title: Unusual root morphology in second mandibular molar with a radix entomolaris, and comparison between cone-beam computed tomography and digital periapical radiography: a case report.
abstract: BACKGROUND
  Radix entomolaris presents with an unusual morphology and is a rare occurrence. It is mainly observed in mandibular first molars. The incidence varies in different populations but it is far from common. This is especially true for mandibular second molars which possess the lowest prevalence. Some case reports have shown the presence of this finding in mandibular second molars; however, cases of patients of a white background have not been reported.
  
  
  METHODS
  The diagnosis and treatment of an infected radix entomolaris in a mandibular second molar in a 45-year-old white man is presented. The diagnosis was made with standard endodontic techniques. Conventional radiographic imaging was augmented with cone-beam computed tomography scans and three-dimensional images which were constructed with dedicated software. The endodontic treatment was done using accepted endodontic procedures. Clinical and radiographic evidence of healing was seen after a 14-month follow-up.
  
  
  CONCLUSIONS
  The implications of complex and unpredictable root anatomy are discussed in this report. The clinician should consider the possibility of encountering a mandibular second molar with a radix entomolaris. Cone-beam computed tomography is a useful tool in the diagnosis and improvement of root canal therapy.
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, C/ Entrerríos s/n Santiago Compostela, A Coruña, 15782, Spain. elisardolopez@gmail.com.
authors.forename: Elisardo
authors.initials: E
authors.lastname: López-Rosales
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, C/ Entrerríos s/n Santiago Compostela, A Coruña, 15782, Spain. pablocastelobaz@hotmail.com.
authors.forename: Pablo
authors.initials: P
authors.lastname: Castelo-Baz
authors.affiliation: Department of Operative Dentistry and Endodontology, Dental School, Ghent University, Ghent University Hospital, Gent, Belgium. Roeland.DeMoor@UGent.be.
authors.forename: Roland
authors.initials: R
authors.lastname: De Moor
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, C/ Entrerríos s/n Santiago Compostela, A Coruña, 15782, Spain. manuelrz2@gmail.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ruíz-Piñón
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, C/ Entrerríos s/n Santiago Compostela, A Coruña, 15782, Spain. b.martinbiedma@gmail.com.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Martín-Biedma
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Dentistry, University of Santiago de Compostela, C/ Entrerríos s/n Santiago Compostela, A Coruña, 15782, Spain. purivarelap@gmail.com.
authors.forename: Purificación
authors.initials: P
authors.lastname: Varela-Patiño
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology*; D008340:Mandibular Nerve; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology*; D009407:Nerve Block / Q000379:methods*; D011856:Radiographic Image Enhancement; D012390:Root Canal Therapy / Q000379:methods; D014071:Tooth Abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D014092:Tooth Root / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology*; D016896:Treatment Outcome