Makoto Terumitsu1, Hitoshi Matsuzawa2, Kenji Seo3, Masaki Watanabe2, Shigenobu Kurata3, Akiko Suda4, Tsutomu Nakada2. 1. Division of Dental Anesthesiology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. Electronic address: terumitu@dent.niigata-u.ac.jp. 2. Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan. 3. Division of Dental Anesthesiology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. 4. Division of Dental Anesthesiology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan.
Abstract
OBJECTIVE: Magnetic resonance neurography reveals abnormal morphologies of regenerated nerves and overgrown connective tissue in injured trigeminal nerves, suggesting neuroma formation. We hypothesized that such deformities and scar formation contribute to pain symptoms. STUDY DESIGN: High-contrast high-resolution magnetic resonance imaging was utilized to evaluate the inferior alveolar nerve and lingual nerve following traumatic injury in 19 patients. The relationship between the morphologic classification and severity of the sensory disorder was assessed. RESULTS: In all cases, 3-dimensional anisotropy contrast periodically rotated overlapping parallel lines with enhanced reconstruction (3DAC-PROPELLER) successfully revealed the inner structures within the lesion. The isolated type represented the normal course of the nerve isolated from scar-like tissue (8 cases), whereas the deformity type included the deformed nerve either within scar-like tissue or by itself, unassociated with surrounding scar-like tissue (9 cases). In the remaining 2 cases, the nerve tissue and scar-like tissue were incorporated. Patients with the deformity type exhibited significantly more severe pain symptoms compared with patients with the isolated type. CONCLUSIONS: Overgrown connective tissue does not necessarily block regenerating nerves and itself may not cause pain. The morphologic findings on the 3DAC-PROPELLER were relevant to the severity of pain symptoms.
OBJECTIVE: Magnetic resonance neurography reveals abnormal morphologies of regenerated nerves and overgrown connective tissue in injured trigeminal nerves, suggesting neuroma formation. We hypothesized that such deformities and scar formation contribute to pain symptoms. STUDY DESIGN: High-contrast high-resolution magnetic resonance imaging was utilized to evaluate the inferior alveolar nerve and lingual nerve following traumatic injury in 19 patients. The relationship between the morphologic classification and severity of the sensory disorder was assessed. RESULTS: In all cases, 3-dimensional anisotropy contrast periodically rotated overlapping parallel lines with enhanced reconstruction (3DAC-PROPELLER) successfully revealed the inner structures within the lesion. The isolated type represented the normal course of the nerve isolated from scar-like tissue (8 cases), whereas the deformity type included the deformed nerve either within scar-like tissue or by itself, unassociated with surrounding scar-like tissue (9 cases). In the remaining 2 cases, the nerve tissue and scar-like tissue were incorporated. Patients with the deformity type exhibited significantly more severe pain symptoms compared with patients with the isolated type. CONCLUSIONS: Overgrown connective tissue does not necessarily block regenerating nerves and itself may not cause pain. The morphologic findings on the 3DAC-PROPELLER were relevant to the severity of pain symptoms.