title: Osteogenetic changes in elongated styloid processes of Eagle syndrome patients.
abstract: Abnormal elongation of the styloid process, or Eagle syndrome, can be painful, and is associated with differential diagnoses including cranio-facial malformations and vasculo-neurological disturbances. The precise molecular mechanism leading to styloid process elongation is unknown. In this study, elongated styloid processes with periosteal fibrous ligament tissue were obtained from three patients with Eagle syndrome and examined by immunohistochemical methods using different antisera. In all cases, marked bony deposition was found at the apex of the styloid process. The osteogenetic proteins, such as osteonectin, osteocalcin, BMP-2, BMP-4, and RANKL were strongly positive by immunohistochemistry in both the ligament fibers and the periosteal membrane attached to the styloid process apex. Staining for protective proteins, HO-1, HSP-70, and HSP-90 was also positive. These results suggest that styloid process elongation is related to increased expression of osteogenetic and protective proteins. Therefore, we propose that Eagle syndrome results from a protective response to increased tensile stress in the ligament attached to the styloid process, which could also signal osteogenetic protein expression in the periosteal fibrous tissue.
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Jin Young Choi), Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Soung Min
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Jin Young Choi), Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Mi Hyun
authors.initials: MH
authors.lastname: Seo
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Jin Young Choi), Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: Myoung
authors.affiliation: Department of Oral and Maxillofacial Surgery (Head: Prof. Jin Young Choi), Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Dental Hygiene (Head: Prof. Yeon Sook Kim), Cheongju University, Cheongju, South Korea.
authors.forename: Yeon Sook
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Oral Pathology (Head: Prof. Suk Keun Lee), College of Dentistry, Gangneung-Wonju National University, 123 Chibyun-dong, Gangneung 210-702, South Korea. Electronic address: sukkeunlee@hanmail.net.
authors.forename: Suk Keun
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D055396:Bone Morphogenetic Protein 2 / Q000032:analysis; D055415:Bone Morphogenetic Protein 4 / Q000032:analysis; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis; D051547:Heme Oxygenase-1 / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008022:Ligaments / Q000737:chemistry / Q000503:physiopathology; D008297:Male; D009999:Ossification, Heterotopic / Q000378:metabolism / Q000503:physiopathology*; D015675:Osteocalcin / Q000032:analysis; D010012:Osteogenesis / Q000502:physiology*; D015676:Osteonectin / Q000032:analysis; D010521:Periosteum / Q000737:chemistry / Q000503:physiopathology; D053245:RANK Ligand / Q000032:analysis; D013314:Stress, Mechanical; D013701:Temporal Bone / Q000002:abnormalities* / Q000737:chemistry / Q000378:metabolism / Q000503:physiopathology; D055815:Young Adult
chemical_list: C525718:BMP2 protein, human; C525809:BMP4 protein, human; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D015676:Osteonectin; D053245:RANK Ligand; C505688:TNFSF11 protein, human; D015675:Osteocalcin; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1
keywords: Eagle syndrome; Immunohistochemistry; Osteogenetic proteins; Styloid process; Tensile stress