The purposes of this study were to examine the effect of potentially common patient positioning errors in panoramic radiography on imaged mesiodistal tooth angulations and to compare these...

The effect of vertical and horizontal head positioning in panoramic radiography on mesiodistal tooth angulations.

OBJECTIVE To assess whether it is possible to make accurate vertical measurements of the jaws from panoramic radiographs. METHODS Five dry skulls were shifted 5 mm forwards and backwards and tilted 5 degrees up and down in the sagittal plane. Panoramic radiographs of each skull were obtained in nine different positions. In the maxilla, three reference lines were used and vertical measurements were made at the distal surfaces of the first premolar and first molar and in the midline. In the mandible, measurements were made at the distal surfaces of the first premolar and first molar, and at the mental foramen on both sides, and in the midline. The points and lines were marked manually and the radiographs were digitized, magnified and measured. RESULTS Sagittal shifting and tilting had only a slight effect on measurements in the mandible. Sagittal tilting of the head had the greatest effect on all the measurements made from the line between the articular eminences to the alveolar crest, as well as measuremen...

Effect of head positioning in panoramic radiography on vertical measurements: an in vitro study.

The first attempts to image the whole jaw were made with intraoral radiation sources at the beginning of this century. The narrow-beam principle was described in 1922. Experimental work and development of equipment in the 1950s resulted in commercially available machines in the early 1960s. The panoramic technique originated from the need to image the jaws, but it was also applied to other anatomic regions, before CT became available. Panoramic radiography is an essential element in oral radiology today.

History of panoramic radiography

Dental and mandibular arch widths in three ethnic groups in Texas: a radiographic study.

A study of the zone of sharpness of three panoramic x-ray machines and the effect of screen speed on the sharpness zone

The definition of the blurring of narrow beam rotation radiography is revived. The relative value of the blurring is considered to be the most reliable measurement. Calculations of the layer thickness should be based on the definition of the relative blurring. Experimental tests were performed, which confirm the mathematically presented hypothesis and also confirm the validity of the mathematical model of narrow beam rotation radiography presented by WELANDER (1974).

U. Welander

Papers

Blurring and layer thickness in narrow beam rotation radiography.