Abstract
Two cases of children (11 and 12 yrs. old) with craniomandibular disorder (CMD), who complained of TMJ sounds and mouth opening limitation, were reported. Since the possible causes of the cases were considered to be the occlusal premature contacts and lower jaw shift due to the prolonged retention of the lower 2nd primary molar, the retended tooth was extracted. After the extraction of the tooth, significant dentitional and occlusal relations adjusted and all symptoms and signs disappeared within a few months.
The following summerized dentional and occlusal changes were noticed after the treatment of CMD:
1) The midline shift of the lower jaw was corrected.
2) The bilateral asymmetry of the dentition of the lower jaw was corrected.
3) The bilateral asymmetry of the molar occlusion was also adjusted.
4) After treatment, the dentition of the lower jaw shifted to a more balenced position against the upper jaw.
It was revealed from these cases that the prolonged retention of the primary molars leads to the physiological occlusal change of the permanent dentition, and subsequently causes craniomandibular disorders.
