Asynclitis (Greek: “nonconvergence”, Latin: ascendens – “ascending”), or antevertism is an anomaly of the 1st and 2nd rays, characterized primarily by anterior divergence of the 1st rays and buttock position of the head. When the line of the buttocks flows into the armpit, an anterior rise is formed. The relationship of the orbital socket to the suboccipital fissure is concave with the head tilted posteriorly. The position of the head is gluteal.
Anterior insertion occurs most often due to asynclitism of the genital organs of the parents. This defect is formed during the intrauterine development of the child,