1. Diagnostic Approach to Retromolar Trigone Cancer by Multiplanar Computed Tomography Reconstructions 
Silvio Mazziotti, MD, Ignazio Pandolfo, MD, Tommaso D'Angelo, MD, Achille Mileto, MD, Carmela Visalli, MD, Santi Racchiusa, MD, Alfredo Blandino, MD, Giorgio Ascenti, MD 
Canadian Association of Radiologists Journal 
Volume 65, Issue 4, Pages (November 2014)
DOI: /j.carj
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2. Figure 1
Lateral drawing, depicting the relationship between the retromolar trigone region (TR), the temporal muscle tendon (Tm), the masseter (M), and the buccinator (Bc) muscles.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
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3. Figure 2
Coronal drawing of the retromolar trigone region (TR). On the left side, the buccinator muscle (short arrow) and molar teeth were removed. The long arrow indicates the fat space between the buccinator muscle and the masseter muscle (M). On the right side is clearly demonstrated the insertion of the buccinator muscle (Bc) to the pterygomandibular raphe (arrowheads). Pt = Pterygoid muscles.
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4. Figure 3
Axial drawing of the left retromolar trigone region. The relationship between the fat component of the buccal space (B) and the fat of the pterygomandibular space (white arrow) is well demonstrated. Pterygomandibular raphe (black arrow). M = masseter muscle; Pt = pterygoid muscle.
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5. Figure 4
Volume-rendering technique of the mandible, showing the relationship between the retromolar trigone region (TR) and the mandibular mylohyoid ridge (arrows). Lingula (arrowhead); mandibular foramen (asterisk).
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6. Figure 5
Drawing, showing the course of the inferior alveolar nerve (An), lingual nerve (Ln), and mylohyoid nerve (Mn).
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7. Figure 6
A 35-year-old man. Normal subject. Sagittal oblique reconstructions. (A) Axial reference computed tomography, with the 3 sagittal oblique planes (1, 2, 3). (B) Sagittal oblique reconstruction that corresponds to plane 1 (masseter muscle [M]; buccinator muscle [short arrow]; fat plane between the 2 muscles [long arrow]). (C) Sagittal oblique reconstruction that corresponds to plane 2; retromolar trigone (TR) and buccal space (B) are well seen; temporalis muscle (Tm); mandibular canal (black arrow); note the mandibular foramen (dot), which is represented by a piriform fovea that contains adipose tissue and inferior alveolar nerve (arrowhead). (D) Sagittal oblique reconstruction that corresponds to plane 3; pterygoid muscles (Pt) and buccal space (B) with its posteroinferior apex (arrow) normally characterized by an acute angle shape.
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8. Figure 7
A 35-year-old man. Normal subject. Coronal oblique reconstructions. (A) Axial reference computed tomography with the 3 coronal oblique planes (1, 2, 3). (B) Coronal oblique reconstruction that corresponds to plane 1; buccal space (B) and fat plane (black arrow) localized between the masseter muscle (M) and the buccinator muscle (white arrow) are well seen. Tm = temporalis muscle. (C) Coronal oblique reconstruction that corresponds to plane 2; anatomic relationship between the temporalis muscle insertion (Tm), masseter muscle (M), and the mylohyoid muscle (My) are well demonstrated. (D) Coronal oblique reconstruction that corresponds to plane 3; the relationship between the retromolar trigone region (TR), pterygoid muscles (Pt), and parapharyngeal space (black arrow) are shown. M = masseter muscle.
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9. Figure 8
A 35-year-old man. Normal subject. Coronal reconstructions. (A) Axial reference computed tomography, with the 3 coronal planes (1, 2, 3). (B) Coronal reconstruction that corresponds to plane 1; the fat plane between the buccal space (B) and fat tissue of the cheek (long arrow) is well seen. M = masseter muscle; buccinator muscle (short arrow). (C) Coronal reconstruction that corresponds to plane 2; see the insertion of both temporalis (Tm) and internal pterygoid (Pt) muscles that converge in the retromolar trigone region. T = tongue; My = mylohyoid muscle. (D) Coronal reconstruction that corresponds to plane 3; pterygoid muscles (Pt) and pterygomandibular adipose space (arrow) are well represented; on the coronal view, the pterygomandibular adipose space presents a typical triangular shape. Sp = soft palate; T = tongue.
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10. Figure 9
A 42-year-old woman. Normal subject. Multiplanar curved reconstruction. (A) Axial reference computed tomography, with curved reconstruction plane passing through the buccal space (B), pterygomandibular space, and parapharyngeal space (P). (B) Reconstruction that corresponds to curved reconstruction plane; the anatomic relationship between the retromaxillary expansion of the buccal space (B) and the parapharyngeal space (P) through the adipose component of the pterygomandibular space (arrows) is shown; the anatomic continuity of these spaces is apparent because fascial layers separate them.
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11. Figure 10
A 43-year-old man with squamous cell carcinoma of the retromolar trigone. (A) Anterolateral spreading; axial reference computed tomography with oblique sagittal reconstruction planes (1, 2). (B) Sagittal oblique scan that corresponds to plane 1; the neoplasm invades the fat plane (black arrow) between the masseter muscle (M) and buccinator muscle (white arrow) that appears thickened. (C) Coronal oblique reconstruction that corresponds to plane 2; tumour invades the buccal space (B), determining obliteration of its acute inferior apex (asterisk); the involvement of the lower insertion of temporalis muscle (Tm) also can be seen; bone erosion (short arrow); normal mandibular foramen (long arrow).
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12. Figure 11
A 57-year-old man with squamous cell carcinoma of the retromolar trigone (rTR). Oblique coronal reconstruction, showing rTR carcinoma (C) infiltrating the medial pterygoid muscle (Pt); the parapharyngeal space (arrow) is spared. M = masseter muscle.
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13. Figure 12
A 61-year-old man with squamous cell carcinoma of the retromolar trigone (rTR). Coronal reconstruction, showing rTR carcinoma (C) that spread along the pterygomandibular raphe (arrow).
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14. Figure 13
A 65-year-old woman with squamous cell carcinoma of the retromolar trigone (rTR). Oblique coronal reconstruction, showing rTR cancer (C) spreading caudally, towards the mylohyoid muscle (My) insertion; neoplastic infiltration of the buccal space (B) and of the masseter muscle (M) also can be demonstrated. T = tongue.
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15. Figure 14
A 78-year-old man with squamous cell carcinoma of the retromolar trigone (rTR). (A) Reconstructed image obtained with bone algorithm along an oblique-sagittal plane, showing marginal erosion of the alveolar ridge; the mandibular canal (arrows) does not appear involved. C = rTR cancer. (B) Reconstructed image obtained with soft tissues algorithm along an oblique-sagittal plane, showing rTR cancer (C) obliterating the fat contained in the mandibular foramen (arrow); marginal erosion of the alveolar ridge (arrowheads).
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16. Figure 15
(A) Maximum intensity projection reconstruction, showing the outcome of marginal mandibulectomy (arrows). (B) Surface shaded display reconstruction, showing the outcomes of segmental mandibulectomy; note that, in the segmental mandibulectomy, the proximal edge of resection should always enclose the mandibular foramen because of its close relationship with retromolar trigone to avoid perineural diffusion.
Canadian Association of Radiologists Journal  , DOI: ( /j.carj )
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