Preoperative analysis of the contours of the face

Because of the countless variations in the shape of the face, most of the analytical measurements used to determine aesthetic standards are unreliable. Modern analysis and the determination of angles are the first step in determining the contour. However, facial correction is a three-dimensional procedure that exponentially increases the variability of the structure and the final results of treatment. A good understanding of skeletal anatomy and the ability to determine individual topographic features help the surgeon select the optimal implant and method of its installation.

The increase in the skeletal components of the face with alloimplants alters the deepest, skeletal level of the face in three dimensions. Evaluation of the face before the operations to change the contour begins with the formation of an idea of the individual features of skeletal anatomy and the definition of signs of aesthetic flaws. Determining the relationship between structural and topographic features is important for achieving the best results by choosing the optimal shape, size and position of the implant.

Evaluation of defects in the contour of the lower jaw

The definition of the zonal principles of anatomy in the premadibular space allows the surgeon to create an individual contour of the chin and the lower part of the cheeks. Chin implants have traditionally been placed on the area between the chin holes. This well-known place is only one segment or zone of the lower jaw, which can be successfully changed. Implants, installed only in the central segment, without spreading to the sides, often create an unnatural ledge that looks unattractive. The median lateral zone of the premandibular space can be defined as the region extending from the chin holes to the oblique line of the horizontal part of the mandibular bone. When this zone increases, in addition to the central part of the chin, the contour of the anterior line of the lower jaw extends. This is the basis for the development of extended anatomical and anteriorly chin implants. Zadnebochnaya zone, the third zone of the premandibular space, which includes the posterior half of the horizontal part of the jaw body, the angle of the jaw and the first 2-4 cm of the ascending branch. This zone can be modified by an implant for the angle of the lower jaw, which will expand or lengthen the posterior part of the angle of the lower jaw, creating a stronger line of the posterior part of the jaw.

The zonal principle of skeletal anatomy is convenient for dividing the area of the middle part of the face into certain anatomical zones. Zone 1, the largest area, includes most of the zygomatic bone and the first third of the zygomatic arch. An increase in this zone pushes out a cheek-like elevation. This creates a sharp, angular appearance. Zone 2 covers the middle third of the zygomatic arch. Correction of this zone, together with zone 1, accentuates the cheekbone from the side, expanding the upper third of the face. Zone 3, the paranasal region, lies between the infraorbital foramen and the nasal bone. The vertical line, which is lowered from the infraorbital foramen, indicates the lateral edge of zone 3, which delimits the area of the medial dis-section as the cheekbone increases. Increment of the volume of zone 3 adds completeness under the eye socket. Zone 4 captures the posterior third of the zygomatic arch. The increase in this area gives an unnatural appearance and, in most cases, is not shown. The tissues that cover this zone are attached to the bone, and caution is necessary here because the temporo-zygomatic branches of the facial nerve pass superficially behind the temporal parietal fascia, over the zygomatic arch, and may be damaged. Zone 5 is a subtotal triangle.

Defects of the contour of the middle part of the face

Topographical classification of defects in the contour of the middle part of the face is very convenient as a reference guide for correlating the anatomical characteristics of deformation with certain implants. Type I deformation occurs in patients who have a good fullness of the middle part of the face, but insufficient development of the skeletal component of the zygomatic area. In this case, it would be preferable to implant in the form of an envelope on the cheekbone, increasing it and creating a higher zygomatic arch. The large surface area of the implant gives better stability and helps to reduce rotation and displacement. Extending the implant downward into the subculus space creates a more natural transition from the region of maximum magnification to the adjacent regions of relative decrease. Type II deformation is observed in patients with atrophy and omission of soft tissues of the middle third of the face in the subculo area, with adequate development of the cheekbone. In this case, subcular implants are used to increase or fill these defects or to create a forward projection. Type II strain is most common, found in the majority of aging people, in whom a suture implant is effectively used in combination with a surgical facelift. Type III deformation occurs in patients with thin skin and protruding cheekbones. This combination causes a sharp transition from the zygomatic bone at the top to the area of pronounced zapping, located under the cheekbone, which gives the impression of an extremely depleted, turned into a skeleton of the face. Type IV deformation, which is described as a "volume deficient" person, is the result of maldevelopment of the cheekbone and soft tissue deficit in the subculture area. In this situation, the combined zygomatic / subculture implant should serve two purposes: it must proportionally increase the insufficient skeletal structure in the zygomatic area and fill the void created by the absence of soft tissues in the subculture area. Since this condition is also associated with premature aging of the skin in the form of excessive wrinkles and deep folds in the middle third of the face, patients are often considered the best candidates for rhytidectomy. A complete recovery of the middle third of the face and an increase in the lateral sections of the mandible with a combination of the cheekbone / under the cheekbone implant and the anterior-cheek implant created a structural basis for achieving a positive result of the rhytidectomy performed and successfully removed the deep folds that were medially present in the middle part of the face. The deformation of the type of gutter (type V) is limited by a deep groove, often arising on the connection of the thin eyelid skin and thicker cheek skin. With this deformation, the expressed fold extends downward and lateral from the inner corner of the eye gap through the lower edge of the orbit and the infraorbital part of the malar bone. To correct this deformation, implants are used from silicone elastomer, pPTPE, as well as fat.

The only approach for correcting submandibular and nosocial occlusions is to lift the soft tissues of the infraorbital area and the middle third of the face, in combination with a superficial lift of the cheeks. This affects the tissue bias vector in the aging process. A superficial lift involves lifting the thicker skin of the cheeks and subcutaneous tissues to close the lower edge of the orbit. This also reduces the severity of the upper part of the nasolabial sweet. This effect is most effective in the laterals, to the level of the middle line of the pupil. With heavier gingival medial strain, if additional enlargement is required, infraorbital fat located in the region of the marginal arch or a special implant may be used simultaneously. Separation in the surface plane is better than deep periosteal excision because of ease of execution, direct access to the elastic cheekbone cushion and a small number of complications. To perform the braces of the middle part of the face, of course, care is required and knowledge of the anatomy of this area. If there is an excess elevation of the middle third of the face (or hypercorrection is weak in the form of the infraorbital skin), the tension downward, created by the muscles of the mouth, can lead to a shift of the lower eyelid. Methods of tightening the cheeks are still new and subject to modifications as they are increasingly used when rejuvenating the middle part of the face.

[1], [2], [3], [4], [5], [6], [7]