You-Jin Choi1, Sung-Yoon Won1, Jae-Gi Lee1, Kyung-Seok Hu1, Sung-Taek Kim1, Tanvaa Tansatit1, Hee-Jin Kim1. 1. Mr Choi is a Graduate Student, Dr Hu is an Associate Professor, and Dr H-J Kim is a Professor, Division of Anatomy and Developmental Biology, Department of Oral Biology, Human Identification Research Institution, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Republic of Korea. Dr Won is an Assistant Professor, Department of Occupational Therapy, Semyung University, Jecheon, Republic of Korea. Dr Lee is an Assistant Professor, Department of Dental Hygiene, School of Health and Medicine, Namseoul University, Choenan, Republic of Korea. Dr S-T Kim is a Professor, Department of Oral Medicine, TMJ and Orofacial Pain Clinic, College of Dentistry, Yonsei University, Seoul, Republic of Korea. Dr Tansatit is a Professor, Chula Soft Cadaver Surgical Training Center and Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Abstract
BACKGROUND: The forehead is a common site for injection of botulinum neurotoxin type A (BoNT-A) to treat hyperactive facial muscles. Unexpected side effects of BoNT-A injection may occur because the anatomy of the forehead musculature is not fully characterized. OBJECTIVES: The authors described the lateral border of the frontalis in terms of facial landmarks and reference lines to determine the safest and most effective forehead injection sites for BoNT-A. METHODS: The hemifaces of 49 embalmed adult Korean cadavers were dissected in a morphometric analysis of the frontalis. L2 was defined in terms of FT (the most protruding point of the frontotemporal region), L0 (the line connecting the infraorbital margin with the tragus), and L1 (the line parallel to L0 and passing through FT) such that L2 was positioned 45° from L1 and passed through FT. RESULTS: The distance from FT to the superior margin of the orbicularis oculi was 12.3 ± 3.3 mm. The frontalis extended more than 5 cm along L2 in 49 of 49 cases (100%), more than 6 cm in 47 cases (95.9%), more than 7 cm in 34 cases (69.4%), more than 8 cm in 11 cases (22.4%), and more than 9 cm in 3 cases (6.1%). The lateral border of the frontalis ran parallel to and within 1 cm of the medial side of L2. CONCLUSIONS: Surface anatomy mapping can assist with predicting the lateral border of the frontalis to minimize the side effects and maximize the efficiency of BoNT-A injections into the forehead.
BACKGROUND: The forehead is a common site for injection of botulinum neurotoxin type A (BoNT-A) to treat hyperactive facial muscles. Unexpected side effects of BoNT-A injection may occur because the anatomy of the forehead musculature is not fully characterized. OBJECTIVES: The authors described the lateral border of the frontalis in terms of facial landmarks and reference lines to determine the safest and most effective forehead injection sites for BoNT-A. METHODS: The hemifaces of 49 embalmed adult Korean cadavers were dissected in a morphometric analysis of the frontalis. L2 was defined in terms of FT (the most protruding point of the frontotemporal region), L0 (the line connecting the infraorbital margin with the tragus), and L1 (the line parallel to L0 and passing through FT) such that L2 was positioned 45° from L1 and passed through FT. RESULTS: The distance from FT to the superior margin of the orbicularis oculi was 12.3 ± 3.3 mm. The frontalis extended more than 5 cm along L2 in 49 of 49 cases (100%), more than 6 cm in 47 cases (95.9%), more than 7 cm in 34 cases (69.4%), more than 8 cm in 11 cases (22.4%), and more than 9 cm in 3 cases (6.1%). The lateral border of the frontalis ran parallel to and within 1 cm of the medial side of L2. CONCLUSIONS: Surface anatomy mapping can assist with predicting the lateral border of the frontalis to minimize the side effects and maximize the efficiency of BoNT-A injections into the forehead.
Authors: Andrew Blumenfeld; Stephen D Silberstein; David W Dodick; Sheena K Aurora; Catherine C Turkel; William J Binder Journal: Headache Date: 2010-10 Impact factor: 5.887
Authors: J Alastair Carruthers; Nicholas J Lowe; M Alan Menter; John Gibson; Marian Nordquist; Julie Mordaunt; Patricia Walker; Nina Eadie Journal: J Am Acad Dermatol Date: 2002-06 Impact factor: 11.527