LONGITUDINAL PREDICTABILITY OF AF-BF VALUE IN ANGLE CLASS-I PATIENTS

AF-BF is a linear cephalometric measure of the anteroposterior jaw rel ationship in the sagittal plane. A retrospective, longitudinal study w as made to determine the mean Caucasian American AF-BF values at ages 8 and 18 years for 30 male and 32 female participants of the Bolton Gr owth Study. Mean AF-BF values (+/- s.d.) for males were 7.3 +/- 2.7 mm at 8 years and 6.5 +/- 4.2 mm at 18 years. Mean AF-BF values (+/- s.d .) for females were 6.7 +/- 2.1 mm at 8 years and 5.2 +/- 2.9 mm at 18 years. No significant difference was found between the mean AF-BF val ues for males and females at either age group (P < 0.05). The decrease in AF-BF mean values with increasing age both for males and females w as statistically significant. The correlation (r) for the AF-BF values was 0.49 (P < 0.05) for females and 0.86 (P < 0.05) for males. With i ncreasing age, the mean difference between ANB values for females was 1.40 +/- 1.60 and 1.10 +/- 1.40 for males. The correlation of ANB angl e and AF-BF provides a clinically useful tool for the cephalometric as sessment of anteroposterior sagittal discrepancies of maxillary and ma ndibular denture bases.