As outlined above frenectomies are done on the labial frenulum for dental problems. They are also done on the lingual frenulum or frenum (there are many correct spellings of these words). Most often this is done to correct speech problems but it can also correct feeding problems, stop drooling, prevent caries and dental malocclusions, prevent obstructive sleep apnea, bedwetting (related to the apnea), aid in digestion, and in social interactions.

Yes, frenectomies hurt. Frenotomies are not such a big deal as the tissue is non-vascular and also not full of nerves. If the lingual frenulum is thick with nerves and/or blood vessels or muscle tissue a frenotomy is not possible and a frenectomy would be called for. Frenotomies are most often done on infants for breastfeeding problems related to tongue immobility. Older children and adults more often require frenectomies. I would speculate that this is probably because if the problem were a simple fibrous tissue one then it would have ruptured on its own in the first few years of life. Those left in an "older" person are more likely the thicker variety. Also, an "older" person is going to need to relearn speech, eating and breathing patterns.