The purpose of this prospective, longitudinally-controlled study was to analyze the isolated effect of spurs on the craniofacial and dentoalveolar complex of patients presenting anterior open bite due to tongue dysfunction. Following a standardized treatment protocol, fifteen patients (mean age 13 years, 10 months+/-5 years, 7 months) underwent treatment with a fixed palatal spur appliance for a mean duration of 9.13 months. The cephalometric analysis was based on lateral cephalograms taken before (T1) and directly after the spur therapy (T2). All patients experienced an elongation of the maxillary and mandibular alveolar processes. The alveolar process height of the maxilla showed a highly significant mean growth increment of 1.61 mm, the alveolar process height of the mandible of 1.36 mm. The mean increase in overbite was 1.95 mm and highly significant. In addition, after spur therapy, a significant uprighting of the lower incisors was observed, which also resulted in a significant increase in the overjet. With the help of spurs, an elongation of the alveolar process heights of the upper and lower jaws was achievable for all patients presenting an anterior open bite due to tongue dysfunction. The results indicate a change in the neuromuscular behavior pattern of the tongue which brought about the correction of the dysfunction and, finally, the increase in overbite.