Background: There are many factors to assess face morphology and standard occlusion, in which sagittal relationship index is an important one. This index in cephalometric film can help to study developmental changes, to evaluate structures of bone and soft tissues, and to make decisions in orthodontic treatments. Objectives: Determination of the sagittal relationship index on cephalometric film in Vietnamese citizens aged 18 to 19 years. Subjects: 100 Vietnamese (42 men and 58 women) aged 18 to 19 years, who had 28 healthy and natural teeth. Method: Descriptive cross-sectional study. All participants were X-rayed on cephalometric film and then special points, angles, and planes were defined on these films. Data was analyzed by using one-way ANOVA test, t - Student test in Epi-Info software version 6.04 and SPSS version 10.0. Results and conclusion: Some sagittal craniofacial indexes on cephalometric film were defined as followed: in both sexes, mean SNA (degree) = 81.99 +/- 3.77 (82.81+/-4.40 in men, 81.40+/-3.16 in women, p> 0.05); mean SNB = 79.66 +/- 4.10 (82.81+/-4.36 in men, 78.40+/-3.40 in women, p< 0.05); mean ANB = 2.33 (1.40 in men, 3.00 in women, p< 0.05); mean l/SN = 109.36 +/- 6.46 (110.55+/-7.77 in men, 108.49+/-5.22 in women, p> 0.05); mean 1/ MP = 95.85 +/- 6.86(93.68+/-7.27 in men, 108.49+/-6.15 in women, p> 0.05); mean 1/1 = 120.02 +/- 13.06 (125.42+/-9.08 in men, 116.10+/-14.13 in women, p< 0.05). These findings showed that the Vietnamese populaces have alveolar protrusive tendency.
Sagittal relationship index ; cephalometric film