Relationships between cervical vertebrae and mandibular canine developmental stages for skeletal maturation evaluation

Health care professionals, including orthodontists and pediatric dentists, are interested in predicting the adolescent growth spurt for treatment planning and timing purposes. Methods for assessing growth potential utilize criteria such as chronological, skeletal, physiologic and dental age. One of the most widely employed and researched skeletal assessment methods is the serial use of hand-wrist radiographs. Considered by many to be a reliable and valid indicator of skeletal maturity, the method is not infallible. Also, radiation hygiene issues discourage many practitioners from taking serial hand-wrist radiographs. Thus, the search for more predictable and cost effective indicators of skeletal maturity continues. Two such indicators worth attention are the mandibular canine and the cervical vertebrae. Objectives: To determine the relationship between the developmental stages of the mandibular canine and the lateral profiles of the second through sixth cervical vertebrae at starting age of peak height velocity (SAPHV). Methods: Lateral cephalometric and 45° lateral oblique radiographs of twenty-four subjects, fifteen females and nine males, that originated from the files of The University of Michigan Elementary and Secondary School Growth Study were used to assess canine and cervical vertebrae developmental stages. Results: Assessment of these two indictors utilizing the inspectional technique is extremely reliable. The association between SAPHV versus mandibular canine stage is significant only when both sexes are considered together. The association between SAPHV versus cervical vertebrae stage is significant for females only. No significant association exists between SAPHV versus the combined “score” of cervical vertebrae and mandibular canine stage. No significant association exists between the cervical vertebrae stage at SAPHV and the mandibular canine stage at SAPHV. Conclusions: This skeletal maturity assessment method is not reliable given the limited association between these two variables at starting age of peak height velocity.