link
Bookmarks
Masticator Muscle Atrophy
Rebecca S. Cornelius, MD, FACR
To access 4,300 diagnoses written by the world's leading experts in radiology, please log in or subscribe.Log inSubscribe
0
0
7
0

KEY FACTS

  • Terminology

    • Imaging

      • Pathology

        • Clinical Issues

          • Diagnostic Checklist

            TERMINOLOGY

            • Synonyms

              • Denervation atrophy
            • Definitions

              • Alteration in appearance of muscle groups from loss of innervation by mandibular nerve
                • Mandibular nerve = 3rd division (CNV3) of trigeminal nerve (CNV); only division with motor function
              • CNV3 motor innervation
                • Muscles of mastication
                  • Medial & lateral pterygoid, masseter, & temporalis muscles
                • Tensor muscles
                  • Tensor veli palatini & tensor tympani muscles
                • Floor of mouth muscles
                  • Mylohyoid & anterior belly digastric muscles
              • Denervation pattern identified
                • Acute (< 1 month): Muscles slightly enlarged with edema; enhancement seen
                • Subacute (1-12 months): Fatty replacement & atrophy begin
                • Chronic (12-20 months): Fatty atrophic muscles with significant volume loss

            IMAGING

            • General Features

              • CT Findings

                • MR Findings

                  • Imaging Recommendations

                    DIFFERENTIAL DIAGNOSIS

                      PATHOLOGY

                      • General Features

                        • Gross Pathologic & Surgical Features

                          • Microscopic Features

                            CLINICAL ISSUES

                            • Presentation

                              • Demographics

                                • Natural History & Prognosis

                                  • Treatment

                                    DIAGNOSTIC CHECKLIST

                                    • Consider

                                      • Image Interpretation Pearls

                                        Selected References

                                        1. Wilson MH et al: Focal atrophy of the masticatory muscles caused by pure trigeminal motor neuropathy: case report. Br J Oral Maxillofac Surg. 54(1):e13-4, 2016
                                        2. Chiba M et al: Unilateral atrophy of the masticatory muscles and mandibular ramus due to pure trigeminal motor neuropathy: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol. 113(6):e30-4, 2012
                                        3. Chong V: Imaging the cranial nerves in cancer. Cancer Imaging. 4 Spec No A:S1-5, 2004
                                        4. Ho TL et al: Subacute mandibular and hypoglossal nerve denervation causing oedema of the masticator space and tongue. Neuroradiology. 45(4):262-6, 2003
                                        5. Ariji Y et al: Denervation atrophy of the masticatory muscles in a patient with nasopharyngeal cancer: MR examinations before and after radiotherapy. Dentomaxillofac Radiol. 31(3): 204-8, 2002
                                        6. Kato K et al: Motor denervation of tumors of the head and neck: changes in MR appearance. Magn Reson Med Sci. 1(3):157-64, 2002
                                        7. Fischbein NJ et al: MR imaging in two cases of subacute denervation change in the muscles of facial expression. AJNR Am J Neuroradiol. 22(5):880-4, 2001
                                        8. Caldemeyer KS et al: Imaging features and clinical significance of perineural spread or extension of head and neck tumors. Radiographics. 18(1):97-110; quiz 147, 1998
                                        9. Antoniades K et al: Hemifacial atrophy secondary to poliomyelitis. Int J Oral Maxillofac Surg. 26(3):215-6, 1997
                                        10. Russo CP et al: MR appearance of trigeminal and hypoglossal motor denervation. AJNR Am J Neuroradiol. 18(7):1375-83, 1997
                                        11. Davis SB et al: Masticator muscle enhancement in subacute denervation atrophy. AJNR Am J Neuroradiol. 16(6):1292-4, 1995
                                        12. Petersilge CA et al: Denervation hypertrophy of muscle: MR features. J Comput Assist Tomogr. 19(4): 596-600, 1995
                                        13. West GA et al: Magnetic resonance imaging signal changes in denervated muscles after peripheral nerve injury. Neurosurgery. 35(6): 1077-85; discussion 1085-6, 1994
                                        14. Fleckenstein JL et al: Denervated human skeletal muscle: MR imaging evaluation. Radiology. 187(1):213-8, 1993
                                        15. Uetani M et al: Denervated skeletal muscle: MR imaging. Work in progress. Radiology. 189(2): 511-5, 1993
                                        16. Schellhas KP: MR imaging of muscles of mastication. AJR Am J Roentgenol. 153(4):847-55, 1989
                                        17. Polak JF et al: Magnetic resonance imaging of skeletal muscle. Prolongation of T1 and T2 subsequent to denervation. Invest Radiol. 23(5): 365-9, 1988
                                        18. Shabas D et al: Magnetic resonance imaging examination of denervated muscle. Comput Radiol. 11(1): 9-13, 1987
                                        19. Harnsberger HR et al: Major motor atrophic patterns in the face and neck: CT evaluation. Radiology. 155(3):665-70, 1985
                                        Related Anatomy
                                        Loading...
                                        Related Differential Diagnoses
                                        Loading...
                                        References
                                        Tables

                                        Tables

                                        KEY FACTS

                                        • Terminology

                                          • Imaging

                                            • Pathology

                                              • Clinical Issues

                                                • Diagnostic Checklist

                                                  TERMINOLOGY

                                                  • Synonyms

                                                    • Denervation atrophy
                                                  • Definitions

                                                    • Alteration in appearance of muscle groups from loss of innervation by mandibular nerve
                                                      • Mandibular nerve = 3rd division (CNV3) of trigeminal nerve (CNV); only division with motor function
                                                    • CNV3 motor innervation
                                                      • Muscles of mastication
                                                        • Medial & lateral pterygoid, masseter, & temporalis muscles
                                                      • Tensor muscles
                                                        • Tensor veli palatini & tensor tympani muscles
                                                      • Floor of mouth muscles
                                                        • Mylohyoid & anterior belly digastric muscles
                                                    • Denervation pattern identified
                                                      • Acute (< 1 month): Muscles slightly enlarged with edema; enhancement seen
                                                      • Subacute (1-12 months): Fatty replacement & atrophy begin
                                                      • Chronic (12-20 months): Fatty atrophic muscles with significant volume loss

                                                  IMAGING

                                                  • General Features

                                                    • CT Findings

                                                      • MR Findings

                                                        • Imaging Recommendations

                                                          DIFFERENTIAL DIAGNOSIS

                                                            PATHOLOGY

                                                            • General Features

                                                              • Gross Pathologic & Surgical Features

                                                                • Microscopic Features

                                                                  CLINICAL ISSUES

                                                                  • Presentation

                                                                    • Demographics

                                                                      • Natural History & Prognosis

                                                                        • Treatment

                                                                          DIAGNOSTIC CHECKLIST

                                                                          • Consider

                                                                            • Image Interpretation Pearls

                                                                              Selected References

                                                                              1. Wilson MH et al: Focal atrophy of the masticatory muscles caused by pure trigeminal motor neuropathy: case report. Br J Oral Maxillofac Surg. 54(1):e13-4, 2016
                                                                              2. Chiba M et al: Unilateral atrophy of the masticatory muscles and mandibular ramus due to pure trigeminal motor neuropathy: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol. 113(6):e30-4, 2012
                                                                              3. Chong V: Imaging the cranial nerves in cancer. Cancer Imaging. 4 Spec No A:S1-5, 2004
                                                                              4. Ho TL et al: Subacute mandibular and hypoglossal nerve denervation causing oedema of the masticator space and tongue. Neuroradiology. 45(4):262-6, 2003
                                                                              5. Ariji Y et al: Denervation atrophy of the masticatory muscles in a patient with nasopharyngeal cancer: MR examinations before and after radiotherapy. Dentomaxillofac Radiol. 31(3): 204-8, 2002
                                                                              6. Kato K et al: Motor denervation of tumors of the head and neck: changes in MR appearance. Magn Reson Med Sci. 1(3):157-64, 2002
                                                                              7. Fischbein NJ et al: MR imaging in two cases of subacute denervation change in the muscles of facial expression. AJNR Am J Neuroradiol. 22(5):880-4, 2001
                                                                              8. Caldemeyer KS et al: Imaging features and clinical significance of perineural spread or extension of head and neck tumors. Radiographics. 18(1):97-110; quiz 147, 1998
                                                                              9. Antoniades K et al: Hemifacial atrophy secondary to poliomyelitis. Int J Oral Maxillofac Surg. 26(3):215-6, 1997
                                                                              10. Russo CP et al: MR appearance of trigeminal and hypoglossal motor denervation. AJNR Am J Neuroradiol. 18(7):1375-83, 1997
                                                                              11. Davis SB et al: Masticator muscle enhancement in subacute denervation atrophy. AJNR Am J Neuroradiol. 16(6):1292-4, 1995
                                                                              12. Petersilge CA et al: Denervation hypertrophy of muscle: MR features. J Comput Assist Tomogr. 19(4): 596-600, 1995
                                                                              13. West GA et al: Magnetic resonance imaging signal changes in denervated muscles after peripheral nerve injury. Neurosurgery. 35(6): 1077-85; discussion 1085-6, 1994
                                                                              14. Fleckenstein JL et al: Denervated human skeletal muscle: MR imaging evaluation. Radiology. 187(1):213-8, 1993
                                                                              15. Uetani M et al: Denervated skeletal muscle: MR imaging. Work in progress. Radiology. 189(2): 511-5, 1993
                                                                              16. Schellhas KP: MR imaging of muscles of mastication. AJR Am J Roentgenol. 153(4):847-55, 1989
                                                                              17. Polak JF et al: Magnetic resonance imaging of skeletal muscle. Prolongation of T1 and T2 subsequent to denervation. Invest Radiol. 23(5): 365-9, 1988
                                                                              18. Shabas D et al: Magnetic resonance imaging examination of denervated muscle. Comput Radiol. 11(1): 9-13, 1987
                                                                              19. Harnsberger HR et al: Major motor atrophic patterns in the face and neck: CT evaluation. Radiology. 155(3):665-70, 1985