The document discusses various aspects of tooth eruption including: 1) It describes the different stages and movements of tooth eruption including pre-eruptive, eruptive, and post-eruptive phases. 2) It discusses several theories of the mechanisms that drive tooth eruption including root elongation, bone remodeling, dental follicle signaling, and periodontal ligament contraction. 3) It explains the histological changes that occur in tissues overlying, surrounding, and underlying erupting teeth including bone remodeling and formation of the eruption pathway.

1. ERUPTION AND
SHEDDING AND
TEETHING
Presentation by-
Nikita Panpaliya

2. contents
 DEFINITION
 TYPES OF TOOTH
ERUPTION, ITS STAGES
 MOVEMENTS OF TOOTH
ERUPTION
a) PRE ERUPTIVE PHASE
b) PREFUNCTIONAL PHASE
c) POST ERUPTIVE PHASE
 THEORIES OF TOOTH
ERUPTION
 MECHANICS OF TOOTH
ERUPTION
 ERUPTION RHYTHM
 CHRONOLOGY &
SEQUENCE OF TOOTH
ERUPTION
 DISTURBANCES IN
ERUPTION
 SHEDDING OF
DECIDUOUS TEETH
 CONCLUSION
 REFERENCES

3. DEFINITION
‘Erumpere’ : to break out
Eruption : cutting of the tooth through the
gum
Maury Massler and Schour(1941):
James K Avery (1990):
Orbans:

4. Types of mammalian eruption
CONTINUOUSLY GROWING
CONTINUOUSLY EXTRUDING
CONTINUOUSLY INVESTED
TOOTH

5. Schour and Noyes 1931
 Stage I : Preparatory stage
 Stage II : Migration of the tooth toward the oral
epithelium
 Stage III: Emergence of crown tip into the oral cavity
 Stage IV: First occlusal contact
 Stage V : Full occlusal contact
 Stage VI : Continuous eruption
ANATOMIC STAGES

7. Movements leading to tooth eruption
Pre eruptive tooth movement
Eruptive/pre functional tooth
movement
Post eruptive/ functional tooth
movement

8. PRE ERUPTIVE TOOTH
MOVEMENT
 Movement of tooth germ
Bodily tooth movement
Eccentric movement

9. RELATIVE POSITION: PRIMARY &
PERMANENT TEETH
ANTERIOR TEETH
POSTERIOR TEETH

10. ERUPTIVE TOOTH MOVEMENT
Four major events:
Root formation
Movement
Penetration
Intra-oral occlusal / incisal movement

11.  Requires space for elongation
of root.
 1st there is proliferation of
epithelial root sheath,
 Initiates root dentin and
formation of pulp tissue
 Increase in fibrous tissue of
surrounding dental follicle.
Root formation

12. Movements
 Occurs incisally or occlusally
through bony crypt of jaws to
reach oral mucosa.
 movement occur due to need
for elongating roots to have
space to form.
 Reduced enamel epithelium
contacts & fuses with oral
epithelium

13.  epithelium proliferates and
forms firm attachment with oral
epithelium.
 This results in formation of
doubled layered epithelium
over lying erupting crown

14. Penetration
 Tip of the crown enters oral
cavity breaking through fused
epithelial layer.
 Causes degeneration of
membrane
 Beginning stage of clinical
eruption
 As crown erupts further lateral
borders become dentogingival
junction.
 Reduced enamel epithelium
surrounds tooth like cuff
known as junctional epithelium

15. HISTOLOGIC CHANGES
 Changes in tissues overlying teeth
 Changes in tissues around the teeth
 Changes in tissues underlying teeth

16.  Dental follicle becomes altered
forming a pathway for erupting
teeth.
 Altered tissue over lying teeth
becomes visible as an inverted
triangular known as Eruption
pathway
CHANGES IN TISSUES OVERLYING TEET

17. Bone resorption Gubernacular cord & canal
DEVELOPING PATH WAY
 Follicular fibers at periphery is regarded as Gubernacular Dentis or
Cord
 Macrophages appear in soft tissue.
Causes release of hydrolytic enzymes - aid in destruction of tissues

18. OSTEOCLASTS
 Osteoclast are found along borders of resorptive bone over lying teeth.
 loss of bone overlying teeth keeps pace during eruptive movement.
A: OSTEOCLAST-LIKE CELLS

19.  Osteoblast and osteoclast
constantly remodel bone as
tooth enlarges.
 Tooth erupt with increased
amount of supporting alveolar
bone
 part of height increase for
developing face .

20.  Permanent anterior teeth
establish an eruptive path
way lingual to primary
anterior teeth.
 Premolars under the
primary molar.
 Permanent molar teeth
erupt into free alveolar
space behind primary
molars

21.  Small foramina in mandible and maxilla acts evidence for eruption
sites for anterior permanent teeth .

22.  Resorptive forces of bone and teeth results from action of osteoclast.
 Arises from monocytes of circulating blood stream.
 These monocytes fuse to form multinucleated osteoclast
– resorb hard
tissue
monocyte

23.  Cell membrane modified by enfolding area – Ruffled border
 Increases surface area & allows cell to function maximally

24. Changes in tissues around teeth:
 Tissues around teeth undergo
changes during tooth eruption.
 first periodontal fiber appear
near the cervical area.
 Extend at angle coronal to
root.
 Alveolar bone is remodeled to
accommodate forming root

25.  As eruption proceeds collagen
fibres become visible along forming
root.
 Area become densely populated
with fibroblast.
 Special type fibroblast may be seen
in PDL known as myofibroblast.
 It has contractile capability & may
aid in force needed in tooth
eruption.

26.  As tooth moves occlusally
alveolar bone increases in
height.
 Changes shape to
accommodate passage of
crown.
 Tooth migrate occlusally
resulting in new bone
formation around root. Size of
the crypt decreases .
 Osteoclastic and osteoblastic
acitivty still occurring around
teeth.

27. Blood vessels become more dominant in developing ligament &
exert additional pressure on erupting tooth.

28. Alveolar bone remodelling taking place in response
to eruption

29. Changes in tissues underlying teeth
 Changes occur in the follicular
tissue underlying erupting
tooth.
 Changes takes place in soft
tissue and fundic bone.
 Changes in fundic bone occurs
as compensatory to
lengthening of root.

30.  Fibroblast appear more in number and forms strands which
mature into calcified trabeculae.
 Trabeculae forms bone ladder at root apex; becomes denser as
additional bone plate appear.
 Tooth reaches occlusion ,bone ladder gradually resorb to make
space for developing root tip.

31. During root formation
 The dentin of root apex tapers to fine edge.
 Fibroblast form collagen around root apex, fiber bundle
becomes attached to cementum to form Root dentine.

32. At the end of this phase
 Dense bone forms around the
root apex.
 Bundle of fibres attach to
apical cementum and alveolar
bone to support tooth.

33. POST ERUPTIVE TOOTH
MOVEMENT
 Post eruptive movement are made by tooth after
reaching functional position in occlusal plane.
 They are three categories :-
1) Accommodation for growth
2) Compensation for occlusal wear
3) Accommodation for interproximal
wear.

34. 1) Accomodation for growth:
 PEM that accommodate growth of
the jaws are completed toward
end of second phase when jaw
growth ceases.
 Readjustment of position of tooth
socket takes place by deposition
of new bone at alveolar crest.
 This compensates increasing
height of jaws.

35.  Readjustment occur between age group of
14-18 yrs.
 Apices of teeth move 2-3mm away from
inferior dental canal –regarded as fixed
reference point.
 This movement occur early in girls than boys.
 Burst of condylar growth separates jaws of
teeth =======> further eruptive movement.

36. 2) Compensation for occlusal
wear
 Compensation for
occlusal wear is
achieved by
continued
cementum
deposition around
apex of tooth.
 Deposition of
cementum in this
location occurs after
tooth is moved.

37. 3) Accomodation for interproximal
wear
Proximal wear occur at contact points b/w
teeth on their proximal surface.
Inter-proximal wear is compensated by
mesial or approximal drift.
Forces bringing about mesial drift are multi-
factorial.
a) Anterior component of occlusal force.
b) Soft tissue pressure
c) Contraction of transeptal ligament.

38. i)Anterior component of occlusal force
 When teeth are
brought in contact,
an anteriorly
directed force is
generated.
 This anterior force is
result of mesial
inclination of teeth
and summation of
intercuspal planes.

39. ii) Contraction of transeptal
ligament
 Plays a vital role in maintaining tooth position.
 Transseptal fibres running between adjacent
teeth draw the tooth and maintain them in
contact.
 Evidence
1) Orthodontically moved teeth
2) Bisected teeth
3) Remodelling by collagen
phagocytosis .
 Mesial drift is achieved by contractile
mechanism of transseptal fibres.

40. iii) Soft tissue pressure
pressure by the cheeks and tongue may
push teeth mesially.
These pressures are eliminated by
constructing an acrylic dome over
teeth… still mesial drifts occurs.
Indicates soft tissue does not play a
major role in creating mesial drift.
Soft tissue pressure does influence tooth
position.

41.  Alveolar bone increases in density
 PDL establish into separate groups
 Arteries established and nerves organized
in PDL

42. SUMMARY OF TOOTH ERUPTION
CHANGES THAT OCCUR IN THE
PREERUPTIVE STAGE
PREFUNCTIONAL STAGE
FUNCTIONAL ERUPTIVE
STAGE WITH CLINICAL
CONTACT

43. THEORIES OF TOOTH ERUPTION
Maury Massler, Schour Am J of Orth 1941, 552-571

44. Root elongation theory
Bone remodeling theory
Dental follicle theory
Periodontal ligament contraction theory
Vascular theory
Blood vessel thrust theory
Pulpal constriction theory
Growth of periodontal tissues theory
Pressure from muscular action
Resorption of alveolar crest theory
Hormonal theory
Foreign body theory
Cellular proliferation theory

45. ROOT ELONGATION THEORY
Hunter(1778), Magitot, Nasmyth, Kolliker et al
Evidence for theory: Crowns pushed into oral cavity
by virtue of growth and elongation of roots
Orbans:
Evidence against theory:
1)Rootless teeth
2)Submerged teeth
3)Supra-eruption
4)Distance travelled by some teeth
(canines)

46. GROWTH OF PERIODONTAL TISSUE THEORY
Pull by surrounding connective tissue - UNDERWOOD
Evidence: Periodontal membrane pulls the tooth into
occlusion
Drawback: histolgic examination-reverse is true.
Alveolar bone growth – Herman & Nessel
Evidence: squeezes the tooth out of alveolus into oral
cavity.
Drawback:
x-ray & histological sections showed that bone doesn’t actually touch
the tooth.
can be applied only upon single conical roots.
multirooted teeth could not erupt by this mechanism.

47. VASCULAR THEORY
 Constant (1896)
Blood pressure in surrounding tissues may be the
impelling force in eruption of teeth.
 Tomes:
1) Blood pressure keeping up a state of tension may
operate to push solid body in direction of least
resistance.
2) Concomitant resorption of structure lying in path of
erupting tooth will provide space for erupting tooth.
Clinical evaluation:
1) Submerged teeth erupt by mechanical
irritations under the influence of hyperemia.
2) Hyperemia in periodontitis causes
supraeruption.

48. BLOOD VESSEL THRUST THEORY
Eruption involves blood supply to tooth, similar to
vascular theory
Two forces generated in blood vessels of pulp & PDL:
1) Hydrodynamic force:
Alteration in momentum flux of blood flowing
through curved arteries, capillaries and veins.
2) Hydrostatic force:
1) From the presence of blood in those vessels.
2) Arteries enter the periodontal ligament at right
angles providing migratory force.

49. Vascular theory Blood vessel thrust theory
Force is exerted by vascular
fluid
Forces would be outside the
blood vessels
Tissue fluid pressure acts
equally in all direction
Pressure generated pressing on
surrounding bone.
Force exerted by blood
Inside the blood vessel
Pressure generated in pulp acts
mainly toward cusp
No pressure is placed on bone

50. BONE REMODELING THEORY
Statement: Inherent growth pattern of mandible or
maxilla moves teeth by selective deposition &
resorption of bone in immediate neighborhood of
tooth.
Experimental evidence:
Removal of developing premolar without disturbing dental
follicle
Marks and Cahill (1984) -tooth germ replaced by metal or
silicone replica & dental follicle is retained
In both above cases eruption occurs with formation of
eruptive pathway
“Programmed” bony remodeling

51. Evidence against theory:
◦ Formation of eruptive pathway within bone
without developing & growing teeth;
◦ Bone remodeling occur only in presence of
dental follicle.

52. DENTAL FOLLICLE THEORY
Malassez
Statement: Provide conduit and chemo-
attractant for osteoclasts

53. Reduced enamel epithelium
Cytokines( EGF & TGFβ)
Follicular cells
Colony stimulating factor 1
Interleukin -1α
Differentiate monocytes to osteoclasts
Promote bone resorption
Secretes proteases
Assist breakdown of follicle
To produce path of least resistance

54. SIGNALING
MOLECULES
 CSF-1
 EGF
 IL-1
 TGF alpha
 TGF beta-1

55.  This epithelial signaling explains the
remarkable consistency of eruption times.
 Also explains why the radicular follicle,
which is not associated with REE, does not
undergo degeneration but instead forms the
PDL.
 Drawback:
How force is produced to move a tooth?
NOT explained.

56. PERIODONTAL LIGAMENT TRACTION
THEORY
Statement: force for eruptive tooth movement
resides in the PDL.
Mechanisms:
◦ Collagen constriction
◦ Constriction due to fibroblasts
Experimental evaluation:
◦ Interfering collagen synthesis – Vitamin C
- Latharytic agent
◦ Sectioning and placing a barrier

57.  For force to be translated into eruptive
tooth movement:
 Collagen fiber bundles must have oblique orientation
 Orientation must be maintained

58. To conclude the theories:
The force moving the teeth is most
likely generated by the contractile
property of PDL fibroblast;
however, it is a multifactorial
phenomena with assistance from
root growth
PDL formation &
collagen remodelling.

59. MECHANICS OF TOOTH ERUPTION
Symmetrical increase in size of spherical bony
crypt
Series of vectors of force of equal magnitude
arising from a central origin
Forces within follicle= Bone remodeling forces
Calcification of crown provides new mass
against which forces act
Alteration in distribution of forces and
resorption of apical end
Forces within follicle>bone remodeling forces
Bony remodeling due to action of many forces
within follicle
Action of eruptive force> Forces resisting
Dynamic relationships between surrounding
alveolar bone, eruptive force and erupting
tooth influence rate of eruption
Resistance greatly reduced
Accelerated eruption

60. RHYTHM OF ERUPTION
¤ Cicardian rhythm exist during pre-functional stage.
¤ Teeth intrude transiently during mastication & then
erupt significantly overnight.
¤ Mean daily eruption velocity: 71µm/day
¤ Effect on eruption of a supine position v/s an
upright position during night is due to change in
intra-oral pressure.

61. Dissection b/w growth & eruption
Growth…
Eruption…
Clinically:
 Eruption can occur long after the growth of
enamel & dentin is completed.
 Premature extraction of primary molar
causes acceleration in rate of eruption of
premolar without any concomitant
acceleration of growth of dentin.

62. Primary dentition

66. 24 Months = 16
Erupted Teeth
30 Months = 20
Erupted Teeth
18 Months = 12
Erupted Teeth
12 Months = 8
Erupted Teeth
6 Months = 4
Erupted Teeth
6+4 logic for Primary teeth

67. Permanent teeth

70. CLINICAL SIGNIFICANCE
Logic of 4- for permanent dentition:

71.  Eruption occurs earlier in
boys: primary dentition
girls: permanent dentition
 Mandibular teeth erupts earlier
 Difference in 1 or 2 months on either sides should
not be considered abnormal
 It takes 1.5 – 2.5 months to reach occlusal plane
from beginning of clinical eruption

72. VARIATIONS IN SEQUENCE OF
ERUPTION
 Maxillary canine erupt before first and second PM
 Mandibular second molar erupt before second PM
 Maxillary first PM before second PM followed by
canine
 Eruption of maxillary canine often delayed

73. FACTORS INFLUENCING
ERUPTION

74. Disturbances in eruption of teeth
 Premature eruption: natal & neo-natal teeth
 Delayed eruption v/s retarded eruption
 Eruption cyst
 Unerupted teeth , multiple or single
 Embedded v/s Impacted teeth
 Eruption sequestrum
 Eruption haematoma
 Ectopic eruption
 Ankylosed deciduous teeth/Submerged teeth
 Transposition

75. NATAL AND NEONATAL TEETH
Congenital teeth, Fetal teeth, Predecidual teeth
 Natal teeth Massler & Savara (1950)
 Neonatal teeth
 Primary teeth -95%, Supernumerary – 5%
LI (85%) > UI (11%) > LC & M (3%) > UC&
M(1%)
 Etiology :
Abnormal superficial position of tooth germ
Associated with several syndromes and
congenital defects

76. • Fully developed in
shape
• Comparable
morphology to primary
teeth
• Good prognosis
Classification’s
Spouge & Feasby (1966)
Mature Immature
• Structure & development
is incomplete
• Poor prognosis

77. Hebling (1997)
1) Shell – shaped crown poorly fixed to the alveolus by
gingival tissue & absence of root;
2) Solid crown poorly fixed to the alveolus by gingival tissue
& little / no root;
3) Eruption of the Incisal margin of the crown through
gingival tissue;
4) Edema of gingival tissue with an unerupted but palpable
tooth.

78. Problems associated with natal & neonatal teeth:
Riga fede disease:
Ulceration on ventral surface of tongue
 mobility
 trauma to premaxillary region
 trauma to mothers breast
 Danger of aspiration
 disturbance of feeding.

79. DIAGNOSIS
Clinically: Primary teeth of normal dentition / Supernumerary
teeth
Radiograph:
D/D:
Bohn’s nodules
Cysts of dental lamina

80. Management:
Factors to be considered to maintain these teeth or not:
 Degree of mobility
 Inconveniences during feeding
 Possibility of traumatic injury
 Whether teeth is a part of natural dentition or is
supernumerary.
 Incisal margin smoothening
 Extraction
Only after 10days of life
Or
Administer vit K (0.5- 1.0mg), IM

81. DELAYED ERUPTION
When there is delay in development & the resulting
consequent delay in eruption is known as delayed
eruption.
 Causes
◦ Local
◦ systemic

82. LOCAL FACTORS:
- Malposition of developing tooth
- Supernumerary teeth
- Ankylosis
- Ectopic eruption
- Insufficient space
- Over retained primary teeth
- Dilacerations
- Impaction
- Traumatic injury
- Cleft palate
- Fibrotic gingiva
- Cysts & tumours
SYSTEMIC FACTORS:
Endocrinopathies
- Hypothyroidism
- Hypoparathyroidism
- Hypopitutiarism
Syndromes
- Down
- Cleido cranial dysplasia
- Osteopetrosis
- Chondro ectodermal dysplasia
Heredity Idiopathic
others - Fibromatosis gingivae
- Gardner syndrome
- Rickets

83. Apert syndrome
Downs syndrome
Chondro ectodermal
dysplasia

84. Cleidocranial dysplasia

85. Hypo thyroidism

86. RETARDED ERUPTION
Per rasmussen (1983):
Retarded eruption is defined as time
taken for eruption beyond mean
eruption time

87. Misconception:
Extraction of predecessors provokes
eruption.
Management:
Maintain the primary teeth in good condition
until they shed.
To improve esthetics
To offer surgery & orthodontics when needed.

88. Delayed eruption v/s retarded
eruption:
Tooth formation &
eruption are in co-
ordination with
each other.
Tooth formation &
eruption are out of
co-ordination.

89. Bluish swelling
Site
Asymptomatic
Treatment
ERUPTION
HEMATOMA
(Eruption Cyst)

90. Eruption sequestrum
Starkey & Shafer
Etiology
R/F
Significance
Management

91. Teething
 It is a process by which teeth erupt after penetration of
the overlying gums
“Adam and Eve had many advantages, but the principle one was that they escaped
teething.”

92. Crying Restlessness
Loss of apatite
Increased salivation
Biting objects

93. Non pharmacological management :-
 Teething rings (chilled)
 Hard sugar free teething rusks/bread sticks/oven
hardened bread
 Cucumber (peeled)
 Frozen items (anything from ice cubes, frozen
banana, sliced fruit)
 Pacifier (even frozen)
 Rub gums with clean finger, cool spoon, wet
gauze
 Reassuarance
Pharmacological management :-
 Analgesics/antipyretics :
Lignocaine based products
Choline salicylate products
Paracetomol based preparations :
3-12 mths=60-120mg
1-5 yrs =120-250mg
 Topical anesthetic products
 Alternative holistic medicine:-
Management:

94. EMBEDDED AND IMPACTED TEETH
o Embedded teeth
Suheiro (1986)
o Impacted teeth
Reijo Ranta(1985)
o Incidence: Bergstrom 1977
Mandibular 3rd molar > maxillary
canine > mandibular 2nd premolar

96. TREATMENT OPTIONS
1.Extraction of impacted tooth and movement of adjacent tooth
in its position
2.Autotransplantation of impacted tooth
3.Prosthetic replacement of impacted tooth either with crown or
with implant
4. Surgical exposure and placing a traction force to bring it into
the arch
Sufficient space is achieved by
1.Extraction of succedaneous tooth or some other tooth or teeth
2.Molar distalisation or expansion
Once space is achieved, surgical exposure of the tooth is
performed

97. Etiology:
 occur due to arch length inadequacy
 Tooth mass redundancy
 Site: 1st permament molar > canine.
Ectopic eruption

98. Decreasing order of occurrence: canine-first premolar;
canine-lateral incisor; lateral incisor-central incisor; and
canine-central incisor.
 Complete transposition is
a situation in which both
the crowns and the entire
root structure are
transposed.
 Incomplete transposition
is a condition describing
an interchange in the
positions of the crowns of
two permanent teeth
within the same quadrant
of the dental arch, while
the root apices remain in
their relative positions.
TOOTH TRANSPOSITION
Tooth transposition is the eruption of a tooth in a space
normally occupied by another tooth…

99. CAUSE
Shapira and Kuftinec: tooth buds interchange, retained
deciduous canines, migration of the erupting canine,
heredity, bone disease, and trauma to deciduous teeth in
cases where dilaceration of the permanent incisor roots is
found adjacent to transposed teeth.
Hitchin (1956), Platzer (1968), and Mader(1979) stated
that it probably occurs as a result of change in the usual pre-
eruptive path of the canine. Trauma to the deciduous
dentition was suggested as the possible cause for
transposition in the cases with dilacerated teeth adjacent to
transposed teeth.

100. ANKYLOSED / SUBMERGED TEETH
Nazif et al 1983
Biederman 1962
Cause (Shafer 1983)
Diagnosis-clinical
-radiograph

101. TREATMENT OPTIONS
The best treatment according to Proffit is the surgical luxation
of the tooth followed by orthodontic traction.
In case of a severely ankylosed and malpositioned tooth,
following are the treatment options:
1. Exodontia followed by reimplantation. External resorption
usually occurs .
2. Exodontia followed by placement of an osseointegrated
implant and hydroxiapatite.
3. Exodontia followed by prosthetic rehabilitation,

103. CONTENTS
 Definition
 Causes
 Mechanism of resorption and
shedding
Odontoclast
Pressure
 Pattern of shedding:
Anterior teeth
Posterior teeth
 Clinical considerations
Remanants of primary teeth
Retained primary teeth
Submerged primary teeth

104. Definition:
 James Avery 1990
 Orbans
Humans are considered
Diphyodont.

105. Causes of shedding:
 Loss of root
 Loss of bone
 Increased force

106. MECHANISM OF SHEDDING:
ODONTOCLAST:
 Derived from monocytes of circulating blood stream
 Multinucleated with clear attachment zone and ruffled
border
 Present in a cup shaped depression “Howships’s
lacuna

108.  Single rooted teeth exfoliate before
root resorption is complete.
hence, Odontoclast are generally not
found in pulp chamber of these teeth.
Odontoblast layer remain intact.
 In molars, roots are completely
resorbed & the crown is partially
resorbed before exfoliation.
hence, odontoblast layer is replaced by
odontoclast which resorb primary &
secondary dentin.

109. MECHANISM
PRESSURE FROM ERUPTING TOOTH
odontoclast appear at predicted sites of pressure
hard tissue resorption
2 phases of resorption
Extracellular Intracellular

110. Odontoclast
Hard tissue matrix
Collagen network disruptedCrystals released
Disrupted collagen fibrils
Destroyed by fibroclast
Uptake of crystals in vacuoles

111. Pressure of erupting permanent tooth:
directed to bone separating the crypt
Later eruptive force: directed at root of
primary tooth resulting in resorption of
cementum & dentin
During the process of resorption:

112. Ruffled border acts as proton pump adding H+
Primary lysosomes release hydrolytic enzymes
Large vacuoles with acid phosphatase activity
Secretion of neutral proteases including
collagenase
Clear zone represents attachment apparatus
Resorbing Root Dentin

113. Erupting successional teeth
Growth of face and jaws
Enlargement in size and strength of muscles of
mastication
Increase forces on primary teeth > PDL can
withstand
Trauma to ligament & initiation of resorption
PRESSURE

114. A)Resorption pattern in anterior teeth
 Permanent tooth germ placed lingual
to apical third of primary roots.
 Resorption begins at lingual surface
in apical third.
 followed by labial direction.
 Later resorption occurs horizontally.
 Horizontal resorption allows
permanent tooth to erupt in position.
PATTERN OF SHEDDING:

115. B) Pattern of resorption of posterior teeth
The growing premolars situated
between the roots molars
First resorption of interradicular
bone
Followed by resorption of
adjacent surfaces of primary
tooth roots.
Premolars continue to erupt
until primary molars roots are
entirely resorbed

116. To summarize
shedding:
Pressure From Erupting Tooth
Root Loss
Decreased Tooth Support
Not able to bear increased masticatory load
Exfoliation

118. CLINICAL CONSIDERATION
Remnants of deciduous teeth
Retained deciduous teeth
Submerged deciduous teeth

119. Conclusion

120. REFERENCES
 AR Tencate’s; Oral Histology 5th &6th edition
 Orban’s; Oral Histology & Embryology 11th edition
 Berkovitz; Oral Anatomy, Histology & Embryology
 James K Avery; Essentials of oral histology-A clinical
approach
 Mc Donald’s; Dentistry for child and adolescent 8th edition
 Smith; Atlas of Oral pathology

121. Am J Orthod Dentofac Orthop 1995;107:38-47
Am J Orth 1941;27: 552-576
BDJ 1996; 181(3)91-5
BDJ 2002, 192(5): 251-55
J Dent child 30: 80-4
J Clin Pediatr Dent 21(3): 205-211,1997