Anomalous morphology of an ectopic tooth in the maxillary sinus on three-dimensional computed tomography images

Abstract

We describe a case of an incidentally-diagnosed ectopic tooth showing anomalous morphology in the maxillary antrum, using three-dimensional reconstruction of computed tomography images of the tooth obtained by multi-detector computed tomography.

Keywords: Ectopic tooth; MDCT; Three-dimensional reconstruction; anomalous morphology; maxillary sinus.

Figure 1

52 year-old lady presented with a right nasolabial cyst. CT image showing an ovoid nasolabial cyst (arrow) measuring 1.3cm (anteroposterior) × 1.2cm (width) × 1.4cm (height). Axial image (A). Coronal reconstructed image (B). Sagittal reconstructed image (C). (Toshiba Aquilion, 187mAs, 120kV, 5mm-thin axial slices, without intravenous contrast)

Figure 2

52 year old lady with absent left first maxillary molar. Axial CT image showing absence of the left first maxillary molar at its expected location. (Toshiba Aquilion, 187mAs, 120kV, 5mm-thin axial slices, without intravenous contrast)

Figure 3

52 year old lady with an ectopic tooth in left maxillary sinus. CT images showing an ectopic tooth lying transversely in the posterolateral wall of the left maxillary sinus, with its cusps pointing laterally. A lucent line is seen extending obliquely from the dentine layer through the pulp cavity towards the cementum layer. Axial image (A). Coronal reconstructed image (B). Oblique reconstruction of the tooth (C). (Toshiba Aquilion, 187mAs, 120kV, 5mm-thin axial slices, without intravenous contrast)

Figure 4

52 year old lady with an ectopic tooth showing anomalous morphology. 3D-reconstructed CT images of the ectopic tooth with different rendering showing various layers of the ectopic tooth, including a large distinct cusp (arrow) and five less distinct smaller cusplets (arrowheads) at its crown (A). A double-rooted tooth with normally-configured root canal in the longer curved root, an incomplete root canal without apical foramen in the shorter root, and an anomalous canal extending from the dentine layer to the cementum layer in the groove between the roots. In addition to the two pulpal horns, a prominent projection is seen extending from the roof of the pulp cavity towards the direction of the central fossa (B). (Toshiba Aquilion, 187mAs, 120kV, 5mm-thin axial slices, without intravenous contrast.) 3D-reconstructed CT images of a typical maxillary first molar, showing four cusps, three roots (C) and three corresponding root canals (D). (Toshiba Aquilion, 150mAs, 120kV, 5mm-thin axial slices, without intravenous contrast).