Contents lists available at ScienceDirect Complementary Therapies in Clinical Practice journal homepage: www.elsevier.com/locate/ctcp Does auriculotherapy have therapeutic effectiveness? An overview of systematic reviews Andreia Vieira a,b,c,* , Ana Mafalda Reis c , Luís Carlos Matos d , Jorge Machado a,c , António Moreira e a ICBAS - Institute of Biomedical Sciences, University of Porto, 4099-030, Porto, Portugal b Santa Maria Health School, 4049-024, Porto, Portugal c Laboratory of Applied Physiology, ICBAS - Institute of Biomedical Sciences, University of Porto, 4099-030, Porto, Portugal d Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, s/n, 4200-465, Porto, Portugal e Sport Sciences School of Rio Maior, 2040-413, Rio Maior, Portugal ARTICLE INFO Keywords: Auriculotherapy Auricular acupuncture Acupressure Pain Insomnia Smoking cessation ABSTRACT Background and purpose: Auriculotherapy is a therapeutic technique used for a wide variety of conditions. Nevertheless, similarly to any health related intervention, the clinical use of this therapy requires scientific evidence of effectiveness in order to support its rational use. The main goal of this article is to critically analyze published literature on auriculotherapy and to provide an overview of the effectiveness of this technique in the management of health disorders. Methods: The inventory of published reviews on this subject was carried out in November 2017, by assessing the following computerized databases: PubMed, MEDLINE, PsycINFO, EBMR, Cochrane Database of Systematic Reviews, CINAHL Plus NRC and Science Direct. Were only considered the systematic reviews based on meta- analysis with high methodological quality described according to AMSTAR (Assessment of Multiple Systematic Reviews). The eligible articles were systematically reviewed to find out in which health conditions aur- iculotherapy can be used with effectiveness. Results: A total of 14 reviews were eligible according to the inclusion and exclusion criterions. Those reviews were focused on the management of insomnia, smoking cessation and pain, within the clinical scope of Neurology, Orthopaedics and Rheumatology. Conclusions: Auriculotherapy has shown to have positive effects while associated to conventional treatments of insomnia, chronic and acute pain. Further well designed studies are required to evaluate the effectiveness of this technique in the treatment of other health conditions. 1. Introduction Mammalian ear is a complex structure with origin in tissues of neural crest, mesoderm, endoderm and ectodermal. This anatomic structure includes ossicles, cartilage, muscles, nerves, blood vessels and epithelial membranes [1]. The current understanding of the mechan- isms behind different reflex therapies, such as auriculotherapy, stands on the embryological hypothesis as well as on the strong innervation of the ear. In fact, the ear is one of few anatomic structures built up of tissue from each of the primary tissues found in an embryo. Therefore, this could hypothetically be related to the representation of the human body in the ear reflexology charts [2–5]. International standards and nomenclature were firstly developed in the nineties with the contribute of the World Health Organization (WHO). Most recently, Auricular Acupuncture Points (AAPs) were accepted as a biomathematical model of the brain's anatomical orga- nization. This view come out while assessing the neurophysiological correlations between auricular zones and their brain correspondences [6]. The sensory innervation of vegetative nerve centers receives in- formation from the internal organs by electrical impulses conducted through Alpha, Beta and Gamma fibers. In turn, these are disseminators of sensitive perceptions to touch, pressure, temperature and proprio- ception that reach the sensory nuclei of the cranial nerves and the posterior horn of the Spinal Cord [3,5,7–10]. The information provided by thermal, algic and proprioceptive stimuli is transmitted from the auricular pavilion by the fibers of the following nerves: i) aur- iculotemporal nerve; ii) auricular branch of the vagus nerve (ABVN); iii) minor occipital nerve (sensitive branch of the cervical plexus) and iv) greater auricular nerve [3,5,7–10]. The auriculotemporal nerve https://doi.org/10.1016/j.ctcp.2018.08.005 Received 18 February 2018; Received in revised form 11 July 2018; Accepted 21 August 2018 * Corresponding author. Santa Maria Health School, 4049-024, Porto, Portugal. E-mail address: andreia.vieira@santamariasaude.pt (A. Vieira). Complementary Therapies in Clinical Practice 33 (2018) 61–70 1744-3881/ © 2018 Published by Elsevier Ltd. T