development of teeth and occlusion in details, starting from the gum pads to till the permanent occlusion

2. Development of
occlusion

3. Definition
OCCLUSION
Maximum intercuspation of maxillary and mandibular
teeth with minimal overjet and overbite when the jaws
are closed.
It is the normal relationship of the so called occlusal
inclined planes of the teeth when the jaws are closed,
accompanied by the correct proximal contacts and
axial positioning of all teeth, and the normal growth,
development, location and correlation of the various
associated tissues and parts.

5.  The mouth of neonate
 The primary teeth and occlusion
 The mixed dentition period
 Permanent teeth and occlusion
 Dentitional and occlusal development in young adult
 Clinical Implications

6. PRE-DENTAL
PERIOD/
DENTATE
PERIOD
DECIDUOUS DENTITION
PERIOD
MIXED
DENTITION
PERIOD
PERMANENT
DENTITION
PERIOD
Period after
birth, neonate
does not have
any teeth.
Lasts for 6
months after
birth.
Primary teeth begin to
erupt at the age of 6
months
Completed by 2-21/2
years of age.
Begins at
around 6
yrs of age
Deciduous
and
permanent
teeth
present.
Presence
of all
permanent
teeth.
DEVELOPMENTAL PERIODS

7. FEATURES
PRE-DENTAL
PERIOD/
DENTATE
PERIOD
DECIDUOUS
DENTITION PERIOD
MIXED
DENTITION
PERIOD
PERMANENT
DENTITION
PERIOD
Alveolar
ridge is
called as
‘gum pads’.
Spacing in
deciduous
dentition.
Terminal plane
relation of the
deciduous molars.
Deep bite.
 First
Transitional
period.
 Emergence of the
first permanent
molars.
 The exchange of
deciduous
incisors with the
permanent
incisors.
Angle’s class
1
 Angle’s class
2
Angle’s class
3

8. PRE-
DENTAL
PERIOD/
DENTATE
PERIOD
DECIDUOUS
DENTITION PERIOD
MIXED DENTITION
PERIOD:
PERMANEN
T
DENTITION
PERIOD:
Flat curve of
Spee.
Shallow cuspal
interdigitation.
Incisors are more
vertically placed.
 Inter-
transitional
period.
 Second
transitional
period.
 Leeway space of
Nance.
 Ugly duckling
stage.

10. BARNETT’S STAGES OF OCCLUSAL DEVELOPMENT

11. PREDENTATE PERIOD

12. PRE-DENTAL / DENTATE PERIOD
 THE GUM PADS
 The alveolar process at the time of birth are known as GUM PADS.
 They are pink, firm, horse shoe shaped and covered by a dense layer
of fibrous periosteum.
 They develop into two parts: labio-buccal portion and lingual portion
and are separated from each other by a groove called as the ‘Dental
Groove’

13. 1. They are divided into ten segments by ten grooves called
‘Transverse groove’
2. The transverse groove between the canine and first
deciduous molar segment is called the ‘lateral sulcus’
3. ‘Gingival groove’ separates the gum pad from the palate
and floor of the mouth in upper n lower arch separately.
4. The upper and lower gum pads are similar to each other.

14. Predentate Period
Anatomy of Gum pads
 Dental groove
 Gingival groove
 Transverse groove
 Lateral sulcus

15. Predentate Period: Gum pads
 Arch-
 Complete overjet
 Contact area
 Infantile anterior open
bite

16. Not normal in……
Predentate Period
 Precociously
erupted primary
teeth
 Natal teeth
 Neonatal teeth
 Pre-erupted teeth
 Predeciduous teeth
At birth, during 1st month, during 2-3 months,
supernumerary calcified structure.

17. Natal, neonatal teeth
 Natal teeth- teeth that are already present at the
time of birth.
 Neonatal teeth- teeth which grow in during the
first 30 days after birth.
 Precocious Dentition- teeth erupting during the
3-5th month of life.
 Normal Dentition -6 months

18. 85% are the deciduous mandibular incisors
and are more frequent among females..

20. Clinical appearance:
The appearance of each natal teeth can be classified into 4
categories:
categorie 1 Shell like crown structure loosely attached to
alveolus by the oral mucosa.
categorie 2 Solid crown loosely attached to alveolus by
oral mucosa.
categorie 3 Incisal edge of crown just erupted through
mucosa.
categorie 4 Mucosal swelling with tooth unerupted but
palpable.

21. Associations
 Most of the time, natal teeth are not related to a
medical condition. However, sometimes they may be
associated with:
 Ellis-van Creveld Syndrome
 Hallermann-Streiff syndrome
 Riga fede desease
 Soto syndrome

22. Complications:
 Traumatic ulcerations on ventral surface of tongue,
frenulum and lip.
 Ulcerations of sublingual area in infants (Cardarelli
1857)
 In 1881 Riga and Fede described this lesion
histologically.

23. Predentate Period :
Self correcting anomalies
 Retrognathic mandible
 Anterior open bite

24. Predentate Period:
Self correcting anomalies
Infantile swallowing pattern Introduction of solid
food in diet
 Characteristic features (Moyers)
 During swallowing jaws are apart and tongue is placed between
gum pads
 Mandible is stabilized by contraction of facial muscles

25. DECIDUOUS DENTITION
PERIOD

26. Teething
Child is accompanied by number of relatively minor symptoms.
 Signs and symptoms associated with teething
-pain
-inflammation
-general irritability
-disturbed sleep
-drooling
-gum rubbing/biting/sucking
-loss of appetite
- diarrhea
- intra oral ulcers
- increase in body temperature

27. 27
Management:
- Teething rings
- Hard sugar free teething
rusks
- Frozen items
- Pacifier

28.  Pharmacological management :
Topical agents : this group of medicaments includes
local anesthetics and minor analgesics.
Lignocaine products : Lignocaine HCl is a local
anesthetic that is rapidly absorbed through mucous
membrane giving relief from pain.
Around 7.5 of gel should be placed on a clean finger
or cotton bud and rubbed onto the painful area.

29.  Choline salicyate based products :
their main pharmacological advantage over Lignocaine
based preparations is that in addition to providing
analgesia they also possess anti-inflammatory and
antipyreticproperties thus reducing swelling.
 Systemic analgesics :
 Paracetamol –
Recommended dose : 3-12 months = 60-120mg
1 -5 yrs = 120-250mg
These doses are repeated at 4-6 hourly interval .

30. DECIDUOUS DENTITION PERIOD
FEATURES:
SPACING IN DECIDUOUS DENTITION
TERMINAL PLANE RELATION OF THE DECIDUOUS MOLARS
DEEP BITE
THE DENTAL ARCHES ARE WIDE ‘U’ SHAPED
FLAT CURVE OF SPEE
SHALLOW CUSPAL INTERDIGITATION
INCISORS ARE MORE VERTICALLY PLACED

31. SPACING OF DECIDUOUS DENTITION
Physiological spaces or developmental spaces.
 The presence of spaces in the primary dentition is
important for the development of permanent dentition and
absence of spaces in the primary dentition is an indication that
crowding of teeth occur.
 In maxillary arch-4mm
 In mandibular arch-3mm

32. PRIMATE SPACES:
 Spacing seen mesial to
the maxillary canines and
distal to the mandibular
canines are wider than in
other spaces.
 These physiological
spaces are called
Primate spaces or
Simian spaces or
Arthropoid spaces.
(Baume)

33. TERMINAL PLANE RELATION OF THE
DECIDUOUS MOLARS
 The mesio-distal relation between the distal
surfaces of the upper and lower second deciduous
molars is called the terminal plane.
 There can be 3 types are given by Baume:
1) Flush terminal plane
2) Mesial step terminal plane
3) Distal step terminal plane.

35. DEEP BITE
 A deep bite may occur in the initial stages of
development.
 The lower incisal edges often contact the cingulum
area of the maxillary incisors.
 This deep bite is later reduced.

36. Deciduous dentition
Primary dental arches
 Arch length and circumference

37. Deciduous dentition:
Primary dental arches
 Arch width

38. Deciduous dentition:
Development of occlusion
 Primary dental arches
 Ovoid in shape
 Role of tongue
 In maxilla
 Increased intercanine width by
6 mm between 3-13 yrs
 Increased Intermolar width of
2 mm between 3-5 yr

39. Development of occlusion
 In mandible
 Increased intercanine
width by 3.7 mm between
3-13 yrs
 Increased Intermolar width
of 1.5 mm between 3-5 yr
 Loss of arch length in
mixed and permanent
dentition
 Up righting of incisors,
loss of leeway space

40. Self correcting anomalies of
Deciduous dentition
 Anterior deep bite

41. Self correcting anomalies of Deciduous
dentition
 Physiologic spaces

42. Self correcting anomalies of Deciduous
dentition
 Primate space
 Early mesial shift
 Flush terminal plane
 Early mesial shift
 Late mesial shift
(Leeway space)

43. Thank you

44. MIXED DENTITION PERIOD
 The mixed dentition period can be
classified into three phases:
1. First transitional period.
2. Inter-transitional period.
3. Second transitional period.

45. FIRST TRANSITIONAL
PERIOD
 The first transitional period is characterized
by:
1. Emergence of the first permanent molars.
2. The exchange of deciduous incisors with the
permanent incisors.

46. EMERGENCE OF THE FIRST
PERMANENT MOLARS
 The location and relation of the first permanent molar
depends much upon the distal surface relationship
between the upper and lower second deciduous
molars.
 The first permanent molars are guided into the dental
arch by the distal surface of the second deciduous
molars.

47.  Early Mesial Shift:
the forward
movement of the first
permanent molar utilizing the
primate space is termed as
Early Mesial
Shift.(baume1951)
 Late Mesial Shift:
when the deciduous
second molars exfoliate the
permanent first molars drift
mesially utilizing the leeway
space. This occurs in the late
mixed dentition period and is
called Late Mesial
Shift.(clinch,davey1951)

48. First transitional period -- Baume classification
Terminal plane Permanent dentition
Flush terminal plane Initially endon, later class I
Mesial step terminal plane Initially class I, later classIII
Distal step terminal plane Class II

49. Mixed dentition
First transitional period
 Incisor eruption
 Mandible
 Develop lingually to primary
roots
• Exfoliation of deciduous .lateral
.incisor
– activation of eruption and
labial movement
 Lateral eruption- Crowding

50. Mixed dentition
First transitional period

51. The exchange of incisors
 The mandibular central incisors are usually the first to
erupt.
 The permanent incisors are considerably larger than
the deciduous teeth they replace.
 This difference between the amount of space needed
for the accommodation of the incisors and the amount
of space available for this is called incisor liability.
 The incisal liability is roughly about 7 mm in the
maxillary arch and about 5 mm in the mandibular arch
(wayne)

52.  THE INCISAL LIABILITY IS OVERCOME BY
THE FOLLOWING FACTORS:
A. Utilization of physiologic spaces seen in
primary dentition.
B. Increase in inter-canine width.
C. Change in incisor inclination

53. INTER-TRANSITIONAL PERIOD
 In this period the maxillary and mandibular
arches consist of deciduous and permanent
teeth.
 Between the permanent incisors and the first
permanent molars are the deciduous molars and
canines.
 This phase during the mixed dentition period is
relatively stable and no change in occur.

54. SECOND TRANSITIONAL PERIOD
 The second transitional period is characterized
by the replacement and alignment of the
deciduous molars and canines by the premolars
and permanent cuspids respectively.
 The feature of second transitional period are:
1. Leeway space of Nance.
2. Ugly duckling stage.

55. Mixed dentition
Second transitional period
 Mandible
 Favourable eruption sequence
 6-1-2-3-4-5-7
 Maxilla
 Sequence of eruption
 6-1-2-4-5-3-7 or 6-1-2-4-3-5-7

56. Mixed dentition
Second transitional period
 2nd molar eruption
 Last to erupt before 3rd molar

57. LEEWAY SPACE OF NANCE
The combined mesio-distal width of the
permanent canines and premolars is
usually less that of the deciduous
canines and molars.
The surplus space is called Leeway
space of Nance.
The amount of leeway space is greater
in the mandibular arch than in the
maxillary arch.
Maxilla = 1.8 mm
Mandible = 3.4 mm

58. Mixed dentition
 Self correcting
anomalies
 Anterior open bite

59. THE UGLY DUCKILNG STAGE
 Also known as BROADBENT
PHENOMENON.
 It is a transient or self correcting
malocclusion seen in the maxillary
incisor region between 8-9 years of age,
seen during the eruption of the permanent
canines.
 As the developing canines erupt, they
displace the roots of the lateral incisors
mesially. This results in transmitting of
the force on to the roots of the central
incisors which also get displaced
mesially.
 A resultant distal divergence of the
crowns of the incisors occur leading to
creation of diastema in the incisor region.
 This condition usually corrects by itself
when canines erupt as the pressure is
transferred from the roots to the crown of
the incisors.

60. Mixed dentition:
Self correcting anomalies
 Mandibular anterior
crowding
 Increased intercanine width
 Tongue pressure
• Labial movement and
inclination of incisors

61. Mixed dentition:
Self correcting anomalies
 Ugly Duckling
Midline diastema
 Eruption of canine
7 Year
8 Year 11 Year

62. Mixed dentition:
Self correcting anomalies
 End on molar
relation
 Late mesial shift
 Leeway space

63. PERMANENT DENTITION PERIOD
All the teeth have erupted in the oral cavity.
Three types of permanent molar relation
1. Angle’s class 1: mesiobuccal cusp of the maxillary
first permanent molar occludes with the buccal groove
of the mandibular first permanent molar.
2. Angle’s class 2: The distobuccal cusp of the maxillary
first permanent molar occludes with the buccal groove
of the mandibular first permanent molar.
3. Angle’s class 3: The mesiobuccal cusp of the 1st
molar occludes between first and the second
permanent molars.

64. Features of permanent dentition
period
 Coinciding the midline
 classI molar relationship of
permanent Ist molar
 Decrease overjet and overbite
 Curve of spee

65. Dentition and occlusal changes in young adults
 Curve of Wilson:-
 A mediolateral curvature
to occlusal plane
 Curve that contacts the
buccal and lingual cusp
tips of posterior teeth
• Maxillary arch
– Slight buccal
inclination
• Mandibular arch
– Lingual
inclination

66. Dentitional and occlusal changes in young adults
 Curve of spee
 Anteroposterior
direction the occlusal
plane
 Inclination of teeth in
lateral view
 The average value
2.5 – 3 mm

67. Andrew’s six keys of occlusion
(1960-1964)
 Inter- arch
relationship
 Molar
 Maxillary 1st
• Mesiobuccal cusp
• Mesiolingual cusp
• Distal marginal ridge
The mesiobuccal cusp of the permanent maxillary first molar occludes
in the groove between the mesial and middle buccal cusps of the
permanent mandibular first molar.

68. Andrew’s six keys of occlusion
 Mesio-distal crown
Angulation
 The gingival portion
of the long axis of
crown is more distal
than the incisal
portion

69. Andrew’s six keys of occlusion
 Labio-lingual crown
inclination
 Maxillary incisors
 Positive inclination
 Mandibular incisors
 Slightly negative
inclination.

70. Andrew’s six keys of occlusion:
Labio-lingual crown inclination
 The Canines and premolars
 negative and similar.
 Maxillary first and second molars
 More negative than canines and premolars.

71. Andrew’s six keys of
occlusion
 Absence of rotation

72. Andrew’s six keys of
occlusion
 Tight contact

73. Andrew’s six keys of occlusion
 Curve of spee
 The depth of the curve of Spee ranges from a flat
plane to slightly concave surface.

74. THANK YOU