George Campbell, the owner of the All 1 Smile chain of clinics, repeatedly failed to check the qualifications of staff who carried out orthodontic work. One employee attempted to straighten a patient's teeth with no dental training at all, a tribunal heard.
Campbell fixed a child's braces after confusing one of their baby teeth for an adult one, causing "irreparable harm" and a lifetime of "extensive restorative treatment".
He also mistakenly extracted patients' healthy teeth and referred children for surgery at hospital they did not need, the General Dental Council heard.
Campbell has two orthodontic practices in Glasgow, and others in East Kilbride, Greenock, Cumbernauld, Hamilton and Kilmarnock. He was referred to the GDC in September 2011 after complaints about the treatment of 30 patients.
A conduct and competence committee has now suspended Campbell for nine months after finding him guilty of a series of charges during a 35-day tribunal.
"There are a number of grave failings in your clinical practice highlighted by the findings," chair Stewart Goulding said.
Campbell, who attended the London hearing, had denied the bulk of the allegations against him.