Measuring cortical thickness on panoramic radiographs: a validation study of the Mental Index.
OBJECTIVE
To validate the Mental Index assessment obtained from panoramic radiographs.


METHODS
Ten dried mandibles were selected, and standardized panoramic radiographs were obtained. The specimens were then perpendicularly sectioned at the mental foramen region, and the inferior mandibular cortical thickness was recorded using a digital caliper. Measurements of panoramic radiographs were compared with the dried mandibles. Four observers carried out twice the measurements for the panoramic radiographs. Two observers performed twice the measurements of the dried mandibles. Reliability was assessed by duplicate measurements.


RESULTS
Agreement between the actual mandible measurements and the radiographic assessment was moderate for the noncorrected measurements. Agreement between anatomic and radiographic measurements improved remarkably after standard correction for magnification.


CONCLUSIONS
Bone status reports based on measuring cortical thickness of the lower border of the mandible at the mental foramen based on panoramic radiographs, i.e., Mental Index, are accurate. Compensation for magnification, however, is necessary.
Dutra
Vinicius
V
Department of Diagnostic Imaging, School of Medicine, Federal University of Sao Paulo, Porto Alegre, Brazil. cdiodontologia@terra.com.br
Susin
Cristiano
C
da Costa
Nilza Pereira
NP
Veeck
Elaine Bauer
EB
Bahlis
Alexandre
A
Fernandes
Artur da Rocha Correa
Ada R
D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D010024:Osteoporosis / Q000000981:diagnostic imaging; D011862:Radiography, Panoramic / Q000379:methods*