Curvatures of occlusal planes CURVE OF WILSON:in the mandibular arch,that curve (viewed in the frontal plane)which is concave above and contacts the buccal and lingual cusp tips of the mandibular molars;in the maxillary arch,that curve (viewed in the frontal plane)which is convex below and contacts the buccal and lingual cusp tips of the maxillary molars. 1902 Curvatures of occlusal planes CURVE OF WILSON: in the mandibular arch, that curve (viewed in the frontal plane) which is concave above and contacts the buccal and lingual cusp tips of the mandibular molars; in the maxillary arch, that curve (viewed in the frontal plane) which is convex below and contacts the buccal and lingual cusp tips of the maxillary molars