Typical geckos have close to 100 exposed teeth at birth and continuously replace them every few months (3). Leopard Gecko Tooth Replacement. Leopard geckos have tooth ‘families’ that form rows in the lizard’s mouth. Within these rows, new generations of teeth form constantly from before hatching until death. The replacement teeth are formed in the successional lamina and develop lingual (towards the tongue) compared to the erupted teeth. Each replacement tooth grows in size until it eventually surfaces from inside of the tissue and displaces the tooth in it’s place. This turnover process usually takes between 3 and 4 months (3).