Relationship between cranial and mandibular growth and the stages of maturation of the cervical vertebrae

Quantification of the expectation of craniofacial growth during the pubertal growth spurt (PGS) is helpful in orthodontic diagnosis and treatment planning. Thus, this study investigated whether the stages of the vertebral maturation index (VMI) would be valid for estimating cranial and mandibular growth during the initial stages of PGS, testing the null hypothesis that these structures do not demonstrate differential growth dependent on the maturation stage. A study population of 45 patients of both genders with 2 lateral cephalometric radiographs, taken at a 12-month interval, was selected from files. All patients should not have been previously submitted to orthodontic treatment and should be before or during the peak stage of PGS. The S-N and Co-Gn cephalometric measurements were traced on both radiographs of each patient, by computed cephalometric tracings, for evaluation of skull and mandible, respectively. The growth of these structures was established by the difference between the measurements obtained on both tracings. The VMI stage was also estimated on the radiographs, determining the position of patients on the PGS curve at two periods, baseline and after 12 months. Cephalometric tracings and VMI estimates were performed by two calibrated examiners. Descriptive statistics revealed that both cephalometric measurements increased during the study period, especially Co-Gn, which demonstrated (ANOVA and Tukey's test; 5% significance level), a statistically significant peak of development (p = 0.001), when the patient was in the VMI stage representing the PGS peak. It was concluded that the VMI stages were valid for the analysis of cranial growth and especially of mandibular growth at the initial stages of PGS, thus rejecting the null hypothesis

Reliability and correlation analysis of two skeletal maturation evaluation indexes: hand-wrist index and cervical vertebrae index

AIM: the aim of this study were to evaluate the reliability and correlation of two different skeletal maturation evaluation indexes. METHODS: two hundred and ten hand-wrist and cephalometric radiographs from files of patients with 7- 18 years old were used. The hand-wrist radiographs were used to determine the skeletal maturation index (SMI) and the cephalometric radiographs to determine the cervical vertebrae maturation index (CVMI). Four independent evaluators were asked to examine twice each radiography and to verify the reliability of each index. The stages of SMI and CVMI were compared to evaluate the relationship between them. RESULTS: the results were not statisticaly different among the four evaluators on SMI and CVMI indexes (p<0.00001). The correlation average to SMI was 95% for the first evaluation and 93.5% for the second evaluation. On the CVMI, the correlation average was 84% for the first evaluation and 74% for the second evaluation. The correlation intraoperator did not showed significant difference (p<0.00001) and the average for SMI was 93.5% and for CVMI was 80%. Comparing the indexes, there was no statistical differences (p<0.00001) with correlation of 62% in the first evaluation and 80% in the second evaluation. CONCLUSION: results from the two indexes suggest they are reliable to estimate the skeletal maturation. There is a correlation between the two indexes, however caution must be taken when using only the CVMI index.OBJETIVO: o objetivo deste estudo foi avaliar a confiabilidade e a correlação de dois índices de estimativa da maturação esquelética. METODOLOGIA: foi utilizada uma amostra de 210 radiografias carpais e telerradiografias laterais, de arquivo, de pacientes de ambos os gêneros, com idade entre 7 e 18 anos. As radiografias carpais foram utilizadas na determinação do Índice de Maturação Carpal (IMC) e as telerradiografias laterais na determinação do Índice de Maturação Vertebral (IMV). Cada grupo de radiografias foi examinado e reexaminado por 4 avaliadores, para analisar a confiabilidade de cada índice, e ainda foi realizada a comparação entre os estágios do IMC e do IMV, para avaliar a correlação entre os índices. RESULTADOS: os resultados demonstraram que não houve diferença estatisticamente significante entre os 4 observadores nas avaliações do IMC e do IMV (p<0,00001), sendo as médias de correlação para o IMC de 95% na primeira e 93,5% na segunda avaliação, e para o IMV 84% na primeira e 74% na segunda avaliação. Na correlação intra-avaliadores também não houve diferença estatisticamente significante para nenhum dos avaliadores (p<0,00001), onde a média para o IMC foi de 93,5% e para o IMV de 80%. Na comparação entre os índices, mais uma vez não houve diferença estatisticamente significante (p<0,00001), sendo a correlação de 62% na primeira e de 80% na segunda avaliação. CONCLUSÕES: conclui-se que os dois índices mostraram-se confiáveis para estimar a maturação óssea e que há correlação entre os mesmos. Entretanto, sugere-se cautela na avaliação isolada pelo IMV.11012