The effect of the alteration the natural head position (NHP) on the cephalometric measurements

Paulo Eduardo NEGREIROS, Vânia Célia Vieira de SIQUEIRA

This work aimed to study the alterations of angular and linear cephalometrics measurements used in cephalometry, when the natural head position (NHP) is modiied during the taking of cephalometric radiography, its inluence in the orthodontic diagnosis, and the reliability and reproducibility of NHP for successive radiographs. One hundred and eighty cephalometrics radiographs were taken in lateral norm of 30 female patients with age range of 21,3 years old. The X-ray were obtained in two series within 15 days interval among them. In each of the series, the natural head position (NHP), the NHP added of 5 degrees (NHP+5º) and NHP with 5 degrees of lexion (NHP-5º) were registered from each patient. The obtained results demonstrated that the linear measurements S-N, ENA-ENP, Co-Gn, Go-Gn, and the angular measurements SNA, ANB, PP.GoGn, 1.PP, IMPA, 1.1, SN.VER and HF.VER did not present statistically signiicant alterations among the studied positions and the two series of radiographic taken as well. The angular measurements of SNB, SN.GoGn, FMA, SN.PP, Z Angle, Co-Go presented statistically signiicant alterations. It was concluded that the angular and linear measurements appraised did not present signiicant alterations when the NHP modiied within of the angular variation strip studied, which did not lead to doubtful diagnosis or interpretations. Due to low variation of the angulations of the SN.VER and HF.VER angles, it was demonstrated that the employment of the Guiding Unit of Positioning presented in this work, allows the reproducibility of the natural head position with great reliability within a + 5º variation strip of NHP.

Keywords: Cefalometry. Orthodontics. Diagnosis. Natural Head Position.

Wednesday, May 01, 2024 19:14