Complex sentence: These may have been due to increased risk from disease once the protective antibodies in a mother's milk ended after weening and greater exposure to hard and soft tissue trauma, and subsequent infection, as children became more mobile by crawling and toddling.
Split into simpler sentences: These may have been due to increased risk from disease once the protective antibodies in a mother's milk ended after weening. There was also greater exposure to hard and soft tissue trauma, and subsequent infection, as children became more mobile by crawling and toddling.