Glossary of mammalian dental topography

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Many different terms have been proposed for features of the tooth crown in mammals.

The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn in 1907 and is, although with many variations, the one that continues today. [1][2][3]

  • The suffix "-cones /-conids" (upper molar/lower molar) is added to the main cusps: Paraconus, Metaconus, Protoconus and Hypoconus on the upper molar, and Paraconid, Metaconid, Protoconid, Hypoconid and Entoconid on the lower molar. This name is used for both bunodont and selenodont molars, that is, as many for "buno" pillar-like cusps as for "selenes" crescent-like cusps.
  • The suffix "-conule /-conulid" (upper molar/lower molar) is added to the secondary cusps. For example, Metaconule, Hypoconulid.
  • The suffix "-style/-stylid" (upper molar/lower molar) is added to the peripheral cusps that are found in the cornices or cingulus of the tooth. These cusps are traditionally named according to their proximity to the main cusps, although some anatomists prefer to name them according to their position on the tooth.
  • The suffix "-loph/-lophid" (upper molar/lower molar) is added to the crests that join cusps together. They include in the name one the cusps involved. For example, the hypolophid is the ridge that unites the hypoconid with the entoconid. These ridges often have secondary ridges: the secondary crest of the ectoloph is called crista; antecrochet to that of the protoloph, and crochet to that of the metaloph.
  • The suffix "-crista / -cristid" (upper molar / lower molar) is used for the ridges that come out of the cusps but do not connect them with other cusps. It is also used to name the edges of selenes.
  • To the structures in the lingual part of the molar, the prefix "ento-" ("internal") is often added, while those of the lingual part are added the prefix "ecto-" ("external"). the mesial part of the molar is often added the prefix "pre-" (from "previous") while those of the distal part are added the prefix "post-" ("posterior"). The mesial part is that which is towards the incisors.
  • The suffix "-flexus / -flexid" (upper molar / lower molar) is used for the open valleys in the occlusal surfaces of the hypsodont teeth. When this valleys are enclosed, they are called fossetes/fossetids (upper molar / lower molar). Sometimes they are used also for the folds of the teeth, although the proper name for the folds is sulcus (pl. sulci).
  • The cusp prefixes "para-", "meta-", "proto-", "hypo-", etc., are related to the succession and position of the cusps according to the ancient tritubercular theory of the evolution of molars from Cope and Osborn. Although this theory has lost its validity, they continue to use the names for the description of the molars. The prefix "proto" referred to the original cusp which would be homologous to a single cusp tooth according to Osborn, and would be the first cusp to appear not only in evolution but in development.[1] This was criticized early by studies of embryology where it was shown that the first cusp in the embryonic development of the upper molars was the paraconus. Later this was shown to be variable and the first cusp to appear in ontogeny would not be related to the evolution of the tooth.[2]

Image GalleryEdit

CRICETIDAE MOLAR TEETH NOMENCLATURE AFTER REIG(1977).[4]Edit

 
Cricetidae molar teeth nomenclature after Reig, 1977.

Upper teethEdit

Name Nomenclature term is used in Definition Comments Image
Anterolingual conule Reig (1977)[4] A conule on the lingual side of an anterocone divided by an anteromedian flexus or fossette
Anteromedian flexus Reig (1977)[4] A longitudinal flexus dividing the anterocone into anterolabial and anterolingual conules
Anterolabial conule Reig (1977)[4] A conule on the labial side of an anterocone divided by an anteromedian flexus or fossette
Anterocone Reig (1977)[4] A cusp at the front of the tooth that may be divided into anterolabial and anterolingual conules
Protostyle Reig (1977)[4] A style in front of the protocone, in the protoflexus
Protoflexus Reig (1977)[4] A flexus between the protocone and the anterolingual conule
Anterior mure Reig (1977)[4] A crest connecting the anterocone to the protocone
Protocone Reig (1977)[4] One of the main cusps, at the anterolingual side
Enterostyle Reig (1977)[4] A style between the protocone and the hypocone, in the hypoflexus
Enteroloph Reig (1977)[4] A crest connecting the enterostyle to the mesocone
Hypoflexus Reig (1977)[4] A flexus between the protocone and the hypocone
Mesocone Reig (1977)[4] A conule in the median mure where the mesoloph is attached to it
Median mure Reig (1977)[4] A crest connecting the protocone/paracone to the hypocone/metacone
Hypocone Reig (1977)[4] One of the main cusps, at the posterolingual side
Procingulum Reig (1977)[4] The front part of the tooth, before the anterior mure
Anteroflexus Reig (1977)[4] A flexus between the anteroloph and the anterolabial conule
Anteroloph Reig (1977)[4] A crest between the paracone and the anterolabial conule that may be connecting to a parastyle
Parastyle Reig (1977)[4] A style in front of the paracone
Paraflexus Reig (1977)[4] A flexus in front of the paracone
Protolophule Reig (1977)[4] A small crest in the paraflexus, connected to the protocone
Paraloph Reig (1977)[4] A crest attaching the paracone to the protocone or the median mure
Paracone Reig (1977)[4] One of the main cusps, at the anterolabial side
Paralophule Reig (1977)[4] A small crest attached to the back side of the paracone
Mesoflexus Reig (1977)[4] A flexus between the mesoloph and the paracone
Mesostyle Reig (1977)[4] A style at the labial margin between the paracone and metacone
Mesoloph Reig (1977)[4] A crest in front of the metaflexus, connected to the median mure
Metaflexus Reig (1977)[4] A flexus in front of the metacone
Metalophule Reig (1977)[4] A small crest attached to the front side of the metacone
Metacone Reig (1977)[4] One of the main cusps, at the posterolabial side
Metaloph Reig (1977)[4] A crest attaching the paracone to the hypocone
Posteroflexus Reig (1977)[4] A flexus between the posteroloph and the metacone
Posterostyle Reig (1977)[4] A crest on the posterolabial corner of the molar
Posteroloph Reig (1977)[4] A crest at the back of the molar, connected to the hypocone

Lower teethEdit

Name Nomenclature term is used in Definition Comments Image
Anterolingual conulid Reig (1977)[4] A conulid on the lingual side of an anteroconid divided by an anteromedian flexid or fossettid
Anteromedian flexid Reig (1977)[4] A longitudinal flexid dividing the anteroconid into anterolabial and anterolingual conules
Anterolabial conulid Reig (1977)[4] A conulid on the labial side of an anteroconid divided by an anteromedian flexid or fossettid
Anteroconid Reig (1977)[4] A cusp at the front of the tooth that may be divided into anterolabial and anterolingual conulids
Anterolabial cingulum Reig (1977)[4] A crest before the protoconid and protoflexid
Protostylid Reig (1977)[4] A stylid in front of the protoconid, in the protoflexid
Protoflexid Reig (1977)[4] A flexid between the protoconid and the anterolabial conulid
Anterior murid Reig (1977)[4] A crest connecting the anteroconid to the protoconid
Protoconid Reig (1977)[4] One of the main cusps, at the anterolabial side
Ectostylid Reig (1977)[4] A stylid between the protoconid and the hypoconid, in the hypoflexid
Ectolophid Reig (1977)[4] A crest connecting the ectostylid to the mesoconid
Hypoflexid Reig (1977)[4] A flexid between the protoconid and the hypoconid
Mesoconid Reig (1977)[4] A conulid in the median murid where the mesolophid is attached to it
Median murid Reig (1977)[4] A crest connecting the protoconid/metaconid to the hypoconid/entoconid
Hypoconid Reig (1977)[4] One of the main cusps, at the posterolabial side
Procingulum Reig (1977)[4] The front part of the tooth, before the anterior murid
Anteroflexid Reig (1977)[4] A flexid between the anterolophid and the anterolingual conulid
Anterolophid Reig (1977)[4] A crest between the metaconid and the anterolabial conulid that may be connecting to a metastylid
Metastylid Reig (1977)[4] A stylid in front of the metaconid
Metaflexid Reig (1977)[4] A flexid in front of the metaconid
Protolophulid Reig (1977)[4] A small crest in the mesoflexid, connected to the protoconid
Metalophid Reig (1977)[4] A crest attaching the metaconid to the protoconid or the anterior murid
Metaconid Reig (1977)[4] One of the main cusps, at the anterolingual side
Metalophulid Reig (1977)[4] A small crest attached to the back side of the metaconid
Mesoflexid Reig (1977)[4] A flexid between the mesolophid and the paraconid
Mesostylid Reig (1977)[4] A stylid at the labial margin between the metaconid and entoconid
Mesolophid Reig (1977)[4] A crest in front of the entoflexid, connected to the median murid
Entoflexid Reig (1977)[4] A flexid in front of the entoconid
Entolophulid Reig (1977)[4] A small crest attached to the front side of the entoconid
Entoconid Reig (1977)[4] One of the main cusps, at the posterolingual side
Entolophid Reig (1977)[4] A crest attaching the entoconid to the hypoconid or median murid
Posteroflexid Reig (1977)[4] A flexid between the posterolophid and the metaconid
Hypolophulid Reig (1977)[4] A small crest in the posteroflexid attached to the posterolophid
Posterostylid Reig (1977)[4] A crest on the posterolingual corner of the molar
Posterolophid Reig (1977)[4] A crest at the back of the molar, connected to the hypoconid

See alsoEdit

ReferencesEdit

  1. ^ a b Osborn, Henry Fairfield, 1857-1935. (1907). Evolution of mammalian molar teeth to and from the triangular type : including collected and revised researches on trituberculy, and new sections on the forms and homologies of the molar teeth in the different orders of mammals. Kessinger Publishing. ISBN 978-1-4368-4090-3. OCLC 810943856.
  2. ^ a b MacCord, Katherine (2017). Development, evolution, and teeth: how we came to explain the morphological evolution of the mammalian dentition. Arizona State University.
  3. ^ Szalay, Frederick S. (1969). "Mixodectidae, Microsyopidae, and the insectivore-primate transition. in Bulletin of the AMNH ; v. 140, article 4". hdl:2246/1130. Cite journal requires |journal= (help)
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq Reig, Osvaldo A. (2009). "A proposed unified nomenclature for the enamelled components of the molar teeth of the Cricetidae (Rodentia)". Journal of Zoology. 181 (2): 227–241. doi:10.1111/j.1469-7998.1977.tb03238.x. ISSN 0952-8369.