D.D.S., School of Dentistry, National Taiwan University College of Medicine, 1962
D.D.Sc., Graduate Institute of Dental Sciences (Major in Oral and Maxillofacial Surgery), Nihon University, Japan, 1970
Clinical staff, 1st Department of Oral and Maxillofacial Surgery, Tokyo Medical and Dental University Dental Hospital, Japan,(1970-1972)
Dean of School of Dentistry and Director of Graduate Institute of Clinical
Dentistry, College of Medicine, National Taiwan University Head of Department of Dentistry, National Taiwan University Hospital,(1988-1994)
Professor of Oral and Maxillofacial Surgery, School of Dentistry, N.T.U.(1984-2002)
President of R.O.C. Association of Oral and Maxillofacial Surgeons (1989-1991)
Chairman（1992~1995, 1998~1999）and Council member, Council of Dental Advisers, National Department of Health(1992-2003)
Council member, Council of Cancer Control, Aquired Immunodifficiency Syndrome and Dental Advisers, National Department of Health, (1992~)
Council member, Forum Council on Health Promotion and Disease Prevention, National Health Research Institute, (1998-2002)
Committee member, Head and Neck Cancer Committee, Cancer Study Group, National Health Research Institute, (2000~)
Chairperson, Committee on Dental Medicine, National Department of Health, (2003~)
Committee member, Committee on Medical Ethics, National Department of Health (2005~ )
1. Oral and Maxillofacial Surgery
2. Oral Oncology
3. Oral Cancer Prevention / Oral Cancer Screening
4. Health Hazard of Areca Nut and Betel Quid chewing
Main Research Interests
- Osteoradionecrosis of jaws－its diagnosis and treatment, dental management for radiation therapy of head and neck cancer patients(Oral oncology)
- Modified closed subcondylar osteotomy (MCSO) as a special operation in orthognathic surgery for dentofacial deformities
- Betel quid carcinogenesis in Taiwan, oral cancer prevention and screening for oral cancer / oral mucosal lesions
- L.J. Hahn, Clinico-Pathological study of dentigerous cyst, Nihon University dental Journal 44:263-281, 1970.
- L.J. Hahn, Osteoradionecrosis of the mandible clinical observation and treatment in 45 cases, Journal of the Formosan Medical association, 82:451~460, 1983.
- L.J. Hahn, Immediate manibular reconstruction using cobalt chromium meshes after resection for ameloblastomas, with report of these cases, Chinese Dentcel Journal, 1:83-97, 1982.
- M. Y-P Kuo, L.J. Hahn, C.Y. Hong, J.H. Kao and D.S. Chen, Low prevalence of hepatitis C virus infection among dentists in Taiwan, Journal of Medical Virology, 40:10-13, 1993.
- Y.B. Tang Chen, H.C. Chen and L.J. Hahn, Major mandibular reconstruction with vascularized bone graft:indicatiobs and selection of doner tissue, Microsurgerg. 15:227-237, 1994.
- J.H. Jeng, M.L. Kuo, L.J. Hahn, and M.Y-P Kuo, Genotoxic and non-genotoxic effects of betel quid ingredients on mucosal fibroblasts in vitro, Journal of Dental Research 73:1043-1049, 1994.
- J.H. Jeng, L.J. Hahn, F.J. Lu, Y.J. Wang and M.Y.P. Kuo, Eugenol triggers different pathological effects on human oral mucosal fibroblasts, Journal of Dental Research 73:1050-1055, 1994
- M. Y-P Kuo, J.H. Jeng, C.P. Chiang and L.J. Hahn, Mutation of Ki-ras oncogene codon 12 in betel quid chewing-related human oral squamous cell carcinoma in Taiwan, Journal of Oral Pathology and Medicine 23:70-74, 1994.
- Jeng JH, Chang MC, Hahn LJ. Role of areca nut in betel quid-associated chemical carcinogeness; current awareness and future prospectives. Oral Oncol 2001; 37:477-492.
- Cheng SJ, Lee JJ, Ting LL, Tseng IY, Chang HH, Chen HM, Kuo YS, Hahn LJ, Kok SH.A clinical staging system and treatment guidelines for maxillary osteoradionecrosis in irradiated nasopharyngeal carcinoma patients. Int J Radiat Oncol Biol Phys. 2006 Jan 1;64(1):90-7.