Radiodiagnostic Properties of Maxillary Antroliths

Primary outcomes

1. Antrolith descriptive analysis

   Time frame: for three days from the beginning of the study

   CBCT images were examined in axial, sagittal, and coronal slices to investigate the presence of antroliths. The age and sex information of the detected cases were recorded.

2. Antrolith localization and relationship the dental status evaluation

   Time frame: for three days from the beginning of the study

   Each sinus cavity exhibiting antroliths was evaluated for distribution and location as follows: (1) unilateral or bilateral, (2) single or multiple, (3) tooth extraction/root canal treatment/residual root fragment/implant/periodontal disease and/or periapical lesion (any dental cause of sinus inflammation), (4) premolar or molar region, and (5) sinus floor, lateral wall, or medial wall.

3. Antrolith and mucosal thickness classification

   Time frame: for three days from the beginning of the study

   the detected antroliths were categorized according to the classification of Cho et al. In this classification made according to the sizes of antroliths, Punctate = ≤3 mm in both height and width, Linear = ≤3 mm and more than treble in width, and Amorphous = >3 mm in both width and height.

   Additionally, the locations of the openings of the maxillary sinus ostiums were evaluated, and mucosal thickening, if any, was measured. Mucosal thickness measurements were made on coronal slices using NewTom's NNT viewer measuring tool. Similar to Chen et al., the sinus membrane thickness was measured perpendicular to the bone wall, from the maximum thickest region. Similar to Chen et al.'s classification of sinus membrane thickness measurements, which used Block and Dostoury's classification, the mucosal thickness was classified into three subgroups: membrane thicknesses <2 mm, 2-5 mm, and >5 mm. Also, similar to the article by Cho et al., the degree of inflammation in the maxillary sinus was

4. Antrolith volume measurement

   Time frame: for three days from the beginning of the study

   3D reconstruction and volume measurements of antroliths were performed using the ITK SNAP software (free software under the GNU General Public License developed by the National Institutes of Health, the US National Institute of Biomedical Imaging and Bioenergy needs, the US National Library of Medicine, the Universities of Pennsylvania and North Carolina, and an independent group of developers).

5. Different images evaluation for antrolit

   Time frame: for three days from the beginning of the study

   In addition, the visibility of antroliths detected on CBCT was also evaluated using panoramic radiographs taken from the patient (Fig 2). The detectability of antroliths in DPRs was evaluated by observers as detectable, suspicious, and undetectable.