1. Therapeutic dentistry department
Un-carious defects of teeth. Classification. Pathomorphology, clinic and diagnostics of defects that are developed before and after eruption of teeth. Treatment.
Therapeutic dentistry department

2. Uncarious lesions of teeth
Developmental Alterations of Teeth
Post-eruptive Alterations of Teeth

3. Developmental Alterations of Teeth
I. Lesions that occur in the stage of dental follicle development, before eruption:
1. hypoplasia;
2. hyperplasia of enamel (enamel pearls);
3. endemic fluorosis;
4. developmental disturbances and disorders of eruption;
5. genetic disturbances of tooth development.

4. Posteruptive Alterations of Teeth
II. Lesions that occur after teeth have been erupted:
1. tooth wear: attrition, abrasion, wedge-shaped defect;
2. erosion;
3. necrosis of hard tooth tissues;
4. hyperesthesia;
5. trauma of teeth;
6. fluorosis;
7. discolorations of teeth:
intrinsic stains
extrinsic stains

5. LOCALIZED DISTURBANCES IN ERUPTION
DEVELOPMENTAL DISTURBANCES AND DISORDERS OF ERUPTION
LOCALIZED DISTURBANCES IN ERUPTION
PRIMARY IMPACTION- Teeth cease to eruption before emergence
ANKYLOSIS -Cease of eruption after emergence and anatomic fusion of tooth cementum or dentin with alveolar bone

6. Impaction
3rd molars, maxillary canines, mandibular premolars, mandibular canines, maxillary premolars, maxillary central incisors, maxillary lateral incisors, and mandibular second molars; usually angulated or diverted
Factors associated with impaction:
Crowding and deficient maxillofacial development
Overlying cysts or tumors
Trauma
Reconstructive surgery
Thickened overlying bone or soft tissue
A host of systemic disorders, diseases or syndromes

7. Classification : Partially erupted or full bony impaction
according to angulation: Mesioangular, distoangular, vertical, horizontal or inverted

8. ANKYLOSIS
Infraocclusion, secondary retention, submergence, reimpaction, reinclusion

9. ANKYLOSIS Clinical And Radiographic Features
Pathogenesis is unknown, may be secondary to many factors and result in PDL barrier deficiency.
May occur at any age, any tooth
Most affect 8~9yr-old children and D , E , D , E
PDL absent
Occlusal, periodontal problems, impaction of the underlying teeth
Treatment and Prognosis
Variable : extraction, orthodontics, segmental osteotomy

10. Premature eruption Neonatal teeth: within 30 days
Natal teeth: newborns
Most are prematurely erupted deciduous teeth
Removal only if mobile and at risk of aspiration

11. Disturbances in tooth form
may present as dilacerated teeth, double teeth, dens invaginatus and enamel pearls
Anhidrotic ectodermal dysplasia showing
conical teeth, giving an undesirable, Dracula-like appearance.

12. Gemination, Fusion, Concrescence

13. Gemination single tooth germ division tooth no.: normal
single root & root canal + 2 complete or incomplete separated crowns
tooth no.: normal
twinning

14. Fusion Union of 2 separate tooth germs
Contact of tooth germ before calcified
Confluent of the dentin
Complete- form a single tooth
Incomplete- after calcified begins
Tooth no. : less one

15. Concrescence
Fusion after root formation
Cementum united
Traumatic injury or crowding
Pre-extraction x-ray check

16. Talon cusp Eagle’s talon
Lingual projection from the cingulum area of ant. teeth
Most contain a pulp horn
Both in deciduous & permanent dentition

17. Dens invaginatus
( central tubercle, occlusal tuberculated premolar; Leong’s premolar; evaginated odontome; occlusal enamel pearl )
An accessory cusp or a globule of enamel on central groove or buccal cusp of premolars or molars; unilateral or bilateral.
15% in Asians, rare in whites

18. Dens invaginatus
Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept.

19. Shovel-shaped incisors

20. Dens in dente Tooth within a tooth, incidence 5%
(Dens invaginatus; Dilated composite odontome)
Tooth within a tooth, incidence 5%
Invagination of the enamel organ into dental papilla before calcification
Coronal type: 3 types
maxillary lateral incisors are common

21. Dens invaginatus, coronal type II

22. Dens invaginatus Radicular type Hertwig’s sheath invagination
Food deposition→ caries → pulp infection
Restorated as soon as possible

23. Taurodontism “Bull-like “ teeth Bi- or trifurcation near the apex
Pulp chamber : greater apico-occlusal height and no constriction at the cervical of the tooth

24. Enamel pearl. There is a small mass of enamel at the root
Enamel pearls
Enamel pearl. There is a small mass of enamel at the root
bifurcation

25. Supernumerary roots Any tooth may develop accessory roots
No rtg required, but critical important in endodontic procedure

26. Dilaceration Angulation, sharp bend of root or crown
Trauma during tooth is forming
Pre-extraction x-ray check

27. DISTURBANCES IN THE NUMBER OF TEETH
Missing teeth
% , excluding 3rd molars, female predominance
Hypodontia: missing one or more teeth
Oligodontia: missing 6 or more teeth
Anodontia: total missing % 4

28. Hypodontia

29. Congenital absence of lateral incisors with spacing of the anterior teeth.

30. Supernumerary teeth, hyperdontia
Mesiodens
Paramolar
Supplemental teeth

31. Mesiodens The most common in supernumerary.
Premaxillary area , usually between upper central incisors
Cone-shaped crown & short root
One or two in number

32. Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept.

33. DISTURBANCES OF TOOTH SIZE
Microdontia
True:
1.General -pituitary dwarfism
2. Single -peg lat., 3rd molar
Relative microdontia

34. Macrodontia True macrodontia : 1. Generalized-pituitary gigantism
2. Localized- single, hemifacial hypertrophy
Relative macrodontia: small jaw, child

35. Disturbances in the structure of teeth Disturbances of enamel
■ Genetic disturbances
- Amelogenesis imperfecta.
■ Local disturbances:
- Infection.
- Trauma.
- Idiopathic.
■ Generalised disturbances:
- Infections.
- Fluorosis.
- Neonatal events, e.g. premature birth, rhesus incompatibility.

36. Amelogenesis imperfecta
(Hereditary enamel dysplasia; Hereditary brown enamel; Hereditary brown opalescent teeth)
Defects in--
Formative stage→hypoplastic type → defective formation of matrix
Calcification stage →hypocalified → defective mineralization of formed matrix
Maturation stage → hypomaturation → enamel crystallites remain immature
Genes mutation : AMELX, ENAM, MMP-20, KLK4, DLX3

37. 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

38. Hypoplastic type
Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept.

39. Hypoplastic type

40. 2.Hypomaturation
normal thickness of enamel, but mottled surface; cloudy white, yellow or brown, opaque in color
softer than normal
same density as dentin

41. Hypomaturation type
Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept.

42. 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

43. Hypocalcified type

44. Tricho-dento-osseous syndrome
Hypoplastic-Hypomaturation type

45. Factors associated with enamel defects
ACQUIRED DISTURBANCES OF ENAMEL FORMATION
Factors associated with enamel defects
Local-
1.Local acute mechanical trauma
2. Electric burn
3. Irradiation
4. Local infection: periapical inflammatory disease

46. Acquired disturbances of enamel formation
Environmental enamel defects:
1.Hypoplasia: pits, grooves or large area of missing enamel
2. Diffuse opacities: variation in translucency, normal thickness, white opacity without clear boundary
3. Demarcated opacities: increased opacity, a sharp boundary with adjacent normal enamel, normal thickness

47. Acquired disturbances of enamel formation
Most acquired enamel defects result in areas of HYPOPLASIA, which may be due to either a defect in matrix production or a defect in mineralisation.
Localized - only a single tooth is affected
Generalized - several teeth are affected

48. Turner’s hypoplasia, Turner’s tooth
Permanent teeth
Periapical inflammatory disease of the overlying deciduous tooth, less frequently in anterior teeth
Traumatic injury- not rare
-45% children sustain injury to their deciduous teeth, 23% permanent teeth development disturbed
Turner’s hypoplasia secondary to previous trauma

49. Turner’s teeth

50. Generalized defects are sometimes referred to as chronological hypoplasia
The overwhelming majority of chronological hypoplasia are the result of disturbances in the first 10 months of life and the teeth usually affected are:
■ The first permanent molars.
■ Upper central incisors.
■ Lower lateral incisors and canines.

51. Chronological hypoplasia due to metabolic upset
Chronological hypoplasia due to metabolic upset. Unlike the hereditary types of amelogenesis imperfecta, defects are linear and thought to correspond to a short period of amelogenesis disturbed by a concurrent severe illness

52. Syphilitic hypoplasia
Congenital syphilis
Hutchinson’s incisors & mulberry molars

53. Congenital syphilis; Hutchinson's teeth
Congenital syphilis; Hutchinson's teeth. The characteristics are the notched incisal edge and the peg shape tapering from neck to tip.

54. Disturbances in the structure of teeth Disturbances of dentine
This genetic disorder is characterised by defective dentine matrix production and two types have been described.
Dentinogenesis imperfecta type 1 occurs in association with osteogenesis imperfecta, in which there is defective bone formation. It is very uncommon.
Dentinogenesis imperfecta type 2 is the commonest form. It has the following features:
■ Both the permanent and primary dentition are affected.
■ The teeth have a normal shape on eruption but appear amber–brown or purple–blue in colour.
■ The enamel shears away from the poorly formed dentine which quickly wears away.
■ The pulps become obliterated with abnormal dentine.

55. Clinical features type I : deciduous severe than permanent teeth;
type II: equally affected;
type III: both dentitions affected.
Gray to brownish violet or yellowish brown color, with translucent or opalescent hue.
Enamel lost early through fracture, esp. on the incisal & occlusal surface, and dentin attrition rapidly.
Caries rate is not increased.

56. Dentinogenesis imperfecta

57. Regional odontodysplasia
Developmental Structural Abnormalities Involving Both Enamel and Dentin
Regional odontodysplasia
(odontodysplasia; odontogenic dysplasia; odontogenesis imperfecta; ghost teeth)
One or several teeth in a localized area
Maxi. > Mand.; both dentitions
most in ant. area
Delayed or total failure eruption
Irregular appearance
Defective mineralization

58. Radiographic features 1. Radiodensity ↓, “ghost appearance”
2. Large pulp, thin enamel & dentin
On one side of the midline the deciduous incisors have poor root formation with thin radicular dentine and enamel. A poorly organised spotty calcification is present at the site of the permanent successors.

59. Odontogenesis Imperfecta
Shell teeth
Initial reported in the Brandywine population
Normal thickness of enamel associated with extremely thin dentin and dramatically enlarged pulps (due to insufficient and defective dentin formation)
Short roots.

60. Kaohsiung Medical University, Oral Pathology and image Diagnosis Dept.

61. ENDEMIC DENTAL FLUOROSIS
Acceptable measures of fluorine in water according to hygienic standards is –
0,8-1,2 (1,5) mg/l. Fluorosis is the term given to changes in the enamel which are associated with excess ingestion of fluoride
Fluorosis. Moderate effects from an area of endemic fluorosis. Irregular patchy discolouration.

62. Dental fluorosis
Retention of the amelogenin protein in enamel structure → hypomineralized enamel → permanent hypomaturation → increased surface and subsurface porosity → alters light reflection and create white, chalky area

63. Dental fluorosis
Critical period for clinical dental fluorosis is the 2nd and 3rd year of life, dose dependent
Caries resistant

64. POSTERUPTIVE DEFECTS
II. Lesions that occur after teeth have been erupted:
1. tooth wear: attrition, abrasion, wedge-shaped defect;
2. erosion;
3. necrosis of hard tooth tissues;
4. hyperesthesia;
5. trauma of teeth;
6. fluorosis;

65. Attrition
Tooth to tooth contact during occlusion and mastication, some are physiologic
Accelerated by: poor quality or absent enamel, premature contact, intraoral abrasives, erosion, grinding habits
Incisal, occlusal and interproximal surfaces

66. Abrasion
Pathologic loss of tooth structure or restoration secondary to the action of an external agent (ex. Toothbrush, hair grips, toothpicks, chewing tobacco, biting thread, dental flossing…)
Toothbrush abrasion: horizontal buccal cervical notches of exposed radicular cementum and dentin with smooth surface.
Greater on prominent teeth ( canines, premolars , and teeth adjacent to edentulous area) and side of the arch opposite to the dominant hand
Demastication- when tooth wear is accelerated by chewing an abrasive substance between opposing teeth (both attrition and abrasion)

67. Abrasion

68. Abrasion
Improper use of hair grips
Long-term use of tobacco pipe

69. Abfraction
Repeated tooth flexure caused by occlusal stresses (tensile stress)
→ concentrate at the cervical fulcrum
→ may produce disruption in the chemical bonds of enamel crystal
→cracked enamel can be lost or removed by erosion or abrasion
Wedge-shaped cervical defects, deep, narrow V-shaped, not allow toothbrush to contact base; if the defect, often affect a single tooth
Almost exclusively on facial surface and more often in bruxism, higher in mandibular dentition

70. Abfraction

71. Erosion
Chemical process, exposure to acidic foods or drinks, medications (chewable Vit. C, aspirin), involuntary regurgitation (ex. esophagitis, pregnancy), voluntary regurgitation (ex. psychologic problems, bulimia)
Perimolysis- dental erosion from gastric secretion
Facial surface of maxillary anteriors affected-dietary source
Posterior teeth extensive loss of occlusal surface, and palatal surface concave dentin surrounded by an elevated enamel rim- regurgitation of gastric secretion
上顎前牙的腐蝕可能是食物因素而起, 而舌側及咬合面的腐蝕則可能是內生性的, 如胃液逆流而來。

72. concave dentin surrounded by an elevated enamel rim
Erosion
concave dentin surrounded by an elevated enamel rim

73. Erosion
A bulimia patient

74. Treatment and prognosis of tooth wear
Resolve pain and sensitivity
Identify the cause of tooth structure loss
Protection

75. ENVIRONMENTAL DISCOLORATION OF TEETH
Extrinsic- surface accumulation of exogenous pigment
Intrinsic-secondary to endogenous factors that result in discoloration of underlying dentin

76. Extrinsic stains
Bacterial- Chromogenic bacteria, green, black-brown, orange coloration Frequently in children, labial surface of maxillary ant. in gingival third
Iron- formation of ferric sulfide
Tobacco
Food and beverage- chlorophyll
Gingival hemorrhage- Hb. breakdown to biliverdin
Restorative material – ex. Amalgam
Medications- iron, iodine, silver nitrate, chlorhexidine, stannous fluoride

77. Intrinsic stains Amelogenesis imperfecta Dentinogenesis imperfecta
Dental fluorosis
Erythropoietic porphyria –
autosomatic recessive disorder of porphyrin metabolism, increased synthesis and excretion of porphyrins and their related precursors
Porphyrin deposition in teeth, reddish-brown coloration, red fluorescence when exposed to a Wood’s UV light
Present both in dentin and enamel in deciduous teeth, but only dentin affected in permanent teeth

78. Erythropoietic porphyria
Hyperbilirubinemia

79. Intrinsic stains
Hyperbilirubinemia- bilirubin, breakdown product of RBC, jaundice (yellow-green discoloration), erythroblastosis fetalis, biliary atresia
Biliverdin deposition, green discoloration of teeth (chlorodontia)
Ochronosis-alkaptonuria, blue-black discoloration
Trauma- coronal discoloration, pulp necrosis
Localized RBC breakdown

80. Intrinsic stains Medications-
Tetracycline (bright yellow to dark brown), chlortetracycline (gray-brown), oxytetracycline (yellow) , minocycline hydrochloride
Time of administration dose, duration
Avoid from pregnancy up to 8 yrs of age

81. Minocycline hydrochloride
Tx for Acne
Blue-gray from incisal 3/4, to dark green or black in roots, also affect developed teeth
Skin, nail, sclera, conjunctiva, thyroid, bone discoloration in susceptible individuals
Stained alveolar bone

82. Treatment and prognosis
Extrinsic stains- polishing
Intrinsic stains- bleaching, bonded restoration, crowns

83. Uncomplicated crown fracture
TRAUMA
Uncomplicated crown fracture

84. Complicated crown fracture

85. Crown-root fracture
Root fracture