Landmarks used in the present study. 1, Rs*R2+3; 2, R4*r-m; 3, M1*r-m; 4, br*d; 5, m-cu*M3; 6, m-cu*M4;7, m-cu*CuA;8, A1*CuA; 9, Basal end of CuA; 10, Basal end of M4; 11, Basal end of M3; 12, M3*m-m; 13, Basal end of M2; 14, Basal of M2; 15, m-m*M2; 16, Basal end of M1; 17, Basal end of R5; 18, R5*R4; 19, Basal end of R4; 20, Basal end of R2+3