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Permanent Teeth

The first permanent teeth begin to emerge into the mouth at the age of 6 and for the following 6–12 years the primary (deciduous) teeth are gradually replaced by the permanent ones. After the emerging of the second molars the permanent dentation is considered complete1. The age of the maturation and eruption of the most distal (third) molars is variable between populations2,3 and the complete eruption (stage D) is rarely observed in all four quadrants4.

  • 1 Nelson S, Ash M. Wheeler's Dental anatomy, physiology and occlusion. 9th ed. Elsevier, 2010, p.1.
  • 2 Acharya A. Age estimation in Indians using Demirjian’s 8 teeth method. J Forensic Sci, 2011, 56(1):124–127.
  • 3 Applicability of the Demirjian method for dental age estimation in western Turkish children. Acta Odontol Scand, 2015, 73(2):121–125.
  • 4 Renton T, Wilson N. Problems with erupting wisdom teeth: Signs, symptoms, and management. Br J Gen Pract, 2016, 66(649):e606–e608.
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    Icon of crossfade image
    Skull with complete set of permanent teeth. The frontal view Permanent teeth. Crowns and roots. The frontal view
    Skull with complete set of permanent teeth. The lateral view Permanent teeth. Crowns and roots. The lateral view
    Skull with full set of permanent teeth that is rarely seen in real life. The anterior & lateral aspect. Click the images above to see the teeth with the roots. Note the relative size and spatial orientation of the roots in the alveolar bone.

    Tooth Surfaces and Numbering System

    On the past two centurires, many classifications of tooth numeration have been proposed1–3 and some new ones are still emerging4. To avoid confusion, we use only one classficationon on this website – the most commonly used tooth numbering system recommended by the World Dental Federation5.

    According to that classfication each permanent tooth is encoded by the combination of two digits: the first refers to the quadrant (1–maxillar right; 2–maxillar left; 3–mandibular left; 4–mandibular right). and the second refers to the order number of tooth, starting from the midline:

  • 1 Zsigmondy A. A practical method for rapidly noting dental observations and operations. Br J Dent Sci, 1874, 17:580–582.
  • 2 Peck S, Peck L. A time for change of tooth numbering systems. J Dent Educ, 1993, 57(8):643–647.
  • 3 Haderup V. Dental nomenklatur og stenograft. Dansk Tandl Tidskr, 1891 3:3.
  • 4 Havale R, Sheetal B, et al. Dental notation for primary teeth: a review and suggestion of a novel system. Eur J Paediatr Dent, 2015, 16(2):163–166.
  • 5 Keiser-Nielsen S. Fédération Dentaire Internationale: Two-digit system of designation teeth. Int Dent J, 1971, 21:104–106.
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    The full set of permanent teeth in standard position. Teeth numbering system recommended by the World Dental Federation The full set of permanent teeth in standard position. Teeth numbering system recommended by the World Dental Federation

    Another point worth mentioning is the specific terminology used to describe the surfaces and other landmarks of the teeth. The teeth surround the oral cavity and do not coincide with the anatomical planes (sagittal, coronal, horisontal). For this reason, terms such as "anterior", "posterior", "medial" and "lateral" are not used in dental anatomical terminology and are substituted by "lingual" (facing the tongue), "buccal/labial" (facing the cheeks or lips), "mesial" & "distal":

    Icon of crossfade image The teeth surfaces and directions used in dentistry. Mesial vs Distal. Labial and buccal vs lingual.
    The teeth surfaces and directions used in dentistry. Mesial vs Distal. Labial and buccal vs lingual. The teeth surfaces and directions used in dentistry. Approximal surface vs contingent area. The mesial, buccal, distal, lingual and occlusal surface of tooth
    Surfaces and directions
    Please note that the outer (vestibular) surface of teeth is devided into the "labial" and "buccal", as the angulus oris projects slightly lateral to the canine tooth
    The list of terms: Facies vestibularis s. facialis – Vestibular, or facial surface
    Facies buccalis – Buccal surface
    Facies labialis – Labial surface
    Facies lingualis – Lingual surface
    Facies occlusalis s. masticatoria – Occlusal, or masticatory surface
    Directio mesialis – Mesial direction
    Directio distalis – Distal direction
    Facies approximalis – Approximal surface
    Area congingens – Contingent area

    Detailed Review of the Permanent Incisors, Canines, Premolars et Molars

    Incisors

    Incisors with roots. The position of incisors relative to the frontal aspect of skull
    Тhe permanent set of teeth has two incisors in each quadrant. The maxillar incisors are noticeably larger, than mandibular ones. The main feature of the incisor is the single sharp edge at the top of the crown. Other features, such as a single root, or absence of the cusps are less specific. The main function of the incisors is to pierce and cut the food during mastication process.
    Icon of crossfade image Multiple views of maxillary first incisor with the main anatomical landmarks
    Multiple views of maxillary first incisor: the labial, lingual, mesial and occlusal aspects Multiple views of maxillary first incisor with the main anatomical landmarks
    Right maxillary first incisor.
    Note the presence of so-called "cingulum", connecting the marginal crests on the lingual surface of incisors and canines. This structure represents the rudimentary lingual cusp. To get an impression of well-developed lingual cusps, refer to the premolar teeth.
    The list of terms: Corona dentis – Crown of tooth
    Cervix dentis – Neck of tooth
    Radix dentis – Root of tooth
    Apex radicis dentis – Apex of root of tooth
    Foramen apicis radicis dentis – Apical foramen of root of tooth
    Tuberculum dentis – Dental tubercle
    Fossa lingualis – Lingual fossa
    Margo incisalis – Incisal margin
    Crista marginalis – Marginal crest
    Cingulum

    Canines

    Canines with roots. The position of canines relative to the frontal aspect of skull
    The permanent dentition has one canine in each quadrant. These are the longest teeth and the maxillary canine teeth are not much larger than the mandibular ones. The main feature of the crowns is the massive single pointed cusp. The word originate from the Latin canis – dog, emphesizing the carnivorous nature of this type of teeth, related to the piercing and tearing the food during mastication process. But the most important function of these teeth for humans is to guide the teeth into the intercuspal position (occlusion) through the mechanism called "canine guidance*".
  • *Ash M, Ramfjord S. Occlusion. 4th ed, Saunders, Philadelphia, 1995
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    Multiple views of maxillary right canine: the labial, lingual, mesial and occlusal aspects Multiple views of maxillary right canine with the main anatomical landmarks
    Right maxillary canine.
    Note the groove on the mesial aspect of the canine root. In about 5% of cases* this groove is deep enough to completely split the root and the canal – the variant called a bifurcated root.
    The list of terms: Corona dentis – Crown of tooth
    Cervix dentis – Neck of tooth
    Radix dentis – Root of tooth
    Apex radicis dentis – Apex of root of tooth
    Foramen apicis radicis dentis – Apical foramen of root of tooth
    Apex cuspidis – Apex of cusp
    Crista cuspidis mesialis – Mesial cusp ridge
    Crista cuspidis distalis – Distal cusp ridge
    Crista marginalis mesialis – Mesial marginal ridge
    Crista marginalis distalis – Distal marginal ridge
    Cingulum Crista lingualis – Lingual ridge
    Fossa mesiolingualis – Mesiolingual fossa
    Fossa distolingualis – Distolingual fossa
  • * Plascencia H, Cruz A, et al. Mandibular canines with two roots and two root canals: case repport and literature review. Case Rep Dent, 2017:8459840.
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    Premolares

    Premolars with roots. The position of premolars relative to the lateral aspect of skull
    The premolars are located distal to the canines, two in each quadrant in the permanent dentition. The main peculiarity of premolars is the presence of two cusps, so sometimes the term premolar is substituted with "bicuspid". However, the term can be misleading, as mandibular premolars can have three, or even four cusps*.
  • * Bansal P, Nikhil V, et al. Four cuspal maxillary second premolar with single root and three root canals: Case report. J Conserv Dent, 2016, 19(4):373–376.
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    Icon of crossfade image Multiple views of maxillary first premolar with the main anatomical landmarks
    Multiple views of maxillary first premolar: the labial, lingual, mesial and occlusal aspects Multiple views of maxillary first premolar with the main anatomical landmarks
    Right maxillary first premolar.
    The number of roots varies between premolars. Clasically the maxillary first premolar is described as a tooth with two roots. Recent studies based on computed-tomography have confirmed this in European1 and Arab2 (~60% prevalence), but not in Chinese populations (~30% prevalence)2. All other premolars (second maxillar and both mandibular) have only one root in more than 80% of cases1–4.
    The list of terms: Corona dentis – Crown of tooth
    Cervix dentis – Neck of tooth
    Radix buccalis – Buccal root
    Radix lingualis – Lingual root
    Apex radicis dentis – Apex of root of tooth
    Apex cuspidis buccalis – Tip of buccal cusp
    Apex cuspidis lingualis – Tip of lingual cusp
    Crista cuspidis distobuccalis – Distobuccal cusp ridge
    Crista marginalis distalis – Distal marginal ridge
    Crista cuspidis distolingualis – Distolingual cusp ridge
    Crista cuspidis mesiobuccalis – Mesiobuccal cusp ridge
    Crista marginalis mesialis – Mesial marginal ridge
    Crista cuspidis mesiolingualis – Mesiolingual cusp ridge
    Sulcus developmentalis marginalis mesialis – Mesial marginal developmental groove
    Sulcus developmentalis centralis – Central developmental groove
    Crista triangularis lingualis – Lingual triangular ridge
    Crista triangularis buccalis – Buccal triangular ridge
    Fossa triangularis distalis – Distal triangular fossa
    Fossa triangularis mesialis – Mesial triangular fossa
  • 2 Martins J, da Silva Marques D, et al. Second root and second root canal prevalence in maxillary first and second premolars assessed by cone beam computed tomography – a systematic review and meta-analysis. Rev Port Estomatol Med Dent Cir Maxilofac, 2019, 60(2):37-50
  • 2 Al-Zubaidi S, Almansour M, et al. Assessment of root morphology and canal configuration of maxillary premolars in a Saudi subpopulation: a cone-beam computed tomographic study. BMC Oral Health, 2021, 13;21(1):397.
  • 3 Cleghorn B, Christie W, et al. The root and root canal morphology of the human mandibular first premolar: a literature review. J Endod, 2007, 33(5):509–516.
  • 4 Cleghorn B, Christie W, et al. The root and root canal morphology of the human mandibular second premolar: a literature review. J Endod, 2007, 33(9):1031–1037.
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    Molares

    Molars with roots. The position of Molars relative to the lateral aspect of skull
    The molars are largest and best anchored teeth, performing the main portion of work in mastication process. The maxillary first and second molars each have three full sized roots (two buccal and one lingual), while the mandibular first and second molars usually have only two roots, mesial and distal. The third molars are usually smaller, with greater variability and occasionally appear as anomalies with little or no resemblance to neighboring teeth*.
  • * Nelson S, Ash M. Wheeler's Dental anatomy, physiology and occlusion. 9th ed, Saunders, St. Louis, 2010, p.184, p.203.
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    Icon of crossfade image Multiple views of maxillary and mandibular first molar with the main anatomical landmarks
    Multiple views of maxillary and mandibular first molar: the labial, lingual, mesial and occlusal aspects Multiple views of maxillary and mandibular first molar with the main anatomical landmarks
    Right upper & lower first molar.
    The main feature of the molar crown is 4-5 well-developed cusps, due to which crowns of molars are the largest among all other teeth. Currently, International Anatomical Terminology for molars is insufficient in terms of detailed terminology for the occlusal aspect1. The terminology presented in the illustration above is largely based on terms published in Wheeler's textbook of dental anatomy2.
    The list of terms: Common terms for maxillary and mandibular first molar
    Linea cervicalis – Cervical line
    Truncus radicis – Root trunk
    Cuspis distobuccalis – Distobuccal cusp
    Cuspis distolingualis – Distolingual cusp
    Cuspis mesiolingualis – Mesiolingual cusp
    Cuspis mesiobuccalis – Mesiobuccal cusp
    Crista cuspidis distobuccalis – Distobuccal cusp ridge
    Crista cuspidis distolingualis – Distolingual cusp ridge
    Crista cuspidis mesiolingualis – Mesiolingual cusp ridge
    Crista cuspidis mesiobuccalis – Mesiobuccal cusp ridge
    Crista marginalis distalis – Distal marginal ridge
    Crista marginalis mesialis – Mesial marginal ridge
    Fossa centralis – Central fossa
    Fossa triangularis distalis – Distal triangular fossa
    Fossa triangularis mesialis – Mesial triangular fossa
    Dens molaris maxillaris primus dexter – Right maxillary first molar
    Radix distobuccalis – Distobuccal root
    Radix mesiobuccalis – Mesiobuccal root
    Radix lingualis – Lingual root
    Fossa distalis – Distal fossa
    Crista obliqua – Oblique ridge
    Sulcus centralis fossae centralis – Central groove of central fossa
    Sulcus transversus cristae oblique – Transverse groove of oblique ridge
    Sulcus obliquus distalis – Distal oblique groove
    Sulcus buccalis – Buccal groove
    Sulcus lingualis – Lingual groove
    Dens molaris mandibularis primus dexter – Right mandibular first molar
    Radix distalis – Distal root
    Radix mesialis – Mesial root
    Sulcus developmentalis mesiobuccalis – Mesiobuccal developmental groove
    Sulcus developmentalis distobuccalis – Distobuccal developmental groove
    Sulcus developmentalis lingualis – Lingual developmental groove
    Sulcus developmentalis centralis – Central developmental groove
  • 1 FIPAT. Terminologia Anatomica. 2nd ed. FIPAT.library.dal.ca. Federative International Programme for Anatomical Terminology, 2019 Part II, terms 901–938.
  • 2 Nelson S, Ash M. Wheeler's Dental anatomy, physiology and occlusion. 9th ed, Saunders, St. Louis, 2010.
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    First published: 7/Dec/2022