The Primary (Deciduous) Dentition PDF

The Primary (Deciduous) Dentition Faye Marie Bana-Evaristo, DMD, MS, FPFA  Lesson 1 Importance of primary teeth Lesson 2 Major contrasts between primary and permanent teeth Lesson 3 Description of P...

The Primary (Deciduous) Dentition Faye Marie Bana-Evaristo, DMD, MS, FPFA  Lesson 1 Importance of primary teeth Lesson 2 Major contrasts between primary and permanent teeth Lesson 3 Description of Primary teeth Importance of primary teeth Nomenclature: Primary teeth; Baby’s teeth; Milk teeth; Temporary teeth Implies that they are useful for a short period * needed for many years of growth and physical development Importance of primary teeth FUNCTIONS (IMPORTANCE) ○ Needed for efficient mastication of food ○ Provide support for cheeks and lips maintaining a normal facial appearance and smile ○ Necessary for formulation of clear speech ○ Critical for maintaining space and arch continuity required to provide room for the eruption of permanent teeth. (normal occlusion)  Lesson 2 Major contrasts between primary and permanent teeth Major contrasts between primary and permanent teeth PRIMARY TEETH: Are smaller in overall size and crown dimensions. Have markedly more prominent cervical ridges (BCR). Are narrower at their “necks” Are lighter in color Have roots that are widely flared Buccolingual diameter is less in dimension. Major contrasts between primary and permanent teeth Crowns of primary anterior teeth are wider mesiodistally than their crown length. Cervical ridges of enamel of anterior teeth are more prominent.. Roots of primary anterior teeth are narrower and longer. ○ Narrow roots with wide crowns present an arrangement at the cervical 3rd that differs markedly from permanent anterior teeth. Major contrasts between primary and permanent teeth Buccal and lingual surfaces of primary molars are flatter above the cervical curvatures, narrower oclusal surfaces. Cervical ridges buccally (BCR) of primary molars are more pronounced ( 1st molars) Crowns and roots of primary molars at cervix are more slender mesiodistally. Major contrasts between primary and permanent teeth Roots are longer and more slender and flare more, extending out beyond projected outline of the crowns. The flare allows more room between the roots for the developing permanent crowns. Primary teeth are usually less pigmented and are whiter in appearance. Major contrasts between primary and permanent teeth Pulp Chambers and Pulp Canals: Enamel is relatively thin and has a consistent depth. Dentin thickness between pulp chambers and enamel is limited. Major contrasts between primary and permanent teeth Pulp Chambers and Pulp Canals: Pulp horns are high, pulp chambers are large than permanent teeth. Primary roots are narrow and longer than crown width and length Molar roots of primary teeth flare markedly and thin out rapidly as the apices are approached  Lesson 3 Description of Primary teeth Primary Max. Central Incisor Primary Max. Central Incisor M-D is greater than cervico-incisal length Root length greater than crown length Highly developed cingulum extending toward incisal edge creating mesial & distal fossa. Cervical ridges well-developed at cervical 3rd of crown labial & lingual Primary Max. Lateral Incisor Primary Max. Lateral Incisor Cervico-incisal length greater than mesiodistal Cervical ridges well-developed at cervical 3rd of crown labial & lingual Root is much longer in proportion to its crown Primary Mandibular Central Incisor Primary Mandibular Central Incisor MMR,DMR,cingulum are well-developed Cervical contours more pronounced Primary Mandibular Lateral Incisor Primary Mandibular Lateral Incisor Cingulum well-developed Surface between MRs is concave Well-developed cervical ridges Primary Maxillary Canine Primary Maxillary Canine Crown constricted at cervix Long, well-developed sharp cusp ○ Mesial slope longer Lingual ridge connects cingulum to cusp tip Root long, slender, tapering, more than twice the crown length Primary Mandibular Canine Primary Mandibular Canine Crown and root shorter than max canine “thicker” at the neck Less pronounced cervical ridges (Labial & Lingual) Primary Maxillary First Molar Primary Maxillary First Molar -Smooth buccal surface with little or no evidence of dev’tal grooves Pronounced BCR -Occlusal outline slightly scalloped, no definite cusp form Shape and size suggest that it was designed to be the “premolar Primary Maxillary First Molar Roots are slender and long, spread widely Tri-rooted, bifurcations begins immediately at the CEJ (typical for dec. molars) Primary Maxillary First Molar Occlusal Aspect “Form varies from that of any tooth in the permanent dentition” OCCLUSAL ANATOMY Cusps= ML (longest), MB, DB, DL (small and rounded) Ridge – cusp ridges, triangular ridges, MRs ○ Oblique ridge (MLTR+DBTR) Primary Maxillary First Molar Occlusal Aspect OCCLUSAL ANATOMY Grooves: CDG, BDG, distal dev’tal groove Fossa – central fossa, MTF and DTF, Pits - central pit, MP, DP, -resembles max 1st premolar Primary Maxillary Second Molar Primary Maxillary Second Molar resembles permanent max 1 st molar but smaller crown larger than primary 1 st molar -crown narrow at cervix Primary Maxillary Second Molar MBc & DBc (equal size) with BDG Cusp of Carabelli – poorly developed, traces of dev’tal lines / dimples Roots longer, slender, bifurcation closer to CEJ Primary Maxillary Second Molar Occlusal Aspect -resembles permanent max. molar but is smaller -larger than deciduous first molar Crown is rhomboidal Primary Maxillary Second Molar Occlusal Aspect OCCLUSAL ANATOMY Cusp : MLc, MBc, DLc, DBc 5th Cusp Ridges: Cusp ridges Triangular ridges MMR, DMR Oblique ridge Primary Maxillary Second Molar Occlusal Aspect OCCLUSAL ANATOMY Grooves: CDG, BDG, LDG, DDG, Supplementary gr. Fossa: CF, DF, MTF, DTF Pit: CP, MDP, DDP Primary Mandibular First Molar Primary Mandibular First Molar Varies so much, do not resemble any tooth, deciduous or permanent Appears strange & primitive Primary Mandibular First Molar Crown constricted a little at cervix Distal portion of crown shorter than mesial. Two buccal cusp, no groove. Primary Mandibular First Molar Mesial portion of crown is almost twice as tall as the distal Crown and root converge markedly towards MMR- well-developed, almost considered as small cusp. Primary Mandibular First Molar Extreme curvature buccally at cervical 3rd- BCR (pronounced) Flat buccal outline above BCR MMR IS WELL-DEVELOPED Primary Mandibular First Molar Occlusal line is rhomboidal OCCLUSAL ANATOMY Cusp: MLc –largest, best developed MBc; DLc ‘ DBc Ridges: cusp ridges MMR, DMR triangular ridges Primary Mandibular First Molar OCCLUSAL ANATOMY Grooves: CDG; BDG; LDG supplementary gr. Fossa: CF; MTF; DTF Pit: CP, MP, DP Primary Mandibular Second Molar Primary Mandibular Second Molar Resembles permanent mand 1st molar. Crown is constricted at cervix. Primary Mandibular Second Molar Present 3 cusps of almost equal in size (MBc; DBc; Distal cusp) Two buccal grooves: MBDG , DBDG Primary Mandibular Second Molar Roots are twice as long as crown. Bifurcation is very close to cervix Flattened buccal surface above BCR Constricted occlusal table Primary Mandibular Second Molar Occlusal outline somewhat rectangular. Resembles perm. Mand 1st molar OCCLUSAL ANATOMY Cusps: MBc, DBc, Dc = equal size MLc, DLc = equal size Ridges: cusp ridges MMR, DMR triangular ridges Primary Mandibular Second Molar OCCLUSAL ANATOMY Grooves: CDG, MBDG DBDG , LDG supplementary gr. Fossa: CF , MTF , DTF Pit: CP, MDP, DDP Thank you! Quiz Next Meeting