PMC7787847_01
A panoramic radiograph obtained during the initial visit.
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The panoramic radiograph revealed a "ground-glass" appearance in the left maxillary sinus and left mandibular body and ramus; a periapical radiolucency was observed with the left maxillary first premolar and first molar (Figure 1).
Computed tomography (CT) image obtained at the initial visit. CT shows bone hyperplasia and "ground-glass" appearance at the left maxilla, mandible, and sphenoidal bone, along with an osteolytic lesion extending from the root apex of the left maxillary first molar to the inferior aspect of the left infraorbital foramen and canal in the "ground-glass" lesion. Axial (a), coronal (b), and sagittal (c) CT views.
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Computed tomography (CT) revealed severe bone hyperplasia and "ground-glass" appearance with the left maxilla, mandible, and sphenoid bone, along with an osteolytic lesion extending from the root apex of the left maxillary first molar to the inferior aspect of the left infraorbital foramen and canal in the "ground-glass" lesion (Figure 2).
Bone scintigraphy findings obtained during the initial visit. Bone scintigraphy shows an accumulation of technetium medronic acid in the right skull base, cervical spine, left maxilla, and left mandible.
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Bone scintigraphy revealed the accumulation of technetium medronic acid in the right skull base, cervical spine, left maxilla, and left mandible (Figure 3).
Surgical specimen. (a) A characteristic pattern of disconnected, bizarrely contoured dysplastic trabeculae enmeshed in primitive mesenchymal cells (hematoxylin and eosin, x200). (b) Granulation tissue can be observed in the mesenchymal stroma (hematoxylin and eosin, x100).
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Fibrous dysplasia with granulation tissue was observed on pathological examination of the surgical specimen (Figure 4).
A custom-made splint. The 10 cm resin handle (with a connector), which was used to fix the reference frame (*) and the gutta-percha markers are placed in asymmetric positions into both the splint (black arrowheads) and resin handle (red arrowheads) for marker-based pair-point registration.
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The splint was composed of 3 mm thick Erkoloc-Pro plates (Erkodent, Pfalzgrafenweiler, Germany), and the resin extended to a point 1 cm below the incisal edges of the anterior teeth (Figure 5).
Marker-based pair-point registration using the custom-made splint, which is integrated with the reference frame and registration markers. The reference frame (white arrowhead) is fixed to the connector of the splint. The numbered landmarks (the 11 gutta-percha markers) are indicated within the optical tracking range of the navigation system and registered point-by-point in succession, using the pointer (black arrow).
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The practical procedure of the marker-based pair-point registration was as follows (splint-to-CT data registration): the numbered fiducial gutta-percha markers were indicated and registered point-by-point in succession within the optical tracking range of the navigation system, using the pointer (Figure 6). The splint was set on the maxillary dentition, and the presence of registration errors were determined with the pointer to assess the median positions of the maxillary central incisors and mesiobuccal line angles of the maxillary first molars on both sides.
Screenshot of the navigation system during registration. The red points indicate the numbered landmarks (gutta-percha markers in the splint) for the marker-based pair-point registration. Deviations of each landmark are less than 1.0 mm.
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It took approximately 3 min to complete and confirm the marker-based pair-point registration before surgery; the mean fiducial registration error (FRE) was 0.68 +- 0.30 mm (Figure 7).
Intraoperative photographs. (a) The custom-made splint, which was integrated with the reference frame (white arrowhead), is set on the maxillary dentition. (b) The surgical field can be viewed clearly. (c) The positions of the osteolytic lesion are accurately identified in the surgical field using the pointer. (d) Placement of simple sutures at the vertical incision and horizontal mattress suture at the gingival margin.
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A three-sided flap was subsequently elevated, and the splint was reinserted (Figure 8). Simple sutures were placed at the vertical incision, and horizontal mattress sutures were placed at the gingival margin after the splint was removed (Figure 8).
Intraoperative screenshot of the navigation system. The red line indicates the planned site for curettage. The contact of the pointer with the inferior border of the infraorbital foramen (purple line) is indicated.
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The positions of the infraorbital foramen and canal were accurately identified in the surgical field using the pointer, which facilitated the removal of the osteolytic lesion (Figure 9).