Accuracy of measurements of mandibular anatomy and prediction of asymmetry in panoramic radiographic images

Abstract

Panoramic radiographs should be used with caution in making absolute measurements or relative comparisons. Even when internal fiducial calibration for image distortion of anatomy is used, measurements such as those assessing posterior mandibular facial symmetry may be unreliable.

Evaluation of the panoramic image formation in different anatomic positions

“…Panoramic image formation depends on the spatial location of anatomical structures in the image layer (7). In the present study, a critical situation was observed as regards image formation at the mandibular symphysis level, particularly in the anterior region, which showed no middle portion, and significant differences were observed in comparison with other horizontal levels.…”

“…Brown et al (2), on the other hand, found no change in magnification when evaluating the image layer vertically. Whereas for width, or depth, the rotation speed is constant, which caused a stable magnification in the image layer along the vertical axis (7,19). Previous studies have also found a large difference between the horizontal and vertical magnification (14,17,19).…”

“…Thus, radiographic image formation is directly affected by the shape of the image layer, which varies among different panoramic x-rays units (7). The image layer has a curved shape, and is three-dimensional, constituted of three different portions: middle, inner and outer.…”

Sex determination by using mandibular ramus: A digital radiographic study

“…[5] The brightness and contrast enhancement and enlargement of the images provide an reproducible method of measuring the chosen points. [6,7] The measurements taken from mandibular ramus are subjected to linear discriminant function.…”

Estudo clínico e radiográfico dos aspectos morfológicos da cadeia estilo-hióidea em sujeitos com disfunção temporomandibular e dor orofacial

“…Em concordância com outros autores, é recomendável que no caso de confirmação de mineralização e alongamento na região da cadeia estilo-hióidea o profissional faça a análise radiográfica completa a fim de obter análises do processo estilóide em vários planos (radiografia panorâmica, radiografia cefalométrica lateral, uma radiografia ântero-posterior e uma radiografia da ATM (Eagle, 1949;HOLLINSHEAD, 1962;GOSSMAN;TARSITANO, 1977;RODRIGUES;CHILVARQUER, 1991) e a história detalhada do paciente (NORONHA et al, 1987;REIS et al, 2001 Em se tratando das radiografias, sabe-se que as radiografias cefalométricas são consideradas mais fidedignas (BAUMRIND E FRANTZ, 1971A, 1971B;HOUSTON, 1983) quando comparadas às radiografias panorâmicas (LASTER et al 2005), pelo fato da radiografia cefalométrica lateral sofrer menos distorções e revelar uma imagem mais próxima do real (ONGKOSUWITO et al, 2009). No presente estudo, foi encontrado que as medidas medidas do comprimento do processo estilóide realizadas entre as diferentes tomadas radiográficas (radiografia panorâmica e radiografia cefalométrica lateral), foram similares ou seja, não houve diferença estatística significante entre elas.…”