atlantodental interval

atlantodental interval

Neuroradiology The distance between the dens and anterior ring of C1, which is ≤ to 3 mm in adults, and ≤ 5 mm in children, which is altered in Pts with atlantoaxial subluxation. See Atlantoaxial subluxation.
References in periodicals archive ?
A greater anterior atlantodental interval (AADI), however, requires damage to the alar and apical ligaments, potentially combined with changes of the bony shape of the dens axis (Figure 1) [9].
Previous investigations declared that the posterior atlantodental interval (PADI), depicting the distance between the posterior surface of the odontoid and the anterior margin of the posterior ring of the atlas, which regularly measures 19-27 mm, is diagnostically more conclusive regarding the risk of spinal cord compression and resulting neurological disorders [4,16, 17].
Anterior Atlantodental Interval. The AADI in intact specimen measured 1.62 mm [+ or -] 0.62 on average.
Posterior Atlantodental Interval. The extent of the PADI in intact specimen ranged from 17.57 mm minimally to 20.86 mm maximally in neutral position of the cervical spine, averaging 18.85 mm [+ or -] 1.25.
Some cases are reported to be asymptomatic until the spinal cord is irreversibly compromised at a posterior atlantodental interval of 14 mm or less.
A report of two cases described subjects with idiopathic atlantoaxial instability (measured as 8 mm atlantodental interval) who presented with cervico-occipital pain and no neurological deficits.
(6) In adults, the atlantodental interval should be within 3 mm.
The atlantodental interval was not apparently widened, and there were no associated fractures.