Introduction: The purpose of the study is to determine reliability of true horizontal (TH) plane with Frankfort horizontal (FH) plane in cephalometric measurements.
Materials and methods: One hundred lateral cephalograms were collected and traced using FACAD software, all cephalometric measurements which included FH plane as reference planes were used in this study. Cephalometric tracing was done with FH plane as reference plane and another set of measurements with TH plane as reference plane was done. Statistical tests were done using independent sample t-test (p <0.05).
Results: Results of an independent t-test revealed a statistically insignificant difference that was observed for all the parameters assessed (p <0.05). Both angular and linear measurements showed an insignificant difference between FH and TH.
Conclusion: Within the limitations of the study, the results show that the FH plane is closest and as reliable as the TH plane. The variation of FH was least for all the parameters assessed.
Keywords: Cephalometrics; FACAD software; Frankfort horizontal plane; Natural head position True horizontal plane..