Important elements of chin anatomy
Last reviewed: 23.04.2024
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Although the basics of the anatomy of the mandible lower are familiar to aesthetic surgeons, some points need to be emphasized. The position of the chin holes is variable enough, but usually they are located below the second premolar. Anatomical studies show that in 50% of cases the chin holes are at the level of the second premolar, in 25% of cases between the first and second premolars, and in the remaining 25% of cases - behind the second premolar.
In the lower jaw of a young man, the chin holes are usually located in the middle between the alveolar ridge and the lower edge of the jaw, about 25 mm lateral to the midline, although this distance can be 20 to 30 mm. In children, they are lower and anterior, and as you age, because of the atrophy of the alveolar process, the chin holes are closer to the alveolar margin, while retaining a fairly constant distance from the lower edge of the jaw.
That is, their relative position becomes higher. Even in the senile jaw between the chin holes and the edge of the lower jaw, at the point of attachment of the muscles, a distance of more than 8 mm is maintained. The vascular bundle leaves the chin opening upward and is surrounded by a dense shell.
The importance of the anatomy of the chin holes in the aging mandible directly correlates with the level of safety in the surgical installation of the enlarged mandible implants. The anatomical features of this area clearly indicate that the surgeon produces a careful dissection, creating a pocket for the implant below the chin holes, but above the level of attachment of the muscles along the lower edge of the jaw. Usually 10 mm of space is available here.
Properly made implants should have a height of 6-8 mm in this zone. Since the neuromuscular bundle is surrounded by a dense shell and runs from the chin aperture upwards, using an elevator in the 8-10 mm space can affect the beam and even stretch it somewhat, but it is very difficult to break the beam. Although this anatomical feature creates conditions for safe operation, care should be exercised when removing the pocket wall.