Relationship of difficult forceps delivery to dental arches and occlusion.

This study examined the relationship between the extensive use of forceps procedures during delivery and later occlusal characteristics. The work uses data collected in National Collaborative Perinatal Research Project (USA), in which more than 60,000 pregnancies and the children's health were followed by regular medical tests and examinations. Of these, a subsample of 2,074 children participated in dental examinations, including the production of dental casts with wax bites to register occlusion. A total of 84 children, 55 boys and 29 girls, were coded as having undergone difficult or very difficult forceps deliveries. A control group was matched by age, sex, race, and site of dental examination. The results show a significant increase in asymmetric molar occlusion (P < 0.005) and canine relations (P < 0.001) in the study group. The sagittal length of the mandibular arch was increased in the difficult forceps delivery group (P < 0.01). In conclusion, difficult forceps procedures are associated with a later asymmetric occlusion.