Cleft lip corrected at age of 8 months upper jaw advancement done at age 21 facing breathing issues, whistle sound while brthn , is this bcz of surgey?

Possibly: I think it's a good idea to check in with your oral and maxillofacial surgeon. If there is suspicion of obstruction of your airway this can be serious and should be evaluated. You may need a sleep specialist if your breathing is impaired at night.

Cleft : Cleft lip/palate patients will invariably have eaustachian tube problems. This is not because of the surgery. It is because of the pathology that causes the cleft. Even though the palate/lip is repaired, the eustachian tube and the muscles that lift the soft palate cannot be repaired. So you have chronic otitis media. Have you ever had a myringotomy ?

Could be: Whistling sounds from the nose when breathing indicates turbulent airflow in the nose. Often the sound comes from a hole in the nasal septum. You have had enough major facial surgery that it is certainly plausible that the whistling is an effect of the surgery. Have an ENT doc look in your nose and see what is going on structurally.