PMC6701314_01
A panoramic radiograph obtained before the extraction. The radiograph shows that the right lower third molar was horizontal (Pell and Gregory Class I, position A). There are no prior bone lesions associated with the molar, such as cyst and tumor.
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The tooth was partially and horizontally impacted (Pell and Gregory Class I, position A) (Figure 1).
A panoramic radiograph obtained during the initial visit. The radiograph shows radiolucency from the extraction socket to the right mandibular angle.
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Panoramic radiograph showed a radiolucency from the extraction socket to the right mandibular angle (Figure 2).
Coronal computed tomography (CT) scans obtained during the initial visit. CT shows a destruction of buccal cortical bone from the socket to the right mandibular angle and a formation of bone sequestrum. Although the lingual cortical bone is intact, there is periosteal reaction around the buccal bone destruction.
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Although the lingual cortical bone was intact, there was periosteal reaction around the buccal bone destruction (Figure 3).
Sagittal magnetic resonance imaging (MRI) obtained during the initial visit. MRI shows that the mandibular bone marrow from the right ramus to the body has a high signal density on short-tau inversion recovery (STIR) images and the cortical bone is partially raptured. Moreover, filaments in the low-density area are observed in the high-density area.
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Magnetic resonance imaging (MRI) revealed that the mandibular bone marrow from the right ramus to the body had a low signal density on T1-weighted images and a high signal density on short-tau inversion recovery (STIR) images (Figure 4).
Bone scintigraphic findings obtained during the initial visit. Bone scintigraphy shows a strong accumulation of technetium medronic acid (99mTc-MDP) in the right mandibular ramus.
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Bone scintigraphy showed a strong accumulation of technetium medronic acid (99mTc-MDP) in the right mandibular ramus (Figure 5).
An intraoperative photograph. The size of the defect of the buccal cortical bone was 25 mm (height) x 8 mm (width) x 6 mm (depth), which reached from the extraction socket to the right mandibular angle.
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The size of the defect of the buccal cortical bone was 25 mm (height) x 8 mm (width) x 6 mm (depth), which reached from the extraction socket to the right mandibular angle (Figure 6).
Surgical specimen of the granulation tissue. (a) The majority of the surgical specimen is granulation tissue composed of lymphocytes (black arrowheads) and plasma cells (white arrowheads), with neutrophil infiltration (black arrows) (H-E, x400). (b) The surgical specimen includes neonatal bone accompanied by many osteoblasts (black arrowheads) (H-E, x400). (c) Colonies of Actinomyces sp. (black arrowheads) are recognized in the inflammatory infiltrates (Gram, x400).
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Pathological findings of the surgical specimen revealed that the granulation tissue had drusen of colonies of Actinomyces sp. and gram-positive bacillus (Figures 7(a)-7(c)).
Three-dimensional computed tomographic (3D CT) scan obtained during the initial visit (a). 3D CT (b) and coronal CT (c) scans obtained 6 months after sequestrectomy and curettage. Although the CT obtained at the initial visit shows destruction of buccal cortical bone from the socket to the right mandibular angle and formation of bone sequestrum (a), CT obtained at 6 months shows bone healing at the lesion site, except for the remaining slight slit of the buccal cortical bone (b, c).
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The trismus and paresthesia of his lower lip and mental region in the right side disappeared completely, and no relapse occurred during the 6-month follow-up (Figures 8(a)-8(c)).