4. Eruption rate
Theories of eruption
Molecular event in eruption
Sequence of eruption
Factor affecting eruption
Clinical problems during eruption
Shedding
Definition
Causes of shedding
Clinical consideration
Factor affecting development of dentition
References
5. Introduction
•The word ERUPTION refers
to cutting of the tooth through
the gums
•From Latin Word
“ERUMPERE” Meaning “TO
BREAK OUT”
6. Mono-phyodont :- Only one set of teeth
Di-phyodont :- Two sets of dentition in humans
Poly-phyodont :- Develop many sets
Example :-Sharks (A new set of teeth every two
weeks to replace worn teeth)
7. Active eruption: Compensate incisal and occlusal wear
Passive eruption: Gradual recession of the gingiva and
the underlying alveolar bone
Both active and passive eruption leads to lengthening
of clinical crown
8. Definition
The movement of a tooth from its site of
development within the alveolar process to its
functional position.
( MASSlER AND SCHOUR, 1941)
9. Eruption is only part
of the total pattern of
physiological tooth
movement.
10. Some of the permanent teeth, erupt after the roots of
the deciduous tooth have been resorbed .
The deciduous teeth make this journey uninterrupted.
11. (1) Any region of a dental follicle has the potential for initiating and
regulating bone resorption & bone formation
(2) Movement of teeth during eruption preparing a path
through bone or soft tissues and moving them along this path.
3. Root formation is accommodated during tooth eruption and is a
consequence, not a cause of the process.
4 .Bone formation and root formation move an erupting tooth
through the oral epithelium and into its position within the dental
arch at the occlusal plane.
12. Active tooth eruption begins in an
intraosseous environment.
• Bone resorption, necessary for eruption, is
regulated by dental follicle.
Bone resorption & formation associated
with tooth eruption depend upon dental
follicle and is associated with high cell
proliferation.
13. • Degeneration of C.T. ( blood vessels and degeneration
of nerves) immediately overlying the erupting teeth
• Eruption pathway – altered tissue area overlying the teeth
• Macrophages destroy cells and fibers by secreting
hydrolytic enzymes
Gubernacular Cord formation
14. The permanent tooth passes through
a band of fibrous C.T.
GUBERNACULUM, connects the
tooth germ with oral mucosa.
Essentials of Oral Histology and
Embryology. James Avery,
2nd edition
15. As the successional teeth erupt, gubernacular canal
widens enabling tooth to erupt
16. Given by Noyes & Schour
Stage I: Preparatory stage (opening of the bone crypt)
Stage II: Migration of the t00th towards the Oral epithelium
Stage III: Emergence of crown tip into the oral cavity
Stage IV: First occlusal contact (clinical eruption)
Stage V : Full occlusal contact
Stage VI: Continuous eruption
18. Two types of tooth movement
in pre-eruptive phase
1. Total bodily movement
2. Relative movement:- one part remains fixed while rest
continues to grow leading to change in center of tooth
germ
19. Movements small, local and not in the direction
of eruption.
Small random movements of the forming tooth occur
during crown development. Etiology is not known.
20. Permanent premolars move from occlusal level of primary molars to a
position enclosed within the primary tooth roots
Permanent teeth develop lingual to incisal level of the primary anterior teeth ,as primary
teeth erupt, the permanent crowns are lingual to the apical 3rd of primary roots
Respond to positional changes of neighboring crowns
To compensate jaw growth
To place teeth in position
Essentials of Oral Histology and Embryology.
James Avery, 2nd edition
23. All teeth develop within the
alveolar bone of the jaws.
Challenge of intraosseous
stage is to escape from bone
Redirect the growth of
alveolar bone to surround
and support developing root.
24. These metabolic events begin in enamel epithelium &
continued &coordinated by the dental follicle.
Process can be plastic, asymmetrical to accommodate
root growth and tooth drift.
Movement of tooth through bone requires a
coordinated resorption &bone deposition.
25. Thickening and transformation of
enamel epithelium and fusion
with oral epithelium.
At this point, the rate of
eruption accelerates.
Formation of eruption pathway
is completed soon after the
cusps reach the alveolar crest.
26.
27.
28. Clinical crown:-
The exposed
crown extending from cusp
tip to the area of the gingival
attachment
Anatomic crown:-
Entire crown, extending from
cusp tip to the CEJ
29. A major accomplishment
of mucosal penetration
is formation of the
JUNCTIONAL
EPITHELIUM .
Epithelial attachment is
continually renewed over
tooth surface during
eruption.
30. Alveolar crest itself growing in height, tooth must overtake
this growth and continue eruption.
Accomplished by root growth and bone deposition at the
base of the crypt.
Pre-occlusal eruption from gingival emergence to the
occlusal plane
31. As occlusal plane is
approached, tooth eruption
slows ,but continues at a
slow pace through the 5th
decade of life.
33. Readjustment completed toward end of 2nd decade
Need of Movements divided into
1. Accommodation for
growth of jaw
2. Readjustment of
position of socket (due
to increase in jaw height)
34. • Axial posteruptive movement
• Bone & cementum is deposited and
thickened
Occlusal wear
compensated by
• Mesial drift
Interproximal wear
compensated by
• Anterior component of occlusal force
( enhance mesial drift)
• Contraction of transseptal fibers (main cause)
• Soft tissue pressure (no major role in mesial
drift)
Forces causing
mesial drift
HANAA M. A. ALY Head of Oral Biology Department Alexandria University
36. Initially,
eruption is
slow in bone.
Increases as
the penetrates
the mucosa,
Very slow as it
approaches the
occlusal plane.
Erupting teeth move at different speeds at different
times.
37. The rate of tooth eruption depends on the phase of
movement
Intraosseous phase: 1 to 10 µm/day
Extraosseous phase: 75 μm/day
Environmental factors affecting the final position of the
tooth:
Muscular forces
Thumb-sucking
38. Shifts in speed also
seen in root
formation.
It is fast at first, slows
as the apical foramen
narrows, very slow
after.
39.
40. A number of theories are advanced to account for
the forces generated during eruption.
• HUNTER 1778
Bony remodeling
theory
Root elongation
theory
Pulpal
constriction
Epithelial path
theory
42. Roots form at the time of
eruption, long been considered
as force responsible for eruption
(reviewed by Massler and Schour,
1941).
Root elongation cannot be
expected to move a tooth in
three dimensional space.
43. Evidence against the theory
Eruption of rootless teeth
Witkop, 1975; Shields et al., 1973
Submerged tooth
root formation not required for tooth
eruption, may eruption speed.
Palma C, Coelho A, Gonzalez Y, Cahuana A. Failure of eruption of first and
second permanent molar. J Clin Pediatr Dent ;2003;27:239-46.
44. Studies in NULL Mice or knock-
out Mice have shown that
rootless teeth can erupt and the
follicle is important in eruption
Damage to follicle is most reliable
predictor of failed eruption in
transplantation studies.
45. In periods of rapid root growth, bone formation occurs
only in furcation areas.
Bone growth in apical region occurs only if root growth
is not fast enough to keep up with eruption.
46. Bone deposition beneath the tooth ,
consequence of tooth eruption rather
than cause
Bone growth is partly
responsible for the pre-eruptive
phase helps tooth crypt to move
it into place for eruptive phase.
47. Dental pulp constrict due to vol. of
pulp chamber by dentin formation,
generates a propulsive force.
Evidence against the theory:-
1.Pulpless teeth erupt
2.Premolar will often jump into
occlusion
48. Hair , nail & salivary gland are end
product of epithelial down growth .
Return to surface by path , by
which the original epithelium
grew.
Enamel also an epithelial structure
49. Root grows against the Cushioned
Hammock ligament .
Hammock ligament not extend
across the socket ,only separate
pulp from follicle.
50. Fluid pressure of pulpal tissues
slightly higher than tissue above
erupting tooth.
Vasodilator drugs alter eruption rates.
Tissue fluid pressure may be important
in pre-eruptive phase.
51. Pulling forces set up in the
periodontal ligament could
account for eruption.
During collagen maturation,
cross-linkages occur , shorten
the fibre by 10%.
The theory implies that
collagen resorbed after
maturation ,allow immature
collagen to take place.
52. Drugs which inhibit cross-linkage
(lathyritic agents) reduce eruption
rates in occlusion, but not in teeth
whose eruption is un-impeded.
Illustrates capacity of tension
produced in collagen fibres to
overcome the opposing
masticatory forces.
53. The turnover of collagen in PDL
not rapid enough (half life of a few
days) .
May be consequence rather than
cause
Fibroblasts in vitro are able to
contract collagen gels,
Combination of fibroblast traction
& collagen fibres contraction ,may
account post-eruptive phase .
54. Pressure by rapidly expanding mass of
cells push the tooth out.
Drugs reduce cell division , also reduce
the eruption rate in experimental
animals
Mitotic activity in the basal tissues of the growing root.
55. Evidence Against Theory
Rats incisor root is removed
/sectioned & pinned, remainder
continues to erupt at normal rate
A tooth is prevented from erupting ,
root continues to develop by reversing
back into alveolar bone.
56. Best theory ,explain initial stage of
tooth eruption.
Coronal part of follicle start
resorbing activity when root
formation starts .
Coordinated by selective bone
growth in apical part of the follicle.
58. Schematic sketch of signaling pathway for osteoclastogenesis with
regard to the tissue segments involved (after Wise et al., 2002).
59.
60. • Pull by C.T.-by UNDERWOOD
• Alveolar bone growth – By HERMAN
Growth of periodontal
tissues theory
• By BERTEN- unilateral facial paralysis
Pressure from muscular
action
Resorption of the alveolar
crest
• By Sir Arthur Keith- thyroid and pitutary
gland
Hormonal theory
• By Gottlieb - exfoliate
Foreign body theory
• By CONSTANT 1986- submerged tooth ,
supraeruption
Vascularity theory
Blood vessel thrust theory
61. The six/four rule for primary
tooth emergence
Four teeth emerge for each 6 months of age
1. 6 months: 4 teeth (lower centrals & upper centrals)
2. 12 months: 8 teeth (1. + upper laterals & lower laterals)
3. 18 months: 12 teeth (2. + upper 1st molars & lower 1st molars)
4. 24 months: 16 teeth (3. + upper canines & lower canines)
5. 30 months: 20 teeth (4. + lower 2nd molars & upper 2nd molars)
Summary
1. By 5 months in utero, all crowns started calcification
2. By 1 year old, all crowns completed formation
3. By 2.5 years, all primary teeth erupted
4. By 4 years old, all primary teeth completed root formation
62. Rules of “sixes” in dental
development
1. 6 weeks old in utero :- Beginning of dental
development
2. 6 months old :- Emergence of the first
primary tooth
3. 6 years old :- Emergence of first permanent
tooth
63. The rules of “Fours” for
permanent tooth
development (3rd molars not included)
•At birth, four 1st molars have initiated calcification
•At 4 years of age, all crowns have initiated calcification
•At 8 years, all crowns are completed
•At 12 years, all crowns emerge
•At 16 years, all roots are complete
65. Sequence And Chronology Of Tooth Eruption
Source: http://www.columbia.edu/itc/hs/dental/d9903/lectures/lecture4.pdf
66. Sequence Of Tooth Eruption
Primary :-
CI LI 1M Cuspid 2M
L U U U L
U L L L U
Permanent :-
U1M LCI UL LCU U1PM U2PM UCU L2M L3M
L1M UCI LL L1PM L2PM U2M U3M
69. From Logan WHG and Kronfeld R; slightly modified by McCall and schour
70. From Logan WHG and Kronfeld R slightly modified by McCall and schour
71. Factor affecting
tooth eruption
Genetic factor
Sex
Socioeconomic
condition
Birth weight
Factor affecting
tooth eruption
Hormones and
vitamins
Local causes
Systemic
disorder
72. Deformities or dysfunctions tissues and cells
(Rasmussen And Kotsaki, 1997; Zou Et Al., 2003; Marks, 1995; Marks Et Al., 1996).
2. Supernumerary teeth (Cleido-cranial Dysostosis Or Apert Syndrome (Rosenblum,
1998; Schultze-mosgau Et Al., 2003; Jensen Et Al., 1990; Kaloust Et Al., 1997).
1. Multiple cysts ( Gorlin-goltz Syndrome Or In Cherubism, )
Secondary physical obstacles syndromal diseases
Syndromal diseases or hereditary disorders of tooth
development (Suri Et Al., 2004).
73. It is observed that eruption occure in girls earliar those
of boys
78. Supernumeraries,
Odontogenous Or Non-odontogenous Tumours,
Cysts Or Cleft Anomalies (Mitchell And Bennett, 1992;
Duque Et Al., 2004; Kupietzky Et Al., 2003; Flaitz Et Al.,
2001; Mcguinness Et Al., 2001).
Ankylotic Union Of Tooth And Bone (Raghoebar Et Al., 1991;
Suri Et Al., 2004; Alexander Et Al., 1980).
80. Crowding (Pulver, 1968; Bjerklin And Kurol, 1983).
(Johnsen Et Al., 1977; Northway Et Al., 2000; Yawaka Et Al.,
2002; Diab And Elbadrawy, 2000).
Premature Loss Trauma Of Primary Teeth
Disturbed Resorption
Inflammation
81. Hypoxia, Anemia, Or Renal Failure (Suri Et Al., 2004).
Radioactive Radiation (Minicucci Et Al., 2003; Appleton And Leach, 1991; Kieser Et Al.,
1996).
Exposure To Noxae Such As Tobacco Smoke
Anticonvulsants Drugs
Endocrine Dysfunction
(Suri Et Al., 2004; Barberia Leache Et Al., 1988; Pirinen, 1995).
Extreme Malnourishment (Alvarez And Navia, 1989).
84. Historical practices with no sound basis are many, and
include
Lancing the overlying gingival tissues
Applying leeches
Applying necklaces
Rubbing the gingiva with various animal extracts
administering or applying heavy metal salts or
opiates.
International dentistry S A vol. 12 no. 5
93. Arch length inadequacy or a variety of local factors
may influence a tooth to erupt in a position other than
normal.
94. Spicule of bone overlying the central occlusal fossa of
an erupting permanent molar
95. Fluid mixed with blood, eruption
hematoma
No treatment is typically needed,
Associated with erupting teeth.
Bluish and
translucent dome-
shaped soft tissue
Fluid accumulation within
the space surrounding the
erupting tooth.
96. Small white or gray lesions on mucosa, alveolar ridge
& hard palate.
75% of newborns.
Asymptomatic & shed within 1st three months of life.
97. Epstein’s Pearls
Found on
MID-PALATAL
RAPHE
of hard palate.
Bohn’s Nodules
Remnants of
SALIVARY
GLANDS,
located on
buccal or lingual
mucosa, or hard
palate, away from
the raphe.
Dental Lamina
Cysts
Located on
CRESTS OF
ALVEOLAR
RIDGES.
98. Natal : Neonatal teeth= 3:1
Natal teeth :- Present at birth.
Neonatal teeth :- Erupt within 30 days after birth.
Associated with Riga-Fede Disease Or Syndrome.
Natal teeth are first sign of some syndromes including
Ellis-van Creveld and Hallermann-Streiff.
99. 1
• Difficulties during breast
feeding (discomfort mother &
baby)
2
• Traumatic ulcerations
• Inflammation (tongue; lip)
3
• Extremely mobile
• Concern of aspiration
Riga-Fede
ulceration
100. Submerged Primary Teeth Or
Ankylosed Teeth
Source: Color atlas of clinical oral pathology. Neville, Damm and White. 2nd edition
106. Radiographic diagnosis
Physical barrier Ectopic position Primary retention
Impaction
Age of the pt.
<8 yrs 1st molar
<12 yrs 2nd molar
Observation 6 month and
control of opposing teeth
>8 yrs 1st molar
>12 yrs 2nd molar
Control of opposing teeth and
luxation
Noneruption and
favourable condition
Extraction and
alternate T/t
Noneruption and
unfavourable
condition
Eliminate
physical barrier
Treatment
Protocol For
Delayed Eruption
Palma et al; J Clin Pediatr Dent
2003;27:239-46.
2nd luxation
107. TOOTH CAUSE TREATMENT
max. incisors dilaceration, supernumerary surgical exposure
max. canines palatal unknown surgical exposure, ortho tracton
max.canine labial crowding expansion of arch or removal
mand. canine ectopic unknown removal or transplantation
max 2nd premolar crowding expansion of arch or removal
mand. 2nd premolar unknown removal or transplantation
max 1st molar mesial tilt unknown none or distalization
mand 1st molar mesial unknown none or distalization
max 1st molar infraocclusion ankylosis extraction
mand 1st molar infraocclusion ankylosis extraction
max 2nd molar follicle collision with 3rd
molar
remove 3rd or 2nd molar
mand2nd molar follicle collision with 3rd
molar
remove 3rd or 2nd molar
108.
109. The physiologic process result in the elimination of
deciduous dentition is called exfoliation or shedding.
DEFINITION
110. Shedding Of Teeth
1. Osteoclast / Bone remodeling
2. Odontoclast (cementoclast; dentinoclast)
3. Resorption of soft tissues
Pressure from successional teeth
Odontoclast
Figure Source: Dr. Sandra Meyers
111. Osteoclasts :- Bone resorbing cells derived form monocyte-
macrophage lineage
Giant multinuclear cells with 4-20 nuclei
Resorbs hard tissue by separating mineral from
collagen matrix by action of hydrolytic enzymes
Resorption occurs at ruffled border which greatly increases
surface area of osteoclast in contact with bone
114. The first sign of root resorption seen in primary CI and 1st
molar at age of 4-5 yrs.
Pressure from permanent successor induces differentiation
of odontoclast causes
Root resorption Loss of bone
Loss of
attachment
Loss of PDL
Muscular
growth &
increased
masticatory
forces
weakening of
supporting
structures
115. Shed element following “shedding of primary incisor
•Complete resorption of roots
•Resorption lacunae seen (arrow)
•Most of coronal pulp is intact
Figure Source: Dr. Sandra Meyers
116. Genetically programmed
Odontoclasts stimulated by
the pressure from erupting
permanent teeth and resorb
the root.
Resorbing concavities
howships lacuane
117. Resorption is not a continuous process
1.Periods
of activity
Resorption
occure
Leads to
looseness of
primary teeth
2.Periods
of rests
Deposition of
bone &
cementum
leads to
fixation of
primary teeth
Resorption is
faster than repair
Leads to shedding of
primary teeth
118. Molars shed with some resorption of pulp chamber,
coronal dentin & sometimes enamel
121. Parts of primary roots escape resorption remain
embedded in jaw
May exfoliate or undergo resorption
If Asymptomatic not to be disturbed
Found in region of lower E
122. Tooth retained for a long time beyond their
usual shedding schedule
Cause: Absence or impaction of
permanent successors, Trauma,
damage to dental follicle or developing
PDL lead to union bone & tooth
Retained tooth remain
functional for many years
No active eruption .
123. Causes
Infection Trauma Repair of
resorption
during shedding
May prevent their successors
from eruption or force them
out from their position
Should be
removed
128. MALPOSITION OF TOOTH
LACK OF ARCH SPACE
EARLY LOSS OF PRIMARYTOOTH
ECTOPIC ERUPTION
CONGENITAL ABSENCE OF TOOTH
ANKYLOSIS OF PRIMARY TOOTH
RETAINED DECIDUOUS
SUPERNUMERARY TOOTH
TUMOR
CYST
ABNORMAL HABIT
B. LOCAL FACTOR
129. Guidelines on management of the developing dentition and
occlusion in pediatric dentistry, AAPD v 33 /no.6 11/12
Orban’s oral histology and embryology- eleventh edition
Wheeler’s dental anatomy, physiology and occlusion eight edition
Art and science of orthodontics Textbook of orthodontics –
gurkeerat singh
Textbook of orthodontics- samir bishara
Teething, teething pain and teething remediesInternational
dentistry S A vol. 12 no. 5
Palma et al; J Clin Pediatr Dent ;2003;27:239-46.
Dental Traumatology 2011; 27: 156–158;
Posterior neonatal teeth JOURNAL OF INDIAN SOCIETY OF
PEDODONTICS AND PREVENTIVE DENTISTRY | Jan - Mar 2011 |
Issue 1 | Vol 29 |
130. Hallermann-Streiff syndrome Peter Robotta, Dr Med Dent1/Edgar Schäfer,
Prof Dr Med Dent2 QUINTESSENCE INTERNATIONALVOLUME 42 •
NUMBER 4 • APRIL 2011
Multiple natal teeth: A rare case report Suma Sogi, Shivayogi M Hugar,
Sudha Patil, Shikhar Kumar Indian Journal of Dental Research, 22(1), 2011
ODONTOMAS: REVIEW OF LITERATURE AND REPORT OF A CASE
Santosh Patil ,Farzan Rahman ,Shoaib R Tipu, Sumeeta KaswanOral &
Maxillofacial Pathology Journal [ OMPJ ] Vol. 3 No. 1 Jan - June -2012 ISSN 0976
– 1225
Trauma, solitary bone cyst and delayed eruption of permanent
mandibular incisors European Archives of Paediatric Dentistry 12 (Issue
5). 2011
131. Pediatric dentistry, Pinkham (4th ed.)
Dentistry for child & adolescent, McDonalds (8th ed.) Dentistry for child & adolescent,
McDonalds (9th ed.)
Pediatric dentistry principles & practice, MS Muthu & N Sivakumar (2nd ed.)
Textbook of pedodontics, Shobha Tandon (2nd ed.)
Principles & practice of pedodontics, Arathi Rao (3rd ed.)
Textbook of pediatric dentistry, SG Damle (4th ed.)
Contemporary orthodontics, william r. profit (4th ed.)
Text book of orthodondontic , graber