Evaluating the agreement of skeletal age assessment based on hand-wrist and cervical vertebrae radiography Philipp Beit, a Timo Peltom€ aki, b Marc Sch€ atzle, c Luca Signorelli, d and Raphael Patcas c Zurich and Wil, Switzerland, and Tampere, Finland Introduction: The aim of this study was to examine the agreement of skeletal age assessment based on hand-wrist radiographs with cephalogram-based cervical vertebrae evaluation. To circumvent bias and loss of information from staging, a quantitative approach was applied to determine morphologic changes. Methods: We analyzed 730 sets of radiographs (cephalogram and hand-wrist) of untreated subjects (352 boys, 378 girls; age range, 6-18 years) from a growth study, each sex as a separate sample. Skeletal age was determined on the hand-wrist radiographs according to the method of Greulich and Pyle. Morphometric changes of the vertebral bodies C2 through C4 were measured (concavity, anterior height, and angle) and tested for correlations with the method of Greulich and Pyle. All correlating variables were included in a multiple linear regression to generate a calculated skeletal age. To establish the agreement between the method of Greulich and Pyle and calculated skeletal age, Bland-Altman plots were made, limits of agreement were identified, and cross-tables (before and after peak height velocity) were computed. Similarly, the agreement between the method of Greulich and Pyle and each subject's chronologic age was estimated for comparison. Results: Concavity of C2, C3, and C4; anterior height of C3 and C4; and the angle of C3 correlated with skeletal age highly significantly (P \0.0001) in both sexes, and calculated skeletal age was established based on a linear regression. The agreement between the method of Greulich and Pyle and calculated skeletal age was modest (limits of agreement: boys, 63.5 years; girls, 63.3 years) and substantially weaker than the agreement between the method of Greulich and Pyle and chronologic age (limits of agreement: boys, 12.1 to 1.7 years; girls, 12.2 to 1.2 years). Similarly, calculated skeletal age resulted in considerably more false predictions of peak height velocity (boys, 18.9%; girls, 12.9%) than did chronologic age (boys, 7.1%; girls, 7.4%). Conclusions: Morphometric assessment of age-dependent changes in the cervical spine offers no advantage over chronologic age, in either assessing skeletal age or predicting the pubertal growth spurt. (Am J Orthod Dentofacial Orthop 2013;144:838-47) T he evaluation of skeletal age is essential in many orthodontic treatment approaches, especially regarding the correction of skeletal imbalance. 1 In functional orthopedics, which aims to exploit mandibular growth, success is intimately linked to growth potential. But growth of the mandible is not linear throughout development. 2,3 Chronologic age has been deemed an inadequate indicator to identify stages of growth because of individual variations in timing, velocity, and duration of growth. The periods of acceleration and deceleration during growth are based on the complex endocrine regulation of craniofacial growth. 4 Although a novel approach with insulin-like growth factor I as an indicator for the pubertal growth spurt has been described in scienti- fic literature, this method has not yet reached clinical applicability. 5 Thus, the assessment of biologic age re- mains restricted to 2 approaches: clinical evaluation based on various secondary indicators (sexual matur- ation, longitudinal records of body height, 3,6 menarche in girls, or voice change in boys 7 ) and the appraisal of skeletal maturity based on radiographs (most a Research fellow, Department for Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland. b Head, Oral and Maxillofacial Unit, Department of Ear and Oral Diseases and Department of Otolaryngology, University of Tampere, Tampere, Finland. c Senior lecturer, Department for Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland. d Private practice, Wil, Switzerland. All authors have completed and submitted the ICMJE Form for Disclosure of Po- tential Conflicts of Interest, and none were reported. Address correspondence to: Raphael Patcas, Department for Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Platten- strasse 11, 8032 Zurich, Switzerland; e-mail, raphael.patcas@zzm.uzh.ch. Submitted, May 2013; revised and accepted, July 2013. 0889-5406/$36.00 Copyright Ó 2013 by the American Association of Orthodontists. http://dx.doi.org/10.1016/j.ajodo.2013.07.015 838 ORIGINAL ARTICLE