Citation Information :
Shrinivas KA, Sudhakar SS, Kannan G, Shetty P, Quadras DD, Raghava S. Predictive Equation for Construction of Anatomic Porion with Machine Porion as Reference Point. J Contemp Dent Pract 2023; 24 (4):257-260.
Aim: The aim of the study was to find a relationship between anatomic porion (PoA) and machine porion (PoM) and to construct PoA with the help of machine porion.
Methodology: About 200 pretreatment lateral roentgenic cephalograms were used for the study. Perpendicular distances of PoA and PoM were measured from Sella–Nasion (SN) plane and SN perpendicular plane. The results were tabulated. With the help of statistical analysis, predictive equation was derived to construct PoA and PoM. p-value was set at p < 0.05.
Results: Anatomic porion distance from SN was 24.35 ± 3.96 and from SN perpendicular was 12.89 ± 4.56. Distance of PoM from SN was 22.46 ± 4.20 and from SN perpendicular was 16.76 ± 4.89. Sexual dimorphism was also seen.
Conclusion: There is a relationship between the PoM and PoA, thus, PoA, which is more reliable, can be constructed with the help of PoM, which is easy to reproduce.
Clinical significance: To overcome the inherent limitations of PoA and PoM, the present study aimed to find a relationship between the two so as to easily construct PoA that is more reliable while taking advantage of the ease of reproducibility of PoM.
Pancherz H, Gokbuget K. The reliability of the Frankfort horizontal in roentgenographic cephalometry. Eur J Orthod 1996;18(4):367–372. DOI: 10.1093/ejo/18.4.367.
Broadbent BH. A new X-ray technique and its application to orthodontia. Angle Orthodontist 1931;1:45–66. DOI: 10.1043/0003-3219(1931)001<0045:ANXTAI>2.0.CO;2.
Tweed CH. The Frankfort-mandibular plant angle in orthodontic diagnosis, classification, treatment planning, and prognosis. Am J Orthod Oral Surg 1946;32:175–230. DOI: 10.1016/0096-6347(46)90001-4.
Downs WB. Variations in facial relationships: Their significance in treatment and prognosis. Am J Orthod 1948;34(10):812–840. DOI: 10.1016/0002-9416(48)90015-3.
Lima RS. Localização anatômica do forame auditivo externo em telerradiografias. Ortodontia 1981;14:97–100.
Vilela OV. Manual de Cefalometria. Rio de Janeiro: Guanabara Koogan; 1998.
Adenwalla ST, Kronman JH, Attarzadeh F. Porion and condyle as cephalometric landmarks—an error study. Am J Orthod Dentofacial Orthop 1988;94(5):411–415. DOI: 10.1016/0889-5406(88)90130-8.
Berco M, Rigali PH, Jr, Miner RM, et al. Accuracy and reliability of linear cephalometric measurements from cone-beam computed tomography scans of a dry human skull. Am J Orthod Dentofacial Orthop 2009;136(1):17.e1–17.e9. DOI: 10.1016/j.ajodo.2008.08.021.
Chien PC, Parks ET, Eraso F, et al. Comparison of reliability in anatomical landmark identification using two-dimensional digital cephalometrics and three-dimensional cone beam computed tomography in vivo. Dentomaxillofac Radiol 2009;38(5):262–273. DOI: 10.1259/dmfr/81889955.
Dvortsin DP, Ye Q, Pruim GJ, et al. Reliability of the integrated radiograph-photograph method to obtain natural head position in cephalometric diagnosis. Angle Orthod 2011;81(5):889–894. DOI: 10.2319/010411-2.1.
El-Beialy AR, Fayed MS, El-Bialy AM, et al. Accuracy and reliability of cone-beam computed tomography measurements: Influence of head orientation. Am J Orthod Dentofacial Orthop 2011;140(2):157–165. DOI: 10.1016/j.ajodo.2010.03.030.
Moshiri M, Scarfe WC, Hilgers ML, et al. Accuracy of linear measurements from imaging plate and lateral cephalometric images derived from cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2007;132(4):550–560. DOI: 10.1016/j.ajodo.2006.09.046.