Chewing, speaking, breathing, and even sleeping may be hampered by a jaw that is too short, too big, or crooked. The shape of your jaws has an effect on the appearance of your face. This article explains how the teeth and jaws work. It also goes through some of the most common jaw issues and how to deal with them.
The face's framework is made up of bones. How well the teeth fit together is determined by the size and location of the facial bones. Chewing, speaking, and the functioning of the jaw joint are all influenced by the positions of the jaws and teeth. Soft tissues such as muscles, lips, and tongue are also held and supported by the jaws. The jaws and teeth, of course, play a role in the form and appearance of the face.
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The lower jaw can move freely due to the temporomandibular joints (TMJs).
The bottom row of teeth is supported by the lower jaw (mandible), which also shapes the lower face and chin. This is the bone that moves as you open and close your mouth.
The upper jaw (maxilla) protects the nose and carries the upper teeth. It also forms the centre of the face.
The upper and lower teeth must be straight and match together well for a good bite (occlusion).
The temporomandibular joint (TMJ), also known as the jaw joint, is a bi-arthrodial hinge joint that allows for complex movements. The TMJ is the joint between the mandible's condylar head and the temporal bone's mandibular fossa. The TMJ, teeth, and soft tissue make up this device. Breathing, chewing, and speaking are all regulated by this machine.
TMJ dysfunction can result in extreme pain and restrict one's lifestyle.
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TMJ is a hinge-type synovial, condylar, and synovial joint. The joint has fibrocartilaginous surfaces and is divided into two cavities by an articular disc. Superior and inferior synovial membranes line the superior and inferior articular cavities, respectively.
Capsule- The capsule is a fibrous membrane that surrounds the joint and connects the articular eminence, articular disc, and mandibular condyle neck.
Articular Disc- The articular disc is a fibrous extension of the capsule that extends between the temporomandibular joint's articular surfaces. The disc articulates with the temporal bone's mandibular fossa above and the mandible's condyle below. The joint is divided into two parts by the disc, each with its own synovial membrane. The collateral ligaments attach the disc to the condyle medially and laterally. The superior head of the lateral pterygoid and the joint capsule are connected by the anterior disc. The posterior portion attaches to the mandibular fossa and is referred to as the retrodiscal tissue.
Retrodiscal Tissue- The retrodiscal tissue, unlike the disc itself, is vascular and well-innervated. As a consequence, the retrodiscal tissue is frequently a major contributor to the pain associated with Temporomandibular Disorder (TMD), particularly when the joint is inflamed or compressed.
The mandible, also known as the lower jaw or jawbone, is the tallest, highest, and lowest bone in the human facial skeleton in terms of anatomy. It is responsible for the formation of the lower jaw and the retention of the lower teeth. The mandible is located below the maxilla. It is the skull's only movable bone (discounting the ossicles of the middle ear). The temporomandibular joint connects it to the temporal bone.
The bone is formed in the foetus by the fusion of the left and right mandibular prominences, and the mandibular symphysis, which connects the two sides, can still be seen as a faint ridge in the midline. This is a midline articulation where the bones are joined by fibrocartilage, much like other symphyses in the body.
It consists of:
The body found at the front
A ramus on the left and the right, the rami rises up from the body of the mandible and meets with the body at the angle of the mandible or the gonial angle.
The maxilla is the upper fixed bone of the jaw in vertebrates, shaped by the fusion of two maxillary bones. The stiff palate in the front of the mouth is part of the upper jaw in humans. The intermaxillary suture connects the two maxillary bones, creating the anterior nasal spine. The mandible (lower jaw) is a fusion of two mandibular bones at the mandibular symphysis, which is also a fusion of two mandibular bones. The mandible is the jaw's movable component.
1. Phossy Jaw
Phossy jaw, also known as phosphorus necrosis of the jaw, was an occupational disease that affected people who worked with white phosphorus (also known as yellow phosphorus) without adequate protective equipment.
It was most popular among matchstick factory workers in the 19th and early 20th centuries. White phosphorus vapour, which breaks the jawbones, was the cause.
The disease-causing working conditions have since been eradicated thanks to modern occupational hygiene procedures.
Symptoms:
Many that have a phossy jaw normally experience painful toothaches and gum swelling. With the development of fistula, tooth loss, and repeated abscesses, pus entering the oral mucosa is formed over time.
After three months, the sequestrum (the dead bone that has separated from the living bone) is formed, followed by necrosis of the jaw after six months.
The eventual separation of the sequestrum, which was characterised as porous and light in weight, was a distinguishing feature of this disease. The lower jaw was affected more often than the upper jaw.
In the dusk, the affected bones glowed a greenish-white colour.
Treatment:
Topical antimicrobials, cautious sequestra debridement, and surgery were all used as treatments.
The patient could be saved if the affected jawbones were surgically removed; otherwise, the patient would die of organ failure.
The disease was excruciatingly painful and disfiguring for the patient, with decaying bone tissue and a foul-smelling discharge accompanying it.
However, removing the jaw bone had a significant impact on the patients' ability to eat, contributing to additional health issues such as malnutrition.
2. Locked Jaw-
When the jaw muscles spasm and affect jaw movement, this is known as lockjaw (trismus).
The jaw may become "frozen" in a certain location if a person develops this disease, and They may be unable to open their mouth completely.
Lockjaw is a painful condition that can lead to complications such as choking.
Side effects from medications, cancer care, and tetanus are only a few of the potential causes.
A painful jaw can be crippling, impairing the ability to eat and communicate. Jaw pain can be caused by a variety of factors, including your sinuses and ears, as well as your teeth and jaw. As a result, determining whether your jaw pain is caused by a jaw problem or anything else can be difficult.
The most common cause of jaw pain is an abnormality or damage to the jaw joint, but there are other causes as well. Some of the causes of jaw pain include:
TMDs are the most common cause of jaw pain. TMD is often referred to as TMJ. The hinge joints on either side of your jaw are known as temporomandibular joints.
TMD jaw pain can be caused by a variety of factors. It's also possible to have TMD from several sources at the same time. TMD can be caused by a variety of factors, including:
pain from the muscles that control jaw movement
injury to the jaw joint
excess stimulation of the jaw joint
a displaced disc that usually helps cushion the movements of the jaw
arthritis of the protective disc that cushions the jaw joint
Several factors can harm your jaw joint or the muscles that regulate your jaw movement including:
grinding your teeth at night
involuntary clenching your jaw due to stress and anxiety
trauma to the jaw joint, such as getting hit in the face while playing sports
Cluster headaches are characterised by pain behind or around one eye, but the pain can also spread to the mouth. Cluster headaches are one of the most excruciating headache types.
Sinuses are small air-filled cavities near the jaw joint. If a germ, such as a virus or a bacterium, infects the sinuses, the result may be an accumulation of mucus that places pressure on the jaw joint, causing discomfort.
Dental abscesses, which are serious tooth infections, can also cause referred pain to the jaw.
Nerve compression on the trigeminal nerve, which provides sensation to a large portion of the face, including the upper jaw, is the most common cause of trigeminal neuralgia.
A heart attack can cause pain in other parts of the body, such as the arms, back, neck, and jaw, in addition to the chest. During a heart attack, women, in particular, can feel jaw pain on the left side of their faces.
1. Do Arthropods Have Jaws?
Ans. Yes, Jaws in arthropods are chitinous, opposed laterally, and can be made up of mandibles or chelicerae. These jaws are sometimes made up of many mouthparts. Their primary role is to acquire food, transport it to the mouth, and/or perform preliminary processing (mastication or chewing). Legs are modified mouthparts and associated structures (such as pedipalps).
2. What Kind of Jaw is Present in Amphibians, Reptiles and Birds?
Ans. In comparison to fish, tetrapods have a much simpler jaw. The braincase has fused most of the upper jaw bones (premaxilla, maxilla, jugal, quadratojugal, and quadrate), while the lower jawbones (dentary, splenial, angular, surangular, and articular) have fused together to form the mandible.
A hinge joint between the quadrate and articular articulates the jaw. Tetrapod jaws have different degrees of mobility between jawbones.
Some species have fully fused jawbones, while others have joints that allow the dentary, quadrate, or maxilla to move. The snake skull has the most cranial kinesis, which helps it to move about.
3. How Did Fish Get Jaws?
Ans. Jaws are thought to have evolved from the pharyngeal arches that support the gills of jawless fish. During the Silurian period, around 430 million years ago, the first jaws appeared in now-extinct placoderms and spiny sharks. Fish without jaws had a harder time surviving than fish with jaws, and the majority of jawless fish died out.