Cone beam CT detection of foramen tympanicum or foramen of huschke

Abstract

Free AccessLetter to the editorCone beam CT detection of foramen tympanicum or foramen of huschkeP P JajuP P JajuSearch for more papers by this authorPublished Online:28 Jan 2014https://doi.org/10.1259/dmfr/50909630SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail AboutIn reference to the article “Foramen tympanicum or foramen of Huschke: anatomical cone beam CT study”,1 I wish to congratulate the authors for an informative study on foramen tympanicum by use of the latest cone beam CT images. The authors took great effort in mentioning multiple factors determining the ossification of tympanic bone-like mastication, deglutition and respiration. We wish to address certain aspects of embryonic development of tympanic bone not reported in this article. The tympanic membrane is formed in utero by the connection of the first entoblastic and epiblastic pouches. At 9 weeks' gestational age, four ossification centres develop around the tympanic membrane, fusing to form a U-shaped bone.2 This bone fuses with the squamous portion of the temporal bone during the 35th week of gestational age. Therefore, at birth, the entire tympanic bone is incompletely developed and forms a U shape. Two prominences, one anterior and one posterior to the U-shaped bone, arise and grow towards each other. These two points of ossification fuse at the age of 1 year. Reviewed literature also hypothesized that dehiscence of the tympanic bone is linked to abnormal development of the first branchial arch.3 Furthermore, the tympanic ring could have a role in ossification of the tympanic bone, as congenital cholesteatoma has been linked to abnormal development of the tympanic ring, which cannot stop the migration of the external auditory canal (EAC) ectodermal tissue into the middle ear.4 Therefore, an anomaly of the tympanic ring during embryogenesis could lead to an abnormal ossification of the tympanic bone and to a persistent foramen tympanicum. Also, genetic factors lead to delays in ossification.5 Complications reported for persistence of foramen tympanicum include ear injury during temporomandibular joint arthroscopy performed with an endoscope of less than 3 mm diameter, which may penetrate into the EAC by traversing the persistent foramen.3 Reported otologic complications are tympanic membrane rupture, dislocation of the incus, injury to the tympanic segment of the facial nerve, labyrinthine disruption and ear infection.References1 Tozoglu U , Caglayan F , Harorl A . Foramen tympanicum or foramen of Huschke: anatomical cone beam CT study. Dentomaxillofac Radiol 2012;41:294–297. Link ISI, Google Scholar2 Applebaum EL , Berg LF , Kumar A . Otologic complications following temporomandibular joint arthroscopy. Ann Otol Rhinol Laryngol 1988;97:675–679. Crossref Medline ISI, Google Scholar3 Lacout A , Marsot-Dupuch K , Smoker WRK , Lasjaunias P . Foramen tympanicum, or foramen of huschkle: pathologic cases and anatomic CT study. Am J Neuroradiol 2005;26:1317–1323. Medline ISI, Google Scholar4 Kenji A . Role of the tympanic ring in the pathogenesis of congenital cholesteatoma. Laryngoscope 1983;93:1140–1146. Medline ISI, Google Scholar5 Mao JJ , Nah HD . Growth and development: hereditary and mechanical modulations. Am J Dentofacial Orthop 2004;125:676–689. Crossref Medline ISI, Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited byUsefulness of Cone-Bean Computed Tomography Exams to Detect Foramen of Huschke in Diverse Age GroupJournal of Craniofacial Surgery, Vol. 30, No. 2Evaluation of Foramen Tympanicum Using Cone-Beam Computed Tomography in Orthodontic MalocclusionsJournal of Craniofacial Surgery, Vol. 25, No. 2 Volume 41, Issue 7October 2012Pages: 533-620 © 2012 The British Institute of Radiology History ReceivedApril 22,2012AcceptedMay 08,2012Published onlineJanuary 28,2014 Metrics Download PDF