Cephalometric comparison of anterior cranial base, maxilla and mandible among monozygotic twins

Rodrigo Machado DELABARY, Eduardo Martinelli Santayana de LIMA

This study was conducted with the purpose of comparing the cranial anterior base, length and position of the maxila, length and position of the mandible.Thirty-six lateral x-rays from 18 pairs of white brazilians monozygotic twins, 9 female pairs and 9 male pairs were used. The sample selected only orthodontically untreated subjects and twins that had records taken on the same date, in the same technics. After that the cephalometric tracings were made, and Dentofacial Planner Plus software used to obtain the data. The data were statistically analyzed thru t-student test for independent samples, mean of modulus of difference, standard deviation and confidence interval for each pair and each variable, to verify the magnitude of each variable. It was possible to verify that the craniofacial complex shows an extremely strong genetic control for all studied variables. The linear measurements that indicate the length of the anterior cranial base (S-N), length of the maxilla (PP) and mandible length (Co-Gn) presented less variation. Larger spatial variation for the maxilla and mandible was detected in antero-posterior dimensions when angular measuments were applied. (Mx axis, Md axis, SNA and SNB).

Keywords: Cefalometrics. Monozygotic twins. Craniofacial genetics. Craniofacial morphology

Saturday, December 28, 2024 23:39