One of the paired elements of the facial part of the skull is the zygomatic bone. It forms the zygomatic arch, which is the border of the fossa of the temple.
Building features
The zygomatic bone is a quadrangular flat element. It fastens the facial (visceral) part of the skull with its cerebral region. In addition, with its help, the maxillary bone is connected to the sphenoid, temporal and frontal. All this creates a strong support for her.
There are three surfaces that make up the zygomatic bone. Anatomy highlights the buccal (lateral), temporal and orbital parts.
The first one is convex. It is connected with the maxillary bones, frontal and temporal lobes with the help of three processes. The orbital part is involved in the formation of the lateral wall of the orbit and part of its bottom. The temporal is involved in the formation of the wall of the infratemporal fossa, and its plane is turned back.
Surface of the zygomatic bone
The orbital part is smooth, it is involved in the formation of the anterior parts of the orbit, namely, part of its outer wall and lower section. Outside, this surface passes into the frontobasal process, and in front it is limited by the infraorbital margin. It also has a special zygomatic-orbitalhole. The orbital surface of the frontal process contains a well-marked elevation.
The temporal surface is turned inward and backward. She takes part in the formation of the anterior wall of the fossa of the temple. It also has a zygomatic-temporal opening. The temporal process of the zygomatic bone, extending from its posterior angle, is connected to the zygomatic process of the temporal bone. Together they form the zygomatic arch. Between them is the so-called temporo-zygomatic suture.
Another isolated surface of the bone is the zygomatic. It is smooth, convex in shape with a special tubercle and zygomatic-facial opening. Its upper semicircular edge is the border of the entrance to the orbit from the side and from below. The frontobasic process (considered to be part of it) is the upper outer portion of the indicated surface. It is wider in the anterior than in the posterior. The zygomatic process of the frontal bone is connected precisely with it. Between them is the zygomatic-maxillary suture. It is located on the posterior edge of the upper third of the process, called the frontal.
Also, the zygomatic bone is attached to a large wing of the bone, called the sphenoid. Their connection forms a wedge-zygomatic suture.
Features
Due to the size of this particular element of the facial skull, its shape and angles, which are formed with the front surfaces, determine the body type, sex, race, age.
Specialists note 2 stages of development of the zygomatic bone: connective tissue and bone. It is noteworthy that 2-3 sitesossifications appear in the first trimester of pregnancy. They are already on the 3rd month of intrauterine development.
It is also noteworthy that through the orbital part of the bone, using a thin probe, one can get through the perforating canal into the bone into the zygomatic-temporal and zygomatic-facial foramen.
Possible injury
In case of facial injuries, a fracture of the zygomatic bone cannot be ruled out. It is characterized by deformation and retraction of the corresponding area. In the lower eye part and in the area of the zygomatic arch, you can see the so-called step. At the same time, problems appear when trying to open the mouth or make lateral movements with the lower jaw. Also, fractures are accompanied by retinal hemorrhages and loss of sensation, numbness in the region of the infraorbital nerve.
If the zygomatic bone has been displaced significantly, then nosebleeds from the part on the same side and visual disturbances are possible, which patients describe as double objects. But the exact diagnosis can only be made after an X-ray examination.
Treatment methods
If the fact of a fracture of the zygomatic bone was confirmed in the picture, then this means that it is necessary to restore its anatomical integrity. This is done by repositioning the debris into the correct position. After that, it is desirable to fix them further. If there were no shifts, then the treatment is limited to drug therapy and the appointment of physiotherapy.
Surgical recovery
Surgical intervention is required only in exceptional cases. These include situations when the zygomatic bone of the skull was broken and its processes were displaced.
All surgical interventions can be divided into intraoral and extraoral. The methods of Limberg, Gillies, Dingman are well known. They belong to extraoral methods.
In some cases, its integrity can be restored through an incision in the oral cavity. If the zygomatic bone is fixed with titanium mini-plates, this gives the most stable results.
After any type of intervention, it is important to avoid possible displacement of bone fragments. To do this, limit mouth movements, eat liquid and soft foods, and do not sleep on the damaged side of the face.
Description of extraoral methods
The Limberg method consists in the fact that through a special puncture (sometimes, however, a small cruciform incision is made) in the lower edge of the zygomatic arch, a single-pronged hook is inserted into the cavity. The integrity of the bone is restored by movement, which is done in the opposite direction to the displacement. When it is compared and installed in the correct position, a characteristic click is heard. This restores the symmetry of the face. The step that was in the lower edge of the orbit also disappears.
The Gillies method can be used to restore surface integrity and reposition the temporal process of the zygomatic bone. The operating doctor makes an incision in the scalp. At the same time, he dissects the skin, subcutaneous tissue and temporal fascia. Through the cutthe elevator is brought under the zygomatic arch or bone, a gauze swab is inserted under it. Then, with a special tool, which is used as a lever, the fragment is set in the correct position.
According to the Dingman method, a retractor is inserted into the infratemporal fossa through a 1.5 cm long incision. The dissection is made in the region of the lateral section of the eyebrow. At the same time, after restoring the integrity of the bone surface, the author of the technique recommended applying a wire suture in the region of the lower edge of the orbit, where the frontal process of the zygomatic bone is located.
Intraoral methods
If it is necessary to remove some loose fragments of bones, blood clots, parts of the mucous membrane, then other methods of surgical interventions have been developed. This is possible only when performing intraoral operations, in which a revision of the maxillary sinus is made.
To restore the integrity of the bones, an incision is made in the region of the transitional fold of the alveolar process. At the same time, the periosteal-mucosal flap is exfoliated. This is done with the help of a retractor or Buyalsky's scapula, which is passed under the temporal process of the zygomatic bone.
When carrying out this operation, it is also possible to reduce fragments of the bottom of the orbits. To do this, an iodoform swab is placed in the corresponding sinus. He must fill it tightly in order to keep the bone elements in the correct position for 10-14 days. The end of the specified tampon is displayed in the lower nasal passage. To do this, an anastomosis is first applied.
Fixthe plane of the bone in the correct position is possible with the help of titanium mini-plates or a wire suture applied in the region of the frontal process, the lower edge of the orbits, a ridge called zygomatic-alveolar. But the first method is considered more reliable.
Special occasions
In some situations it is necessary to use implants. They are placed with defects in bone tissue. Doctors often recommend using ceramic implants based on hydroxyapatite in combination with titanium plates in special cases.
If indicated, decompression of the infraorbital nerve may be performed. This is done by releasing its intracanal part and moving it into orbit. To eliminate bone defects of the alveolar ridge, implants made of titanium nickelide can be used. This requires the restoration of the epithelial lining of the sinuses with the help of flaps from the cheek or graft from the palate. This tactic reduces the risk of developing maxillary sinusitis, which can develop after an injury.
Using external seams, you can fix the zygomatic arch. To do this, a plate made of quick-hardening plastic is sewn to it. Under it, iodoform gauze is necessarily laid. It helps to avoid bedsores.
