Yes. In Jainism there is emphasis on cleanliness and purity as part of daily conduct. Brushing your teeth before sunrise is allowed and can be part of your morning cleanliness routine. There is no strict rule in Jain texts prohibiting brushing before sunrise. Different Jain traditions (Digambar and Shwetambar) have their own detailed morning routines, but brushing teeth beforehand is generally acceptable and aligns with the aim of starting the day with purity. If you are following a specific vrata or guru's guidance, you may align with that instruction as well.