U-shaped body of the jawbone to the condoyles and the coronoid processes. The ascending ramus is typically a flat portion of bone. It gives shape to the facial jaw line. Significant proportions of facial injuries, particularly those sustained in traffic accidents and in assaults, result in fractured mandibles. In addition to fractures, mandibular dislocations, or dislocation of the jaw, may occur. The jawbone can be dislocated downwards or sideways, but very rarely is it dislocated to the back. Another medical condition often associated with the mandible is periodontitis, otherwise known as gum disease . Gum disease occurs when bacteria and plaque build up on the teeth, both above and below the gum line.

In advanced cases, the damage is not limited to the gums and teeth but also begins to affect the mandibular bone that holds the teeth in place. The bone is eroded and teeth are often lost. Ad Mandible Synonyms, Mandible Antonyms | Thesaurus.com Cite This Source Word Origin & History mandible 1540s, "jaw, jawbone," from L.L. mandibula "jaw," from L. mandere "to chew." Of insect mouth parts from 1826. Example Sentences for mandible He was a tall man, with a drooping mustache and a nose that beaked at the tip like a butcher-bird's mandible. The premaxill and the end of the mandible are greatly expanded. Rami of mandible anchylosed together at symphysis and suture largely obliterated. In such crania the mandible is wanting, and the teeth are wanting. The distance from Mandible Cape to the mouth of the Mercy was not more than eight miles. The mandible articulates with the cranium by means of a quadrate.

The anterior part of the mandible is narrow and the lower incisors are diminutive and often concealed by the flesh of the gum. The rami of the mandible are not ankylosed together in front. In their massiveness they are unsurpassed save by the mandible from Mauer. Palatal aspect of the cranium and mandible of a Donkey (Equus asinus) 1/5. Dentigerous cyst | Radiology Reference Article | Radiopaedia.org Imaging Differential Diagnosis Epidemiology Dentigerous cysts are the second most common odontogenic cysts after those related to the roots of the teeth ( periapical cysts ) 3. They usually present in the 2nd to 4th decades of life and are uncommonly seen in childhood because they almost exclusively occur in secondary dentition 1-3. Clinical presentation Typically, dentigerous cysts are painless and discovered during a routine radiographic examination, however, they may be large and result in a palpable mass. Additionally, as they grow, they displace adjacent teeth 2. Several cases of dentigerous cysts presenting as recurrent head and neck infection or as a deep neck space abscess have been described.

Pathology A dentigerous cyst is formed by the hydrostatic force exerted by the accumulation of fluid between reduced enamel epithelium and the tooth crown of unerupted teeth 1-3,5. As such the cyst encloses the crown and is attached to the neck at the cementoenamel junction 5. They almost exclusively occur in permanent dentition. Stratified squamous nonkeratinising epithelium lines the cyst. Over 75% of all cases are located in the mandible , with the most commonly involved teeth being 1,3: mandibular third molar (most common) maxillary third molar (2nd most common) maxillary canine mandibular second premolar Associations Dentigerous cysts are usually solitary. However, multiple cysts are recognised to occur in association with syndromes such as: basal cell nevus syndrome 7 Radiographic features Dentigerous cysts are frequently seen on OPGs, and often require no further imaging to make the diagnosis. CT and MRI give additional information and help in distinguishing this entity from other cystic lesions of the mandible and maxilla.

When small, it is difficult to differentiate a dentigerous cyst from a large but normal dental follicle. A working definition is that a dentigerous cyst exists when the distance between the crown and dental sac is greater than 2.5-3.0 mm 5-6. Panoramic radiograph (OPG) Radiographically, dentigerous cysts appear as unilocular well defined pericoronal radiolucencies centred on an impacted or unerupted tooth. They have a thin regular sclerotic margin and expand the overlying cortex without cortical breach (unless superimposed fracture or infection). Their size is extremely variable, ranging from only slightly greater in size than a normal follicle to very large, appearing to hollow-out the majority of the jaw 1-4. Erosion or resorption of the roots of adjacent teeth is sometimes seen 6. CT CT appearances mirror those of radiographs. The relationship to the unerupted tooth can often be better appreciated, and the cyst cavity is filled with water density fluid. Maxillary lesions may project superiorly into the paranasal sinuses or nasal cavity 3-4.

MRI The main role of MRI is help distinguish these lesions from other cystic lesions of the jaw, when appearances are atypical. T1: low signal, similar to water/CSF T2: high signal, similar to water/CSF T1 C+ (Gd): no solid component or enhancement, except for potentially a thin peripheral rim of enhancement 1,3 Treatment and prognosis Treatment usually involves removal of the entire cyst and the associated unerupted tooth. In patients with very large lesion or who are unfit medically, marsupialisaiton is an option 6. Recurrence is uncommon, but may occur if parts of the cyst lining are left in situ 6. Complications pathological jaw fracture: if large enough very rarely dentigerous cysts may develop into a mural ameloblastoma 2 there is a potential of development of squamous cell carcinoma in the context of chronic infection Differential diagnosis When small, it is difficult to differentiate a dentigerous cyst from a large but normal dental follicle 5-6. Jaw Joint Problems, TMJ Problems Jaw Joint Problems The temporomandibular joint (TMJ / jaw joint) is located in front of the ear where the skull and the lower jaw meet.

The joint allows the lower jaw (mandible) to move and function for eating, talking etc. The joint itself is made up of two bones that are separated by a disc of cartilage (a tough tissue). Ligaments and muscles surround the joint. Diagram Showing the Position & Anatomy of the TMJ / Jaw Joint Problems with the jaw joint are very common but typically only last a few months before getting better. In some instances, only the muscles are affected (known as myofacial pain dysfunction), whereas in others, the cartilage and ligaments may also be a problem (known as internal derangement of temporomandibular joint). The most common symptoms are: Joint noise - such as clicking, cracking, crunching, grating or popping. Pain - usually a dull ache in and around the ear. The pain may radiate, i.e. move forwards along the cheekbone or downwards into the neck. Headache. Trismus - inability to open your mouth fully. Most jaw joint problems are made worse by chewing and are aggravated at times of stress. What causes jaw joint problems? Pain is caused by the muscles in and around the jaw joint tightening up.

Joint noise occurs if the disc of cartilage moves out of its normal position between the bones of the jaw joint. Most commonly, the disc slips forward and a noise is made when it returns to its normal position in between the bones. The noise sounds louder to some patients than others because the joint is just in front of the ear. The ligaments and muscles surrounding the joint can in turn go into spasm, producing pain and a difficulty in opening the mouth properly. Why have I got jaw joint problems? The cartilage in the jaw joint is thought to slip forwards because of over-use of the muscles surrounding the jaw. The over-use commonly produces tightening of the muscles and may occur as a result of chewing habits, such as grinding or clenching the teeth when under stress (usually when asleep). Nail biting or holding things between the teeth can also cause jaw joint problems. Less commonly, missing back teeth, an uneven bite or an injury to the jaw can lead to the problem. Often, no obvious cause is found. Are my problems anything to worry about? Jaw joint problems are usually not serious and do not lead on to other problems, e.g. arthritis of the jaw joint. However, they are a nuisance.

Fortunately, jaw joint problems usually respond well to simple treatments. What are the Treatments? Treatments vary depending on whether you are suffering from myofacial pain dysfunction, internal derangement of the temporomandibular joint or a combination of both. On the whole, treatment is aimed at trying to reduce the workload of the muscles, so allowing the disc of cartilage to return to a normal position in the joint. This includes such advice as: Eat a soft diet that requires little chewing - allowing the over-worked muscles to rest. Take painkillers - anti-inflammatory medication (e.g. Ibuprofen) is good and can be taken as either tablets or applied as a gel on the outside of the joint. Use heat - e.g. wrap a hot water bottle filled with warm water in a towel and apply it to the side of your face. Identify and stop any bad habits, such as clenching or grinding. Although, this may be difficult as they are often 'subconscious', i.e. you may not be aware you are doing them. Use relaxation therapy and learn techniques to control tension and stress. Jaw joint exercises - your doctor will advise you on the best kind of exercises for your problems.

Please remember to follow them as instructed. Rest the joint as much as possible, e.g. avoid yawning. Wear a clear plastic splint that fits over the teeth and is worn mainly at night (a Bite Raising Appliance). This helps support the joint and surrounding muscles. Follow a physiotherapy programme. Replace missing teeth to balance the bite (if appropriate). What happens if these methods do not help? Surgery is only carried out in a small number of cases. This can involve manipulation of the joint whilst you are asleep, or more rarely, surgery carried out with a mini telescope. In extreme cases, it may be necessary to open the joint and operate on the bones, cartilage and ligaments. Can jaw joint problems develop into anything worse? It is important to realise that jaw joint problems, although a nuisance, are not sinister and usually respond well to relatively simple measures over a period of time. Patients can manage most of the treatments themselves. Occasionally, jaw joint problems may return after several years. It is very rare for jaw joint problems to progress to anything serious, like arthritis.

TMJ TMJ TMJ (Temporomandibular Joint) or TMD (Temporomandibular Joint Disorder or Dysfunction) involves pain or loss of function of the temporomandibular (jaw) joint and surrounding muscles. It can cause long-term hypersensitivity of the nerves surrounding the immediate area. It is not a progressive or degenerative disorder, and its prevalence does not increase with age. Approximately 7 million adults have pain on or near the TMJ. It occurs in all age groups, seems to affect women more frequently than men. TMD is currently the most common orofacial disorder seen by health care workers today. The TMJ, located just anterior the external ear, is a hinge joint and with its disk, acts as a moveable socket. The two temporomandibular joints consisting of soft tissues such as joint capsules, masticatory muscles, and ligaments connect the mandible to the skull which is cushioned by an articular disk.

The TMJ and surrounding muscles consist of: - condylar process: hinges the jaw to the skull - disk: positioned between the condylar process and the skull - synovial membrane: a single layer of cells that line the inner surface of the TMJ. * muscles - temporalis: closes and retract mandible - masseter: closes mandible - medial pterygoid: closes mandible - lateral pterygoid : opens, protrudes mandible, allows side-to-side movement * The neural innervation of the muscles of mastication is from the mandibular division of the trigeminal nerve; blood is supplied by the muscular branches of the maxillary artery. - suprahyoid muscles: are considered accessory muscles of mastication and aid in mandibular depression when the hyoid bone is fixed by contraction of the infrahyoid muscles. - buccinator: cheek muscle - temporomandibular ligament: most important; it originates at the inferior aspect of the zygomatic arch; limits excessive lateral or posterior movement of the condyle.

The mandible's main function is for chewing, other functions that pertain to speech include: helping to adjust the size of the vocal tract and while articulating there is a collaborative interaction of the tongue and mandible. If the mandible does not move during speech, vocal tract adjustments (exclusive of soft palate and some pharyngeal wall movements) are made entirely by the tongue. * trauma (to the mandible itself) - sports related injuries (boxing, football, soccer, rugby, wrestling, hockey, baseball, water and snow skiing, etc.) - MVA injuries (whiplash) * malocclusion and hyperactivity that goes along with this condition * enlarged mandibular condyles * missing teeth * faulty occlusion * bimaxillary protrusion ï¿½ occlusion is normal but the entire dentition is forward with respect to the facial profile.

* systematic inflammatory disease, infections, or viruses (measles, mumps, infectious mono) * osteoarthritis * prolonged opening of the mouth * singing and gum chewing * mouth breathing Trauma - causes muscle guarding due to the pain-spasm cycle, which increases the pull of the lateral pterygoid muscle on the disc, resulting in a stretching of the posterior and lateral collateral ligaments. Stress - causes overactivity of the muscles of mastication, which results in a clenching or gnashing of the mandible (buxism). * pain in the TMJ (jawache, earache, and/ or headache with possible dizziness) * pain in the muscles of mastication * restricted mandibular movement (locking of the jaw) * joint sounds (clicking, popping, or grating in the TMJ and mandibular movements) (~ noise by themselves are not considered TMD and approx. 44% of the general population has clicking) * pain when chewing * hearing loss * ear pain or stuffiness in the ear * nasopharyngeal symptoms such as swallowing difficulties or numbness or burning sensations in the tongue, palate, or throat.

* related pain may be felt in the dorsum of the neck, sternocleidomastoid region, or trapiezius muscle - what increases and decreases symptoms - pain ranking and intensity - recent and past dental history II. Examine general facial appearance and posture - visually check if body is in correct alignment (no forwardness of arms, shoulders, and head) - facial symmetry - hypertrophy of the masseter muscle ( the masseter is easily seen by having the person clench the jaw closed very tightly and there should be equal size bilaterally) III. Palpation of the TMJ region This is usually quick and simple: *masseter: during contraction and relaxation *temporalis: muscle palpated over its origin Anterior- The lateral aspect of the TMJ space is palpated just anterior to the ear, and chief findings of inflammation or trauma to the joint are swelling, increased temperatures, or pain with palpation. Have patient open and close mouth while palpating bilaterally. * normal - should move smooth and equally * abnormal - feel one side rotate before other - shift laterally while mandible is moving Posterior- Put little fingers inside ears, press gently anteriorly.

Have patient open and close mouth several times, assessing for pain and equal motion bilaterally * normal - should have equal motion * abnormal - pain upon closing is indicative of posterior capsulitis (caused by mandibular condyle positioned too far posteriorly) IV. Range of motion testing // Visual Opening of the mouth varies in degrees of motion available based on the physical size of individuals. General guideline for mandibular opening is see if the patient can place two knuckles or fingers in the open mouth. * If they cannot, then this is a positive finding of hypomobility * If they can place 3 or more knuckles in mouth, this is positive for hypermobility Opening and closing of the mouth during range of motion should be examined very carefully visually. Often lateral deviation..... * deviation occurring early in motion opposite side of involvement is usually caused by muscle spasms. * midrange - muscle imbalance * deviation to the involved side at end range of opening is most often due to posterior capsulitis. - Also look for protrusion or jutting of jaw forward using teeth as landmarks. V. Masticatory Muscle Tests Identifies pathological conditions that may exists in the muscles.

This will be evidenced by pain that will be elicited upon application of maximum resistance. To effectively test the muscles of mastication, the following rules should be observed: 1) The head must be supported to eliminate head movement or rotation. 2) the mouth should be partially opened (about 1 cm), 3) the application of force must be gradual enough to enable the client to build maximal resistance, and 4) hand contact with the TMJ should be avoided; pain elicited in the presence of acute joint disease might be confused with the results of muscle testing. - Resistive opening. To muscle test the main opening muscles of the jaw (inferior head of the lateral pterygoid), the client opens his/her jaw slightly and resists the therapistï¿½s "strong" closing force applied to the clientï¿½s chin. - Resistive closing. The therapist applies a strong downward force to the incisal edges of the clientï¿½s lower anterior teeth and attempts to further open the clientï¿½s mouth against strong resistance. - Resistive lateral excursion. This tests the medial and lateral pterygoid muscle simultaneously.

A weak lateral pterygoid muscle might not be obvious on resistive opening muscle tests but would be evident bt comparison with the opposite side. - Resisted protrusion muscle test is some times used to test the main opening jaw muscles. The client opens and protrudes the jaw slightly. The therapistï¿½s supports the clientï¿½s occiput and attempts to force the jaw posteriorly as the client resists. This test might be used to corroborate a vagus response to the resisted opening test.. VI. Listen for Joint Noise This is the most beneficial for TMD because it involves mediate auscultations. You assess for the presence of osteoarthritis in TMJ which will present with grinding and crepitis at end range of motion and can help in disc derangement. Use the stethoscope to listen for joint noise. (* Joint noise should serve only as a confirmation of TMJ after range of motion loss and pain with palpation .

* reduced derangement - (reciprocal click) - click @ 15-20 mm opening the mouth and 2cd click @ 10-15 mm of closing * nonreducing disc - (similar to a tear in the knee - the disc will get in the way of condyle for prevention of movement) - mandibular opening limited to 15-20 mm of motion. VII. Oral Cavity Evaluation The tongue should be evaluated with regard to its size, position at rest, function, length of frenulum, and oral habits. Tongue size is an important factor. A small tongue (microglossia) will not exert enough pressure against the teeth, while a large tongue (macroglossia) will exert too much pressure. In addition, an extremely large tongue may interfere with occlusion. A good buccinator muscle tone is also important in maintaining good oral function. VIII. Imaging Techniques Imaging techniques such as radiographs, computerized tomography scans, and MRI are commonly used by dentist and physicians to view TMJ region. - Radiographs are taken in a panoramic view and in open and closed mouth positions.

They are indicated if osteoarthritis is suspected, but not very beneficial in diagnosing disc derangements. - CT scans and MRI are considered the most accurate imaging methods for evaluating soft tissues in TMJ, but are costly. - Bio (EMG) electromyography can be used to record jaw movements and bite positions in TMD patients. It can also be used to measure chewing muscle activity and helps to diagnose type of TMD. The cause and treatment of TMD are not always straight forward and pain may persist. * Traditional dental treatment for jaw and facial pain involves creating a mouth appliance for the patient to wear. The mouth appliance, or mouth splint, improves headaches, joint and ear symptoms, and facial and back pain after one month of use. * Limit the degree of opening and to rest the joint. This includes a liquid or soft diet, limited movement, and refraining from talking or singing. * Application of heat or cold is systematically effective in reducing acute inflammation and associated muscle spasm. * Physical therapy and stress reduction. * Electronic stimulation of jaw muscles maybe used in biofeedback. * Isometric jaw exercises. * Those with more severe symptoms can be treated surgically. * Medication may help treat TMJ.

Certain drugs may reduce or eliminate hypersensitivity. Research is scanty but supports the following: - Low doses of certain antidepressants may help, but caution must be used in patients with heart disease. - Benzodiazepine drugs may help when pain appears due to muscular or skeletal problems, but they can cause sedation, dependency, or worsen depression. - Drugs such as aspirin, acetaminophen, or ibuprofen may help when inflammation is involved, but long-term use can cause serious gastrointestinal or kidney complications. - Repeated injections of Corticosteroids can damage joints. - Narcotics should be reserved for cases where all other measures have failed. Effects on Lifestyle Persistent pain in the jaw seems to interfere with psychological well-being, especially in chronic situations. ( Study showed that they have more frequent diagnosis of anxiety, affective disorders, and paranoid personalities). From 20% to 30% of TMD patients may have difficulty coping with pain, and may experience some degree of disability are psychological distress. Gould III, J.A., Davis G.S., Orthopaedic and Sports Physical Therapy. Raphael, K., Marbach, J.J., Management of temporomandibular disorders.

Journal of the American Dental Association, Nov 1996 v127 n11 p1595(12). Sailors, M.E., Evaluation of sports-related temporomandibular dysfunctions. Journal of Athletic Training., Oct-Dec 1996 v31 n4 p346(5). SLAVKIN,h.c., A lifetime of motion: temporomandibular joints. Journal of the American Dental Association., July 1996 v127 n7 p1093(6). Denucci, D.J., Dionne, R.A., Dubner, R., Identifying a neurobiologic basis for drug therapy in TMDs. Journal of the American Dental Association. May 1996 v127 n5 p581(13). Moses, A.J., Understanding temporomanibular disorders. Defense Counsel Journal, April 1994 61 n2 p278-281. Exostoses & Tori Exostoses & Tori What is an Exostosis & Torus? These are bony swellings that develop in the mouth. These are not that unusual.

They come in a number of shapes, sizes and positions (that is, either in the midline of the roof of the mouth, the tongue side of the lower jaw or the cheek side of both upper and lower jaws). These bony swellings are given the ‘technical’ names of exostoses or tori. The torus is considered to be a developmental anomaly, although it does not present until adult life and often will continue to grow slowly throughout life. Photos of bony swellings in the roof of the mouth (palate), Tori Palatinus The Torus Palatinus commonly forms towards the back of the hard palate (roof of mouth) in the midline. The swelling is rounded and symmetrical, sometimes with a midline groove. It is not usually noticed until middle age and, if it interferes with the fitting of a denture, it can be removed. Most palatal tori are less than 2 cm in diameter but their size can change throughout life.

The prevalence of palatal tori ranges from 9% - 60% of the population and are more common than bony growths occurring on the mandible (lower jaw), known as torus mandibularis (ranges from 5% - 40%). The prevalence rate for tori is 27 / 1,000 adults. These bony lumps are not present until the late teen and early adult years and many, if not most, continue to slowly enlarge over time. Fewer than 3% occur in children. Taken as a group, these bony lumps are found in at least 3% of adults and are more common in females than in males. Photos of bony swellings in the floor of the mouth, Tori Mandibularis. Superficial bony masses / lumps found in another site (of the mouth or body) are typically given the catch-all name of exostosis or osteoma. They are considered to be trauma-provoked inflammatory responses or true (benign) neoplasms.

Unless such a bony prominence is specifically located, is stalked or is associated with an osteoma-producing syndrome such as the Gardner syndrome, there may be no means by which to differentiate an exostosis from an osteoma, even under the microscope. What are the signs & symptoms of an exostosis & torus? Tori can be categorised by their appearance. Arising as a broad base and a smooth surface, flat tori are located on the midline of the palate and extend symmetrically to either side. Spindle tori have a ridge located at their midline. Nodular tori have multiple bony growths that each have their own base. Lobular tori have multiple bony growths with a common base. The torus may be bosselated or multi-lobulated but the exostosis is typically a single, broad-based, smooth-surfaced mass, perhaps with a central sharp, pointed projection of bone producing tenderness immediately beneath the surface mucosa. Slowly enlarging, recurrent lesions occasionally are seen, but there is no malignant transformation potential.

The patient should be evaluated for Gardner syndrome should there be multiple bony growths or lesions not in the classic torus or buccal exostosis locations. Intestinal polyposis and cutaneous cysts or fibromas are other common features of this autosomal dominant syndrome. What are the causes of an exostosis & torus? Tori / buccal exostoses may be the outcome of mild, chronic peri-osteal ischæmia secondary to mild nasal septum pressures (palatal torus) or the torquing action of the arch of the mandible (mandibular torus) or lateral pressures from the roots of the underlying teeth (buccal exostosis) but this is largely speculation. The size of the tori may fluctuate throughout life and in some cases the tori can be large enough to touch each other in the midline of mouth. Consequently, it is believed that mandibular tori are the result of local stresses and not solely on genetic influences.

Neither the torus nor the exostosis requires treatment unless it becomes so large that: • it interferes with function or denture placement • suffers from recurring traumatic surface ulceration (usually from sharp foods, such as potato chips or fish bones) • contributing to a periodontal condition If removal of the tori is needed, surgery can be done to reduce the amount of bone, but the tori may reform in cases where nearby teeth still receive local stresses. When treatment is elected, the tori may be chiseled off of the jaw or removed via bone-burr cutting / smoothing through the base of the bony lump. Useful Articles: Tori mandibularis form on the tongue-side of the lower jaw, in the region of the premolars / bicuspids (and above the location of the mylohyoid muscle's attachment to the mandible). They are typically (90% of cases ) bilateral (i.e on both sides) forming hard, rounded swellings. The management is the same as that of the same as that of the torus palatinus.

A buccal exostosis is the formation of an exostosis (bone mass) on the outer, cheek-facing side of the maxilla (upper jaw) just above the teeth or the cheek-facing side of the mandible (lower jaw). They are less common on the lower jaw. They begin to develop in early adulthood and may very slowly enlarge over years. They are painless and self-limiting but may contribute to periodontal disease (gum disease / pyorrhoea) if they become too large. They can be removed with surgery. Buccal exostoses have no malignant potential. Last Updated 26th February 2014

Question: What is the common name of the mandible?
Answer: Jawbone