19 June 2019

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Diagnostic efficacy of orthopantomography in sinus disease

Lara Figini

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Panoramic radiography, also known as orthopantomography (OPG), is commonly used in facial and dental pain investigations. This radiographic modality shows the bones of the jaws, teeth, and supporting structures including the temporomandibular joints and the maxillary sinuses. In this tomographic technique to obtain these images, a thin “focal trough” along the dental arch is used to produce a 2-dimensional image of the jaws. A disadvantage of the technique is that structures outside the focal trough can be blurred or not visible at all. The maxillary sinuses generally extend between 28.9 mm and 47.6 mm in the antero-posterior diameter, which is deeper than the focal trough that is designed to encompass the alveolar bone. The panoramic image includes only a portion of the maxillary sinuses, which might limit the value of this radiographic technique for the diagnosis of sinus lesions. In a study conduct by Prof Anderson et al., the authors tried to determine: ·      the diagnostic efficacy of orthopantomography (OPG) for sinus diseases using Cone Beam Computed Tomography (CBCT) as control ·      which diseases can be diagnosed using panoramic radiography and which CBCT.  

MATERIALS AND METHODS
The images of 714 individuals who underwent OPG and CBCT on the same day were assessed separately by 2 dental radiologists. The results were compared by using Gwet’s AC1 statistical methods.  

RESULTS
In total, 1322 maxillary sinuses were imaged. The sensitivity of OPG for the detection of any maxillary sinus pathology was poor compared with CBCT, but the specificity was high.
The sensitivity of OPG for detecting mucosal thickening was 36.7%.
The positive predictive value of OPG for diagnosing mucosal thickening was 79.9 %, but the negative predictive value was 51.9%.
Inter-observer agreement was strong (0.912) for all lesions except mucosal thickening.  

CONCLUSIONS
From the data of this study, which must however be confirmed by other similar studies, it can be concluded that the orthopantomography has a low efficacy in the diagnosis of sinus diseases, even if examined by an experienced dental radiologists. OPG can be useful in excluding disease, but 3-dimensional scanning is necessary for the definitive investigation of sinus lesions.

For additional informations: 
Panoramic radiography is of limited value in the evaluation of maxillary sinus disease