Palatogingival groove also known as radicularlingual groove is a developmental anomaly involving the lingual surface of the maxillary incisors. They are inconspicuous. funnel-shaped. extend for varying distances on root surface and occur due to infolding of the hertwigs epithelial root sheath. https://www.bekindtopets.com/hot-mega-Swish-Supreme-Glide-Track-White-great-pick/