Tools
Anatomy, Head and Neck: Glabella
Introduction
The glabella is a median elevation between two superciliary arches. Glabella is present just above the nasion- an intersection of internasal and frontonasal suture. The skin covering the glabella is known as glabellar skin, which is also the source of redundant thick skin commonly used for reconstruction of the upper nasal dorsum and medial canthal area.[1] Historically, the use of glabellar skin was first described by Carl Von Graefe in his manuscript devoted to rhinoplasty, "Rhinoplastik." Glabellar skin is the area nowadays treated with botox for aesthetic purposes.[2]
Structure and Function
Register For Free And Read The Full Article
Search engine and full access to all medical articles- 10 free questions in your specialty
- Free CME/CE Activities
- Free daily question in your email
- Save favorite articles to your dashboard
- Emails offering discounts
Learn more about a Subscription to StatPearls Point-of-Care
Structure and Function
The glabella is a bony point present on the frontal bone between two superciliary arches; Superciliary arches are the prominent bony part just above the medial one-third of the supraorbital margins.[3] Superciliary arches are more prominent in males than females. The glabella is in near relation to frontal sinuses and nasion.[4] It is also an important bony landmark for sexual dimorphism, developmental and comparative anatomy, and gives attachment to fibers of the orbital part of orbicularis oculi and procerus muscle.[5][6] Transverse head of corrugator supercilii fuses with orbicularis oculi fibers.[6][7]
Procerus, corrugator supercilii, depressor supercilii, orbicularis oculi, and frontalis fibers combinedly make glabellar complex.[8][9] The belief is that repeated pulling of the skin by these hyperdynamic muscles contributes to the formation of rhytids, described as fine lines to deep furrows. Glabellar complex muscle produces different patterns of wrinkles and lines on the forehead by contraction and relaxations. There are five known types of patterns identified in European and American races, while researchers have identified six patterns in the Asian race.[10][11][12] These hyper functional lines are implicated in the multifarious facial expressions such as fatigue, quizzical, and mistakenly at times, anger. In contrast to other facial wrinkles, which are secondary to deterioration of the cutaneous scaffolding of the skin, glabellar rhytids are dynamic yet functional.[13][14]
Embryology
In the fourth week of embryological life, five facial primordia appear around the stomodeum (a frontonasal prominence, paired maxillary prominence, and paired mandibular prominence). Glabella and frontal bone develop from the frontal part of the frontonasal prominence.[15][16] The unpaired frontonasal prominence develops in the midline of the embryo and becomes the intranasal depression. Structures derived from from the frontonasal prominence include the forehead, bridge of the nose, philtrum, septum, middle portion of the upper lip and primary palate.[16]
The fetal skull shows suture in the middle of the frontal bone known as a metopic suture. The metopic suture generally fuses at the age of one year; sometimes, it persists even after the age of one year. Remnants of the interfrontal (metopic) sutures remain as the glabella.[17][18]
The muscles of the glabellar complex develop from the second pharyngeal arch.[19][16]
Blood Supply and Lymphatics
The glabella is the bony landmark present in the outer table of the frontal bone in the middle of the superciliary arches; the glabella receives blood supply from the diploic veins present between the outer and inner table of the frontal bone. Arteries supplying the skin and muscles over the glabella gives branches to glabella also.[20] [21]
Supraorbital and the supratrochlear arteries (branches of the ophthalmic artery) supply forehead and medial canthal area.[21] The ophthalmic artery is the branch of the internal carotid artery. After originating from the ophthalmic artery, the supraorbital artery passes through the supraorbital notch, where it divides into two branches: a superficial branch and a deep branch.[22][23] Superficial branches include the vertical and brow branches, while the medial, oblique, and lateral rim branches are deep.[23][24]
The superficial vertical branch of the supraorbital artery anastomoses with the supratrochlear artery and the frontal branch of the superficial temporal artery in the forehead. The superficial branches of the supraorbital artery course superficially within the subcutaneous layer. Supraorbital and supratrochlear arteries anastomose with the angular artery at the medial angle of the eye to form an arterial arcade.[23][24][25][26] The supratrochlear artery also branches from the ophthalmic artery and exits the superomedial orbit. The artery becomes subcutaneous 15 to 25 mm above the supraorbital rim. It can be relatively superficial, being about 2 mm deep in the muscle layer.[25][26] A branch of the dorsal nasal artery supplies the glabella and the inferior and middle transverse regions of the forehead, laterally it anastomosis with supratrochlear arteries.[27][28]
The glabella is drained by meningeal veins, supratrochlear and supraorbital vein. The supratrochlear and supraorbital veins join near the medial canthus to form the angular vein, which descends deep into the nasolabial fold. At the inferior border of the nose, it joins the superior labial vein to become the facial vein, which crosses the body of the mandible. Facial vein unites with the anterior division of the retromandibular vein to form the common facial vein, which ultimately drains in the internal jugular vein.[26][25]
The glabella and glabellar complex drain into the preauricular and deep parotid lymph nodes.[29][30]
Nerves
The sensory nerve supply of the skin over the glabella is from the ophthalmic division of the trigeminal nerve and its branches. The frontal nerve (branch of the ophthalmic division of trigeminal nerve) divides into supratrochlear and supraorbital nerves. The supratrochlear nerve exits the orbit between the pulley of the superior oblique muscle and supraorbital foramen, passes under the corrugator muscles to supply the skin of the glabella, medial forehead, upper eyelid, and medial conjunctiva.[31] The supraorbital nerve exits the frontal bone through the supraorbital foramen/notch and divides into the superficial and deep branch. The superficial branch penetrates the frontalis muscle and courses superiorly in the subcutaneous plane to the vertex of the scalp. The deep branch passes laterally between the periosteum and deep aspect of the frontalis muscle to supply the temporoparietal scalp.[31][32]
The motor nerve supply of the glabellar complex muscles is by the facial nerve. The facial nerve exits the stylomastoid foramen to enter the parotid gland and divides into temporal, zygomatic, buccal, marginal mandibular, and cervical branches. The temporal branch of the facial nerve crosses the zygomatic arch, and lateral orbital rim to reach the frontalis muscle. The innervation of the corrugator muscles is via the temporal and zygomatic branches of the facial nerve. Procerus muscle may receive supply by the temporal, zygomatic, or deep buccal branch of the facial nerve. The zygomatic or the upper buccal division sends a nerve cranially along the side of the nose to innervate the nasalis, followed by the procerus and corrugator.[33]
Muscles
The glabellar complex consists of the medial brow depressors: corrugator supercilii, depressor supercilii, procerus, and the medial fibers of orbicularis oculi muscles; In some cases, nasalis fibers contribute to form the glabellar complex.[8][9] The complex can further subdivide into the group that produces vertical glabellar lines and horizontal glabellar lines.
Paired corrugator supercilii, known as brow depressor, pulls the brow medially and inferiorly to produce the vertical glabellar lines.[34] The corrugator originates from the superciliary arch passes between the fibers of orbicularis oculi and frontalis muscle before inserting into the dermis. Laterally, it becomes more superficial as it interdigitates with the frontalis muscle before it insets to the skin of the medial brow. Medially, the corrugator is confluent with procerus muscle.[10][6]
The procerus is a small thin pyramidal muscle. It originates from the junction of the inferior portion of the nasal bone and upper lateral cartilage. Procerus ascends superiorly to insert into the glabella. Procerus becomes confluent with the frontalis along the medial canthus. This brow depressor is implicated in the formation of horizontal nasal root creases.[10]
The depressor supercilii appears in between the orbicularis oculi and corrugators. It originates at the medial orbital rim near the lacrimal bone and inserts onto the medial portion of the orbit into the dermis of the medial eyebrow, just inferior to the insertion of the corrugator.[35][9]
Physiologic Variants
The bony glabella does not have a significant difference between males and females, but glabella shows a significant difference between races.[36][37][38][39] Diploe thickness of the glabella increases as the age advances up to the age of 18th years.[40][41][42][37]
Soft tissue thickness over glabella increases as the advancement of age and body mass index.[43][44][45][46][47]
Corrugator supercilii muscle shows five different patterns rectangular shaped, corrugator supercilii with three bellies, corrugator supercilii with duplicate muscle, irregular flat, and hypoblastic type. Corrugator supercilii with frontalis muscle creates six different types of verticle lines on the forehead.[48][49][50]
Variation in shapes of procerus muscle affects forehead lines. Nerve supply to the corrugator supercilii varies among individuals.[8][51][52]
There have been some cases where the supratrochlear artery was absent. Another notable variation is when the supratrochlear artery pierces the frontalis muscle posteriorly in the middle third division of forehead and ascend superiorly on the periosteal level.[53][54]
Surgical Considerations
Glabellar skin has a profuse blood supply and enough mobility, because of this characteristic it is used frequently to repair external nasal defects.[55][56][57][58]
The nasal glabellar rotation flap, initially described by Gillies and later modified by Reiger, has evolved into a choice flap for nasal defects.[58]
Clinical Significance
Glabella lines or glabellar rhytids are the short vertical skin wrinkles between the eyebrows, over the glabella. They are often the first wrinkles to show on the forehead. Glabellar rhytids are usually intermittent and are most prominent when angered or perplexed.[59][60][61][62][10] In 2012 Almedia et al. classified five types of glabellar contraction patterns depending on the eyebrow movements: "U," "V," "Omega," "Inverted omega," and "Converging arrows."[63] Kim et al. clinically described five wrinkles patterns: "U," "'11," "X," "Pi," and "I." [50]
Glabellar rhytids appear deep due to the thick skin of the glabella compared to the crows' feet (wrinkles at the lateral end of the eyes).[64][10][65][59] Glabellar rhytides become more prominent in advanced age; nowadays, botulinum toxins are injected to hide glabellar rhytides for aesthetic purposes.[66][67][68][69] The first area to receive cosmetic treatment with botox A injection was the glabella. It was common to decrease the mass of the glabellar musculature during a brow lift, to facilitate glabellar furrowing and decrease downward draw on the brow.[70][10][71]
Glabellar tap reflex is one of the primitive reflexes; tapping the glabella elicits blinking that normally disappear after 4 to 5 taps.[72][73][74] Some works have reported enhanced glabellar tap reflex in patients with anterior cerebral artery infarction.[75] Glabellar tap reflex is one of the early signs of Parkinsonian disorders.[76][77][78]
Media
(Click Image to Enlarge)
Front of the skull showing Glabella, Superciliary arch and Nasion.
Contributed by the Dr. Pradip Chauhan (MS ANATOMY), Department of Anatomy, P.D.U. MEDICAL COLLEGE, RAJKOT, Gujarat, India.
(Click Image to Enlarge)
VERTICAL GROOVES ON GLABELLAR SKIN ON MOVEMENT OF EYEBROW.
Contributed by the Dr. Pradip Chauhan (MS ANATOMY), Department of Anatomy, P.D.U. MEDICAL COLLEGE, RAJKOT, Gujarat, India.
(Click Image to Enlarge)
INTERFRONTAL (METOPIC) SUTURE AND FUTURE SITE OF GLABELLA IN FETAL SKULL
Contributed by the Dr. Pradip Chauhan (MS ANATOMY), Department of Anatomy, P.D.U. MEDICAL COLLEGE, RAJKOT, Gujarat, India.
(Click Image to Enlarge)
SCHEMATIC DIAGRAM SHOWING MUSCLE OF GLABELLAR COMPLEX
Contributed by the Dr. Pradip Chauhan (MS), Department of Anatomy, P.D.U. MEDICAL COLLEGE, RAJKOT, Gujarat, India.
References
Sanjuan-Sanjuan A, Ogledzki M, Ramirez CA. Glabellar Flaps for Reconstruction of Skin Defects. Atlas of the oral and maxillofacial surgery clinics of North America. 2020 Mar:28(1):43-48. doi: 10.1016/j.cxom.2019.11.004. Epub [PubMed PMID: 32008708]
Schlager S, Kostunov J, Henn D, Stark BG, Iblher N. A 3D Morphometrical Evaluation of Brow Position After Standardized Botulinum Toxin A Treatment of the Forehead and Glabella. Aesthetic surgery journal. 2019 Apr 8:39(5):553-564. doi: 10.1093/asj/sjy205. Epub [PubMed PMID: 30124769]
De Rose J, Laing B, Ahmad M. Skull Abnormalities in Cadavers in the Gross Anatomy Lab. BioMed research international. 2020:2020():7837213. doi: 10.1155/2020/7837213. Epub 2020 Feb 19 [PubMed PMID: 32149137]
Arnaud E, Renier D, Marchac D. Development of the frontal sinus and glabellar morphology after frontocranial remodeling for craniosynostosis in infancy. The Journal of craniofacial surgery. 1994 May:5(2):81-92; discussion 93-4 [PubMed PMID: 7918861]
Level 2 (mid-level) evidenceGodde K, Thompson MM, Hens SM. Sex estimation from cranial morphological traits: Use of the methods across American Indians, modern North Americans, and ancient Egyptians. Homo : internationale Zeitschrift fur die vergleichende Forschung am Menschen. 2018 Sep:69(5):237-247. doi: 10.1016/j.jchb.2018.09.003. Epub 2018 Sep 21 [PubMed PMID: 30269926]
Knize DM. Muscles that act on glabellar skin: a closer look. Plastic and reconstructive surgery. 2000 Jan:105(1):350-61 [PubMed PMID: 10627005]
Abramo AC, Do Amaral TP, Lessio BP, De Lima GA. Anatomy of Forehead, Glabellar, Nasal and Orbital Muscles, and Their Correlation with Distinctive Patterns of Skin Lines on the Upper Third of the Face: Reviewing Concepts. Aesthetic plastic surgery. 2016 Dec:40(6):962-971 [PubMed PMID: 27743084]
Brown TM, Drake TM, Krishnamurthy K. Anatomy, Head and Neck, Procerus Muscle. StatPearls. 2023 Jan:(): [PubMed PMID: 30521184]
Lorenc ZP, Smith S, Nestor M, Nelson D, Moradi A. Understanding the functional anatomy of the frontalis and glabellar complex for optimal aesthetic botulinum toxin type A therapy. Aesthetic plastic surgery. 2013 Oct:37(5):975-83. doi: 10.1007/s00266-013-0178-1. Epub 2013 Jul 12 [PubMed PMID: 23846022]
Level 3 (low-level) evidenceKamat A, Quadros T. An observational study on glabellar wrinkle patterns in Indians. Indian journal of dermatology, venereology and leprology. 2019 Mar-Apr:85(2):182-189. doi: 10.4103/ijdvl.IJDVL_211_17. Epub [PubMed PMID: 29620040]
Level 2 (mid-level) evidenceJiang H, Zhou J, Chen S. Different Glabellar Contraction Patterns in Chinese and Efficacy of Botulinum Toxin Type A for Treating Glabellar Lines: A Pilot Study. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2017 May:43(5):692-697. doi: 10.1097/DSS.0000000000001045. Epub [PubMed PMID: 28244900]
Level 3 (low-level) evidenceJia Z, Lu H, Yang X, Jin X, Wu R, Zhao J, Chen L, Qi Z. Adverse Events of Botulinum Toxin Type A in Facial Rejuvenation: A Systematic Review and Meta-Analysis. Aesthetic plastic surgery. 2016 Oct:40(5):769-77. doi: 10.1007/s00266-016-0682-1. Epub 2016 Aug 5 [PubMed PMID: 27495260]
Level 2 (mid-level) evidenceAbramo AC. Anatomy of the forehead muscles: the basis for the videoendoscopic approach in forehead rhytidoplasty. Plastic and reconstructive surgery. 1995 Jun:95(7):1170-7 [PubMed PMID: 7761503]
Level 3 (low-level) evidenceAbramo AC. Muscle Insertion and Strength of the Muscle Contraction as Guidelines to Enhance Duration of the Botulinum Toxin Effect in the Upper Face. Aesthetic plastic surgery. 2018 Oct:42(5):1379-1387. doi: 10.1007/s00266-018-1157-3. Epub 2018 Jul 9 [PubMed PMID: 29987485]
Fuchs A, Inthal A, Herrmann D, Cheng S, Nakatomi M, Peters H, Neubüser A. Regulation of Tbx22 during facial and palatal development. Developmental dynamics : an official publication of the American Association of Anatomists. 2010 Nov:239(11):2860-74. doi: 10.1002/dvdy.22421. Epub [PubMed PMID: 20845426]
Level 3 (low-level) evidenceCasale J, Giwa AO. Embryology, Branchial Arches. StatPearls. 2023 Jan:(): [PubMed PMID: 30860722]
Weinzweig J, Kirschner RE, Farley A, Reiss P, Hunter J, Whitaker LA, Bartlett SP. Metopic synostosis: Defining the temporal sequence of normal suture fusion and differentiating it from synostosis on the basis of computed tomography images. Plastic and reconstructive surgery. 2003 Oct:112(5):1211-8 [PubMed PMID: 14504503]
Boyajian MK, Al-Samkari H, Nguyen DC, Naidoo S, Woo AS. Partial Suture Fusion in Nonsyndromic Single-Suture Craniosynostosis. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association. 2020 Apr:57(4):499-505. doi: 10.1177/1055665620902299. Epub 2020 Feb 4 [PubMed PMID: 32013562]
Frisdal A, Trainor PA. Development and evolution of the pharyngeal apparatus. Wiley interdisciplinary reviews. Developmental biology. 2014 Nov-Dec:3(6):403-18. doi: 10.1002/wdev.147. Epub 2014 Aug 29 [PubMed PMID: 25176500]
Level 3 (low-level) evidenceKim B, Inoue Y, Imanishi N, Chang H, Shimizu Y, Okumoto T, Kishi K. Anatomical Study of Perfusion of a Periosteal Flap with a Lateral Pedicle. Plastic and reconstructive surgery. Global open. 2017 Sep:5(9):e1476. doi: 10.1097/GOX.0000000000001476. Epub 2017 Sep 19 [PubMed PMID: 29062647]
Khan TT, Colon-Acevedo B, Mettu P, DeLorenzi C, Woodward JA. An Anatomical Analysis of the Supratrochlear Artery: Considerations in Facial Filler Injections and Preventing Vision Loss. Aesthetic surgery journal. 2017 Feb:37(2):203-208. doi: 10.1093/asj/sjw132. Epub 2016 Aug 16 [PubMed PMID: 27530765]
Bonasia S, Bojanowski M, Robert T. Embryology and anatomical variations of the ophthalmic artery. Neuroradiology. 2020 Feb:62(2):139-152. doi: 10.1007/s00234-019-02336-4. Epub 2019 Dec 20 [PubMed PMID: 31863143]
Toma N. Anatomy of the Ophthalmic Artery: Embryological Consideration. Neurologia medico-chirurgica. 2016 Oct 15:56(10):585-591 [PubMed PMID: 27298261]
Luibil N, Lopez MJ, Patel BC. Anatomy, Head and Neck, Orbit. StatPearls. 2023 Jan:(): [PubMed PMID: 30969665]
Nguyen JD, Duong H. Anatomy, Head and Neck: Inferior Alveolar Arteries. StatPearls. 2023 Jan:(): [PubMed PMID: 31613516]
Hanick A, Ciolek P, Fritz M. Angular Vessels for Free-Tissue Transfer in Head and Neck Reconstruction: Clinical Outcomes. The Laryngoscope. 2020 Nov:130(11):2589-2592. doi: 10.1002/lary.28540. Epub 2020 Feb 19 [PubMed PMID: 32073659]
Level 2 (mid-level) evidenceNguyen JD, Duong H. Anatomy, Head and Neck, Lateral Nasal Artery. StatPearls. 2023 Jan:(): [PubMed PMID: 31536287]
Choi DY, Bae JH, Youn KH, Kim W, Suwanchinda A, Tanvaa T, Kim HJ. Topography of the dorsal nasal artery and its clinical implications for augmentation of the dorsum of the nose. Journal of cosmetic dermatology. 2018 Aug:17(4):637-642. doi: 10.1111/jocd.12720. Epub 2018 Jul 29 [PubMed PMID: 30058278]
Berger DMS, van Veen MM, Madu MF, van Akkooi ACJ, Vogel WV, Balm AJM, Klop WMC. Parotidectomy in patients with head and neck cutaneous melanoma with cervical lymph node involvement. Head & neck. 2019 Jul:41(7):2264-2270. doi: 10.1002/hed.25670. Epub 2019 Feb 14 [PubMed PMID: 30762921]
Wiener M, Uren RF, Thompson JF. Lymphatic drainage patterns from primary cutaneous tumours of the forehead: refining the recommendations for selective neck dissection. Journal of plastic, reconstructive & aesthetic surgery : JPRAS. 2014 Aug:67(8):1038-44. doi: 10.1016/j.bjps.2014.04.017. Epub 2014 May 20 [PubMed PMID: 24927861]
Huff T, Weisbrod LJ, Daly DT. Neuroanatomy, Cranial Nerve 5 (Trigeminal). StatPearls. 2023 Jan:(): [PubMed PMID: 29489263]
Li L, London NR Jr, Prevedello DM, Carrau RL. Intraconal Anatomy of the Anterior Ethmoidal Neurovascular Bundle: Implications for Surgery in the Superomedial Orbit. American journal of rhinology & allergy. 2020 May:34(3):394-400. doi: 10.1177/1945892420901630. Epub 2020 Jan 23 [PubMed PMID: 31973546]
Seneviratne SO, Patel BC. Facial Nerve Anatomy and Clinical Applications. StatPearls. 2024 Jan:(): [PubMed PMID: 32119456]
Alouf E, Murphy T, Alouf G. Botulinum Toxin Type A: Evaluation of Onset and Satisfaction. Plastic surgical nursing : official journal of the American Society of Plastic and Reconstructive Surgical Nurses. 2019 Oct/Dec:39(4):148-156. doi: 10.1097/PSN.0000000000000287. Epub [PubMed PMID: 31790044]
Hur MS. Anatomical relationships of the procerus with the nasal ala and the nasal muscles: transverse part of the nasalis and levator labii superioris alaeque nasi. Surgical and radiologic anatomy : SRA. 2017 Aug:39(8):865-869. doi: 10.1007/s00276-017-1817-z. Epub 2017 Jan 28 [PubMed PMID: 28132092]
Krüger GC, L'Abbé EN, Stull KE, Kenyhercz MW. Erratum to: Sexual dimorphism in cranial morphology among modern South Africans. International journal of legal medicine. 2015 Nov:129(6):1285. doi: 10.1007/s00414-015-1233-z. Epub [PubMed PMID: 26210635]
Manthey L, Jantz RL, Bohnert M, Jellinghaus K. Secular change of sexually dimorphic cranial variables in Euro-Americans and Germans. International journal of legal medicine. 2017 Jul:131(4):1113-1118. doi: 10.1007/s00414-016-1469-2. Epub 2016 Oct 18 [PubMed PMID: 27757580]
Krüger GC, L'Abbé EN, Stull KE, Kenyhercz MW. Sexual dimorphism in cranial morphology among modern South Africans. International journal of legal medicine. 2015 Jul:129(4):869-75. doi: 10.1007/s00414-014-1111-0. Epub 2014 Nov 14 [PubMed PMID: 25394745]
Casado AM. Quantifying Sexual Dimorphism in the Human Cranium: A Preliminary Analysis of a Novel Method. Journal of forensic sciences. 2017 Sep:62(5):1259-1265. doi: 10.1111/1556-4029.13441. Epub 2017 May 26 [PubMed PMID: 28547887]
Alexander SL, Rafaels K, Gunnarsson CA, Weerasooriya T. Structural analysis of the frontal and parietal bones of the human skull. Journal of the mechanical behavior of biomedical materials. 2019 Feb:90():689-701. doi: 10.1016/j.jmbbm.2018.10.035. Epub 2018 Nov 1 [PubMed PMID: 30530225]
Hatipoglu HG, Ozcan HN, Hatipoglu US, Yuksel E. Age, sex and body mass index in relation to calvarial diploe thickness and craniometric data on MRI. Forensic science international. 2008 Nov 20:182(1-3):46-51. doi: 10.1016/j.forsciint.2008.09.014. Epub 2008 Nov 8 [PubMed PMID: 18996658]
Sabancıoğulları V, Koşar Mİ, Salk I, Erdil FH, Oztoprak I, Cimen M. Diploe thickness and cranial dimensions in males and females in mid-Anatolian population: an MRI study. Forensic science international. 2012 Jun 10:219(1-3):289.e1-7. doi: 10.1016/j.forsciint.2011.11.033. Epub 2011 Dec 23 [PubMed PMID: 22197522]
Ajwa N, Alkhars FA, AlMubarak FH, Aldajani H, AlAli NM, Alhanabbi AH, Alsulaiman SA, Divakar DD. Correlation Between Sex and Facial Soft Tissue Characteristics Among Young Saudi Patients with Various Orthodontic Skeletal Malocclusions. Medical science monitor : international medical journal of experimental and clinical research. 2020 Feb 26:26():e919771. doi: 10.12659/MSM.919771. Epub 2020 Feb 26 [PubMed PMID: 32101535]
Smith SL, Buschang PH. Midsagittal facial tissue thicknesses of children and adolescents from the Montreal growth study. Journal of forensic sciences. 2001 Nov:46(6):1294-302 [PubMed PMID: 11714138]
Pithon MM, Rodrigues Ribeiro DL, Lacerda dos Santos R, Leite de Santana C, Pedrosa Cruz JP. Soft tissue thickness in young north eastern Brazilian individuals with different skeletal classes. Journal of forensic and legal medicine. 2014 Feb:22():115-20. doi: 10.1016/j.jflm.2013.09.014. Epub 2013 Oct 3 [PubMed PMID: 24485435]
Cha KS. Soft-tissue thickness of South Korean adults with normal facial profiles. Korean journal of orthodontics. 2013 Aug:43(4):178-85. doi: 10.4041/kjod.2013.43.4.178. Epub 2013 Aug 22 [PubMed PMID: 24015387]
Kim JY, Kau CH, Christou T, Ovsenik M, Guk Park Y. Three-dimensional Analysis of Normal Facial Morphologies of Asians and Whites: A Novel Method of Quantitative Analysis. Plastic and reconstructive surgery. Global open. 2016 Sep:4(9):e865 [PubMed PMID: 27757330]
Yu M, Wang SM. Anatomy, Head and Neck, Eye Corrugator Muscle. StatPearls. 2023 Jan:(): [PubMed PMID: 31194420]
Hwang K. Revisiting the Skin Lines on the Forehead and Glabellar Area. The Journal of craniofacial surgery. 2018 Jan:29(1):209-211. doi: 10.1097/SCS.0000000000004073. Epub [PubMed PMID: 29077679]
Kim HS, Kim C, Cho H, Hwang JY, Kim YS. A study on glabellar wrinkle patterns in Koreans. Journal of the European Academy of Dermatology and Venereology : JEADV. 2014 Oct:28(10):1332-9. doi: 10.1111/jdv.12286. Epub 2013 Oct 30 [PubMed PMID: 24168325]
Level 2 (mid-level) evidenceCaminer DM, Newman MI, Boyd JB. Angular nerve: new insights on innervation of the corrugator supercilii and procerus muscles. Journal of plastic, reconstructive & aesthetic surgery : JPRAS. 2006:59(4):366-72 [PubMed PMID: 16756251]
Hwang K. Surgical anatomy of the facial nerve relating to facial rejuvenation surgery. The Journal of craniofacial surgery. 2014 Jul:25(4):1476-81. doi: 10.1097/SCS.0000000000000577. Epub [PubMed PMID: 24926717]
Phumyoo T, Jiirasutat N, Jitaree B, Rungsawang C, Uruwan S, Tansatit T. Anatomical and Ultrasonography-Based Investigation to Localize the Arteries on the Central Forehead Region During the Glabellar Augmentation Procedure. Clinical anatomy (New York, N.Y.). 2020 Apr:33(3):370-382. doi: 10.1002/ca.23516. Epub 2019 Nov 21 [PubMed PMID: 31688989]
Cong LY, Phothong W, Lee SH, Wanitphakdeedecha R, Koh I, Tansatit T, Kim HJ. Topographic Analysis of the Supratrochlear Artery and the Supraorbital Artery: Implication for Improving the Safety of Forehead Augmentation. Plastic and reconstructive surgery. 2017 Mar:139(3):620e-627e. doi: 10.1097/PRS.0000000000003060. Epub [PubMed PMID: 28234824]
Valladares-Narganes LM, Pérez-Bustillo A, Pérez-Paredes G, Rodríguez-Prieto MÁ. Combination of a glabellar flap and a transposition flap for the reconstruction of 2 noncontiguous nasal defects. Actas dermo-sifiliograficas. 2014 Mar:105(2):193-5. doi: 10.1016/j.ad.2013.10.006. Epub 2013 Dec 20 [PubMed PMID: 24360727]
Level 3 (low-level) evidencePollard WL, Xia Y, Sorace M. Repair of a Large Glabellar/Nasal Defect. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2019 Dec:45(12):1673-1676. doi: 10.1097/DSS.0000000000001734. Epub [PubMed PMID: 30550516]
Konofaos P, Alvarez S, McKinnie JE, Wallace RD. Nasal Reconstruction: A Simplified Approach Based on 419 Operated Cases. Aesthetic plastic surgery. 2015 Feb:39(1):91-9. doi: 10.1007/s00266-014-0417-0. Epub 2014 Nov 21 [PubMed PMID: 25413009]
Level 2 (mid-level) evidenceFliss DM, Freeman JL. The nasal glabellar flap. The Journal of otolaryngology. 1994 Feb:23(1):6-7 [PubMed PMID: 8170023]
Goodman GJ, Armour KS, Kolodziejczyk JK, Santangelo S, Gallagher CJ. Comparison of self-reported signs of facial ageing among Caucasian women in Australia versus those in the USA, the UK and Canada. The Australasian journal of dermatology. 2018 May:59(2):108-117. doi: 10.1111/ajd.12637. Epub 2017 Apr 10 [PubMed PMID: 28397327]
Hsieh DM, Zhong S, Tong X, Yuan C, Yang L, Yao AY, Zhou C, Wu Y. A Retrospective Study of Chinese-Specific Glabellar Contraction Patterns. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2019 Nov:45(11):1406-1413. doi: 10.1097/DSS.0000000000001808. Epub [PubMed PMID: 30789513]
Level 2 (mid-level) evidenceMonheit G, Lin X, Nelson D, Kane M. Consideration of muscle mass in glabellar line treatment with botulinum toxin type A. Journal of drugs in dermatology : JDD. 2012 Sep:11(9):1041-5 [PubMed PMID: 23135645]
Goodman GD, Kaufman J, Day D, Weiss R, Kawata AK, Garcia JK, Santangelo S, Gallagher CJ. Impact of Smoking and Alcohol Use on Facial Aging in Women: Results of a Large Multinational, Multiracial, Cross-sectional Survey. The Journal of clinical and aesthetic dermatology. 2019 Aug:12(8):28-39 [PubMed PMID: 31531169]
Level 2 (mid-level) evidencede Almeida AR, da Costa Marques ER, Banegas R, Kadunc BV. Glabellar contraction patterns: a tool to optimize botulinum toxin treatment. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2012 Sep:38(9):1506-15. doi: 10.1111/j.1524-4725.2012.02505.x. Epub 2012 Jul 16 [PubMed PMID: 22804914]
Level 2 (mid-level) evidenceTrelles MA, Pardo L, Benedetto AV, García-Solana L, Torrens J. The significance of orbital anatomy and periocular wrinkling when performing laser skin resurfacing. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2000 Mar:26(3):279-86 [PubMed PMID: 10759810]
Level 2 (mid-level) evidenceAlexis AF, Grimes P, Boyd C, Downie J, Drinkwater A, Garcia JK, Gallagher CJ. Racial and Ethnic Differences in Self-Assessed Facial Aging in Women: Results From a Multinational Study. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.]. 2019 Dec:45(12):1635-1648. doi: 10.1097/DSS.0000000000002237. Epub [PubMed PMID: 31702594]
Ong AA, Sherris DA. Neurotoxins. Facial plastic surgery : FPS. 2019 Jun:35(3):230-238. doi: 10.1055/s-0039-1688844. Epub 2019 Jun 12 [PubMed PMID: 31189195]
Wang J, Su Y, Zhang J, Guo P, Huang C, Song B. A Randomized, Controlled Study Comparing Subbrow Blepharoplasty and Subbrow Blepharoplasty Combined with Periorbital Muscle Manipulation for Periorbital Aging Rejuvenation in Asians. Aesthetic plastic surgery. 2020 Jun:44(3):788-796. doi: 10.1007/s00266-020-01630-4. Epub 2020 Feb 18 [PubMed PMID: 32072216]
Level 1 (high-level) evidenceYi DJ, Hwang S, Son J, Yushmanova I, Anson Spenta K, St Rose S. Real-World Safety And Effectiveness Of OnabotulinumtoxinA Treatment Of Crow's Feet Lines And Glabellar Lines: Results Of A Korean Postmarketing Surveillance Study. Clinical, cosmetic and investigational dermatology. 2019:12():851-856. doi: 10.2147/CCID.S227493. Epub 2019 Nov 19 [PubMed PMID: 31819582]
Ascher B, Rzany B, Kestemont P, Hilton S, Heckmann M, Bodokh I, Noah EM, Boineau D, Kerscher M, Volteau M, Le Berre P, Picaut P. Significantly Increased Patient Satisfaction Following Liquid Formulation AbobotulinumtoxinA Treatment in Glabellar Lines: FACE-Q Outcomes From a Phase 3 Clinical Trial. Aesthetic surgery journal. 2020 Aug 14:40(9):1000-1008. doi: 10.1093/asj/sjz248. Epub [PubMed PMID: 31550352]
Level 1 (high-level) evidenceQuereshy FA. Rejuvenation of the Facial Upper Third. Atlas of the oral and maxillofacial surgery clinics of North America. 2016 Sep:24(2):xi. doi: 10.1016/j.cxom.2016.06.001. Epub 2016 Jul 9 [PubMed PMID: 27499478]
Starkman SJ, Sherris DA. Association of Corrugator Supercilii and Procerus Myectomy With Endoscopic Browlift Outcomes. JAMA facial plastic surgery. 2019 Sep 1:21(5):375-380. doi: 10.1001/jamafacial.2018.2084. Epub [PubMed PMID: 31046060]
Modrell AK, Tadi P. Primitive Reflexes. StatPearls. 2023 Jan:(): [PubMed PMID: 32119493]
Salandy S, Rai R, Gutierrez S, Ishak B, Tubbs RS. Neurological examination of the infant: A Comprehensive Review. Clinical anatomy (New York, N.Y.). 2019 Sep:32(6):770-777. doi: 10.1002/ca.23352. Epub 2019 Mar 8 [PubMed PMID: 30848525]
Damasceno A, Delicio AM, Mazo DF, Zullo JF, Scherer P, Ng RT, Damasceno BP. Primitive reflexes and cognitive function. Arquivos de neuro-psiquiatria. 2005 Sep:63(3A):577-82 [PubMed PMID: 16172703]
Level 2 (mid-level) evidenceKobayashi S, Maki T, Kunimoto M. Clinical symptoms of bilateral anterior cerebral artery territory infarction. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2011 Feb:18(2):218-22. doi: 10.1016/j.jocn.2010.05.013. Epub 2010 Dec 14 [PubMed PMID: 21159512]
Level 3 (low-level) evidenceBrodsky H, Dat Vuong K, Thomas M, Jankovic J. Glabellar and palmomental reflexes in Parkinsonian disorders. Neurology. 2004 Sep 28:63(6):1096-8 [PubMed PMID: 15452308]
Thomas RJ. Blinking and the release reflexes: are they clinically useful? Journal of the American Geriatrics Society. 1994 Jun:42(6):609-13 [PubMed PMID: 8201145]
Marterer-Travniczek A, Danielczyk W, Müller F, Simanyi M, Fischer P. Release signs in Parkinson's disease with and without dementia. Journal of neural transmission. Parkinson's disease and dementia section. 1992:4(3):207-12 [PubMed PMID: 1627254]