DEVELOPMENTAL DISTURBANCES OF TEETH

Dr. Saleem Shaikh

DEVELOPMENTAL DISTURBANCES IN STRUCTURE OF TEETH Enamel hypoplasia Dentinogenesis imperfecta Dentin dysplasia Regional odontogenic dysplasia

ENAMEL HYPOPLASIA ENAMEL HYPOPLASIA

Defect of enamel due to disturbance during its formative process

Ameloblasts are among the most sensitive cells in the body

During the formative stages of enamel the ameloblast cells are susceptible to various factors which can disturb the process and the effect of which are reflected on the surface enamel after the eruption of tooth

Types

Based on causative factors:

Enamel hypoplasia Enamel hypoplasia

Hereditary (Amelogenesis Imperfecta)

Environmental

Focal(Turners hypoplasia)

Generalized

Differences between hereditary & environmental enamel hypoplasiaDifferences between hereditary & environmental enamel hypoplasia

Hereditary 1. Both dentition

affected

2. Only enamel is affected

3. Affected tooth shows diffuse or vertical orientation of defects

Environmental1. Either one

dentition affected

2. Affects enamel and other calcified structures

3. Affected tooth shows defect which is horizontally arranged

Hereditary enamel hypoplasia Amelogenesis imperfecta Hereditary enamel hypoplasia Amelogenesis imperfecta

Hereditary enamel dysplasia; Hereditary brown enamel; Hereditary brown opalescent tooth

It is a heterogenous group of hereditary disorders of enamel formation Entirely an ectodermal disturbance. The condition involves only the enamel while dentin, cementum & pulp remain normal

3 types 1. Hypoplastic type - Defective matrix deposition 2. Hypocalcification type – Defective calcification3. Hypomaturation type- Defective maturation

Classification

1. Hypoplastic type Generalized Pitted, autosomal dominantLocalized Pitted, autosomal dominant Localized Pitted, autosomal recessiveDiffuse Smooth, autosomal dominantDiffuse Smooth, X-linked dominantDiffuse Rough, autosomal dominantEnamel agenesis autosomal recessive 2. Hypomaturation type

Diffuse pigmented, autosomal recessive

Diffuse, X-linked recessiveSnow capped, X-linkedSnow capped, autosomal dominant

3. Hypocalcification type Diffuse,Autosomal dominantDiffuse,Autosomal recessive

Hypoplastic type Hypoplastic type

The disease affects the stage of matrix formation Teeth exhibit complete absence of enamel or there may be

presence of enamel on some focal areas Enamel thickness is usually below normal Quantity is affected, but quality of formed enamel is normal Tooth appears as though prepared for receiving a prosthetic

crownRadiographic features -

Enamel may appear totally absent or as a thin lineRadiodensity of affected enamel is similar to that of normal enamel (greater than dentin)

Hypocalcification type Hypocalcification type

The disease affects the stage of early mineralization Enamel is of normal thickness(quantity not affected) Tooth is normal in shape on eruption, but the enamel is lost

very easily Enamel is soft & can be easily removed with a blunt

instrument Enamel is yellowish brown on eruption

Radiodensity of affected enamel is lesser than that of normal enamel and is equivalent to normal dentin

Hypomaturation type Hypomaturation type

The disease affects the stage of maturation Enamel is of normal thickness (quantity not affected) Teeth are normal in shape but enamel is opaque white or

brownish in colour Enamel does not have normal hardness & translucency and

tend to chip off easily It Can be pierced with an explorer tip with firm pressure Snow capped teeth - It is the mildest form of

hypomaturation type of amelogenesis imperfecta. The enamel is of near normal hardness & has a zone of

white opaque enamel on the incisal or occlusal one quarter to one third of crown.

Demonstrates an anterior to posterior distribution and have been compared to a denture dipped in white paint

Radiodensity of affected enamel is much lesser than that of normal enamel

Environmental enamel hypoplasiaEnvironmental enamel hypoplasia

FOCAL ENAMEL HYPOPLASIA; Also known as Turner’s hypoplasia;

Most common form of enamel hypoplasia

Occurs due to trauma or infection to deciduous teeth

Usually affects single tooth & is called as Turners tooth

Hypoplasia ranges from a mild, brownish discolouration to a severe pitting of enamel surface on the labial aspect

Frequently involved teeth are permanent maxillary/mandibular bicuspids & maxillary incisors

Severity of hypoplasia depends on severity of infection,

degree of tissue involvement and stage of tooth formation

Pathogenesis Pathogenesis

Deciduous teeth

Trauma Periapical Infection

Affect the ameloblastic layer of permanent tooth

Disturb the enamel formation

Enamel defects

Generalized Enamel Hypoplasia Generalized Enamel Hypoplasia

The ameloblasts in the developing tooth germ are sensitive to external stimuli

Any systemic or environmental disturbance can result in abnormalities in enamel formation which manifests as defects on the surface of tooth

It affects numerous teeth which are being formed at the time of disturbance

Clinically the defects can manifests as

1. Hypoplasia

2. Diffuse opacities

3. Demarcated opacities Most often it manifests as a horizontal line of enamel

hypoplasia with pits & grooves CHRONOLOGIC HYPOPLASIA -

The line on the tooth surface indicates the zone of enamel hypoplasia

The location of the line corresponds with the developmental stage of affected tooth & width indicates the duration of the disturbances

Causes Causes

PrenatalInfections (Rubella, Syphilis)Malnutrition, Metabolic & Neurological disorders during

pregnancy Chromosomal abnormalities Excess chemical intake (Tetracycline, Fluoride)

Neonatal Birth injury Premature delivery Prolonged laborLow birth weight

Postnatal Severe childhood infections (Viral exanthematous fever)Congenital heart diseases Nutritional deficiencies (Vit-B, Vit-D)Endocrinal disorders

Enamel hypoplasia due to nutritional deficiency and exanthematous fevers

Enamel hypoplasia due to nutritional deficiency and exanthematous fevers

Serious nutritional deficiency is potentially capable of producing enamel hypoplasiaThe teeth that form within the first year after birth are affected.Teeth most frequently affected are central & lateral incisors, cuspids and first molars.Premolars, 2nd & 3rd molars are rarely affected, since their formation does not begin until the age of 3 or laterPresents as pitting of the tooth surface

Enamel hypoplasia due to congenital syphilisEnamel hypoplasia due to congenital syphilis

Hypoplasia is not of pitted variety Involves the permanent maxillary & mandibular incisors and 1st

molars Anterior teeth are referred to as Hutchinson’s incisors and

posterior teeth are referred to as mulberry molars. Characteristically, the upper central is screw driver shaped,

the mesial and distal surfaces tapering and converging towards the incisal edge.

Incisal edge is usually notched. Middle lobe of tooth is affected The crowns of first molars are irregular & constricted, and the

enamel of the occlusal surface and occlusal third of tooth appears to be arranged in an agglomerate mass of globules rather that well formed cusps.

Resembles a mulberry, hence the name mulberry molars

Enamel hypoplasia due to fluorideEnamel hypoplasia due to fluoride

Excess amounts of fluoride can result in enamel defect known as dental fluorosis./ mottled enamel

The severity increases with an increase in amount of fluoride in the water.

The optimum range of fluoride in drinking water is 0.7 -1.2 ppm

Increased levels of fluoride interferes with calcification process of the enamel matrix leading to the formation of hypomineralized enamel

These alterations results in an increased surface and subsurface porosity of the enamel which alters the light reflection and creates the appearance of white chalky areas which later gets stained

Clinical featuresClinical features

Affected teeth are caries resistant Wide range of manifestations depending on fluoride levels Grading

Questionable changes White flecking or spotting of enamel

Mild changes White opaque areas involving more of tooth surface

areas Moderate and severe changes

Pitting and brownish staining of surface Corroded appearance

Mild cases- Bleaching of teeth Severe cases- Prosthetic crowns

Dentinogenesis Imperfecta Dentinogenesis Imperfecta

A hereditary defect of dentin in the absence of any systemic disorder, consisting of opalescent teeth composed of irregularly formed and undermineralized dentin that obliterates the coronal and root pulpal chambers.

Also known as “Hereditary opalescent dentin”, “Capdepont’s teeth”

Severely affects the deciduous teeth than permanent teeth (Incisors & 1st molars; Least involved teeth- 2nd & 3rd molars)

Teeth exhibits a gray to brownish violet or yellowish brown appearance

Involved teeth exhibits a characteristic unusual translucent or opalescent hue.

Enamel is normal but fractures and chips away easily leads to exposed dentin and functional attrition presumably because of defective DEJ

Teeth are not particularly sensitive & are not caries prone

Type I Associated with osteogenesis imperfecta, blue

sclera        Type II

Not associated with osteogenesis imperfecta unless by

chance  This type is most frequently referred to as

Hereditary opalescent dentin

Most common type    Type III

Brandywine type, racial isolate in Maryland state Same clinical presentation of Type I or II with

multiple pulpal exposures in deciduous dentition

Classification (Shafer)

DENTINOGENESIS IMPERFECTA 1: Dentinogenesis imperfecta without osteogenesis imperfecta (opalescent dentin), this corresponds to dentinogenesis imperfecta type II of Shields classification.

DENTINOGENESIS IMPERFECTA 2: Brandywine type dentinogenesis imperfecta: this corresponds to dentinogenesis imperfecta type III of Shields classification.

  There is no substitute in the present classification for the

category designated as DI Type I of the previous classification (Shield’s ).

Radiological features Radiological features

Exhibit bulb-shaped or bell shaped crowns with constricted CEJ (tulip shaped)

Thin & blunted roots Early obliteration of root canals and pulp chamber Cementum, PDL & bone appears normal Type II exhibits great variability in deciduous teeth, ranging

from normal to those changes of type I Shell teeth

Apparently normal enamel

Extremely thin dentin (may involve entire tooth or isolated to the root)

Enormous pulp chambers (not as a result of resorption, but due to insufficient dentin)

Appear as shells of enamel & dentin surrounding enormous pulp chambers and root canals.

Histopathological features Histopathological features

Enamel & mantle dentin are normal Remaining dentin is severely dysplastic & exhibits vast

areas of inter-globular dentin Dentinal tubules are short, disoriented, irregular & widely

spaced Scanty odontoblasts line the pulp and they can be seen in

the defective dentin Smooth DEJ

Treatment is aimed at preventing excessive tooth attrition & improving esthetics

Metal / Ceramic crowns & over dentures can be given

Dentin dysplasia Dentin dysplasia A hereditary defect characterized by defective dentin

formation & abnormal pulpal morphology Autosomal dominant disorder Type I – Radicular dentin dysplasia

Also known as “Rootless teeth” Type II – Coronal dentin dysplasia

MildSevere

Clinical features Clinical features

Type I Type II

Disturbance in development of radicular dentin

Disturbance in development of coronal dentin

Normal crowns both structurally & morphologically

Semi-transparent opalescent primary

teeth Normal appearance in the permanent teeth

Color of teeth normal with slight bluish translucency in cervical region

Amber – grey color

Early loss of dentin organization results in extremely short rootsLater disorganization results in minimal root changesAffected teeth exhibits short roots, delayed eruption , severe mobility & premature exfoliation

Radiological features Radiological features Type I Type II

Permanent teeth: Features vary on the proportion of organized versus disorganized dentin Early disorganization - extremely short roots with little or no pulpSomewhat Later disorganization - crescent or chevron shaped pulp chambers overlying shortened roots that exhibit no pulp canals Late disorganization – normal pulp chamber with large pup stone

Permanent teeth: Exhibits abnormally large pulp chambers and apical extension described as flame shaped or thistle-tube in shape. Pulp stones present

Deciduous teeth affected severely with little or no detectable pulp

Deciduous teeth shows bulbous crowns, cervical constriction and early obliteration of pulp (Resembles DI)

Periapical radiolucencies around the defective roots

Absence of periapical radiolucencies

Histopathological features Histopathological features

Type I Type II

Normal enamel Normal enamel and radicular dentin with partial obliteration of root canals

Portion of coronal dentin is usually normal and may show tubular dentin apical to itPulp is obliterated by calcified tubular dentin, osteodentin & fused denticles

Near normal coronal dentin with numerous areas of interglobular dentin near the pulp

Normal dentinal tubule formation appears to be blocked so that new dentin forms around obstacles and takes on characteristic appearance described as lava / stream flowing around boulders

Abnormally large pulp chambers with pulp stones

Regional Odontodysplasia Regional Odontodysplasia

It is a uncommon non-hereditary developmental disturbances of tooth characterized by defective formation of enamel & dentin with abnormal calcifications of pulp & follicle

Also known as “Ghost teeth”

Cause - Local ischemic change during odontogenesis Clinical features: More common in permanent dentition More common in maxilla Affects several teeth in a single quadrant Maxillary anterior teeth affected more Failure of eruption or delayed eruption of affected teeth Teeth are deformed, yellowish – brown in color with a soft leathery

surface

Radiological features Radiological features

Marked decrease in radio density of teeth Enamel & dentin are very thin & radiological

distinction not possible Extremely large & open pulp chamber with pulp stones Ghostly appearance of affected teeth

Abnormal enamel & dentin Large pulp chamber with pulp stones Calcification in follicular connective