Skeletal Maturation Assessment in Orthodontics

To assess skeletal maturation in orthodontic patients using hand-wrist and cervical vertebrae methods and (2) To characterise the morphological differences ofthe craniofacial and cervical vertebrae at different ages in two different populations. Subjects and Methods: The study included 2,167 patients with hand-wrist and lateral cephalometric radiographs:· 648 Indonesian males, 303 Caucasian males (age range 10 to 17 years), 774 Indonesian females and 442 Caucasian females (age range 8 to 15 years). Each hand-wrist radiograph was classified according to the Skeletal Maturation Index (SMI) developed by Fishman (1982). Similarly, cervical vertebrae maturation was assessed using lateral cephalograms and classified into the stages described by Baccetti et al. (2002). The craniofacial and cervical vertebrae were traced from lateral cephalograms and then digitised using a customised computer program. Results: The first part ofthe study (Chapter 2) was undertaken to establish intra-operator repeatability ofall available methods. The results showed acceptable agreement for the SMI, CVM Index and the cephalometric data. The next section (Chapter 3) aimed to describe the skeletal maturation stages of both ethnic groups. On avera&,e, the Caucasian children attained each stage earlier than the Indonesians, although the differinces were less obvious in females than in males. In Chapter 4, the ages ofattainment ofthe peak pubertal growth for the selected craniofacial parameters were determined. It appeared that the Caucasian males attained peak pubertal growth slightly earlier than their Indonesian peers for most parameters. Interestingly, in females, the Indonesian reached peak pubertal growth earlier than the Caucasians for the majority ofparameters. In both ethnic groups, on average, the females reached peak pubertal growth of the craniofacial parameters earlier than the males. Chapter 5 describes Receiver Operating Characteristic (ROC) analysis to assess, and compare, the ability ofthe SMI and CVM Index in discriminating between patients who have yet to attain peak pubertal growth and those who have reached/passed peak pubertal growth. The findings confirmed the validity of both indices, with the SMI· showing slightly superior results. Nevertheless, the differences between the two indices ranged between only 1and 7%. The final chapter (Chapter 6) investigated the differences in the craniofacial and cervical vertebrae structures at different ages in both ethnic and gender groups. For most parameters, there was no evidence of statistically significant differences in craniofacial and cervical vertebrae structures between the ethnic groups. Even though there were some statistically significant findings, these differences were unlikely to be clinically relevant. Conclusions: Differences in the age of attainment of each skeletal maturation stage and the peak pubertal growth of craniofacial parameters, exist between the two ethnic and gender groups. This study also confirmed the validity of both the SMI and CVM Index in detecting peak pubertal growth. However, the differences between them were low, hence this study strongly questions the benefit of taking additional hand-wrist radiographs when the use of lateral cephalograms can be optimised. For most parameters, the differences in craniofacial and cervical vertebrae structures between the two ethnic and gender groups were not statistically significant. , Although a small number ofparameters were statistically significant, the actual differences were low in magnitude and unlikely to be clinically relevant.EThOS - Electronic Theses Online ServiceGBUnited Kingdo