Fracture of jaws

Japanese: 顎骨骨折 - がくこつこっせつ（英語表記）Fracture of jaws

What kind of injury?

The jawbone is the base of the face below the eyes and moves when chewing. lower jaw ( Science ) (lower jaw) and facing it Upper jaw ( Journal ) The upper and lower jaws are made up of two bones. Both the upper and lower jaws are originally formed as left and right bones, but in the lower jaw they fuse together in the midline to become one. Teeth grow in the jaws and begin to bite together, recording the relative positions of the upper and lower bones.

A jaw fracture is an injury in which the jawbone is broken or crushed (Figure 23). In many cases, it occurs when the jaw or face is struck hard against something, such as in a fall, punch, sports accident, or bicycle or car accident. In rare cases, the jawbone may break spontaneously without any effort on the part of the elderly.

How symptoms manifest

Dental alveolar ( Seems like ) Fractures are easy to spot, as they can be painful when you tap on the tooth or you can't bite properly. After a strong force is applied, typical symptoms include bleeding from the mouth or nose, sudden swelling, and misalignment of the bite. Symptoms are not necessarily limited to the area where the force was applied; in the lower jaw, pain when moving the jaw, and in the upper jaw, double vision may be the main symptom.

In some cases, you may not notice any obvious symptoms immediately after the injury, but only notice a misalignment of the bite a few days later. In this case, the fracture is likely to be in the angle of the mandible (the jaw area) or the temporomandibular joint (in front of the ear), which cannot be seen directly from inside the mouth.

Testing and diagnosis

Immediately after the injury, the doctor will first observe bleeding and breathing, then proceed to examine and test the jaw injury itself. Visual and palpable examinations can give an idea of the presence and location of a fracture, but for a more detailed assessment, an X-ray is required. Recently, CT scans have become available to provide a fairly detailed diagnosis, and the extent of the injury is determined in conjunction with clinical findings.

In the upper jaw, type 1 is a horizontal break at the line under the nose, type 2 is a break from the base of the nose to the upper molars cheekbone ( Today ) The Le Fort classification is often used, which divides glaucoma into type 1, where the glaucoma breaks diagonally between the eyes, and type 3, where the glaucoma breaks horizontally at eye level.

In the lower jaw, fractures often occur in the midline of the jaw, the angle of the mandible, and the temporomandibular joint, areas where excessive force is likely to be concentrated.

Treatment methods

Treatment methods vary greatly depending on the location of the break. In general, in acute severe cases, the treatment is aimed at preventing life-threatening conditions such as respiratory failure and bleeding, and even after that, Occlusion and chewing ( Commuting ) We perform radical reduction and fixation surgery as soon as possible to minimize jaw and facial dysfunction and scarring, including disability.

For other types of fractures, if the degree of displacement of the fracture site is large, surgical treatment is required, and if it is small, the basic treatment is to ensure the bite (intermaxillary fixation, which ties the upper and lower jaws together). In the past, intermaxillary fixation was the first choice, but recently, treatment methods that connect the bones as accurately as possible and allow patients to return to normal life as soon as possible are being used.

If the fracture is smaller, such as in the alveolar fracture (the area under the gums where the teeth are), the bone (and teeth) will be moved back into place and the teeth and metal wires will be used to hold them in place. It may be necessary to treat the nerve of the tooth later.

Kazuo Shimogo

Figure 23 Largely displaced mandibular fracture
">

Figure 23 Largely displaced mandibular fracture

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

Japanese:

どんな外傷か

　眼より下の顔の土台になるのがあごの骨（顎骨）で、ものを噛む時などに動かす下顎(かがく)（下あご）とそれに向かい合う上顎(じょうがく)（上あご）からなっています。上下ともに元々は左右の骨として発生してきますが、下顎では正中で硬く癒合して一体化しています。あごには歯が生えてきて噛み合うようになり、上下の骨の位置関係がきっちりと記録されています。

　あごの骨が砕けたり折れたりするけがが顎骨骨折です（図23）。多くの場合、転んだり、殴られたり、スポーツ事故、自転車・自動車事故などで、あごや顔面を何かに強く打ちつけた時に発生します。高齢者では、何もしなくても顎骨が自然に折れてしまうこともまれにあります。

症状の現れ方

　歯槽(しそう)骨折の場合は、歯を叩くと痛かったり、噛み合わせることができなかったりするので、容易に見つけられます。強い力が加わったあと、口や鼻からの出血があったり、急なはれ、噛み合わせのずれなどが平均的な症状です。症状は必ずしも力が加わった部分にとどまらず、下顎ではあごを動かした時の痛み、上顎ではものが二重に見えるなどの症状が主になることもあります。

　受傷後すぐにははっきりした症状に気づかず、数日してから噛み合わせがずれていることで気づくこともあります。この場合は、口のなかから直接見えない下顎角部（エラの部分）や顎関節部（耳の前）の骨折が考えられます。