Human teeth and animal teeth are not delicate. A genetic predisposition of soft enamel may run in your family. Also, genetic disorders can affect the dentin, which is the layer beneath your enamel. These states can lead to compromised teeth that crack and break.
Advanced periodontal conditions can also cause brittle teeth. If left untreated, gingivitis, an inflammation of the gums, can lead to more severe inflammation around the teeth and weakening of the bone. Certain personal habits also contribute to the weakening of the teeth. Brushing your teeth too often or too forcefully can strip your enamel, making your teeth more vulnerable to decay and breakage.