• Berkovitz BK, Holland GR, Moxham BJ. 2002. Oral Anatomy, Histology and Embryology. 3rd Ed. Edinburgh, London, New York, Philadelphia, St. Louis, Sidney, Toronto: Mosby.
  • Cleghorn BM, Christie WH, Dong CC. 2007a. The root and root canal morphology of the human mandibular first premolar: A literature review. J Endod 33: 509516.
  • Cleghorn BM, Christie WH, Dong CC. 2007b. The root and root canal morphology of the human mandibular second premolar: A literature review. J Endod 33: 10311037.
  • Cleghorn BM, Christie WH, Dong CC. 2008. Anomalous mandibular premolars: A mandibular first premolar with three roots and a mandibular second premolar with a C-shaped canal system. Int Endod J 41: 10051014.
  • Fishel D, Buchner A, Hershkowith A, Kaffe I. 1976. Roentgenologic study of the mental foramen. Oral Surg Oral Med Oral Pathol 41: 682686.
  • Kartal N, Ozcelik B, Cimilli H. 1998. Root canal morphology of maxillary premolars. J Endod 24: 417419.
  • Keele KD. 1979. Leonardo da Vinci's ‘Anatomia Naturale’. The inaugural John F. Fulton lecture. Yale University School of Medicine November 3, 1978. Yale J Biol Med 52: 369409.
  • Keele KD, Pedretti C. 1979. Leonardo da Vinci: Corpus of the anatomical studies in the collection of Her Majesty the Queen at Windsor Castle. 2 vols. London and New York: Phaidon Press.
  • Lanz von T, Wachsmuth W. 2004. Praktische Anatomie: Kopf: Uebergeordnete Systeme. Sonderausgabe der 1985 erschienen 1. Auflage. 1985. Berlin Heidelberg: Springer-Verlag.
  • Leonardo da Vinci. 1977. Anatomical drawings from the Royal Collection. London: Royal Academy of Arts. p 50.
  • Libfeld H, Rotstein I. 1989. Incidence of four-rooted maxillary second molars: Literature review and radiographic survey of 1,200 teeth. J Endod 15: 129131.
  • Maggiore C, Gallottini L, Resi JP. 1998. Mandibular first and second molar. The variability of roots and root canal system. Minerva Stomatol 47: 409416.
  • Malagnino V, Gallottini L, Passariello P. 1997. Some unusual clinical cases on root anatomy of permanent maxillary molars. J Endod 23: 127128.
  • Matsuda Y. 1927. Location of the dental foramina in human skulls from statistical observations. Int J Orthod Oral Surg 13: 299305.
  • Peikoff MD, Christie WH, Fogel HM. 1996. The maxillary second molar: Variations in the number of roots and canals. Int Endod J 29: 365369.
  • Putz R, Pabst R. 2006. Sobotta: Atlas of Human Anatomy Vol 1: Head, Neck and Upper Limb. Munich: Elsevier.
  • Ring ME. 1985. Dentistry: An Illustrated History. St. Louis, MO: Mosby.
  • Vertucci FJ. 1978. Root canal morphology of mandibular premolars. J Am Dent Assoc 97: 4750.
  • Weine FS. 1996. Endodontic Therapy. 5th Ed. St. Louis, MO: Mosby.
  • Ten drawings by Leonardo da Vinci. The Royal Collection at Windsor Castle © 2008: URL: