38. Acquired and developmental disturbances of the teeth shape, position and morphology. Clinical manifestation, diagnosis, prevention, treatment

Question 1

Acquired and developmental disturbances of the teeth

Gemination

Answer 1

• Aka schizodontia
• Developmental anomaly=>single tooth bud divides, into tooth w/ bifid crown and common root
• Primary and permanent dentitions affected
• Prevalence in maxillary anterior region
• Trauma suggested as possible cause, but exact etiology unknown
• Tooth larger than normal w/ notched or clefted crown
• Diagnosis=>
• Radiographic Features:
• Enlarged, notched crown
• Two pulp chambers
• Single root and pulp canal

Question 2

Acquired and developmental disturbances of the teeth

Fusion (synodontia)

Answer 2

• Aka synodontia
• Two normally separated tooth buds unite, forming single large tooth
• Can involve entire length of teeth or just roots, where dentine and cementum shared
• Affected tooth larger than usual, and tooth count reveals missing tooth
• Frequently in mandibular region and can be associated w/ conditions like thalidomide-induced embryopathy
• Diagnosis=>
• Radiographic Features:
• Two pulp chambers
• Two root canals

Question 3

Acquired and developmental disturbances of the teeth

Taurodontism

Answer 3

• Elongated crown and an apically displaced furcation=>
• Pulp chambers w/ increased apical-occlusal height
• May be seen as isolated incidents within families or associated w/ syndromes such as Down syndrome and Klinefelter’s syndrome
• Diagnosis=>
• Radiographic Features:
• Elongated crowns
• Apically displaced furcation
• Treatment=>
• Generally, no treatment required unless associated w/ other dental conditions

Question 4

Acquired and developmental disturbances of the teeth

Dens evaginatus

Answer 4

• Aka Talon’s cusp
• Well-delineated additional cusp forms on surface of anterior tooth=>
• Extends at least halfway from cementoenamel junction (CEJ) to incisal edge
• Additional cusp may interfere w/ occlusion
• Treatment=>
• If occlusion affected, additional cusp removed

Question 5

Acquired and developmental disturbances of the teeth

Dens invaginatus

Answer 5

• Aka dens in dente
• Deep surface invagination of crown or root that is lined w/ enamel
• Types=>
• Type I: Confined to crown
• Type II: Extends below CEJ and ends in blind sac, which may or may not communicate w/ adjacent pulp
• Type III: Extends through root and perforates apical area without immediate communication w/ pulp
• Depth of invagination varies, ranging from slight enlargement of cingulum to deep infolding extending to apex
• Treatment=>
• Type I: Restoration of invagination to prevent caries
• Type II: Temporary placement of calcium hydroxide (Ca(OH)₂) w/ endodontic treatment
• Type III: Closure of openings before pulpal necrosis occurs

Question 6

Acquired and developmental disturbances of the teeth

Hutchinson’s incisors and Mulberry molars

Answer 6

• Dental anomalies associated w/ congenital syphilis
• Hutchinson’s Incisors=>
• Peg-shaped or screwdriver-shaped lateral incisors
• Widely spaced, w/ notched biting surfaces and crescent-shaped deformities
• Mulberry Molars=>
• First permanent molar presents multiple rounded rudimentary enamel cusps=>
• “Mulberry” appearance

Question 7

Acquired and developmental disturbances of the teeth

Concrescence

Answer 7

• Union of two teeth by cementum without confluence of dentin
• Often in posterior maxillary region, especially involving second molar and adjacent impacted third molar
• Classification=>
• True Concrescence: Developmental origin
• Acquired Concrescence: Occurs after tooth development
• Diagnosis=>
• Radiographic Features:
• Cementum of two adjacent teeth appears fused
• Often, no treatment required unless union interferes w/ tooth eruption=>
• Surgical removal

Question 8

Acquired and developmental disturbances of the teeth

Enamel pearls

Answer 8

• Ectopic droplets of enamel that occasionally form on roots=>
• Particularly in bifurcation or trifurcation areas, w/ maxillary molars more commonly
• Minor abnormalities=>nodule of enamel attached to dentine, sometimes containing a pulp horn
• Diagnosis=>
• Visual and Radiographic Features:
• Enamel pearls small, round radiopacities on radiographs
• Treatment=>
• Flattening or removal of enamel pearl if poses risk for plaque accumulation and periodontal disease
• Good oral hygiene essential in affected area

Question 9

Acquired and developmental disturbances of the teeth

Dilaceration

Answer 9

• Abnormal angulation/sharp bend in root or crown
• Etiology=>
• Trauma to developing tooth common cause=>
• Root forms at angle
• In some cases, hereditary factors may be involved
• Angulation may cause complications in tooth eruption or endodontic treatment
• Diagnosis=>
• Radiographic Features:
• A pronounced curve or angulation in tooth root observed.
• Treatment=>
• Often not required unless dilaceration interferes w/ tooth function or alignment

Question 10

Acquired and developmental disturbances of the teeth

Amelogenesis imperfecta and its different types

Answer 10

• Group of conditions caused by defects in genes encoding enamel matrix proteins=>
• Amelogenin and enamelin
• Primary and permanent dentitions
• Types=>
• Hypoplasia
• Hypomaturation
• Hypocalcification
• Treatment=>
• Cosmetic management, such as improving appearance of teeth

Question 11

Acquired and developmental disturbances of the teeth

Amelogenesis imperfecta-Hypomaturation

Answer 11

• Enamel appears normal in form on eruption=>
• Opaque, white to brown-yellow
• Softer than normal
• Radiographic Features=>
• Radiodensity similar to dentine

Question 12

Acquired and developmental disturbances of the teeth

Amelogenesis imperfecta- Hypoplasia

Answer 12

• Inadequate formation of enamel matrix
• Randomly pitted, grooved, thin, translucent enamel
• Radiographic Features=>
• Enamel appears reduced in bulk, w/ thin layer over occlusal and interproximal surfaces=>
• Normal dentine and pulp chambers

Question 13

Acquired and developmental disturbances of the teeth

Amelogenesis imperfecta-Hypocalcification

Answer 13

• Enamel matrix formed in normal quantity but poorly calcified=>
• Weak, chalky, easily worn enamel
• Radiographic Features=>
• Enamel and dentin w/ similar radiodensities

Question 14

Acquired and developmental disturbances of the teeth

Dentinogenesis imperfecta

Answer 14

• Aka hereditary opalescent dentin
• Genetic disorder caused by mutations in dentine sialophosphoprotein (DSPP) gene
• Primary and permanent dentitions
• Abnormal dentine formation, leading to discolored and fragile teeth
• Teeth exhibit blue-brown discoloration w/ distinctive opalescent translucency
• Enamel tends to separate easily from underlying defective dentin, leading to rapid wear
• Radiographic Features=>
• Bulbous crowns
• Cervical constriction
• Thin roots
• Early obliteration of root canals and pulp chambers
• Type I-III

Question 15

Acquired and developmental disturbances of the teeth

Dentinogenesis imperfecta classification

Answer 15

• Classification
• Type I=>
• In association with osteogenesis imperfecta
• Primary teeth more severely affected
• Radiographically, partial or total obliteration of pulp chambers and root canals, roots may be short and blunted
• Type II=>
• Does not occur in association w/ osteogenesis imperfecta
• Teeth present only dentin abnormalities without bone disease
• Radiographically similar to Type I
• Type III=>
• “Brandywine type,” primarily seen in racial isolate in Maryland
• Multiple pulp exposures common in deciduous teeth=>
• Not seen in Types I and II
• Radiographically, large pulp chambers, and enamel appears normal

Question 16

Acquired and developmental disturbances of the teeth

Dentinogenesis imperfecta Treatment

Answer 16

• Preventing loss of enamel and subsequent dentin through attrition crucial
• For posterior teeth, cast metal crowns recommended
• For anterior teeth, jacket crowns placed to improve aesthetics and protect underlying dentin

Question 17

Acquired and developmental disturbances of the teeth

Dentin dysplasia

Answer 17

• Rare genetic disorder aka “rootless teeth,”
• Abnormal dentin formation, leading to malformed roots and pulp morphology
• Type I (Radicular Type)=>
• Primary and permanent dentitions normal in color
• Premature tooth loss due to short roots or periapical inflammatory lesions
• Radiographic Features=>
• Extremely short roots
• Almost complete obliteration of pulp chambers
• Periapical radiolucencies, including granulomas, cysts, and chronic abscesses
• Type II (Coronal Type)=>
• Primary dentition may appear opalescent, while permanent dentition typically normal color
• Radiographic Features:
• Deciduous Teeth: Extremely short roots and almost complete obliteration of pulp chambers
• Permanent Teeth: Abnormally large pulp chambers in coronal portion of tooth=>
• Often filled w/ globules of abnormal dentin
• Treatment=>
• Preventing complications related to short roots and ensuring integrity of the teeth, especially in Type I

Question 18

Acquired and developmental disturbances of the teeth

Regional odontodysplasia

Answer 18

• Aka “ghost teeth”
• Affects structure and formation of enamel and dentin in one or several teeth
• Usually localized to specific region of mouth
• Affected teeth may exhibit delayed eruption or fail to erupt
• Shape of teeth altered=>
• Irregular and malformed
• Radiographic Features:
• Marked reduction in radiodensity, “ghost-like” appearance
• Enamel and dentin very thin, pulp chambers large
• Treatment=>
• Due to poor cosmetic appearance and structural integrity of affected teeth, extraction often=>
• Restoration using prosthetic appliances

Question 19

Acquired and developmental disturbances of the teeth

Shell tooth

Answer 19

• Normal enamel thickness but extremely thin dentin=>
• Enlarged pulp chambers
• Entire tooth or isolated to root
• Frequently in deciduous teeth
• Tooth appears normal size, but radiographs reveal an enlarged pulp chamber with very thin dentin surrounding it
• Treatment=>
• Protecting thin dentine from damage
• Careful dental care and sometimes restorative procedures to prevent fractures