Cephalometry

The history of cephalometry (cephalo- + -metry, "head measurement") can be traced through art, science, and anthropology.

Beginning with Petrus Camper in the 18th century angles began to be employed in the measurement of facial form.

To carry out cephalometry, the X-ray source is placed a steady five feet away from the mid sagittal plane, with film situated just 15 cm from there.

With an object-to-film interval of 15 cm and a source-to-object span of 5 feet, magnification of anatomical landmarks will be reduced in all three dimensions.When attempting to analyze a patient's anatomy through lateral and frontal cephalograms, the challenge arises due to these images being two-dimensional projections of three-dimensional structures.

Magnification and distortion as an outcome of traditional radiography further complicates the process by blurring important details.

[3] Cephalometric analysis is used in dentistry, and especially in orthodontics, to gauge the size and spatial relationships of the teeth, jaws, and cranium.

Cephalometry focuses on linear and angular dimensions established by bone, teeth, and facial measurements.

Due to variations in cranial measurements by population these types of databases can help assist investigators working in a known region.

Researchers created a database cranial measurements utilizing cephalograms of Garo women living in Bangladesh.

Further, the study confirmed that there is not a strong degree of sexual dimorphism between mandibular ramus length until an individual reaches 16 years of age.

This could be applicable in immigration, criminal and civil investigations, adoption of children, or old-age pension requests.

Genetic and environmental factors have been suggested for the presence of variations in cephalic indices among population groups.

This was performed on adult men and women and found that location of the hyoid also correlates with the obstructive sleep apnea/hypopnea syndrome (OSAHS).

Compared with a control group, those with OSAHS had the hyoid bone lower in relation to the mandibular plane.

[9] By using a cephalometric analysis program, a study was able to conclude that people with a reduced midface length and an inferiorly placed hyoid tend to have smaller airways which can lead to obstructive sleep apnea.

In other studies, differences in characteristics were noted in the sagittal and vertical planes of apnea sufferers versus the controls.

They did find that using cephalometry there is a difference in craniofacial morphology of persons with obstructive sleep apnea versus the healthy population.

[10] On recent open public competitions, machine learning and shape analysis algorithms demonstrated the mean error of 1.92 mm for automated landmarking and up to 93.2% of agreement between automated and manual cephalometry[11][12] Advances in technology have allowed scientists and anthropologists to utilize statistical programs in order to estimate ancestry of a skull by taking measurements of various craniometric points.