PMC9452987_01
Preoperative CBCT examination. (a) A fourth molar in the mandible left third molar distal; (b-d) the relationship between roots and mandibular canal in coronal, transversal, and sagittal planes.
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CBCT radiograph revealed that teeth 38# and 39# were vertical median impaction in the left mandibular region, and showed a concrescence between an impacted third molar and a supernumerary fourth molar (Figure 1) they shared similar shape but self-governed root canal system. Besides, teeth 48# was impacted at horizontal-low level (Figure 1). Acteon group France, France)-based anesthesia blocking the inferior alveolar, lingual, and buccal nerve. A mucoperiosteal flap was prepared and raised, and then ostectomy and odontomy were performed using handpiece (Figure S1) and sterile saline irrigation.
Surgery process and follow-up. (a) No wisdom teeth erupting, bleeding, or purulent secretion in the mouth. (b-f) Teeth extraction and alveolar reconstruction. (g) The fragment of teeth. (h, i) Removed stitches without severe complication and the defect of the alveolar socket healed well.
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Antiflogistic and analgesics therapy were applied for 3-5 days (Figures 2(a)-2(g)). After 7 days, the sutures were removed without severe complications (Figures 2(h)-2(i)).
Photomicrographs of histological sections stained with the hematoxylin-eosine stain exhibiting the point of cementum fusion, revealing a real concrescence. Images obtained using (a) a 10x microscope and (b) a 20x microscope.
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The histological examination revealed fusion of cementum between the mandibular third molar and supernumerary fourth molar which is diagnostic for concrescence (Figure 3).
(a) Immediate postoperative panoramic examination showed the empty tooth socket; (b) after six months, CBCT examination showed good bone formation, and the alveolar bone healed well. (c) Transverse section shows increased bone density in empty alveolar bone; (d, e) Coronal and sagittal plane shows increased height of the alveolar bone.
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CBCT examination showed increased bone density (Figure 4).