Concepts of growth process www.indiandentalacademy.com
INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
www.indiandentalacademy.com
Growth of Maxilla & Mandible Clinical Implications of growth & development
www.indiandentalacademy.com
Concept 1 Facial growth and development is a morphogenic process working toward a composite state of aggregate structural and functional balance among all the multiple,regional growing and changing hard and soft tissue parts. www.indiandentalacademy.com
Concept 2 Bone grows by adding new bone tissue on one side of bony cortex and taking it away from other side. -Deposition -Resorption -Cortical drift
www.indiandentalacademy.com
Concept 3 The outside and inside surfaces of bone are completely blanketed by a mosaic like pattern of ‘growth field’.
www.indiandentalacademy.com
Concept 4 Bone produced by covering membrane constitutes about ½ of all cortical bone tissue present ;bone laid down by the lining membrane makes up the other ½. www.indiandentalacademy.com
Concept 5 Bone doesn't grow by itself ,growth is produced by the soft tissue matrix that encloses each whole bone.
www.indiandentalacademy.com
Concept 6 All the various resorptive and depository growth fields throughout a bone don’t have same rate of growth activity .Some depository fields grow much more rapidly than other.The same is true for resorptive.These are called as growth sites. www.indiandentalacademy.com
Concept 7 Remodeling is a process where bone deposition and resorption occurs so as to bring about change in size, shape , relationship of the bone.
www.indiandentalacademy.com
Concept 8 Primary displacement-as bone enlarges it is simultaneously carried away from other bones in direct contact with it .
www.indiandentalacademy.com
Concept 9 Secondary displacement-It is the movement of a whole bone caused by the separate enlargement of other bones.
www.indiandentalacademy.com
Concept 10 Facial growth is a process that requires intimate morphogenic interactions among all of its component growing ,changing and functioning soft and hard tissue parts.No part is developmentally independent and self contained.
www.indiandentalacademy.com
Growth of maxilla and mandible
www.indiandentalacademy.com
Growth of maxilla
www.indiandentalacademy.com
-Develops intramembranously -Growth by three mechanisms Displacement Growth
at sutures Surface remodeling
www.indiandentalacademy.com
Displacement Secondary displacement -important growth mechanism of maxilla [primary dentition ] •-Nasomaxillary complex is moved in downward and forward direction.
www.indiandentalacademy.com
•Primary displacement •-it moves maxilla in forward direction
www.indiandentalacademy.com
Growth at sutures Maxilla connected to the cranium and cranial base by – 1]Fronto-nasal suture 2]Fronto-maxillary suture 3]Zygomatico-maxillary suture 4]Zygomatico-temporal suture 5]Pterygo-palatine suture www.indiandentalacademy.com
Surface remodeling It brings about 1]increase in size 2]change in shape of bone 3]change in functional relationship a) Orbit b) Nose www.indiandentalacademy.com
•c) Palate
d) Maxillary tuberosity –bone deposition at posterior margin
www.indiandentalacademy.com
e) Zygomatic bone –resorption on anterior surface and deposition on the posterior surface
f) Alveolar process-grows downwards and forward carrying teeth .This increases height and depth of palate. www.indiandentalacademy.com
g) Sinus h) Anterior nasal spine –prominence increases by bone deposition .
www.indiandentalacademy.com
Growth sites 1]Maxillary tuberosity 2]Sutures 3]Alveolar border 4]Nasal septum
www.indiandentalacademy.com
Growth of mandible
www.indiandentalacademy.com
Includes • • • • • • • •
Ramus Corpus or the body of mandible Angle of the mandible The lingual tuberosity The alveolar process The chin The condyle The coronoid process www.indiandentalacademy.com
Ramus
•Moves progressively posterior by a combination of deposition and resorption . Functions of remodeling 1]To accommodate muscles 2]To accommodate space 3]To facilitate the lengthening of mandibular body www.indiandentalacademy.com
Corpus or the body of mandible Displacement of the ramus results in the conversion of former ramal bone into the posterior part of the body of mandible. www.indiandentalacademy.com
Angle of the mandible Lingual-Resoption on the posteroinferior aspect while deposition occurs on the anterio-superior aspect Buccal-resorption on the anteriosuperior part and deposition on the postero-superior part . Prominence of antegonial notch and change in gonial angle www.indiandentalacademy.com
The lingual tuberosity -It is an direct equivalent of the max tuberosity.
www.indiandentalacademy.com
•-It moves posteriorly by deposition on posteriorly facing surface. •It also protrudes in a lingual direction .
www.indiandentalacademy.com
The alveolar process Grows upwards ,outwards,forwards . Develops in response to the tooth buds. With increases by growth at suture at 1 year
www.indiandentalacademy.com
The chin Mental protuberance forms by bone deposition . It is accentuated by bone resorption that occurs in the alveolar region above it , creating a concavity. www.indiandentalacademy.com
The condyle Two schools of thought 1]earlier –growth occurs at the surface of the condylar cartilage by means of bone deposition .
www.indiandentalacademy.com
•2]now –growth of soft tissues including the muscles and connective tissue carries the mandible .
www.indiandentalacademy.com
The coronoid process Growth is by ‘V’ principle Deposition occurs on the medial surfaces of left and right coronoid process . It brings about posterior growth movement in the ‘V’ pattern . Growth direction follows the x arrows . www.indiandentalacademy.com
Growth sites of mandible 1]mandibular condyle 2]posterior border of ramus 3]alveolar process 4]lower boarder of mandible 5]suture.
www.indiandentalacademy.com
Clinical implication of growth and development
www.indiandentalacademy.com
Growth Sprut The sudden increase in the growth of general body is called as growth sprut.
www.indiandentalacademy.com
Growth sprut Woodside in study of Burlington groupthree main growth spruts Girls Boys 1]Just after birth 3yrs 3yrs 2]Juvenile 6-7yrs 7-9yrs 3]Pubertal 10-12yrs 12-15yrs
www.indiandentalacademy.com
-occurs nearly 2yrs earlier in girls than boys . -remains for 2-2 1/2yrs for both sexes. -Effected by genetic, environmental, sesonal and cultural factors. Major events during pubertal sprut 1]exchange from mixed to permanent dentition 2]acceleration in overall rate of facial growth 3]differential growth of jaws
www.indiandentalacademy.com
Biological changes seen during puberty BOYS
Stage1-Fat sprut intially maturing boy gains weight and becomes chubby Stage 2-Sprut in height and development of secondary sexual characteristics. Stage 3-Coincides with peak velocity with gain in height Stage 4-Spurt in height ends .Indicates that growth is complete. www.indiandentalacademy.com
GIRLS Stage1-Appearance of secondary sexual characteristics Stage2-occurs 1-1 ½ yrs later stage Stage 3-Marked by onset of mensturatiion.Growth is complete.
www.indiandentalacademy.com
IMPORTANCE OF GROWTH SPRUT 1]offers best time for interceptive orthodontic procedures. Ex.mandibular retrognathism –activator maxillary prognathism-headgear mandibular prognathism-chincap with headgear maxillary retrognathism-facemask
Activator
Headgear
www.indiandentalacademy.com
Chincap with Headgear
Facemask
A]Early maturing girls-pubertal sprut precedes final transition of dentition B]Slow maturing boys www.indiandentalacademy.com
2]expansion-arch and skeletal 3]Excellent indicators for orthodontic treatment . 4]surgical correction There should be correlation between -skeletal age -dental age -chronological age -morphological age and onset of puberty.
www.indiandentalacademy.com
Other uses -important to determine the efficacy of the therapy. -to determine the predictability and future growth direction -recognition and diagnosis of deviation from normal growth
www.indiandentalacademy.com
www.indiandentalacademy.com Leader in continuing dental education
THANK YOU www.indiandentalacademy.com