The arching of the palate in twin foetuses.

The aim of the study is to examine the process of change with age of hard and total palate arching. Differences were compared in the arching of the hard and total palate in pairs of twins of the same sex and in pairs of twins of opposite sexes aged between 4 and 7 months of foetal life. On the basis of the results obtained it may be stated that: 1. There is some delay in the process of development of twin foetuses in comparison with ones from a single pregnancy; 2. There are no substantial differences between male and female twins and between twins from heterosexual pairs; 3. Much greater differences take place in older twins with regard to the features under examination.