FIGURE 2. Occlusal view of lower first molars (m1; 1, 3) and upper third molars (M3; 2, 4) illustrating selected anatomical terms (1, 2) and measurements (3, 4) used in this study. Abbreviations: A, length of the anteroconid complex of m1; A-A', width of the anterior cap of m1; ALCTL, length of anterior loop and central triangles of M3; ALW, width of anterior loop of M3; B, width of opening between triangles 5 and 6 on m1; BRA, buccal re-entrant angle; C, width of opening between triangles 4 and 5 on m1; GAPL, greatest anteroposterior length of M3; GW, greatest width of M3; L, greatest length of m1; LPLW, width of last segment of posterior loop of M3; LRA, lingual re-entrant angle; OW (not shown), greatest width of m1 measured perpendicular to the long axis of the occlusal surface; PLL, length of posterior loop of M3; PLW, width of posterior loop of M3; T, triangle; W, greatest straightline distance between the apices of triangles 4 and 5 on m1; W', greatest straightline distance between the apices of triangles 6 and 7 on m1. Measurements of m1 and their associated abbreviations are from Pfaff (1990) with the exception of A–A', which was redrawn from Repenning (1992).