In this retrospective study, 2 intraoral scans with an interval of at least 1 year were superimposed in 25 oligodontic patients. The differences in vertical eruption (mm) were measured and the orthopantomograms were analyzed for the presence of ankylotic deciduous molars with no successor. The mean eruption of deciduous molars with and without successor was significantly lower than the mean eruption of permanent molars. The eruption of permanent molars was a predictive variable for the eruption of deciduous molars. The number of agenetic elements and the presence of a successor were strongly associated with the eruption of deciduous molars. Also, the mean eruption of deciduous molars with ankylosis was significantly lower than that of deciduous molars without ankylosis. This study showed a strong relationship between the diagnosis of ankylotic deciduous molars and the measurement of negative vertical eruption when monitored by intraoral scans.