Dr. Loh graduated from the University of Singapore in 1976 and obtained his Master of Dental Science from the University of Pittsburgh in 1982 through a scholarship awarded by the National University of Singapore. He was a full time instructor in the National University of Singapore till 1986. He is a visiting professor at the department of orthodontics, Wenzhou Medical College, China.
He was the Honorary General Secretary of the Singapore Dental Association in 1986-1988. He founded the Association of Orthodontists, Singapore in 1991 and was the President for the first 2 years. He is the President of the Asian Pacific Orthodontic Society 2010-2012.
Dr. Loh has given presentation in Australia, Bangladesh, China, India, Indonesia, Japan, Macau, Malaysia, Nepal, Pakistan, Philippines, Singapore, South Korea, Taiwan, Thailand, Vietnam.