RESUMEN
The present study included 132 cases with mental subnormality. The aim of the present work was to investigate the prevalence of the oral and dental abnormalities in patients with mental retardation and to delineate the most common patterns of presentation associated with oro-dental abnormalities. All patients were subjected to full history taking, thorough oro-dental examination and IQ assessment. Chromosomal studies and metabolic screening were done when needed. It was concluded that oro-dental abnormalities are more frequent in patients with severe or profound mental retardation. The oral region abnormalities represent a major problem in the oral health of patients with mental retardation. Medical dental services and care were recommended for the affected cases, since there is no national oral disease prevalence data for patients with mental retardation and developmental disability