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These are lectures of The Gulfie Dentist Online Coaching
19 AUG 2020
19 AUG 2020 · BONE FORMATION / OSSIFICATION :-
INTRAMEMBRANEOUS- within membrane
ï‚· Ossification takes place in the membranes of connective tissue.
ï‚· Cells in the membrane differentiate into osteoblasts,
ï‚· A collagen matrix is formed, which undergoes ossification
ï‚· So basically, these bone is formed from collagen matrix.
ï‚· Mostly flat Bones: maxilla, majority of mandible & cranial vault*
ENDOCHONDRAL – within cartilage
ï‚· Bone formation takes place From within a hyaline cartilage
ï‚· Cartilage cells are replaced by bone cells,ie. osteocytes replace chondrocytes.
ï‚· short and long bones are formed this way
ï‚· ethmoid, sphenoid, occipital (synchondrosis of bones of cranial base*)
ï‚· Some part of mandible (condylar head region)
ï‚· MANDIBLE BONE FORMATION IS BY BOTH endochondral + intramembraneous
19 AUG 2020 · BONE GROWTH
 Don’t confuse bone growth with bone formation above
 Growth of bone is by apposition — layer by layer deposition
ï‚· Whereas cartilage growth is by two ways one is appositional and other is interstitial method, which is how mandibular condyle grows.
ï‚· Mandible growth starts at 6th wk of IUL & completes at 12-13 years
 Individual — 1st bone to ossify — clavicle— entire body
 1st bone to ossify in head — mandible -2nd bone to ossify overall
ï‚· Maxilla growth starts after mandible but completes earlier than mandible
Start (6th wk of IUL)----- (MANDIBLE) --------------finish (12-13 years)
-----------------START -------------------FINISH-------------------------
-------------------------------MAXILLA-----------------------------------
MANDIBLE
 Primary cartilage of mandible — Meckel’s cartilage
but it does not individually induce or contribute to
mandibles growth
 Secondary cartilage — condylar cartilage
ï‚· This cartilage contributes to its growth*
 Direction of growth — anterior and inferiorly
 Direction of apposition @ condylar — posteriorly and superiorly
ï‚· V shape principle- is shown by the mandibular growth
MAXILLA
ï‚· Formed entirely by intramembranous ossification
ï‚· Growth is by apposition at sutures and surface remodelling
 Direction of growth/migration – downward and forward
 Direction of apposition – downward at alveolar area and at tuberosity area
ï‚· MAXILLA IN A NUTSHELL:
o Increases in height by continuous growth at alveolar bone
o Increases in width by mid-palatine suture
o Increases in depth by apposition at anterior region and tuberosity
19 AUG 2020 · SCAMMON’S GROWTH CURVE — GROWTH SPURTS
4 GROWTH SPURTS
1. JUST BEFORE OR AT BIRTH - Most rapid growth in human occur during pre-natal period
2. 1 YEAR AFTER BIRTH
3. PRE-PUBERTAL [GIRLS 5-6YEARS., BOYS 6-8 YEARS]
4. PUBERTY [GIRLS 10-12, BOYS 12-14]
Mandibular growth coincides with 4th growth sprout ie; pubertal
growth
A. Neural — Brain
a. At birth 50%
b. At 4-6 years — 95%
c. So below this age, ie around 3 yrs child will not be able to differentiate colours, tell his name and so.
d. Complete at 15 years age — 100%
B. Genital
a. Begins at 12 years
b. Complete at 18 years
C. Lymphoid / immunity
a. At peak — 200% — 12 years
b. Complete — 100% — 18 years
∴ immunity is highest in children
19 AUG 2020 · BONE JOINTS
 SYNOSTOSIS
Bone formed b/w two bone junction
 SYNCHONDROSIS
Cartilage formed at the junction of two bones
Eg. Spheno-occipital synchondrosis
 SYNDESMOSIS
Ligament formed at the junction of two bones
Eg: stylohyoid
PAIRED & UNPAIRED BONES
Total no. of bones in skull :-
 At birth — 45 bones
 Later — 22 bones *
Unpaired bones in skull :-
A. Frontal [FACE OF SUHAIRA EPPO VIDARUM MACHA?]
B. Occipital
C. Sphenoid
D. Ethmoid
E. Vomer
F. mandible
REST ALL ARE PAIRED
19 AUG 2020 · DEVELOPMENT OF OCCLUSION
 GUM PADS
ï‚· 0-6 months of age
ï‚· Anterior open bite
ï‚· So such complaint of open mouth by mother at this age
o Rx — self correcting anomaly ! (SCA)
 NATAL TOOTH – tooth present at birth
 NEONATAL TOOTH — tooth formed within 15 –
30 days.
 Most common — mandibular (anterior) central incisor
 Syndrome — Rege fede syndrome
 Inability to suck milk —
ï‚· Nutritional deficiency
ï‚· Lower part of tongue irritation.
 ALVEOLAR RIDGE
Transverse grooves — it divides the gum pad into 10
segments for future eruption of the teeth.
CALCIFICATION DATES
 1st calcification seen at 14 weeks of IUL, max sinus develops
 12th week – mandible
 6-10weeks- palate
 4-6 weeks- lip
 In pedo root formation completes 1year after eruption
 As a general rule,
o four teeth erupt for every six months of life,
o mandibular teeth erupt before maxillary teeth,
o teeth erupt sooner in females than males.
o During primary dentition, the tooth buds of permanent teeth develop below the primary
teeth, close to the palate or tongue. Tooth bud is always — lingual / palatal and inferiorly
placed.
19 AUG 2020 · PEDO TEETH
 Smallest — mandibular L1
 First erupting — mandibular C1
 Largest tooth — mandibular 2nd M
PERMANENT TEETH
 Smallest — mandibular CI
 Largest — maxillary 1st M
 First erupting — mandibular CI
SPACES
 In primary teeth — physiologic space
ï‚· It is self correcting anomaly
ï‚· Midline Diastema
 Maxillary 1.7mm — mesial to C
 Mandibular 1.5mm — distal to C
ï‚· They are known as Primate space or Anthropoid space or Simmian space.
SELF CORRECTING ANOMALIES
o Anterior deep bite — 6 months age anomaly
o (SCA) — Self correcting as posterior teeth erupts
o (self – correcting anomaly)
19 AUG 2020 · DECIDUOUS OCCLUSIONS :- PRIMARY 2ND MOLARS
FLUSH TERMINAL PLANE (SCA)
ï‚· Most Commonly seen occlusion*
ï‚· Straight line occlusion
EDGE TO EDGE OR END ON
Crowded , Improper jaw growth
CLASS I OCCLUSION
Mesiobuccal cusp of maxillary 1st M in the mandibular mesiobuccal groove
Usually a flush terminal will end up in class 1 itself
Self – correcting anomaly
MESIAL STEP OCCLUSION
ï‚· Ideal Occlusion
CLASS III – When space is utilized
CLASS I – If space not utilized
DISTAL STEP OCCLUSION
CLASS I – If space is utilized
CLASS II- if space is not utilized
 MIXED DENTITION :-
o Started #6 eruption of mandibular 1st Molars
o Finishes #3 eruption of maxillary C or #5 eruption of mandibular 2nd PM
19 AUG 2020 · PERMANENT SEQUENCE OF ERUPTION
MAXILLA
6 1 2 4 5 3 7
MANDIBLE
6 1 2 3 4 5 7
 1st permanent tooth — mandibular 1st M
 1st successor tooth — mandibular CI
 Last successor tooth — max C *** OR mandibular 2nd PM
19 AUG 2020 · STAGES OF MIXED DENTITION :-
FIRST TRANSITION STAGE [ 6 – 8 ]
 Erupting — C1, L1, 1st Molars
 Anomaly — anterior open bite
o — retrognathic mandible (12-14)
o — ∴ transient class 2
 At 8.5yrs old, there will be equal no of primary and permanent teeth in the mouth,
 Centrals, laterals and 1st molars-permanent
 Canines, 1st molar, 2nd molar-primary
 Incisal Liability
o Maxilla — 7mm
o Mandible — 5mm
 ∴ avg I L = 6 mm
 How is I L Obtained:
o utilising the physiologic spaces
o proclination of anterior
o increase in the inter – canine width
These are lectures of The Gulfie Dentist Online Coaching
Information
| Author | Dr.Mayakha Mariam |
| Organization | Dr.Mayakha Mariam |
| Categories | Courses |
| Website | - |
| thegulfiedentist@gmail.com |
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