What is normal Atlantodental interval?

The atlantodental interval (ADI) is a measurement used to evaluate the atlanto-axial relationship. This distance, described by Hinck et al,6 is conventionally held to be normal when it is less than 3 mm in men and 2.5 mm in women.

What is a normal ADI?

In adults, an ADI of 3-5 mm indicates that the transverse ligament is insufficient. In children, this value may be as large as 4.5 mm and still be considered normal. An ADI of greater than 5 mm is indicative of misalignment of the alar ligaments.

What is Predental space?

Predental Space This is defined as the distance from the anterior aspect of the dens to the posterior-inferior margin of the anterior arch of the atlas. In adults, the predental space measures 2.5 mm or less. However, the measured distance on a lateral radiograph is up to 4.5 mm in normal children.

What is atlantoaxial instability?

Atlanto-axial instability (AAI) is a condition that affects the bones in the upper spine or neck under the base of the skull. The joint between the upper spine and base of the skull is called the atlanto-axial joint. In people with Down syndrome, the ligaments (connections between muscles) are “lax” or floppy.

Where is the Atlantodental interval?

The atlantodental interval (ADI) is the horizontal distance between the anterior arch of the atlas and the dens of the axis, used in the diagnosis of atlanto-occipital dissociation injuries and injuries of the atlas and axis.

How is Craniocervical instability diagnosed?

Craniocervical instability is usually diagnosed through neuro-anatomical measurement using radiography. Upright magnetic resonance imaging is considered the most accurate method, and supine magnetic resonance imaging, CT scan or digital motion X-ray, or Digital X-ray are also used.

Where is odontoid process?

The odontoid process (also dens or odontoid peg) is a protuberance (process or projection) of the Axis (second cervical vertebra). It exhibits a slight constriction or neck, where it joins the main body of the vertebra.

What is an Odontoid fracture?

Fracture = A break in a bone. A type II odontoid fracture is a break that occurs through a specific part of C2, the second bone in the neck. Bones of the spine are called vertebrae. The bone involved in odontoid fracture is the second vertebra, C2, high up in the neck.

What’s a subluxation?

The term “subluxation” is used by doctors of chiropractic to depict the altered position of the vertebra and subsequent functional loss, which determines the location for the spinal manipulation. “Subluxation” has been defined medically as “…a partial abnormal separation of the articular surfaces of a joint.”

What is the dens in anatomy?

Can cervical instability Be Fixed?

Cervical instability is a medical condition in which loose ligaments in your upper cervical spine may lead to neuronal damage and a large list of adverse symptoms. If you have cervical instability, you may be experiencing migraines, vertigo, or nausea. Fortunately, this condition is treatable, though not curable.

What is the interval between the Atlas and the dens?

(ADI) onroentgenograms taken before and after death revealed nochange inthe mea- surement. Stimulated by this finding, we measured the interval between the atlas and the dens inanormal 8year old child and found the same distance, 3.5 mm. A hurried review ofthe literature revealed no adequate study ofthe ADI inchildren.’4

What is the normal basion-dens interval for children?

It is the distance from the most inferior portion of the basion to the closest point of the superior aspect of the dens in the median (midsagittal) plane. Normal values for adults are <12 mm on plain radiographs and <8.5 mm on CT 1. In children, >10 mm suggests atlanto-occipital dissociation 2. 1.

What’s the normal atlas-odontoid distance for a child?

This distance is generally accepted to be between 1 mm and 4 mm (average 2 mm) in 99% of normal children. 9 In this study, an atlas-odontoid distance of 4.5 mm or more was considered to be abnormal and to indicate atlanto-axial instability.

What is the normal size of the atlantodental interval?

It is the distance (in mm) between the posterior cortex of the anterior arch of the atlas and the anterior cortex of the dens in the median (midsagittal) plane. Normal values are: radiographs adults males: <3 mm. females: <2.5 mm 1 (although most authors describe <3 mm) children: <5 mm.