My lingual frenectomy was done by cutting part of the flesh off the bone behind my bottom teeth instead of frenulum itself. is that a normal method?

Lingual frenulectomy: A lingual frenulectomy is the procedure utilized by the physician, usually an ENT , to treat a patient that is tongue tied, a condition called ankyloglossia . It involves dividing the lingual frenulum above the sublingual gland ducts (usually in the middle of this structure). A scissors or a cautery instrument is used to do this and the free edges are sutured together for hemostasis.

Yes: The true attachment for the tongue is huge. A frenectomy will look gruesome for a while. Any oral surgeon who performed such a procedure will require you to return for a post operative evaluation. Discuss your concerns with them at your follow-up appointment. Provided that there was no infection or complications i'd expect 1mm of healing per day.

depends on anatomy: The surgical technique depends on your specific anatomy in the area. Sometimes the attachment is higher on the tongue, others the tissue adjacent to the teeth. Sometimes both. Saving the 'attached' gingiva adjacent to the teeth is critical.