PEDODONTICS 1-4 Dr. Abdullah Abumoamar

Morphology of Deciduous Teeth

Morphology of Deciduous Teeth Studying tooth morphology includes understanding the shape, configuration and parts of a tooth. It is very important for clinical application during performing various procedures. Cavity preparations must conform to the thickness of enamel and dentin .

Morphology of Deciduous Teeth Keeping in mind the location and size of the pulp. Restoration of natural contours and morphology of deciduous teeth is needed for function, which can be achieved only with a good knowledge of tooth morphology

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Crown 1- The crown of the deciduous tooth is shorter than the permanent tooth. 2- The occlusal table of a deciduous tooth is narrower labiolingually than is the permanent tooth. 3- The deciduous tooth is constricted in the cervical portion of the crown

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH 4- The enamel and dentin layers are thinner in the deciduous tooth. 5- The contact areas between the deciduous molars are very broad and flat. 6- The color of the deciduous tooth is lighter than permanent teeth. The refractive index of milk is similar to deciduous tooth enamel. Hence the teeth are termed as milk tooth.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH 7- There is a cervical ridge on both labial and lingual surfaces of deciduous anterior teeth, as well as on the buccal surface of deciduous posterior teeth. This ridge is normally much more prominent than any analogous structure found on permanent molars.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH 8- The enamel rods in the gingival third extend in a slightly occlusal direction from the dentinoenamel junction in deciduous teeth but extend slightly apically in the permanent dentition.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Pulp 1- The pulp of the deciduous tooth is larger than that of the permanent tooth in relation to the crown size. 2- The pulp horns of the deciduous tooth (especially the mesial horns) are closer to the outer surface of the tooth than are those of the permanent tooth.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Pulp 3 - The mandibular molar has larger pulp chambers than does the maxillary molar in the deciduous tooth. 4- The form of the pulp chamber of the deciduous tooth follows the surface of the crown. 5- Usually there is a pulp horn under each cusp .

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Pulp 6- Thin and slender roots pulp canals 7- Accessory canals extend from floor of the pulpal chamber to the furcation or interradicular area. 8- Increased blood supply.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Pulp 9- Responds by inflammatory process, resulting in increased internal resorption 10- Reduced sensitivity to pain due to less number of nerve fibers. 11- Increased reparative dentin formation.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Pulp 12- Poor localization of infection and inflammation. 13- Multiple ramification, making complete debridement impossible.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Root 1- The root of the deciduous anterior tooth is narrower mesiodistally than is that of the permanent anterior tooth. 2- The roots of the posterior deciduous tooth are longer and more slender in relation to crown size than are those of the permanent tooth.

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Features of a Deciduous Root 3- The roots of the deciduous molar flare more as they approach the apex (which affords the necessary room for the development of the permanent tooth buds) than do the permanent molar roots

DIFFERENCES BETWEEN A DECIDUOUS TOOTH AND A PERMANENT TOOTH Numbering Systems:

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Central Incisor: Eruption Labiolingual Mesiodistal Root Length of Crown 8 M 5 6.5 10 6 Deciduous 7-8 Y 7 8.5 13 10.5 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Central Incisor: is similar in many respects to its permanent successor. It has the same arch position, function, and relative shape. In addition to the previously elicited general differences, there are two major specific contrasts to the permanent maxillary central.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Central Incisor: First, there are no mamelons in newly erupted teeth. Second, this is the only anterior tooth of either dentition, in which the mesiodistal crown width is normally greater than the incisocervical crown height

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH The contact points with adjacent teeth are broad, extending from the incisal one-third to the gingival one-third. Anatomy of the pulp: The central incisor has two or three small projections (pulp horns) toward the incisal edge. The mesial pulp horn is most prominent. The pulp horn is approximately 2.3-2.4 mm from the incisal edge about 1.2 mm from the dentinoenamel junction (DEJ).

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Lateral Incisor: Eruption Labiolingual Mesiodistal Root Length of Crown 9 M 4 5.1 11.4 5.6 Deciduous 8-9 6 6.5 13 9 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Lateral Incisor: This tooth similar to the central incisor only the following differences will be pointed out: 1- The deciduous lateral incisor is smaller than the central in all dimensions. However, unlike the central, the crown of the lateral incisor is wider incisocervically than mesiodistally.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Lateral Incisor: 2- Both incisal angles display greater rounding, with the distoincisal angle more so than the mesioincisal. 3- The marginal ridges on the lingual surface are more prominent, deeper lingual fossa. 4- The root outlines are similar, but the lateral's root is relatively longer, and its apex is not so rounded.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Lateral Incisor: -The pulp chamber is smaller and is about 2.6 mm from the incisal edge . - approximately 0.9 mm from the DEJ.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular central incisor Eruption Labiolingual Mesiodistal Root Length of Crown 6 M 4 4.2 9 5 Deciduous 6-7 6 12.5 9.5 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular central incisors These teeth are the first to erupt into the oral cavity The mandibular central incisor is almost flat when viewed from the labial aspect. There are no developmental grooves or mamelons The root is long and cylindrical.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Anatomy of the pulp: The pulp canal follows the outline form of the surface topography of the primary mandibular central The pulp is approximately 2.6 mm from the incisal edge in the primary central incisor.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Lateral Incisors Eruption Labiolingual Mesiodistal Root Length of Crown 10 M 4 4.1 10 5.2 Deciduous 7-8 6.5 5.5 14 9.5 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Lateral Incisors - Anatomy of the pulp: The pulp canal follows the outline form of the surface topography of the primary mandibular lateral incisors. - The pulp of the mandibular lateral incisor has similar dimensions but is somewhat smaller.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary Canines Eruption Labiolingual Mesiodistal Root Length of Crown 16 M 7 13.5 6.5 Deciduous 11-12 8 7.5 17 10 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary Canines - The crown is quite wide mesiodistally, Before wear, the cusp tip is relatively more prominent than that of the permanent tooth. - The mesioincisal slope is normally longer than the distoincisal slope, especially after attrition.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary Canines - Normally, no developmental depressions or imbrication lines are present. The cingulum is quite prominent, as are the lingual ridge and marginal ridges. - Normally, ML and DL fossae are present

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary Canines - Root : From all aspects, the root is similar to the deciduous maxillary incisor roots, except that it is longer. Anatomy of the pulp: The pulp chamber follows the general contour of the tooth. The pulp horn is 3.2 mm from the cuspal tip.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary Canines

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Primary Canines : Eruption Labiolingual Mesiodistal Root Length of Crown 17 M 4.8 5 11.5 6 Deciduous 9-10 7.5 7 16 11 Permanent

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Primary Canines : Resembles the deciduous maxillary canine, but its relative dimensions are somewhat different. The mandibular canine is narrower labiolingually The mesiodistal width of the mandibular canine is also considerably less than that of the maxillary canine.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Primary Canines : The distoincisal slope is longer on the mandibular canine, whereas on the maxillary canine it is the mesioincisal slope which is longer. The cingulum, marginal ridges, and cervical ridges are less pronounced on the crown of the mandibular canine. The mandibular canine root is shorter.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Mandibular Primary Canines :

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars : Eruption Labiolingual Mesiodistal Root Length of Crown 13 M 8.5 7.3 10 5.1 Deciduous 10-11 1th premolar

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars : - The primary maxillary first molar resembles a molar and a premolar. - The occlusal surface consists of three cusps, one each on the mesiobuccal and distobuccal surfaces and one on the lingual surface. This gives the tooth a square look.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars : - Some the occlusal surface consists of four cusps but distolingual cusp is not prominent . Mesiodistal – buccolingual . - CEJ : buccal – lingual

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars : -There is transverse ridge - There is oblique ridge - Fossae : mesial – distal – central - Pits : mesial – distal – central - grooves : central – buccal – disto-occlusal

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars : There is a very prominent buccal cervical ridge. Anatomy of the pulp: The pulp horns correspond to each cusp; the mesiobuccal pulp horn is the most prominent. The mesiobuccal pulp horn is 1.8 mm, The distobuccal pulp horn is 2.3 mm, The palatal pulp horn is 2.0 mm from the cusp tip.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Primary First Molars

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molars : Eruption Labiolingual Mesiodistal Root Length of Crown 25 M 10 8.2 11.7 5.7 Deciduous 10-12 2ed premolar 6-7 11 12 13 7.5 Permanent 1th molar

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molars : The primary second molars are the last primary teeth to erupt The primary maxillary second molar resembles the permanent maxillary first molar in appearance but is smaller. The tooth is rhomboidal. There are four cusps, two on the buccal and two on the lingual aspects.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molars Often there is a fifth cusp or prominence, called as the tubercle of Carabelli on the palatal surface of the mesiopalatal cusp. A prominent transverse or oblique ridge connects the distolingual cusp with the mesiopalatal cusp. There are three roots that are curved to accommodate the developing tooth bud beneath. The enamel is usually 1.2 mm thick uniformly on the tooth.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molars Anatomy of the pulp: There may be four or five pulp horns, which usually are most prominent beneath each cusp tip. The mesiobuccal pulp horn, as usual, is the largest and closest to the DEJ. The mesiobuccal pulp horn is usually 2.8 mm from the DEJ, while the distobuccal horn is 3.1 mm from the DEJ.

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molars : Eruption Labiolingual Mesiodistal Root Length of Crown 25 M 10 8.2 11.7 5.7 Deciduous 10-12 2ed premolar 6-7 11 12 13 7.5 Permanent 1th molar

MORPHOLOGY OF INDIVIDUAL DECIDUOUS TEETH Maxillary Second Molar

Mandibular Primary First Molar Eruption Labiolingual Mesiodistal Root Length of Crown 14 M 7 7.7 9.8 6 Deciduous 10-12 1th premolar

Mandibular Primary First Molar -This tooth has a crown unlike any other primary or permanent tooth. -Its crown is wider mesiodistally than buccolingually, as is characteristic of all mandibular molars of both dentitions

Mandibular Primary First Molar Buccal aspect -The mesial outline is straight occlusogingivally for most of its length -The distal outline is convex -The occlusal outline reveals two buccal cusps, of which the MB cusp is much larger.

Mandibular Primary First Molar - There is a depression separating the two buccal cusp outlines, but rarely does the buccal groove extend onto the buccal surface in the depression. - The cervical line is deeper, and offset toward the mesial, just like it is on the deciduous maxillary first molar. - The cervical ridge is also quite prominent, especially in the mesial portion

Mandibular Primary First Molar Lingual aspect : The lingual surface is shorter occlusocervically than the buccal surface. It is also smooth and convex, lacks any depressions or ridges. The mesial and distal margins are similar to those of the buccal aspect

Mandibular Primary First Molar Lingual aspect The cervical outline is rather straight, unlike the buccal aspect. The occlusal outline shows two lingual cusps, of which the ML cusp is larger and sharper. Portions of the two buccal cusps can also be seen

Mandibular Primary First Molar Mesial aspect The cervical ridge representing the crest of curvature in the gingival third of the buccal outline. Both mesial cusps are visible. The contact area is located near the junction of the occlusal and middle thirds

Mandibular Primary First Molar Mesial aspect The cervical line is located farther cervically on the buccal, and extends to a more occlusal level at the lingual.

Mandibular Primary First Molar Distal aspect All four cusps can be seen from this aspect The distal marginal ridge is much less prominent than the mesial, and is located at a more cervical level. The cervical line is relatively straight, and located at the same level on both the buccal and lingual

Mandibular Primary First Molar Occlusal aspect The general shape of the occlusal table is somewhat rectangular Typical of mandibular molars, the crown is wider mesiodistally.

Mandibular Primary First Molar Occlusal aspect Cusps - The four cusps, from largest to smallest in size, are the MB, ML, DB, DL. Actually, the two mesial cusps are considerably larger than the distal cusps

Mandibular Primary First Molar Occlusal aspect Transverse ridge - The buccal cusp ridge of the ML cusp and the lingual cusp ridge of the MB cusp form a prominent transverse ridge.

Mandibular Primary First Molar Fossae : central fossa, and mesial and distal triangular fossae Pits : only two pits Grooves : C – B - L

Mandibular Primary First Molar Roots : The mesial and distal roots have a location similar to those of permanent mandibular molars. Both roots are widest buccolingually but the mesial root is longer and much wider than the distal root. The apex of the mesial root is normally flat,

Mandibular Primary First Molar

Mandibular Second Molar: Disregarding size, and the general differences between deciduous and permanent molars, this tooth so closely resembles the permanent mandibular first molar, that it will not be necessary to describe it in detail. Major differences include the following: - The MB, DB, and distal cusps are more nearly equal in size on the deciduous tooth.

Mandibular Second Molar: • The primary mandibular second molar resembles a permanent mandibular first molar. • There are five cusps, three on the buccal surface and two on the lingual. • The enamel is uniformly 1.2 mm thick. • There are two roots which are narrow mesiodistally but very broad buccolingually. • The roots are somewhat curved to accommodate the developing tooth bud.

Mandibular Second Molar: • Anatomy of the pulp: There are five pulp horns corresponding to the five cusp tips. The mesiobuccal pulp horn is the largest, extending 2.8 mm from the DEJ, while the distobuccal pulp horn is 3.1 mm from the dentinoenamel junction.

Mandibular Second Molar: Eruption Labiolingual Mesiodistal Root Length of Crown 23 M 8.7 9.9 11.3 5.5 Deciduous 11-12 2ed premolar 6-7 10.5 11 14 7.5 Permanent 1th molar

Mandibular Second Molar:

thank you