TY - JOUR T1 - Odontoid process inclination in normal adults and in an adult population with Chiari malformation Type I. AU - Besachio,David A, AU - Khaleel,Ziyad, AU - Shah,Lubdha M, Y1 - 2015/08/28/ PY - 2015/8/29/entrez PY - 2015/9/1/pubmed PY - 2016/4/8/medline KW - CCJ = craniocervical junction KW - CM = Chiari malformation KW - CM-I = CM Type I KW - Chiari malformation KW - ICC = intraclass correlation coefficient KW - cervical KW - complex Chiari malformation KW - craniocervical junction KW - odontoid inclination KW - pB-C2 = a line drawn through the odontoid tip from the ventral dura perpendicular to a second line from the basion to the inferoposterior aspect of the C-2 vertebral body KW - pB-C2* = a line drawn through the odontoid tip from the posterior odontoid cortex perpendicular to a second line from the basion to the inferoposterior aspect of the C-2 vertebral body SP - 701 EP - 6 JF - Journal of neurosurgery. Spine JO - J Neurosurg Spine VL - 23 IS - 6 N2 - OBJECT: Posterior odontoid process inclination has been demonstrated as a factor associated with Chiari malformation Type I (CM-I) in the pediatric population; however, no studies to date have examined this measurement in the adult CM-I population. The purpose of this study was to evaluate craniocervical junction (CCJ) measurements in adult CM-I versus a control group. METHODS: The odontoid retroflexion, odontoid retroversion, odontoid height, posterior basion to C-2 line measured to the dural margin (pB-C2 line), posterior basion to C-2 line measured to the dorsal odontoid cortical margin (pB-C2* line), and clivus-canal angle measurements were retrospectively analyzed in adult patients with CM-I using MRI. These measurements were compared with normative values established from CT scans of the cervical spine in adults without CM-I. RESULTS: A statistically significant difference was found between 55 adults with CM-I and 150 sex-matched controls (125 used for analysis) in the mean clivus-canal angle and the mean pB-C2 line. CONCLUSIONS: These data suggest that there are sex-specific differences with respect to measurements at the CCJ between men and women, with women showing a more posteriorly inclined odontoid process. There were also differences between the CM-I and control groups: a more acute clivus-canal angle was associated with CM-I in the adult population. These CCJ findings could have an influence on presurgical planning. SN - 1547-5646 UR - https://www.unboundmedicine.com/medline/citation/26315958/Odontoid_process_inclination_in_normal_adults_and_in_an_adult_population_with_Chiari_malformation_Type_I_ L2 - https://thejns.org/doi/10.3171/2015.3.SPINE14926 DB - PRIME DP - Unbound Medicine ER -