Craniomandibular disorders in children--a critical review of the literature.

Reports of prevalences of craniomandibular disorders (CMD) in children and adolescents differ markedly from one study to another. Therefore it is almost impossible to get a clear picture of the magnitude of the disorder in a child population. The aim of this study was to critically compare and analyse the results presented in recent publications in order to get a comprehensive view of the prevalence of CMD in children and adolescents. Fourty epidemiological studies on CMD symptomatology and headache in the age group three to 25 years were included. Eight symptoms and eight signs were chosen for further comparisons and analyses. The prevalences of these signs and symptoms were evaluated and classified according to a set of criteria, in either frequency of "greater clinical relevance" or frequency of "lesser clinical relevance". The evaluation was based on the presented examination methods, definitions and symptom criteria used in the studies. The reported frequencies for the sixteen signs and symptoms are presented graphically. The diagram clearly show great variation in the reported frequencies for most signs and symptoms. If only reported frequencies of "greater clinical relevance" are considered, these variations are less pronounced but still considerable. One major reason for this is inter- and intraindividual variation among the examiners. Another plausible and often overlooked reason is the fact that examination methods designed for adults uncritically have been applied on children without consideration of age and cognitive development of the child.