Association between Clinical Crown Length and Vertical Growth Pattern

OBJECTIVE: To evaluate the association between the clinical crown length and the vertical growth pattern.
METHODS: Subjects (n=174), aged between 14 and 17, were divided into 3 groups. Patients' cephalometric graphies were taken with Digora Optime (Sorodex corp., Finland) and Dolphin Imaging V.10 software (Dolphin Imaging and Management Solutions, Chatsworth, USA) was used for analysis. To evaluate the vertical growth; SNGoGn, sum of posterior angles and jarabak ratio were measured. Groups were defined as normal, hypodivergent and hyperdivergent according to their vertical growth measurements. Stone models scanned and 3D digital images saved with Orthomodel digital orthodontic model software (Orthomodel, Istanbul, Turkey). Clinical crown lengths of 12 teeth were measured on both upper and lower jaws with orthomodel software program.
RESULTS: When compared with the normal group, the clinical crown lengths of teeth numbered 16,23,26,32 were statistically higher in hyperdivergent group (p=0.004, p=0.001, p=0.001, p=0.0036, respectively). The mean ratio of upper anterior segment in hyperdivergent group was significantly higher than normal (p=0.021) group and the mean ratio of upper anterior segment, lower anterior segment and upper posterior segment in hyperdivergent group were significantly higher than the hypodivergent group (p=0.008, p=0.006, p=0.007 respectively).
CONCLUSION: Results showed that the growth pattern appears to effect the clinical crown lengths. Therefore, while planning the treatment, clinical crown length evaluation should be taken into account with the other factors.