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These are lectures of The Gulfie Dentist Online Coaching
19 AGO 2020
19 AGO 2020 · BONE FORMATION / OSSIFICATION :-
INTRAMEMBRANEOUS- within membrane
Ossification takes place in the membranes of connective tissue.
Cells in the membrane differentiate into osteoblasts,
A collagen matrix is formed, which undergoes ossification
So basically, these bone is formed from collagen matrix.
Mostly flat Bones: maxilla, majority of mandible & cranial vault*
ENDOCHONDRAL – within cartilage
Bone formation takes place From within a hyaline cartilage
Cartilage cells are replaced by bone cells,ie. osteocytes replace chondrocytes.
short and long bones are formed this way
ethmoid, sphenoid, occipital (synchondrosis of bones of cranial base*)
Some part of mandible (condylar head region)
MANDIBLE BONE FORMATION IS BY BOTH endochondral + intramembraneous
19 AGO 2020 · BONE GROWTH
Don’t confuse bone growth with bone formation above
Growth of bone is by apposition — layer by layer deposition
Whereas cartilage growth is by two ways one is appositional and other is interstitial method, which is how mandibular condyle grows.
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
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
This cartilage contributes to its growth*
Direction of growth — anterior and inferiorly
Direction of apposition @ condylar — posteriorly and superiorly
V shape principle- is shown by the mandibular growth
MAXILLA
Formed entirely by intramembranous ossification
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
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 AGO 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 AGO 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 AGO 2020 · DEVELOPMENT OF OCCLUSION
GUM PADS
0-6 months of age
Anterior open bite
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 —
Nutritional deficiency
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 AGO 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
It is self correcting anomaly
Midline Diastema
Maxillary 1.7mm — mesial to C
Mandibular 1.5mm — distal to C
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 AGO 2020 · DECIDUOUS OCCLUSIONS :- PRIMARY 2ND MOLARS
FLUSH TERMINAL PLANE (SCA)
Most Commonly seen occlusion*
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
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 AGO 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 AGO 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
Informazioni
| Autore | Dr.Mayakha Mariam |
| Organizzazione | Dr.Mayakha Mariam |
| Categorie | Corsi |
| Sito | - |
| thegulfiedentist@gmail.com |
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