Dental Anomalies in Radiology 王文岑 助理教授 口腔病理影像診斷科 wcwang@kmu.edu.tw 1

學習目標 資料來源 判讀X光片上的牙齒異常 Developmental abnormalities v.s. acquired Ref 1: White SC, Pharoah MJ. Oral Radiology: Principles and interpretation 6th ed. 2009. Ref 2: Neville BW, Damm DD, Allen CM and Bouquot JE. Oral & maxillofacial patholgy 3nd ed. 2009. Ref 3:高醫口腔病理診斷門診病例

Supernumerary Teeth (hyperdontia, supplemental teeth) Developmental Abnormalities Supernumerary Teeth (hyperdontia, supplemental teeth) 1~4% , familial tendency Mesiodens, paramolar Distodens, distomolar teeth Peridens Single : premaxilla, maxillary molar Multiple : premolar area, mandibular M : F = 2 : 1 Impaction or delay eruption of normal teeth; dentigerous cyst Syndrome: Cleidocranial dysplasia, Gardner’s syn. Ref.1 2

Ref.3

Cleidocranial dysplasia Ref.3

Cleidocranial dysplasia Lambdoidal suture, mastoid fontanel 未關閉。 Ref.3

Cleidocranial dysplasia Ref.3

Cleidocranial dysplasia Ref.3

Cleidocranial dysplasia Ref.3

Missing Teeth 8 > 5 > 2 > 1 3~10%, excluding 3rd molars Hypodontia Oligodontia Anodontia 8 > 5 > 2 > 1 1. Ectodermal dysplasia; 2. orofaciodigital syndrome Ref.1 4

Submergence Infraocclusion, Secondary retention, Reimpaction, Reinclusion most affect 8~9y/o children and teeth D & E PDL absent , ankylosis Occlusal and periodontal problems Ref.3

ectodermal dysplasia Ref.1

Ectodermal dysplasia Ref.3

SIZE OF TEETH Macrodontia True generalized type and relative type Macrodontia Hemangioma, hemihypertrophy of the face, pituitary giantism Microdontia pituitary dwarfism supernumerary teeth, 3rd molars, lateral incisors

Macrodontia Microdontia Ref.1

Transposition Two teeth exchanged positions 3 & 4 ; 3 & 2, 657 ERUPTION OF TEETH Transposition Two teeth exchanged positions 3 & 4 ; 3 & 2, 657 Ref.1

Transposition Ref.3

Gemination (twinning) Altered Morphology of Teeth Gemination (twinning) -Division of a single tooth bud primary dentition , esp. incisor region complete twinning increase tooth number pulp chamber is single & enlarged, maybe partial divided Ref.3 Ref.1 9

Fusion (synodontia) -Adjacent tooth germs combined with dentin or enamel bifid crown or two recognizable teeth, reduced number of teeth more common in the primary dentition, esp. anterior region Ref.1,2 7

Concresence - Roots of two or more teeth united by cementum Fusion after root formation Traumatic injury or crowding Pre-extraction x-ray check maxillary molars; 3rd molar & a supernumerary tooth Ref.1 8

Taurodontism -Longitudinal enlarged pulp chamber, increased distance between CEJ to the bifurcation normal crown size & tooth length, shortened roots not recognizable clinically most in molars Trisomy 21 Ref.1 11

Dilaceration A sharp bend or curve in the crown or root maxillary premolars Ref.1 12

Dens in Dente (dens invaginatus) - Infolding of the outer enamel surface into the interior at the anatomically defined pit caries→pulpal disease coronal type: enamel organ infolding into the dental papilla; 2>1>4,5>3 radicular type: invagination of Hertwig’s epithelial root sheath, lined with cementum; 4, 7 Ref.1 13

Dens in Dente radicular type coronal type Ref.1 Dilated odontome

Dens Evaginatus - Outfolding of enamel organ a tubercle on occlusal surface, with enamel surface & dentin core, pulp horn often extends into the evagination premolar or molar pulp infection due to fracture Ref.1 Ref.2 15

Amelogenesis Imperfecta -Disturbance in enamel development Normal dentin & root autosomal dominant or recessive , X-linked 1.Hypoplastic type Thin enamel with pitted, rough or smooth & glossy surface; yellowish to brown undersized, squared crown, lack of contact flat occlusal surface & low cusps, attrition 2.Hypomaturation normal thickness of enamel, but mottled surface; cloudy white, yellow or brown, opaque in color softer than normal same density as dentin 3.Hypocalcified type normal thickness of enamel, density less than dentin normal size & shape when erupt, abrade or fracture away rapidly permeability increase, darkened & stained 4.Hypomaturation-hypocalcified with taurodontism

Amelogenesis Imperfecta Hypocalcified type Hypoplastic type Ref.1

Dentinogenesis Imperfecta (hereditary opalescent dentin) Autosomal dominant hereditary Type I : DI + OI (osteogenesis imperfecta) COL1A1, COL1A2 Type II : Isolated DI. (1/8000) DSPP Type III: DI of the Brandywine type * DSPP A racial isolate in Maryland, DI + multiple pulp exposures in deciduous teeth enamel fractures, attrition severely dark brown to black Radiographic Features of D.I. : bulbous crown, normal size, constriction of the cervical area short & slender roots, occlusal attrition partial or complete obliteration of the pulp chambers, root canals absent or threadlike

Dentinogenesis Imperfecta Ref.1

Dentin Dysplasia Type I (radicular) rare (1:100,000) -autosomal dominant disturbance rare (1:100,000) Type I (radicular) normal color & shaped in both dentition malaligned arch, drifting and exfoliate with little or no trauma short or abnormal root shaped, pulp chamber & root canals completely filled in before eruption 20 % of teeth with type I disease have apical radiolucencies Ref.1

primary dentition appears as D.I., but permanent dentition is normal Dentin Dysplasia TypeII (coronal) primary dentition appears as D.I., but permanent dentition is normal obliterated of the pulp chamber & reduced root canals after eruption roots are normal in shape & proportion Ref.1

Regional Odontodysplasia (odontogenesis imperfecta) - hypoplastic & hypocalcified of both dentin & enamel only a few adjacent teeth in a quadrant affected either primary or permanent teeth central incisors > lateral incisors >canines (maxillary) delayed eruption ghostlike appearance in image large pulp chamber & wide root canals, roots are short & poorly outlined thin enamel , less dense as usual

Regional Odontodysplasia Ref.1

Enamel Pearl (enameloma, enamel drop, enamel nodule) - small globule of enamel on the roots furcation area of molars prevalence : 3 % mesial or distal aspect in Max. molar and buccal or lingual in Mand. molars Ref.1

Talon Cusp - Anomalous hyperplasia of the cingulum of a Max. or Mand. incisor →a supernumerary cusp T shaped in incisal view Differential diagnosed with supernumerary tooth Ref.1 Ref.2

Turner’s Hypoplasia (Turner’s tooth) -a type of enamel hypoplasia - local hypoplastic or hypomineralized defect in crown of a permanent tooth extension of a periapical infection or mechanical trauma from deciduous predecessor most common in lower premolars Ref.2,3

Turner’s tooth (enamel hypoplasia) Ref.1 Ref.3

Congenital Syphilis 30 % p’t develop dental hypoplasia Hutchinson’s incisors & mulberry molars not all p’t with Hutchinson’s teeth or mulberry molars will have congenital syphilis Hutchinson’s incisors (screw driver shape) Ref.1

-Physiologic wearing from occlusal contacts Acquired Pathologic Conditions Attrition -Physiologic wearing from occlusal contacts Incisal, occlusal and interproximal surfaces(contact points) Depends on the abrasiveness of diet, salivary factors, mineralization, emotional tension Bruxism--pathologic condition Crown shorten, reduction of pulp chamber & canals Abrasion -Nonphysiologic wearing by contact with foreign substances Factitious habits or occupational hazards tooth brushing, flossing, pipe smoking, opening hairpins with teeth

Tooth Brushing Injury V-shaped groove in cervical area Sensitive Maxillary premolars >canines > incisors R-L defect at cervical level, well-defined semilunar shapes Ref.1 Ref.3

Dental Floss Injury Cervical portion of proximal surfaces just above gingiva Narrow semilunar R-L, distal surface often deeper than mesial Ref.1

-Chemical action not involving bacteria Erosion -Chemical action not involving bacteria Contact acid with teeth: 1. chronic vomiting or acid reflux from GI disorders 2. consumes large amounts of acid foods 3. occupational exposure Regurgitated acids attack lingual surfaces; diet--labial; industrial–all surfaces Radiolucent defect on the crown

Resorption -Removal of tooth structure by odontoclast Chronic infection (inflammation), excessive pressure and function, tumors and cysts

Internal Resorption - within the pulp chamber or canal, involves resorption of surrounding dentin, results in enlarged pulp space Ref.1

Internal Resorption Ref.1

External Resorption -outer surface of tooth resorbed, most commonly in root surface Localized inflammatory lesions, reimplanted teeth, tumor & cyst, excessive mechanical(orthodontic) and occlusal forces, impactions Common sites : apical & cervical (lateral root surface)

Lateral root surface ER Apical ER Lateral root surface ER Ref.1

Secondary Dentin - Dentin deposited in pulp chamber after primary dentin formatted completely Normal aging process tertiary dentin: pathologic condition after chronic trauma Reduction in size of pulp chamber and canals Begins in the region adjacent to source of stimuli and alters normal shape of chamber Ref.1

Pulp Stone -- Foci of calcification in the pulp R-O within pulp chambers or root canals or extending from pulp chamber into root canals, most common in molars No uniform shape or number Ref.1

Pulpal Sclerosis - Diffuse calcification in pulp chamber and canals Correlation strongly with age Generalized, ill defined collection of fine RO throughout pulp chamber and canals Ref.1

Hypercementosis -Excessive deposition of cementum on roots 1.supraerupated tooth after opposing tooth loss 2.periapical inflammatory lesions 3.hyperocclusion or fractured 4.Paget’s disease 5.hyperpituitarism Smooth or irregular enlargement of root with lamina dura and PDL space Ref.1

Summary DEVELOPMENTAL ABNORMALITIES ACQUIRED PATHOLOGIC CONDITIONS NUMBER OF TEETH SIZE OF TEETH ERUPTION OF TEETH ALTERED MORPHOLOGY OF TEETH Fusion(synodontia) Concresence Gemination(twinning) Taurodontism Dilaceration Dens in dente (dens invaginatus) Dens evaginatus Amelogenesis imperfecta Dentinogenesis imperfecta Dentin dysplasia Enamel pearl Talon cusp Turner’s hypoplasia (Turner’s tooth) Congenital syphilis ACQUIRED PATHOLOGIC CONDITIONS Attrition Abrasion Tooth brushong injury Dental floss injury Erosion Resorption Internal resorption External resorption Secondary dentin Pulp stone Pulpal sclerosis Hypercementosis