Seventy-five children aged 6—17 years (mean age 9.8±4.1 years) that received mandible distraction (MD) at the age of 0—17 years (mean age at MD 6.1±4.3) were included in the study. Indication for MD were hemifacial microsomia (n=41), Goldenhar syndrome (n=4), Robin sequence (n=10), Treacher, Collins syndrome (n=7) or acquired mandible underdevelopment (n=13). Control groups consisted of 22 children aged 5—14 years (mean age 7.0±3.7 years) with mandible underdevelopment of similar origin (hemifacial microsomia (n=15), Goldenhar syndrome (n=2), Robin sequence (n=4), Treacher, Collins syndrome (n=1)) with no history of MD and 80 healthy children aged 6—10 years (mean age 7.1±2.2 years). Case-control study results proved MD to be the risk factor for juvenile paradental cysts (JPCs) with the risk more prominent in early MD cases. JPCs often do not manifest clinically and may resolve spontaneously but in refractory cases lesion curettage without endodontic treatment is an adequate approach, as JPCs are usually not associated with pulp necrosis.