Dental Nomenclature I RSD 811: Session 2

INTRODUCTION Tooth function and types

Five Basic Functions Prehension Mastication Protection Speech Esthetics

Dentition Types Monophyodont Diphyodont Polyphyodont Homodont Heterodont

Primary vs. Permanent

Primary (Deciduous) Dentition Maxillary Mandibular RightLeft

Primary (Deciduous) Dentition Incisors Central incisor Lateral incisor

Primary (Deciduous) Dentition Canines (cuspids) Incisors Central incisor Lateral incisor

Primary (Deciduous) Dentition Canines (cuspids) Molars First molar Second molar Incisors Central incisor Lateral incisor

Primary (Deciduous) Dentition Posterior teeth Anterior teeth

Primary (Deciduous) Dentition

1)Dentition 2) Arch 3) R/L 4) Tooth name Primary Mandibular Right Lateral Incisor

Premolars (bicuspids) First Premolar Second Premolar 32 teeth 3 rd molars

Permanent Maxillary Left First Premolar Dentition Arch R/L Tooth name

Quadrants

Incisors, canines and premolars are all replacement (succedaneous) teeth for the primary teeth.

Permanent Maxillary Left First Premolar

NUMBERING SYSTEMS Universal, Palmer, and International

Universal System Permanent dentition numbered 1-32 Primary dentition uses letters A-T Starts at the patient’s top right, follows across the maxillary arch, drops to lower left then across the mandibular arch Officially adopted by the ADA in 1975

Universal System R L

Universal System RL

Permanent Maxillary Left First Premolar #12

Universal System RL

D Palmer Notation System Numbering begins at the midline A through E for primary dentition 1 through 8 for permanent Quadrant denoted by brackets D

Palmer Notation System

Permanent Maxillary Left First Premolar 4

International (FDI) System aka World Dental Federation or FDI system Similar to Palmer Notation in tooth numbers 1 through 8 starting from midline Uses Quadrant numbers to denote location and dentition Written as: quad# - tooth#

Permanent Maxillary Left First Premolar 2-4

International (FDI) System

GENERAL DENTAL MORPHOLOGY Crown and root surfaces

Four Tissues of a Tooth Cementum Root canal Alveolus / Alveolar bone Gingiva Pulp Dentin Enamel

Landmarks Cementoenamel Junction (CEJ) or Cervical Line

Landmarks Dentinoenamel Junction (DEJ) Cementum Root canal Alveolar bone Gingiva Pulp Dentin Enamel

Tooth Morphology Each tooth is divided into the crown and root

Anatomic vs. Clinical Definitions Anatomic Definitions Crown and root divided by CEJ Anatomic crown Anatomic root

Anatomic vs. Clinical Definitions Clinical Definitions Crown and root divided by the gingival margin Only applies when the tooth is in the mouth and at least partially erupted Clinical crown: visible Clinical root: embedded in the periodontium, i.e. tissues that surround the tooth

Anatomic vs. Clinical Definitions The clinical crown can be longer or shorter than the anatomic crown When would it be shorter?

Root Morphology Teeth usually have one, two or three roots In multi-rooted teeth, the area of division of the roots is the furcation

Root Morphology Two roots – bifurcated A bifurcation is a division into two branches Three roots – trifurcated

Root Morphology Multi-rooted teeth have a root trunk prior to the division and two or more terminal roots

Tooth Surfaces All teeth have five surfaces For posterior teeth, picture a cube sitting on a base Anterior teeth are a little different

Tooth Surfaces The surface opposite the root is named for its function Anterior teeth: Incisal Posterior teeth: Occlusal

Tooth Surfaces Incise – to cut into Occlude – to come into contact with

Tooth Surfaces Two surfaces are named for their position relative to the midline of the face Mesial – closer to the midline Distal – further from the midline Both are referred to as proximal surfaces

Tooth Surfaces The mesial surface of a tooth is normally in contact with the distal surface of the adjacent tooth. When is this not true?

Tooth Surfaces The portion of the proximal surface that touches the adjacent tooth is the contact area or proximal height of contour

Tooth Surfaces If adjacent teeth do not touch, the space between their proximal surfaces is called a diastema

Tooth Surfaces The surface toward the face is the facial surface Labial Buccal

Tooth Surfaces The facial surfaces of the anterior teeth are also called labial surfaces From Latin labia = lips

Tooth Surfaces The facial surfaces of the posterior teeth are also called buccal surfaces Facing the buccinator muscle of the cheek

Tooth Surfaces The surface toward the tongue is the lingual surface From Latin lingua = tongue In the maxillary arch, this can also be referred to as the palatal surface

Division of Teeth Into Thirds: Facial or Lingual View Horizontal Divisions Cervical Middle Incisal (Occlusal) Vertical Divisions Distal Middle Mesial

Division of Teeth Into Thirds: Proximal View Facial (Labial/Buccal) Middle Lingual (Palatal)

Division of Teeth Into Thirds: Root Divisions Apical Middle Cervical

PULP SPACE ANATOMY

Pulp Space Anatomy Collection of nervous, connective, lymphatic, and vascular tissues Resembles the external shape of the tooth Lined with cells (odontoblasts) that produce dentin throughout life

Pulp Space Anatomy The pulp cavity within the anatomical crown is the pulp chamber Pulp horns Roof Floor

Pulp Space Anatomy The opening leading from the pulp chamber into the root canal is the orifice

Pulp Space Anatomy The portion of the pulp cavity within the anatomical root is the root canal Number, location and variation in anatomy of both roots and canal spaces become important Greater variation than in crown

Pulp Space Anatomy The portion of the pulp cavity within the anatomical root is the root canal Accessory canals are small branches off the main canal

Roots: Number and Location Number of roots typically correspond to number of canals There are exceptions to be reviewed later Anterior teeth are single-rooted, usually, therefore have a single canal

Roots: Number and Location Premolars Buccal Lingual

Roots: Number and Location Maxillary Molars Mesiobuccal Distobuccal Palatal

Roots: Number and Location Mandibular Molar Typically two roots, three canals Mesiobuccal Mesiolingual Distal

CORONAL TOPOLOGY Anatomy of the Occlusal/Incisal Surfaces of Teeth

Coronal Topology Lobe – a primary section of formation in the development of a crown (i.e. growth center) All teeth are formed by at least 4 Mandibular First Molar

Coronal Topology Cusp – an elevation or mound on the crown portion of a tooth Makes up a divisional part of the occlusal surface Each cusp of a molar is formed by one lobe Example: Mesiolingual cusp of the mandibular left first molar (#19)

Coronal Topology Developmental Groove – a shallow groove or line between the primary parts of a crown Divides the lobes Example: Mesiobuccal groove

Coronal Topology Ridge – A linear surface elevation named according to its location Triangular Ridges Transverse Ridges Oblique Ridges Marginal Ridges

Coronal Topology Triangular Ridges – Ridges which extend from premolar and molar cusp tips toward the central part of the occlusal surface Named after the cusp to which they belong Example: Buccal cusp Buccal Triangular Ridge

Coronal Topology Transverse Ridges – The union of two triangular ridges transversely crossing the occlusal surface Transverse Ridge

Coronal Topology Oblique Ridges – The union of two ridges obliquely crossing the occlusal surface of a maxillary molar Triangular ridge of the distofacial cusp and the distal ridge of the mesiolingual cusp Oblique Ridge

Coronal Topology Marginal Ridges – Those rounded borders of the enamel which form the mesial and distal margins of: Occlusal surfaces of posterior teeth Lingual surfaces of anterior teeth

Coronal Topology Fossa – an irregular depression or concavity Lingual Fossa Triangular Fossa Central Fossa

Coronal Topology Lingual Fossa – a fossa on the lingual surface of incisors

Coronal Topology Triangular Fossa – a fossa on the occlusal surface of molars and premolars located mesial and distal to triangular ridges

Coronal Topology Central Fossa – a fossa located in the middle of the occlusal surface of molars

Coronal Topology Sulcus – a broad, V-shaped depression or valley running mesiodistally on the occlusal surfaces of posterior teeth; has a developmental groove at the junction of its inclines.

Coronal Topology Groove – A linear depression Developmental Grooves – separate cusps (lobes) Supplemental Grooves – secondary

Coronal Topology Grooves are also named for their location Buccal groove Lingual groove Central groove

Coronal Topology Pit – a small pinpoint depression at the junction of developmental grooves or at terminals of these grooves Central pit Distal pit

Today Facial surfaces of #10 and #12 The mesial surface of #12

Lab FAQ When should I talk to an instructor? Do you feel pretty good about your project and need feedback? Have you been spinning your wheels/working on the same thing for a while? It can be very frustrating in the beginning Instructors are in lab to work with you until 5:00 PM (or 12:00 PM) If you do not catch us by the end of one session, do so at the beginning of the next.

Lab FAQ What if I do not finish a project in the allotted time? This is to be expected, especially early on Everyone learns at different rates Some of you may need more practice time outside of class than others