Fig 3.

Drawing from above and in front (A) of the developing lips and gums. The labiogingival lamina develops in the common mesenchymal tissue of this region. When it dissolves, the labiogingival sulcus that remains separates the lips and gums. The dental lamina develops just behind this region and will give rise to the dental buds, which will form the deciduous and permanent teeth. B, Frontal photograph shows the frenulum of the upper lip, the only remaining vestige of the labiogingival lamina.