can I recover master db?

[Max]

While cleaning up and deleting old databases using phpMyAdmin (set up to mysql databases), I accidentally deleted the master database to one of my websites. All the other databases should still be in place, but after removing the master, I naturally lost access to everything. Structurally, nothing has changed since I've made a backup, but since then, a lot of information was stored. My backup is fairly old, and I was wondering if there is any way to recover the master database without doing the full backup (which would make me lose all data entered since the backup was made).