Developmental anomalies of teeth ,,

developmental anamomalies

1. PRESENTED BY : Dr.LOUIS SOLAMAN SIMON PG 1 ST YEAR DEPARTMENT OF PEDODONTICS & PREVENTIVE DENTISTRY

2. DEVELOPMENT OF TOOTH ....... A GLIMPSE TO PREVIOUS SEMINAR ORIGIN COMPONENTS OF TOOTH GERM COMPONENTS OF TOOTH GERM PRODUCTS ECTODERM OF FIRST ARCH TOOTH GERM E C T O MESENCHYME ENAMEL ORGAN DENTAL PAPILLA DENTAL FOLLICLE CEMENTUM OUTER ENAMEL EPITHELIUM REE DENTIN CERVICAL LOOP STELLATE RETICULUM ROOT FORM PERIODONTAL LIGAMENT STRATUM INTERMEDIUM INNER ENAMEL EPITHELIUM HERS PULP CROWN PATTERN ENAMEL P.E.ATTACHMENT AMELOBLAST ODONTOBLAST UNDIFFERENTIATED MESENCHYMAL CELLS CEMENTOBLAST FIBROBLAST

3. Developmental disturbances means an abnormality where the pathology starts in the embryonic stage of human life , before the formation of the dentition What are Developmental Disturbances ?? Frequency of developmental dental anomalies in Indian population Eur j dent.2010 july;4(3) 263-269

4. Dental lamina formation stage Anodontia Initiation and proliferation Oligodontia Supernumerary teeth Geminated / fused teeth Histodifferentiation Regional odontodysplasia Anomalies at different stages of tooth development

5. Morphodifferentiation ( defects in size & shape ) Macrodontia / Microdontia Dens invaginatus / Dens evaginatus Hutchinson‟s incisors, mulberry molars Talon cusp Taurodontism Apposition ( defects in structure of enamel & dentin ) Amelogenesis imperfecta Enamel Hypoplasia Dentinogenesis imperfecta Dentin dysplasia

6. N umber S ize S hape S tructure G rowth or E ruption Developmental Anomalies of Teeth

7. Developmental Disturbances in Number of Teeth

8. Basic Principles . Butler‟s Field Theory ( 1953 ) most distal members of a class are more asymmetrical than mesial members Int j pediat dent 2004 ; vol 14 ; no 6 ; 446 - 450

9. A nodontia H yperdontia P re- Decidous Dentition P ost Permanent Dentition Developmental Disturbances in Number of Teeth

10. C ongenital absence of teeth 1)True -Total -Partial 2)False -(Extraction) 3)Pseudo (Multiple Unerupted ) Anodontia

11. Congenital absence of teeth May involve both dentitions Associated with Hereditary Ectodermal Dysplasia Total Anodontia

12. H ypodontia-Missing of 1 or more teeth O ligodontia-Missing of 6 or more teeth Common condition M issing-3 rd m olar,lateral incisor,maxilary and mandibular 2 nd premolar. C ongenitally missing primary teeth-uncommon- lat.incisor E tiology-unknown,familial tendency Partial anodontia

13. I ncrease in no. of teeth - SUPERNUMERARY TEETH Closely resemble in size or shape with which associated ETIOLOGY -Supernumerary teeth develop from splitting of permanent bud HYPERACTIVITY THEORY- As a result of local , independent , hyperactivity of dental lamina In some cases, hereditary tendency Hyperdontia or supernumerary teeth

14. DICHOTOMY THEORY : Tooth bud splits – 2 equal or different sized parts – one Eumorphic & other Dysmorphic tooth -- Taylor ( 1972 )

15. 1. CLEFT LIP & PALATE 2. CLEIDOCRANIAL DYSPLASIA 3. GARDENER SYNDROME CONDITIONS

16. CONICAL : MESIODENS TUBERCULATE – CUSP/TUBERCLE (barrel shaped ; may be invaginated ) SUPPLEMENTAL /DUPLICATION ODONTOME-( hamartomatous malformation rather than a neoplasm) COMPOSITE (composed of >1 type of tissue) A) COMPLEX (diffuse mass of dental tissue i.e., totally disorganized) B) COMPOUND (malformation which bears some superficial anatomic similarity to a normal tooth) CLASSIFICATION : ACCORDING TO MORPHOLOGY & LOCATION

17. Most common supernumerary tooth Situated between maxillary central incisors Occurs as : single or paired ;erupted or impacted or inverted MESIODENS

18. 2nd most common supernumerary tooth Situated distal to the 3rd molar Usually small , rudimentary tooth but may be of normal size Maxillary 4th molar is more common than mandibular 4th molar An accessory 4th molar is called Distomolar or DISTODENS FOURTH MOLAR :

19. The epithelial structures in the mouth of the infant before the eruption of the primary teeth Arising from, – An accessory bud of the dental lamina ahead of the deciduous tooth bud. Described as hornified , epithelial structures without roots. Occurs in the gingiva over the crest of the ridge , may be easily removed. Some consider it as a misinterpretation of dental lamina cysts of new born Pre decidous dentition

20. The rare appearance of supernumerary teeth after loss of permanent teeth; most teeth that appear after extraction of permanent teeth are due to eruption of previously impacted teeth particularly after insertion of complete denture.  Majority is due to delayed eruption of retained or embedded teeth. Some may represent post‐permanent or third dentition. But they are actually, multiple supernumerary unerupted teeth. It probably develops from a bud of the dental lamina beyond the permanent tooth germ . Post permanent dentition

21. Supernumerary Teeth -An Overview of Classification, Diagnosis and Management • M. Thérèse Garvey, B.Dent.Sc , D.Orth ., M.Orth ., M.Sc., FDS • • Hugh J. Barry, BDS, MA, FDS, FFD • • Marielle Blake, B.Dent.Sc ., MA, D.Orth ., M.Orth ., FDS(Orth.), MRCD(C) • © J Can Dent Assoc 1999; 65:612-6

22. Developmental disturbances in size of teeth

23. MICRODONTIA MACRODONTIA Developmental disturbances in size of teeth

24. THIS TERM IS USED TO DESCRIBE TEETH WHICH ARE SMALLER THAN NORMAL i.e. OUTSIDE USUAL LIMITS OF VARIATION TYPES : True generalized microdontia Relative generalized microdontia Microdontia involving single tooth MICRODONTIA

25. ALL TEETH smaller than normal Rare Well formed teeth, merely small Associated with PITUITARY DWARFISM True generalised microdontia

26. NORMAL OR SLIGHTLY SMALLER than normal TEETH are present in JAWS Illusion of true microdontia Role of HEREDITARY FACTORS Relative generalised microdontia

27. COMMON condition SITE : maxillary lateral incisor & 3rd molar Supernumerary teeth are frequently small in size ‘ PEG LATERAL ’: in maxillary lateral incisors ,instead of exhibiting parallel or diverging mesial & distal surfaces ,the sides converge or taper together incisally ,forming a peg shaped or cone shaped crown . Microdontia involving single tooth

28. Teeth that are LARGER than normal TYPES : 1. True generalized macrodontia 2. Relative generalized macrodontia 3. Macrodontia of single tooth MACRODONTIA

29. ALL TEETH ARE LARGER than normal RARE Associated with PITUITARY GIGANTISM True generalized macrodontia

30. More common PRESENCE OF NORMAL OR SLIGHTLY LARGER THAN NORMAL TEETH IN SMALL JAWS Illusion of macrodontia Role of HEREDITARY FACTORS Relative generalized macrodontia

31. Unknown etiology TOOTH MAY APPEAR NORMAL IN EVERY RESPECT EXCEPT FOR ITS SIZE Not to be confused with fusion of teeth Macrodontia of single tooth

32. Rhizomegaly / Radiculomegaly RHIZOMICRY root dwarfism / short root anomaly

33. Macrodontia in association with a contrasting character microdontia The Journal of clinical pediatric dentistry,vol.23 1(1) Namdar , FAU - Atasu , M

34. Developmental disturbances in shape of teeth

35. Developmental disturbances in shape of teeth GEMINATION FUSION CONCRESCENCE DILACERATION TALON CUSP DENS IN DENTE DENS EVAGINATUS TAURODONTISM

36. Gemination Attempt of DIVISION OF SINGLE TOOTH GERM BY INVAGINATION Incomplete formation of two teeth Usually one with two completely or incompletely separated crowns that have single root and root canal Exhibit a hereditary tendency Tooth count is normal Unknown cause; trauma may be possible cause

37. Fusion Fused teeth arise THROUGH UNION OF TWO NORMALLY SEPARATED TOOTH GERMS Physical force or pressure produces contact Depending upon stage of development of teeth fusion may be 1. COMPLETE 2. INCOMPLETE If this contact occurs early, at least before calcification begins,2 teeth may be completely united to form a single larger tooth

38. Clinical features Seen in deciduous as well as permanent dentition Higher frequency in anterior and maxillary region It is not always possible to differentiate between gemination and fusion between a normal tooth & supernumerary tooth The term ‘ TWINNING ’ is used to designate the production of equivalent structures by division resulting in one normal & one supernumerary teeth

39. CONCRESCENCE Fusion which occurs after root formation has been completed Teeth are UNITED BY CEMENTUM ONLY Arise as a result of traumatic injury or crowding of teeth with resorption of interdental bone so that the 2 roots are in approximate contact and become fused by deposition of cementum between them It may occur before/after teeth have erupted

40. Dilaceration “ kinked tooth ” or “ sickle – tooth ” Dilaceration refers to AN ANGULATION,OR A SHARP BEND OR A CURVE ,IN ROOT OR CROWN OF FORMED TEETH Due to trauma in the period in which the tooth is forming ( Van Gool ) Position of calcified portion of tooth is changed & the remain of tooth is formed at an angle The curve or bend may occur anywhere along length of tooth depending upon amount of root formed when injury occurred

41. Talons cusp An anomalous structure RESEMBLING AN EAGLE’S TALON Projects lingually from the cingulum of maxillary /mandibular permanent incisor This cusp bends smoothly with tooth except that there is a deep developmental groove It is composed of normal enamel and dentin & contains a horn of pulp tissue …

42. 3 PATTERNS OF TALON CUSPS Trace talon Semi-talon Talon Forms : T –form ; Y -shaped

43. Talons cusp A SSOCIATED WITH RUBINSTEINTAYBI STURGE WEBER OROFACIAL DIGITAL SYNDROMES TREATMENT : PROPHYLACTICALLY RESTORING GROOVE TO PREVENT CARIES Bilateral Palatal Talon Cusps on Permanent Maxillary Lateral Incisors: A Case Report Bahar Ozcelik and Burcu Atila,Eur j Dent 2011.jan 5(1) 113-116

44. Dens in Dente ALSO KNOWN AS ‘ DENS INVAGINATUS , DILATED COMPOSITE ODONTOME ’ Invagination in surface of tooth crown before calcification has occurred CAUSES: 1. increased localized external pressure 2. focal growth retardation/stimulation

45. Dens in dente CORONAL 3 types – TYPE 1 TYPE 2 TYPE 3

46. Oehler’s et al Classification TYPE 1 : • Confined to the crown TYPE 2 : • Extends below CEJ • Ends in a blind sac • May or may not communicate with adjacent dental pulp TYPE 3 : • Extends through the root • Perforates in the apical or lateral radicular area without any immediate communication with pulp

47. Clinical features Maxillary lateral incisors Bilateral Majority represent simply an accentuation on lingual pit RADICULAR VARIETY DISCUSSED BY ‘ BHATT & DHOLAKIA’ Radicular invagination usually results from an infolding of HERS & takes its origin within the root after development is complete TREATMENT : TOOTH PROPHYLACTICALLY RESTORED IN TEETH WITH OPEN APICES,APEXIFICATION WITH Ca(OH)2

48. Dens evaginatus ALSO KNOWN AS ‘OCCLUSAL TUBERCULATED PREMOLAR , LEONG’S PREMOLAR , EVAGINATED ODONTOME , OCCLUSAL ENAMEL PEARL ’ Appears as accessory cusp or globule of enamel on occlusal surface between the buccal and lingual cusp of premolars Proliferation and evagination of an area of inner enamel epithelium during tooth development Unilateral/bilateral Rarely on molars , cuspids , laterals Proliferation & Evagination of IEE ( Tartman )

49. Taurodontism (Bull like tooth) 1913, Keith Tauro - Bull, dont – tooth A PECULIAR DENTAL ANOMALY IN WHICH THE BODY OF TOOTH IS ENLARGED AT EXPENSE OF ROOTS Shaw Classified into- 1. Hypotaurodont 2 . Mesotaurodont 3. Hypertaurodont

50. Taurodontism CAUSES: 1. A SPECIALIZED OR RETROGRADE CHARACTER 2. A PRIMITIVE PATTERN 3. A MENDELIAN RECESSIVE TRAIT 4. AN ATAVISTIC FEATURE 5. A MUTATION RESULTING FROM ODONTOBLASTIC DEFICIENCY DURING DENTINOGENESIS OF ROOT Hammer & his associates believe that the taurodont is caused by failure of HERS to invaginate at proper horizontal level Goldstein & gottlieb stated that condition appears to be genetically controlled & familial in nature Unilateral /Bilateral Permanent > primary teeth 3rd > 2nd > 1st molar ( field effect )

51. RADIOGRAPHIC FEATURES 1. RECTANGULAR IN SHAPE 2. PULP CHAMBER : LARGE 3. LACKS CONSTRICTION 4. ROOTS ARE EXCEEDINGLY SHORT 5. BIFURCATION OR TRIFURCATION – Few mm Taurodontism : A dental rarity CM Jayashankara , Anil Kumar Shivanna , [...], and Paluvary Sharath Kumar J oral maxillofac pathol 2013 sep- dec 17(3) 478

52. Ectopic Enamel / Enamel Pearl Enamel in unusual location DROPLETS OF ECTOPIC ENAMEL Hemispheric structure Most project from the surface of root A localized bulging of odontoblastic layer

53. CLINICAL FEATURES 1. Roots of maxillary molar (common) 2. Mandibular molar 3. Deciduous molar is not rare 4. 1.1-9.7% highest in Asians SITE- on roots of furcation area RADIOGRAPHICALLY -well defined radio opaque nodule

54. PARAMOLAR CUSP OF CARABELLI PROTOSTYLID

55. Developmental disturbances of teeth with respect to shape- a review Srisha Basappa,Naresh Lingaraju,Suchetha Malleshi,Kumarswamy International journal of dental update 2011;1(1):73-79

56. To Be Contd..............

57. Developmental Disturbances in Structure of teeth

58. Developmental Disturbances in Structure of teeth 1 . AMELOGENESIS IMPERFECTA 2. ENVIRONMENTAL ENAMEL HYPOPLASIA 3. DENTINOGENESIS IMPERFECTA 4. DENTIN DYSPLASIA 5. REGIONAL ODONTODYSPLASIA 6. DENTIN HYPOCALCIFICATION

59. Amelogenesis Imperfecta SYNONYMS – HEREDITARY ENAMEL DYSPLASIA ; HEREDITARY BROWN ENAMEL ; HEREDITARY BROWN OPALESCENT TEETH A STRUCTURAL DEFECT OF THE TOOTH ENAMEL WITH COMPLEX INHERITANCE PATTERN ( DXS 85 at Xp22-amelogenin) Developmental of normal enamel occurs in 3 stages – FORMATIVE CALCIFICATION MATURATIVE

60. 3 BASIC TYPES ARE- Hypoplastic Hypocalcification Hypomaturation CLASSIFICATION : CLASSIFICATION OF AMELOGENESIS IMPERFECTA GIVEN BY – WITKOP (1989) TYPE 1 TYPE 2 TYPE 3 TYPE 4

61. CLASSIFICATION( Witkop 1989 ) TYPE 1 HYPOPLASTIC • 1A : Hypoplastic , pitted autosomal dominant • 1B : Hypoplastic , local autosomal dominant • 1C : Hypoplastic , local autosomal recessive • 1E : Hypoplastic , smooth X linked dominant • 1F : Hypoplastic , rough autosomaldominant • 1G : Enamel agenesis , autosomal recessive TYPE 2 HYPOMATURATION • 2A: hypomaturation,pigmented autosomal recessive • 2B: hypomaturation,X linked recessive • 2C : snow capped , autosomal dominant

62. .. TYPE 3 HYPOCALCIFIED 3A : autosomal dominant 3B : autosomal recessive TYPE 4 HYPOMATURATION-HYPOPLASTIC WITH TAURODONTISM , AD HYPOPLASTIC-HYPOMATURATION WITH TAURODONTISM,AD

63. Hypoplastic Type CLINICAL & RADIOGRAPHIC FEATURES : • Inadequate deposition of enamel matrix • Any matrix present will mineralize appropriately • Absence of enamel thickness • Open contact points • Radiographically , thin peripheral outline of radio opaque enamel

64. Hypomaturation Type CLINICAL & RADIOGRAPHIC FEATURES : • Enamel matrix is laid appropriately, there is a defect in maturation of enamel crystal structure • Mottled , opaque white brown yellow discoloration • Enamel surface tends to chip • Radiographically , radio density similar to dentin

65. Hypocalcified Type CLINICAL & RADIOGRAPHIC FEATURES : • No significant mineralization • Enamel very soft & easily lost • Occlusal surface more irregular • Radiographically , radio density of enamel & dentin are similar • Yellow to brown in color

66. Treatment Main problem is aesthetics , sensitivity & loss of vertical dimension The type which exhibits thin enamel ( hypocalcification-hypomaturation )-full coverage crown Patterns without significant crown length : full dentures Less rapid hypo plastic tooth loss : aesthetics is the prime consideration – full crown; facial veneers

67. Environmental Enamel Hypoplasia Incomplete or defective formation of organic enamel matrix of teeth by environmental factors TYPE I. Hereditary type-both dentition Type II. caused by environmental factors-only single tooth CLINICAL FEATURES- I. Mild cases few grooves , pits & fissures II. Severe rows of deep pits III. Most severe forms- considerable portion of enamel may be absent

68. CAUSES LOCAL INFECTION OR TRAUMA – TURNERS TEETH- condition is called TURNERS HYPOPLASIA any infection to 1º teeth that leads to periapical area where ameloblasts of 2º teeth (tooth buds are present) CONGENITAL SYPHILIS – non pitting type maxillary & mandibular 2º incisors & 1st molars HUTCHINSON’S INCISORS MOON’S MOLAR/FOURNIER MOLAR/MULBERRY MOLAR NUTRITIONAL DEFICIENCY-Incisors, canines & 1st molar BIRTH INJURIES ERYTHROBLASTOSIS FOETALIS NEONATAL LINES OR RINGS MULBERRY

69. MULBERRY MOLARS ERYTHROBLASTOSIS FOETALIS

70. CHEMICALS Eg.Tetracycline Mechanism – a chelate of calcium & tetracycline forms. at high concentration, in both ameloblast & odontoblast , protein synthesis is impaired ,this results in hypoplasia of enamel & dentin matrix CRITICAL PERIOD – TEETH IU (months) Deciduous incisors 4 Deciduous canines 5 Permanent incisors & canines 3-5

71. FLUOROSIS PATHOGENESIS – disturbance of ameloblasts during the formative stage of tooth development resulting in defective or deficient enamel matrix GRADE CLINICAL APPEARANCE Very mild, questionable white, opaque,<25% Mild white , opaque,</=50% Moderate white , opaque, brownish Severe opaque,pitted,brown,brittle

72. Dentinogenesis Imperfecta Affected teeth are gray to yellowish brown & have ‘ TULIP SHAPE’ Radiographically,the teeth appear solid, lacking pulp chamber & root canals

73. CLASSIFICATION TYPE 1 I. DENTINOGENESIS IMPERFECTA 1 – D.I. Without osteogenesis imperfecta (opalescent dentin, Shields type II, Capdepont teeth ) DSPP at Gene map locus 4q21.3 D.I. TYPE 1: FREQUENCY -1 in 6000-8000 children, BLUE GRAY OR AMBER BROWN & OPALESCENT RADIOGRAPHICALLY ; teeth have bulbous crowns & obliterated pulp chambers

74. .. TYPE II. DENTINOGENESIS IMPERFECTA 2 - Shieldstype III,Brandywine type D.I. (Shell tooth) D.I. TYPE 2 : brandywine triracial isolate in southern Maryland Multiple pulp exposures may occur Dentin is amber colored & smooth Radio graphically , deciduous- large pulp chambers & root canals Permanent – completely obliterated

75. HISTOLOGICAL FEATURES Irregular tubules , with large areas of uncalcified matrix Tubules are larger in diameter Dentinal tubules in D.I. are disoriented PHYSICAL AND CHEMICAL FEATURES : water content increased 60 % hardness - low TREATMENT : • Full coverage : crowns & roots close to normal shape • Overlay dentures placed on teeth covered with fluoride releasing GIC Vertical dimension rebuilt-metal castings • Newer composite combined with dentin bonding agent – occlusal wear

76. ATYPICAL DENTIN FORMATION WITH ABNORMAL PULP MORPHOLOGY SHIELDS & HIS ASSOCIATES classified it into – TYPE 1 – DENTIN DYSPLASIA TYPE 2 – ANOMALOUS DYSPLASIA OF DENTIN WITKOP referred as – RADICULAR – TYPE 1 CORONAL - TYPE 2

77. TYPE 1 (RADICULAR), Slight amber translucency, Exfoliated prematurely or after only minor trauma Radio graphically ; Deciduous – pulp completely obliterated Permanent – crescent shaped TYPE 2 (CORONAL ) Yellow brown or bluish gray opalescent Clinical appearance of permanent dentition is normal Radio graphically , Deciduous – pulp chamber obliterated Permanent – thistle tube shaped

78. HISTOLOGICAL FEATURES • TYPE 1 (RADICULAR) - lava flowing around boulders • TYPE 2 (CORONAL) – DECIDUOUS : amorphous & atubular dentin in radicular portion PERMANENT : multiple pulp stones or denticles TREATMENT • Preventive care • Meticulous oral hygiene • Shallow restorations – pulpal necrosis • Periapical inflammatory lesions : therapeutic choice guided by root lengths

79. SYSTEMIC DISEASES ASSOCIATED WITH DENTIN DYSPLASIA CALCINOSIS UNIVERSALIS RHEUMATOID ARTHRITIS & VITAMINOSIS SCLEROTIC BONE & SKELETAL ABNORMALITIES TUMOR CALCINOSIS

80. REGIONAL ODONTODYSPLASIA Also known as : Odontogenic Dysplasia Odontogenesis Imperfecta Ghost Teeth ETIOLOGY : 1. Abnormal migration of neural crest cells 2. Latent virus 3. Local circulatory deficiency 4. Local trauma or infection 5. Hyperpyrexia 6. Malnutrition 7. Medication 8. Radiation therapy 9. Somatic mutation 10. Alteration in vascular supply

81. CLINICAL FEATURES a. BIMODAL PEAK b. FOCAL AREA c. MAXILLARY PREDOMINANCE d. SURROUNDING BONE – LOWER DENSITY e. ERUPTED TEETH – IRREGULAR, ROUGH, YELLOW TO BROWN IN COLOR SIGNS & SYMPTOMS : a. DELAYED/FAILURE OF ERUPTION b. EARLY EXFOLIATION c. ABSCESS FORMATION d. MALFORMED TEETH e. NON INFLAMMATORY GINGIVAL ENLARGEMENT RADIOGRAPHIC FEATURES : a. THIN ENAMEL & DENTIN,large Pulp chamber – GHOST TEETH b. LACK OF CONTRAST c. PULP STONES

82. HISTOLOGIC FEATURES ENAMEL : PRISM STRUCTURE – IRREGULAR DENTIN : GLOBULAR AREAS –POORLY ORGANIZED TUBULAR DENTIN PULP : PULP STONES TREATMENT : • RETENTION • NON VITAL – ENDODONTIC THERAPY • TOOTH PREPARATION CONTRAINDICATED • SEVERELY INFECTED / AFFECTED TEETH EXTRACTION

83. DENTIN HYPOCALCIFICATION Caused by environmental factors affecting mineralization There is failure in the fusion of calcium globules , during mineralization , leaving interglobular areas of uncalcified matrix Globular dentin can be easily detected in ground & decalcified sections Hypocalcified dentin is softer

84. [Frequency of the developmental disturbances of tooth structure]. Shoni shikaquaku zaashi,ncbi pubmed 1990;28(2):466-85.

85. DEVELOPMENTAL DISTURBANCES IN GROWTH(ERUPTION) OF TEETH

86. DEVELOPMENTAL DISTURBANCES IN GROWTH(ERUPTION) OF TEETH PREMATURE ERUPTION DELAYED ERUPTION ERUPTION SEQUESTRUM MULTIPLE UNERUPTED TEETH EMBEDDED AND IMPACTED TEETH ANKYLOSED & DECIDUOUS TEETH

87. PREMATURE ERUPTION Natal tooth,Neonatal tooth Polychlorinated biphenyls (PCBs), polychlorinated dibenzo - -dioxins (PCDDs), and dibenzofurans (PCDFs) Hormonal influences like hyperthyroidism ADRENOGENITAL SYNDROME

88. DELAYED ERUPTION In deciduous and permanent teeth, it is difficult to assess unless a gross variation is present. Caused by Systemic conditions like rickets, cretinism, cleidocranial dysplasia. Local factors like fibromatosis gingivae Treatment of the primary condition may lead to eruption of the teeth .

89. ERUPTION SEQUESTRUM Anomaly associated with tooth eruption in children. Described by Starkey and Shafer. It is a tiny, irregular spicule of bone overlying the crown of an erupting permanent molar, found just prior to or immediately following the emergence of the tip of the cusps through the oral mucosa . Etiology : As the molar teeth erupt through the bone, they can separate a small osseous fragment from the surrounding bone similar to a cork screw. In most cases, the fragment undergoes complete resorption before eruption. If the bony spicule is large or the eruption is rapid, complete resorption cannot occur and hence, it is observed .

90. Clinical features The child may complain of slight soreness in the area during function. The spicule directly overlies the central occlusal fossa but is within the soft tissue. It may be seen lying in a tiny depression over the crest of the ridge. As the tooth erupts, the fragment of bone completely sequesters through the mucosa and is lost.

91. Radiographic features It can be recognized even before the tooth eruption. Seen as a tiny, irregular opacity overlying the central occlusal fossa but separated from the tooth itself .

92. MULTIPLE UNERUPTED TEETH Uncommon condition with delayed eruption of teeth. – Deciduous teeth may be retained or – Deciduous teeth would be shed but the permanent teeth would have failed to erupt ( Pseudo‐ anodontia ). Radiographs may be normal but the eruptive forces would be lacking. In association with cleidocranial dysplasia

93. EMBEDDED AND IMPACTED TEETH unerupted usually because of a lack of eruptive force . Impacted teeth are prevented from eruption by some physical barrier in the eruption path like, Lack of space – crowding, premature loss of deciduous teeth. – Rotation of tooth buds. Any tooth may be impacted – usually mandibular third molars (22%), maxillary third molars (18%) and maxillary cuspids (0.9%), premolars and supernumerary teeth . Mandibular teeth are more severely impacted than maxillary teeth.

94. ANKYLOSED TEETH Also called Submerged teeth, Infraocclusion , Secondary retention, Submergence, Reimpaction and Reinclusion . Usually deciduous mandibular second molars with variable degree of root resorption can become ankylosed to bone. This prevents exfoliation and subsequent replacement by permanent teeth. The submerged appearance could be due to – Continued growth of the alveolar process – Crown height of deciduous tooth is less than that of adjacent permanent teeth. It has a solid sound on percussion when compared to the dull, cushioned sound of normal teeth. Radio graphically , partial absence of PDL , with areas of apparent bending between tooth root & bone

95. Overall management of dental anomalies – pediatric dentists Informing & supporting child & parent Establishing a diagnosis Genetic counselling Inter – disciplinary formulation of definitive treatment plan Elimination of pain Restoration of aesthetics Provision for adequate function Maintenance of occlusal vertical dimension Intermediate restorations through childhood & adolescence Planning definitive treatment at optimum age

96. Mechanism of Human Tooth Eruption: Review Article Including a New Theory for Future Studies on the Eruption Process , Inger kjaer,ScientificaVolume 2014 (2014), Article ID 341905, 13 pages

97. REFERENCES Books Cawson , R.A: Cawson’s Essentials of Oral › Oral Pathology and Oral Medicine, › 8th Edition • (pages 18-36) Shafer, et al: A textbook of Oral Pathology, › 5 TH Edition • (pages 52-87) Developmental disorders of the dentition:an update Ophir D klein,Snehalata oberoi,ann huysene,maria hovarokova,miroslav peterka,renata peterkova . Am J Med Genet C Semin Med Genet 2013 November;163(4), doi 10.1002/ajmg.c.31382