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Journal of Cosmetic Dermatology Oct 2021Botulinum toxin A (BoNT-A) has grown tremendously in aesthetic dermatology since 2002 when the United States Food and Drug Administration (FDA) first approved its use... (Review)
Review
BACKGROUND
Botulinum toxin A (BoNT-A) has grown tremendously in aesthetic dermatology since 2002 when the United States Food and Drug Administration (FDA) first approved its use for treating moderate-to-severe glabellar lines. Blepharoptosis, due to local spread of toxin, is a reported side effect of BoNT-A which, although rare, more frequently occurs among inexperienced practitioners.
OBJECTIVES
The purpose of this review is to highlight the causes and management of eyelid ptosis secondary to BoNT-A administration including new anatomic pathways for BoNT-A spread from the brow area to the levator palpebrae superioris muscle.
METHODS
A literature search was conducted using electronic databases (PubMed, Science Direct, MEDLINE, Embase, CINAHL, EBSCO) regarding eyelid anatomy and the underlying pathogenesis, presentation, prevention, and treatment of eyelid ptosis secondary to BoNT-A. Anatomic dissection has been performed to assess the role of neurovascular pedicles and supraorbital foramen anatomic variations.
RESULTS
Blepharoptosis occurs due to weakness of the levator palpebrae superioris muscle. Mean onset is 3-14 days after injection and eventually self-resolves after the paralytic effect of BoNT-A wanes. Administration of medications, such as oxymetazoline hydrochloride or apraclonidine hydrochloride eye drops, anticholinesterase agents, or transdermal BoNT-A injections to the pre-tarsal orbicularis, can at least partially reverse eyelid ptosis. Anatomic study shows that a supraorbital foramen may be present in some patients and constitutes a shortcut from the brow area directly into the orbital roof, following the supraorbital neurovascular pedicle.
CONCLUSION
Providers should understand the anatomy and be aware of the causes and treatment for blepharoptosis when injecting BoNT-A for the reduction of facial wrinkles. Thorough anatomic knowledge of the supraorbital area and orbital roof is paramount to preventing incorrect injection into "danger zones," which increase the risk of eyelid ptosis.
Topics: Blepharoptosis; Botulinum Toxins, Type A; Humans; Neuromuscular Agents; Oculomotor Muscles; Skin Aging
PubMed: 34378298
DOI: 10.1111/jocd.14361 -
Arrhythmia & Electrophysiology Review Apr 2022The name Ivan Mahaim is well-known to electrophysiologists. However, alternative anatomical substrates can produce the abnormal rhythms initially interpreted on the... (Review)
Review
The name Ivan Mahaim is well-known to electrophysiologists. However, alternative anatomical substrates can produce the abnormal rhythms initially interpreted on the basis of the pathways he first described. These facts have prompted suggestions that Mahaim should be deprived of his eponym. It is agreed that specificity is required when describing the pathways that produce the disordered cardiac conduction, and that the identified pathways should now be described in an attitudinally appropriate fashion. The authors remain to be convinced that understanding will be enhanced simply by discarding the term 'Mahaim physiology' from the lexicon. It is fascinating to look back at the history of accessory atrioventricular junctional conduction pathways outside the normal accessory atrioventricular conduction system, and their possible role in rhythm disturbances. It took both the anatomist and the clinical arrhythmologist quite some time to understand the complex anatomical architecture and the ensuing electrophysiological properties. Over the years, the name Mahaim was often mentioned in those discussions, although these pathways were not the ones that produced the eponym. The reason for this review, therefore, is to present relevant information about the person and what followed thereafter.
PubMed: 35990105
DOI: 10.15420/aer.2022.12 -
Clinical Anatomy (New York, N.Y.) Sep 2019The lingual frenulum is recognized as having the potential to limit tongue mobility, which may lead to difficulties with breastfeeding in some infants. There is...
The lingual frenulum is recognized as having the potential to limit tongue mobility, which may lead to difficulties with breastfeeding in some infants. There is extensive variation between individuals in the appearance of the lingual frenulum but an ambiguous relationship between frenulum appearance and functional limitation. An increasing number of infants are being diagnosed with ankyloglossia, with growing uncertainty regarding what can be considered "normal" lingual frenulum anatomy. In this study, microdissection of four fresh tissue premature infant cadavers shows that the lingual frenulum is a dynamic, layered structure formed by oral mucosa and the underlying floor of mouth fascia, which is mobilized into a midline fold with tongue elevation and/or retraction. Genioglossus is suspended from the floor of mouth fascia, and in some individuals can be drawn up into the fold of the frenulum. Branches of the lingual nerve are located superficially on the ventral surface of the tongue, immediately beneath the fascia, making them vulnerable to injury during frenotomy procedures. This research challenges the longstanding belief that the lingual frenulum is a midline structure formed by a submucosal "band" or "string" and confirms that the neonatal lingual frenulum structure replicates that recently described in the adult. This article provides an anatomical construct for understanding and describing variability in lingual frenulum morphology and lays the foundation for future research to assess the impact of specific anatomic variants of lingual frenulum morphology on tongue mobility. Clin. Anat. 32:824-835, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.
Topics: Ankyloglossia; Cadaver; Female; Humans; Infant, Extremely Premature; Infant, Newborn; Lingual Frenum; Lingual Nerve; Male
PubMed: 31116462
DOI: 10.1002/ca.23410 -
Current Biology : CB May 2023In the early 19th century, long before the discovery of the dinosaurs, scientists and the public alike were faced with the realization that strange beasts, wholly...
In the early 19th century, long before the discovery of the dinosaurs, scientists and the public alike were faced with the realization that strange beasts, wholly extinct, were once populating Earth's ancient oceans. In no small part, this realization was through the discovery of the first plesiosaurs (and ichthyosaurs) along the Dorset coast of England in the seaside town of Lyme Regis. There was this large marine reptile resembling a large sea turtle, but with four evenly shaped flippers and looking as though a large snake had been pulled through its carapace. It was soon to be named scientifically Plesiosaurus, in reference to its greater similarity to living reptiles than the Ichthyosaurus (Figure 1). While the Ichthyosaurus was relatively easily understood as a fish-shaped reptile descended from land-living ancestors, the Plesiosaurus was beyond comprehension, even though incomplete skeletons had been unearthed already in the early 18th century. Plesiosaurs seemed so alien that the first complete skeleton, discovered by the famed Mary Anning a little more than 200 years ago (Figure 1A), was considered a fake by the leading anatomist of the day, the Baron Georges Cuvier in Paris. Only study of the original specimen convinced him of the authenticity of this animal but reinforced his seminal insight that there is extinction.
Topics: Animals; Male; Animal Shells; Dinosaurs; England; Environment
PubMed: 37220726
DOI: 10.1016/j.cub.2023.04.018 -
Clinical Anatomy (New York, N.Y.) Sep 2019Surgical release of the lingual frenulum (frenotomy) has become an increasingly common procedure, performed from birth through to adulthood. Surprisingly, detailed...
Surgical release of the lingual frenulum (frenotomy) has become an increasingly common procedure, performed from birth through to adulthood. Surprisingly, detailed anatomy of the in-situ lingual frenulum has never been described, and no anatomical basis has been proposed for the individual variability in frenulum morphology. The lingual frenulum is frequently referred to as a "cord" or "submucosal band" of connective tissue, yet there is no evidence to support this anatomical construct. This paper aims to describe the anatomy of the in-situ lingual frenulum and its relationship to floor of mouth structures. Fresh tissue microdissection of the lingual frenulum and floor of mouth was performed on nine adult cadavers with photo-documentation and description of findings. The lingual frenulum is a dynamic structure, formed by a midline fold in a layer of fascia that inserts around the inner arc of the mandible, forming a diaphragm-like structure across the floor of mouth. This fascia is located immediately beneath the oral mucosa, fusing centrally with the connective tissue on the tongue's ventral surface. The sublingual glands and submandibular ducts are enveloped by the fascial layer and anterior genioglossus fibers are suspended beneath it. Lingual nerve branches are located superficially on the ventral surface of the tongue, immediately deep to the fascia. The lingual frenulum is not a discrete midline structure. It is formed by dynamic elevation of a midline fold in the floor of mouth fascia. With this study, the clinical concept of ankyloglossia and its surgical management warrant revision. Clin. Anat. 32:749-761, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.
Topics: Ankyloglossia; Cadaver; Dissection; Humans; Lingual Frenum; Mandible; Mouth Mucosa
PubMed: 30701608
DOI: 10.1002/ca.23343