Evaluation of the chin; The lips are made slightly open, fully closed and photographed while smiling.
The harmony of the chin between the other anatomical areas of the face should be checked. The harmony of the nose and lips with the chin is extremely important.
The structure of the jaw changes depending on gender, jaw bones-facial problems.
Bone structure and supporting tissue in the jaw are evaluated by examination. This assessment should be made right in the middle. The thickness of the chin soft tissue is 8-10 mm.
There is a fold under the lower lip towards the chin. This is called the labiomental fold. This fold is 4 mm below the vermilion border of the lower lip.
It divides the lower part of the face into 2. The upper lip and lower chin are the most important anatomical structures.
Deformities of the jaw depend on the shape of the bone structure, the thickness of the soft tissue, or the asymmetry of muscle activity (dynamic jaw asymmetry).
Sometimes, with the deepening of the submental groove, the chin may fall flat and down, this is called the Witch’s Jaw deformity (low chin placement). It can develop depending on age and previous surgical procedures.
In some people, the chin pad separates from the chin and a fold develops on it. It is called double chin.
In the evaluation of the profile face, the patient is asked to release his mouth in the evaluation of the jawbone and its corners. This is how the photo is taken. However, one more photograph is taken by clenching the jaw and teeth. When the chin is closed, serious changes occur in this anatomical area and soft tissues of the face in some patients.
In 1 picture, the patient is relaxed. In the 2nd picture, serious changes are observed in the soft tissues as the patient clenches his jaw and teeth.
Many methods are used in the evaluation of the jaw.
perpendicular line through subnasal
The vertical line drawn from the subnasale is used to evaluate the chin and upper and lower lips. The first step in determining this line is to give the patient’s natural head position. The upper lip is 1-2 mm in front of this vertical line, the lower lip is just above the line or 1 mm behind it. It is accepted that the pogonion, which is the most prominent soft tissue of the chin, is 2 mm in front of this line or behind it.
“ Rish technique;Frankfort Horizontal line upright and lower lip vermilion border The line drawn tangent to the chin is the meridian line for the chin and determines the localization of the chin.
legan angle; glabella–subnasale with the line drawn between subnasale- pogonionThe angle formed between the line is 12 degrees (plus minus 4 degrees).
The chin meridian line defined by Gonzales-Ulloa; The line passing through the nasion and perpendicular to the Frankfort Horizontal line is important. The pogonion falls within 5 mm of the line. The pogonion can fall inwards more than 5 mm. This is especially so in women. It gives a feminine image to the person. If the retraction is more than 1 cm, it means 1st degree retraction, 1-2 cm means 2nd degree retraction, and more than 2 cm means 3rd degree retraction. 1st and 2nd degree retractions are corrected with implants and 3rd degree with maxillofacial surgery.