Tooth eruption and shedding, pedodontics -Binaya Bhandari, KUSMS, Dhulikhel, Nepal

1. Tooth Eruption and Shedding
Presented by;
Binaya Bhandari
BDS, final year
KUSMS , NEPAL
1

2. Contents
• Introduction of eruption
• Phases of eruption
• Theories of eruption
• Mechanism of resorption and shedding
• Chronology of human dentition
• Teething and teething problems
• Management of teething problems
• Conclusion
• References 2

3. Eruption
• Eruption is defined as a process whereby the
forming tooth migrates from its intraosseous
location in the jaw to its functional position
within the oral cavity. [ Maury Massler and Schour, 1941 ]
• It is catagorized into three phases
Phase 1 : The pre-eruptive phase
Phase 2 : The eruptive phase
Phase 3 : The post-eruptive phase
3

4. 1. Pre-Eruptive phase
4
-Preparatory phase
- Movement of developing tooth
germs within alveolar processes
prior to root formation
- Bodily movement
-Eccentric growth

5. 2. Eruptive phase
5
Noyes and Schour;
Stage 1 : Preparatory stage
(Opening of bony crypts )
Stage 2 : Migration of tooth
towards the oral epithelium
Stage 3 : Emergence of crown
tip into the oral cavity
Stage 4 : First occlusal contact
Stage 5 : Full occlusal contact
Stage 6 : Continuous eruption

6. 6
The rate of tooth eruption depends on the type of
movement
6
•1 to 10
µm/day
INTRAOOSEOUS
PHASE
•75
μm/day
EXTRAOSSEOUS
PHASE

7. 3. Post- Eruptive phase
• movements made by the tooth after it has
reached its functional position in the occlusal
plane.
77
Accommodation
for growth
Compensation for
occlusal wear
Accomodation for
interproximal wear

8. • ACCOMMODATION FOR GROWTH - Mostly
occurs between 14 and 18 years by formation of new
bone at the alveolar crest and base of socket to keep
pace with increasing height of jaws.
• COMPENSATION FOR OCCLUSAL WEAR -
Compensation primarily occurs by continuous
deposition of cementum around the apex of the tooth.
However, this deposition occurs only after tooth moves.
• ACCOMMODATION FOR INTERPROXIMAL
WEAR - Compensated by mesial or approximal drift.
8

9. Theories of Tooth eruption
• Root elongation theory
• Pulpal constriction theory
• Growth of periodontal tissues
• Pressure from muscular action
• Resorption of alveolar crest
• Hormonal theory
• Foreign body theory
• Cellular proliferation theory
• Vascularity theory
• Blood vessel thrust theory
• Periodontal ligament contraction theory
• Dental follicle theory
• Bone remodelling theory 9

10. 1. Root elongation theory
• Simplest and most obvious mechanism
10
Growth and elongation of roots
Teeth pushed into the oral cavity
Evidence against this theory;
-Rootless teeth
-submerged teeth

11. 2. Pulpal constriction theory
11
Growth of root dentin and
constriction of pulp
Tooth moves occlusally
pressure
Evidence against this theory;
-Pulpless teeth
- Permanent premolar jump
into occlusion after premature
extraction of decidious molar

12. 3. Growth of periodontal tissue
12
-Teeth is pulled by surrounding
connective tissue
-Alveolar bone growth
Evidence against this theory;
- Histologically; Periodontal fibers
are being pulled by tooth and not
vice versa
-Radiographically/Histologically ;
Bone doesn’t actually touch the
tooth

13. 4. Pressure from muscular action
13
Musculature of cheek and lips
upon alveolar process
Squeeze the crown of tooth out
in oral cavity
Evidence against this theory;
-Teeth even erupts in cases of
unilateral facial paralysis

14. 5. Resorption of alveolar crest
14
Resorption of alveolar crest
Expose the crown of the tooth in
oral cavity
Evidence against this theory;
-Histologically; alveolar crest is the
site of most rapid and continuous
growth of bone

15. 6. Hormonal theory
15
Hormones secreted by thyroid and
pituitary gland
Govern eruption of teeth
Evidence against this theory;
- Doesn’t explain the mechanism of
teeth eruption

16. 7. Foreignbody theory
16
Calcified body such as tooth tends
to be exfoliated by tissues just as
does any foreign body

17. 8. Cellular proliferation theory
17
Cellular proliferation of pulpal and
surrounding tissues
Increased osmotic pressure and forces
Eruption of teeth

18. 9. Vascularity theory
18
Rich vascular supply between teeth
and its bony surroundings
Increased pressured by vessels
Eruption of teeth
- Hyperemia; even submerged teeth
erupts
- Hyperemia in periodontitis-
supraeruption of teeth

19. 10. Blood vessel thrust theory
19
Blood supply to the teeth
Hydrodynamic and hydrostatic
forces within blood vessels
Eruption of the teeth

20. 11. Periodontal ligament contraction
theory
20
Shrinking and crosslinking of
fibroblast within periodontal
liagament
Traction forces like locomotion
Eruption of teeth

21. 12. Dental follicle theory
21
Reduced enamel epithelium
cascade of intercellular signals
recruits osteoclast to the follicle
bone remodelling
erution of teeth

22. 13. Bone remodelling theory
22
Bone remodeling
The growth pattern of the maxilla and the
mandible moves teeth by selective deposition
and resorption of bone.
Major proof is when a tooth is removed
without disturbing its follicle tooth germ, an
eruptive pathway still forms within bone as
osteoclasts widen the gubernacular canal.
If the dental follicle is also removed no
eruption path develops.
It establishes absolute requirement for a
dental follicle to achieve bony remodeling
and tooth eruption.

23. 23
Shedding of Decidious teeth

24. 24
Shedding of Decidious teeth
• shedding or exfoliation of deciduous teeth is a
term given to describe the physiologic process
that ultimately leads to replacement of the
deciduous teeth by their corresponding
permanent successors
• resorption with permanent sucessor
• resorption with out permanent sucessor
24

25. Resorption with permanent sucessor
25
Anterior teeth resorption with
permanent sucessor
-Resorption of lingual surface of
apical third of primary tooth root.
-Resorption of labial surface.
-Resorption proceeds horizontally in
incisal direction until primary tooth
sheds & permanent tooth erupts.

26. Resorption with permanent sucessor
26
Posterior teeth resorption with
permanent sucessor
-The growing crown of the
permanent posterior teeth are
situated between the roots
between primary molars
- Initiation is by resorption of
inter-radicular bone followed by
resorption of the adjacent
surfaces of the root of primary
tooth

27. Resorption without permanent
sucessor
• The root is protected from resorption by presence of narrow
PDL cell layers which are composed of:
- Collagen fibers
- Fibroblasts
- Cementoblasts
• Degradation of PDL precede root resorption & removal of
collagen fibers of PDL is considered main step in initiation of
this process.
• As face grows & muscles of mastication enlarge, forces that
are applied on the deciduous teeth become heavier than
periodontal ligament can withstand primary tooth .
27

28. Problems associated with shedding
28
Remnant of decidious dentition;
-parts of the root of decidious
teeth embeded in jaw for
considerable time
-frequently found in association
with permanent premolars
because the roots of lower 2nd
decidious molars are strongly
curved or divergent
Retained decidious teeth;
-Absence of permanet sucessor
- impacted permanent sucessor

29. Nolla’s stage of teeth eruption,1952
29

30. Chronology of human dentition
30
Sequence of primary teeth eruption
Maxillary arch ; A-B-D-C-E
Mandibular arch ; A-B-D-C-E
Sequence of permanent teeth
eruption
Maxillary arch ; 6-1-2-4-5-3-7
Mandibular arch; 6-1-2-3-4-5-7

31. Chronology of human dentition
31
7 ½
9
18
14
24
20
12
16
7
6

32. Chronology of human dentition
32

33. Importance of primary teeth
-Chewing on well-formed teeth helps the jaw bones to grow
and develop properly.
-provide proper space for the eruption of permanent teeth.
-are necessary for proper chewing of food, and normal
digestive processes.
-are also necessary for learning speech sounds and proper
language development.
-Healthy baby teeth are also important for a child's self-
esteem and well being
33

34. Problems associated with primary
teeth eruption
• Teething
• Eruption cyst
• Eruption sequestration
• Ectopic eruption
• Non-eruption
• Natal and neonatal teeth
34

35. 35
Signs and symptoms of teething;
-Pain
-Inflammation
of mucous membrane
-General irritability/malaise
-Disturbed sleep/wakefulness
-Facial flushing/ circumoral rash
-Drooling/sialorrhea
-Gum rubbing/biting/sucking
-Constipation/diarrhea
-Loss of appetite
-Ear rubbing
Management
Non pharmacological
-Teething rings (chilled)
-Hard sugar-free teething rusks
-cucumber (peeled)
- Frozen items like bananas, vegetables
-Pacifiers
-Rub gums with clean finger, wet guaze
-Reassurance
Pharmacological
-Analgesic/antipyretics
-Topical anesthetic agents
-Alternative holistic medicine
Teething .. Process of eruption of first
teeth into the oral cavity

36. 36

37. Steward’s approch to teething
• 1st approach – give the child
freezed teething rings to bite
- greatest relief
• If pain is troublesome, give
appropriate dose of sugar
free paracetamol elixir every
4-6 hourly
• Additional analgesia –
lignocaine based teething
gels 37
Paracetamol
3-12 months = 60-120 mg
1-5 years = 120-150 mg
Lignocaine
7.5mm of gel should be
placed on a clean finger or
cotton bud, and rubbed into
painful areas.

38. Teething problems
38
-Eruption hematoma
-Eruption sequestratrum
-Ectopic eruption
-Natal and neonatal teeth
-Non eruption teeth

39. Eruption hematoma (eruption cyst)
- blood filled cyst
-bluish purple, elevated area of tissue
-occasionally develops few weeks before eruption
of primary/permanent dentition
-results due to trauma to soft tissue during function
-subsides after eruption of teeth
-common area; primary 2nd molar or permanent 1st
molar region
39

40. Eruption hematoma (eruption cyst)
40

41. Eruption sequestrum
-ocasionally seen in the children at the time of eruption of 1st
permanent molar
-composed of cementum like material formed within the
dental follicle
-Hard tissue fragments is generally overlying the central fossa
of associated embedded tooth and contoured of soft tissue
-as tooth erupts, the cusp emerge the fragment sequestrates
-usually little or no clinical significance
41

42. Ectopic eruption
- due to arch length inadequacy or a variety of
local factors
42

43. Natal and neonatal teeth
• -Teeth if present at birth – natal teeth
-Teeth if present within thirty days of life – neonatal
teeth [ Massler and Savara, 1950]
43
Clinical appearance
-most commonly affected -
lower primary central incisor
- normal teeth to poorly
developed, small, conical,
yellowish, white hypoplastic
enamel or dentin and
underdeveloped root

44. Natal and neonatal teeth
44
Etiology
-Hypovitaminosis
- Hormonal stimulation
-Trauma
- Febrile states
-Syphilis
[current concept – superficial
position of the developing tooth
germ predisposes tooth to erupt
early]

45. Natal and neonatal teeth
45

46. Natal and neonatal teeth
46
Management;
-Radiograph : amount of root
development
-Topical chlorhexidine application:
inflammed gingiva around teeth
-Selective grinding of teeth : sharp
incisal edge
- Removal of hypermobile teeth :
avoid risk of aspiration
-Curettage of socket after
extraction : remove any
odontogenic cellular remnants
Complications;
-Traumatic ulceration on the
ventral surface of the tongue,
frenum or lips, ulceration on the
sublingual area.
-Riga and Fede 1881, 1890
decribed “Riga – Fede disease”

47. Non-eruption of teeth
47
Noneruption teeth;
In case of non eruption of teeth
beyond their common schedule
Advisable to give a minor incision to
facilitated their eruption if they are
no associated with impaction or
pathologies
Local causes:
-mucosal barrier
-supernumerary teeth
-injuries to primary teeth
Genetic causes :
-Gardner syndrome
-Cleidocranial dysplasia
Endocrinal causes :
-Hypothyroidism
-Hypoparathyroidism
-Hypopituitarism

48. FACTS
• Why primary teeth are called milk teeth?
- Milk teeth are called so due to their white
color which resembles the color of milk. The
milk teeth are whiter than the permanent
teeth which replace them. The refractive
index of milk teeth is 1.338, similar to that
of milk and hence they are called so.
48

49. FACTS
• Why there is no bleeding on eruption of teeth?
-Reduced enamel epithelium unites with the oral
epithelium.
- REE has no blood supply, As the cells of
the reduced enamel epithelium degenerate,
the tooth is revealed
- The crown breaks the double layer epithelium
overlying it and enters the oral cavity
49

50. FACTS
• Accelerating factors
- Hyperthyroidism
-Hperparathyroidism
-Hyperpituitarism
• Decelerating factors
-Hypothyroidism
-Hypoparathyroidsm
-Hypopituitarism
50

51. Conclusion
• For the clinicians to treat dental problems
knowledge of proper eruption time is very
important .
• A variety of developmental defects that are
evident after eruption of the primary and
permanent teeth can be related to local and
systemic factors.
51

52. References ;
• Textbook of pediatric dentistry- 3rd edition- Nikhil marwah
• Textbook of pedodontics – 2nd edition – Sobha Tandon
• http://www.healthunit.org/dental/children_oral/primary_tee
th_facts.htm
• http://www.32teethonline.com/pediatric-dentistry-teeth-
dental%201.htm
• https://www.google.com/search.wikepedia
• http://www.hindawi.com/journals/scientifica/2014/341905/
• http://phpa.dhmh.maryland.gov/oralhealth/docs1/fact_sheet
s/Infant_and_Toddler_OH-teething.pdf
• https://dentalpguploads.wordpress.com/2013/05/06/nollas-
stage-of-tooth-eruptionaiims-12/ 52

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