Jawbone

introduction

For the insertion of an implant, it is necessary that the jawbone has a corresponding width and depth so that a firm hold for the implant is ensured. Unfortunately, this is not the case for all patients. Due to early loss of teeth, partial dentures worn for a long time or periodontitis, the bone in these patients is broken down to such an extent that implantation is not possible. In the maxillary sinus area, too, there is often very little bone available for an implant to be placed. In both cases, however, a jawbone augmentation (augmentation) create the conditions for an implantation.

Also read our topic: Build up the jawbone

The upper jaw

Colloquially, only the upper row of teeth is often referred to as the upper jaw, but in fact the human upper jaw is the largest bone of the midface. It limits the eye sockets with its upper edge, forms the receptacle for the upper row of teeth on the lower edge and the outer wall of the nasal cavity in the middle. Reaching into the interior of the skull, it also forms part of the bony palate. Parts of the upper jaw are hollow, lined with mucous membrane and are in communication with the nasal cavity. Therefore, these cavities are also called paranasal sinuses - or maxillary sinuses here. They are used to warm up and humidify the air we breathe. Other sinuses exist z. B. in the frontal bone. If the mucous membranes of the paranasal sinuses swell as part of a cold, the openings to the nasal cavity can close, which severely restricts the outflow of mucus. This makes sinus infections painful and sometimes quite persistent.

The upper jaw is notched at the lower edge to accommodate the teeth holding apparatus of the upper row of teeth. Tooth roots and maxillary sinuses sometimes come very close, it can even happen that tooth roots grow into the maxillary sinus, where they are then only covered by mucous membrane. Therefore it can happen that a tooth root inflammation continues into the maxillary sinus or a sinus inflammation becomes noticeable with toothache.

Figure skull from the front and from the left (upper jaw blue)
  1. Upper jaw -
    Maxilla
  2. Zygomatic bone -
    Os zygomaticum
  3. Nasal bone -
    Nasal bone
  4. Tearbone -
    Lacrimal bone
  5. Frontal bone -
    Frontal bone
  6. Lower jaw -
    Mandible
  7. Eye socket -
    Orbit
  8. Nasal cavity -
    Cavitas nasi
  9. Upper jaw, alveolar process -
    Alveolar process
  10. Maxillary artery -
    Maxillary artery
  11. Under eye cavity hole -
    Infraorbital foramen
  12. Ploughshare - Vomer

You can find an overview of all Dr-Gumpert images at: medical illustrations

The lower jaw

The lower jaw consists of a U-shaped bone, the legs of which bend upwards at the lower jaw angle and merge into an ascending branch. These two branches each have two extensions, a rear one, which forms the joint head of the temporomandibular joint, and a front one, to which parts of the masticatory muscles attach. The strongest masticatory muscle in humans, the masseter muscle, starts from the zygomatic arch at the lower jaw angle, the floor of the mouth muscles stretch on the inside of the "U" and connects the lower jaw with the pharynx and hyoid bone. The upper edge of the lower jaw is notched like the upper jaw and carries the teeth holding apparatus of the lower tooth bar.

The temporomandibular joint consists of the posterior extension of the mandibular branch as the joint head and a notch between two cusps on the temporal bone as the joint socket. A joint disk sits between the two joint surfaces, which compensates for differences in their curvature. The cylindrical structure of the joint head on the lower jaw enables rotating, sliding and grinding movements in the jaw joint. Although the temporomandibular joint is surrounded by a capsule and additionally surrounded by ligament structures, it can dislocate due to an accident, a blow, in some people even with a particularly wide mouth opening (e.g. when yawning), in that the joint head of the lower jaw is dislocated in front of the anterior The cusp of the joint socket slips - the mouth can no longer be closed ("jaw lock"). It is usually easy to bring the dislocated joint back into position, but there are people who tend to repeatedly dislocate the temporomandibular joint ("habitual dislocation").

Pain in the temporomandibular joint can also result from uneven loading, for example from toothache, tooth damage or missing teeth, badly fitting crowns or seals - a visit to the dentist and the making of bite impressions can provide information on the cause of the complaints.

Even with increased teeth grinding, which can also happen unconsciously at night, pain in the masticatory muscles and the temporomandibular joints caused by overload occurs. The reasons for the grinding of teeth are not entirely clear, so treating the cause is not always easy. Since u. a. Stress factors are suspected as triggers, relaxation techniques come into consideration, but the successes vary with individual patients. The possible effects of teeth grinding, damage to the teeth themselves, tension in the jaw muscles and overuse of the temporomandibular joints can usually be alleviated by a specially adapted bite guard.

Figure skull from the front and from the left (lower jaw blue)
  1. Lower jaw - Mandible
  2. Crown process -
    Coronoid process
  3. Lower jaw rest -
    Ramus mandibulae
  4. Mandible angle -
    Angulus mandibulae
  5. Upper jaw - Maxilla
  6. Zygomatic bone - Os zygomaticum
  7. Zygomatic arch -
    Arcus zygomaticus
  8. Temporomandibular joint -
    Articulatio temporomandibularis
  9. External ear canal -
    Meatus acousticus externus
  10. Temporal bone - Temporal bone
  11. Frontal bone - Frontal bone
  12. Chin hole - Mental foramen
  13. Eye socket - Orbit
  14. Upper jaw, alveolar process -
    Alveolar process

You can find an overview of all Dr-Gumpert images at: medical illustrations

Structure of the jawbone

The best results for building up the jawbone are obtained with the body's own (autologists) Bone achieved. The bone graft is taken either from the ascending branch of the lower jaw in the wisdom tooth region or from the hipbone if necessary.

Materials for the jawbone structure

In addition, however, bone substitutes are also available for building up the jawbone. These are materials mostly of synthetic origin. It is here above all Hydroxyapatite ceramic, which is offered in granulate form and in sterile packaging. But also materials from animal (Beef or pig) and vegetable (Seaweed) Origin can be used to build new jawbones. A mixture of your own bone and bone substitute is also possible.

Complications of a jawbone augmentation

Possible complications are rejection reactions, allergic reactions and infections caused by the invasion of bacteria. When the sinus floor is raised, perforation of the mucous membrane or penetration of the substitute material can lead to inflammation of the maxillary sinus (Sinusitis) to lead. However, complications are rare.

Jaw pain

Jaw pain can have many different causes. One of these causes can be an inflammation in the jawbone and is treated with an antibiotic. Furthermore, jaw pain can occur due to tension or misaligned teeth. A splint or orthodontic therapy can help here.

Read more on the topic: Occlusal splint

It is also possible that the jawbone is very sensitive to pressure in places. The reason for this can be something called an abscess. This is a type of collection of pus below the tooth. Here, too, the cause is persistent inflammation. A dentist should be consulted if there are typical signs of inflammation (swelling, reddening, warming, pain). The doctor can usually use an X-ray to determine whether the cause of the jaw pain is inflammation and, in this case, prescribe an antibiotic. In the worst case, a badly sore lower jaw can be a sign of a heart attack. Hence, the signs should not be ignored.

Inflammation in the jawbone

Often there is irritation or swelling in the mouth. In most cases these are harmless and go away after a few days. However, if the signs of inflammation persist, these signs may indicate inflammation in the jawbone. The causes of this inflammation can be very different. In many cases, a tooth accident with an accompanying fracture is the reason for the resulting inflammation.

Furthermore, accumulations of pus that have existed for a long time can also be the cause of inflammation of the jawbone.One can differentiate between ostitis (inflammation of the bone) and osteomyelitis (inflammation of the bone marrow). They differ in the parts of the bone affected by the inflammation. Most of these are associated with periostitis (= inflammation of the periosteum).

Inflammation can often be seen on x-rays. It is very important not to ignore the signs of persistent inflammation. Therapy is usually carried out using antibiotics. If left untreated, persistent inflammation can lead to necrosis, in other words, bone death. This in turn can lead to tooth loss.

Jaw bone necrosis

Jawbone necrosis is a dead jawbone. Causes for this can be chronic inflammation, radiation (in connection with cancer treatment) or drugs (especially chemotherapy drugs, or cortisone). The most common are drug-induced jawbone necrosis. A clinical feature is e.g. a small piece of exposed bone in the mouth. In addition to jaw pain, symptoms can include bad breath, sensory disturbances in the lower lip or other pain in the oral cavity.

forecast

With the augmentation of the jawbone with suitable materials, the prerequisite is created to carry out a subsequent implantation. After healing, the prognosis for further dental measures is good.

Summary

The prerequisite for setting jawbones - Implants is the presence of sufficient bone substance. If this is not the case, a Bone building Remedy can be provided. As materials for a bone structure (augmentation) either the body's own bones or bone substitutes of animal, vegetable or synthetic origin are used.
In the maxillary sinus area, a rise in the floor of the maxillary sinus creates (Sinus lift) sufficient Jawbone for an implantation. The implantation of the jawbone can be done either simultaneously or after healing.