A to Z
ORTHODONTICS
Volume: 02
GROWTH
AND
DEVELOPMENT
Dr. Mohammad Khursheed Alam
BDS, PGT, PhD (Japan)
First Published August 2012
© Dr. Mohammad Khursheed Alam
© All rights reserved. No part of this publication may be reproduced stored in a retrieval system,
or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or
otherwise, without prior permission of author/s or publisher.
ISBN: 978-967-5547-91-1
Correspondance:
Dr. Mohammad Khursheed Alam
Senior Lecturer
Orthodontic Unit
School of Dental Science
Health Campus, Universiti Sains Malaysia.
Email:
[email protected]
[email protected]
Published by:
PPSP Publication
Jabatan Pendidikan Perubatan, Pusat Pengajian Sains Perubatan,
Universiti Sains Malaysia.
Kubang Kerian, 16150. Kota Bharu, Kelatan.
Published in Malaysia
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Contents
1. Some definition...…................................................3
2. Cephalocaudal gradient of growth........................3
3. Scammons curve…………….………………….4
4. Bone of the skull………………………………..4-5
5. Growth of the skull…………………………….. 6-7
6. Period of development of dentition.......................7
7. Primate space..........................................................8
8. Incisor liability……………….....…………..........8
9. Lee way space………………………………….8-9
10. Flush terminal plane…………………………...9
11.Ugly duckling stage..........…. …………………10-11
12. Importance of 1st molar…….………………….11
2
Growth
Growth is the increase in size (Todd). It may also be defined as the normal
change in the amount of living substance. eg. Growth is the quantitative
aspect and measures in units of increase per unit of time.
Development
It is the progress towards maturity (Todd). Development may be defined as
natural sequential series of events between fertilization of ovum and adult
stage.
Maturation
It is a period of stabilization brought by growth and development.
CEPHALOCAUDAL GRADIENT OF GROWTH
This simply means that there is an axis of increased growth extending from
the head towards feet. At about 3rd month of intrauterine life the head
takes up about 50% of total body length. At this stage cranium is larger
relative to face. In contrast the limbs are underdeveloped.
By the time of birth limbs and trunk have grown faster than head and the
entire proportion of the body to the head has increased. These processes
of growth continue till adult.
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SCAMMON’S CURVE
In normal growth pattern all the tissue system of the body do not growth at
the same rate. Scammon’s curve for growth shows 4 major tissue system
of the body;
• Neural
• Lymphoid
• General: Bone, viscera, muscle.
• Genital
The graph indicates the growth of the neural tissue is complete by 6-7 year
of age. General body tissue show an “S” shaped curve with showing of rate
during childhood and acceleration at puberty. Lymphoid tissues proliferate
to its maximum in late childhood and undergo involution. At the same time
growth of the genital tissue accelerate rapidly.
Scammon`s curve for growth of the four major tissue systems of the body
NEED TO KNOW ABOUT PHYSICAL GROWTH
• To see whether there is any gross abnormality present or not.
• To plan the therapy.
• To determine the efficiency of the treatment.
BONES OF THE SKULL
A) Bones of the cranial base:
4
A) Fontal (1)
B) Ethmoid (1)
C) Sphenoid (1)
D) Occipital (1)
B) Bones of the cranial vault:
1. Parietal (2)
2. Temporal (2)
C) Bones of the face:
•
Maxilla (2)
•
Mandible (1)
•
Nasal bone (2)
•
Lacrimal bone (2)
•
Zygomatic bone (2)
•
Palatine bone(2)
•
Infra nasal concha (2)
FUSION BETWEEN BONES
1. Syndesmosis: Membranous or ligamentus eg. Sutural point.
2. Synostosis: Bony union eg. symphysis menti.
3. Synchondrosis: Cartilaginous eg. sphenoccipital, spheno-ethmoidal.
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GROWTH OF THE SKULL:
A)
Cranium: 1. Base 2. Vault
B)
Face: 1. Upper face 2.Lower face
CRANIAL BASE:
Cranial base grows at different cartilaginous suture. The cranial base may
be divided into 3 areas.
1. The posterior part which extends from the occiput to the salatercica. The
most important growth site spheno-occipital synchondrosis is situated here.
It is active throughout the growing period and does not close until early
adult life.
2. The middle portion extends from sella to foramen cecum and the sutural
growth spheno-ethmoidal synchondrosis is situated here. The exact time of
closing is not known but probably at the age of 7 years.
3. The anterior part is from foramen cecum and grows by surface
deposition of bone in the frontal region and simultaneous development of
frontal sinus.
CRANIAL VAULT:
The cranial vault grows as the brain grows. It is accelerated at infant. The
growth is complete by 90% by the end of 5th year. At birth the sutures are
wide sufficiently and become approximated during the 1st 2 years of life.
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The development and extension of frontal sinus takes place particularly at
the age of puberty and there is deposition of bone on the surfaces of
cranial bone.
PERIOD OF DEVELOPMENT OF DENTITION
A) From birth to complete eruption of deciduous teeth. From birth to 2½
year.
B) From complete eruption of deciduous teeth to the eruption of first
permanent molar. From 2½ to 6 year.
C) Mixed dentition period. From 6year to 12 year.
D)
Period from the eruption of the 2nd permanent. From 12 year to
onward.
SEQUENCE OF ERUPTION OF DECIDUOUS TEETH
Upper/Lower A B D C E
SEQUENCE OF ERUPTION OF PERMAMENT TEETH
Upper: 6 1 2 4 3 5 7
or
6124537
Lower:
6123457
or 6 1 2 4 3 5 7
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ANTHROPOID SPACE / PRIMATE SPACE / SIMIEN’S SPACE
The space mesial to upper deciduous canine and distal to lower deciduous
canine is characteristically found in primates and hence it is called primate
space.
INCISOR LIABILITY
When the permanent central incisor erupt, these teeth use up specially all
the spaces found in the normal dentition. With the eruption of permanent
lateral incisor the space situation becomes tight. In the maxillary arch it is
just enough to accommodate but in mandibular arch there is an average
1.6 mm less space available. This difference between the space present
and space required is known as incisor liability.
These conditions overcome by;
1. This is a transient condition and extra space comes from slight
increase in arch width.
2. Slight labial positioning of central and lateral incisor.
3. Distal shift of permanent canine.
LEE WAY SPACE (OF NANCE)
Definition:
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The combined mesiodistal width of the permanent canines and pre molars
is usually less that of the deciduous canines and molars. This space is
called leeway space of Nance.
Measurement of lee way space:
Is greater in the mandibular arch than in the maxillary arch
It is about 1.8mm [0.9mm on each side of the arch] in the maxillary arch.
And about 3.4mm [1.7 mm on side of the arch] in the mandibular arch.
Importance:
This lee way space allows the mesial movement of lower molar there
by correcting flush terminal plane.
* LWS can be measure with the help of cephalometry.
FLUSH TERMINAL PLANE (TERMINAL PLANE RELATIONSHIP)
Mandibular 2nd deciduous molar is usually wider mesio-distally then the
maxillary 2nd deciduous molar. This leads to the development of flush
terminal plane which falls along the distal surface of upper and lower 2nd
deciduous molar. This develops into class I molar relationship.
Distal step relationship leads to class 2 relationship.
Mesial step relationship mostly leads to class 3 relationship.
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FEATURE OF IDEAL OCCLUSION IN PRIMARY DENTITION
1. Spacing of anterior teeth.
2. Primate space is present.
3. Flush terminal plane is found.
4. Almost vertical inclination of anterior teeth.
5. Overbite and overjet varies.
UGLY DUCKLING STAGE
Definition:
Stage of a transient or self correcting malocclusion is seen sometimes is
called ugly duck ling stage.
Occurring site: Maxillary incisor region
Occuring age: 8-9 years of age.
Occuring due to: This situation is seen during the eruption of the
permanent canines. As the developing p.c. they displace the roots of lateral
incisor mesially this results is transmitting of the force on to the roots of the
central incisors which also gets displaced mesially. A resultant distal
divergence of the crowns of the two central incisors causes midline
spacing.
This portion of teeth at this stage is compared to that of ugly walk of the
duckling and hence it is called Ugly Duckling Stage.
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Described by Broad bent. In this stage children tend to look ugly. Parents
are often apprehensive during this stage and consult the dentist.
Correction: Corrects by itself, when canines erupt and the pressure is
transferred from the roots to the coronal area of the incisor.
IMPORTANCE OF 1ST MOLAR
1. It is the key tooth to occlusion.
2. Angle’s classification is based on this tooth.
3. It is the tooth of choice for anchorage.
4. Supports occlusion in a vertical direction.
5. Loss of this tooth leads to migration of other tooth.
6. Helps in opening the bite.
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Bibilography:
1. Bhalajhi SI. Orthodontics – The art and science. 4th edition. 2009
2. Gurkeerat Singh. Textbook of orthodontics. 2nd edition. Jaypee, 2007
3. Houston S and Tulley, Textbook of Orthodontics. 2nd Edition. Wright, 1992.
4. Iida J. Lecture/class notes. Professor and chairman, Dept. of Orthodontics, School of dental
science, Hokkaido University, Japan.
5. Lamiya C. Lecture/class notes. Ex Associate Professor and chairman, Dept. of Orthodontics,
Sapporo Dental College.
6. Laura M. An introduction to Orthodontics. 2nd edition. Oxford University Press, 2001
7. McNamara JA, Brudon, WI. Orthodontics and Dentofacial Orthopedics. 1st edition, Needham
Press, Ann Arbor, MI, USA, 2001
8. Mitchel. L. An Introduction to Orthodontics. 3 editions. Oxford University Press. 2007
9. Mohammad EH. Essentials of Orthodontics for dental students. 3rd edition, 2002
10. Proffit WR, Fields HW, Sarver DM. Contemporary Orthodontics. 4th edition, Mosby Inc., St.Louis,
MO, USA, 2007
11. Sarver DM, Proffit WR. In TM Graber et al., eds., Orthodontics: Current Principles and
Techniques, 4th ed., St. Louis: Elsevier Mosby, 2005
12. Samir E. Bishara. Textbook of Orthodontics. Saunders 978-0721682891, 2002
13. T. M. Graber, R.L. Vanarsdall, Orthodontics, Current Principles and Techniques, "Diagnosis and
Treatment Planning in Orthodontics", D. M. Sarver, W.R. Proffit, J. L. Ackerman, Mosby, 2000
14. Thomas M. Graber, Katherine W. L. Vig, Robert L. Vanarsdall Jr. Orthodontics: Current Principles
and Techniques. Mosby 9780323026215, 2005
15. William R. Proffit, Raymond P. White, David M. Sarver. Contemporary treatment of dentofacial
deformity. Mosby 978-0323016971, 2002
16. William R. Proffit, Henry W. Fields, and David M. Sarver. Contemporary Orthodontics. Mosby
978-0323040464, 2006
17. Yoshiaki S. Lecture/class notes. Associate Professor and chairman, Dept. of Orthodontics, School
of dental science, Hokkaido University, Japan.
18. Zakir H. Lecture/class notes. Professor and chairman, Dept. of Orthodontics, Dhaka Dental
College and hospital.
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Dedicated To
My Mom, Zubaida Shaheen
My Dad, Md. Islam
&
My Only Son
Mohammad Sharjil
13
Acknowledgments
I wish to acknowledge the expertise and efforts of the various
teachers for their help and inspiration:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Prof. Iida Junichiro – Chairman, Dept. of Orthodontics,
Hokkaido University, Japan.
Asso. Prof. Sato yoshiaki –Dept. of Orthodontics, Hokkaido
University, Japan.
Asst. Prof. Kajii Takashi – Dept. of Orthodontics, Hokkaido
University, Japan.
Asst. Prof. Yamamoto – Dept. of Orthodontics, Hokkaido
University, Japan.
Asst. Prof. Kaneko – Dept. of Orthodontics, Hokkaido
University, Japan.
Asst. Prof. Kusakabe– Dept. of Orthodontics, Hokkaido
University, Japan.
Asst. Prof. Yamagata– Dept. of Orthodontics, Hokkaido
University, Japan.
Prof. Amirul Islam – Principal, Bangladesh Dental college
Prof. Emadul Haq – Principal City Dental college
Prof. Zakir Hossain – Chairman, Dept. of Orthodontics,
Dhaka Dental College.
Asso. Prof. Lamiya Chowdhury – Chairman, Dept. of
Orthodontics, Sapporo Dental College, Dhaka.
Late. Asso. Prof. Begum Rokeya – Dhaka Dental College.
Asso. Prof. MA Sikder– Chairman, Dept. of Orthodontics,
University Dental College, Dhaka.
Asso. Prof. Md. Saifuddin Chinu – Chairman, Dept. of
Orthodontics, Pioneer Dental College, Dhaka.
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Dr. Mohammad Khursheed Alam
has obtained his PhD degree in Orthodontics from Japan in 2008.
He worked as Asst. Professor and Head, Orthodontics
department, Bangladesh Dental College for 3 years. At the same
time he worked as consultant Orthodontist in the Dental office
named ‘‘Sapporo Dental square’’. Since then he has worked in
several international projects in the field of Orthodontics. He is
the author of more than 50 articles published in reputed journals.
He is now working as Senior lecturer in Orthodontic unit, School
of Dental Science, Universiti Sains Malaysia.
Volume of this Book has been reviewed by:
Dr. Kathiravan Purmal
BDS (Malaya), DGDP (UK), MFDSRCS (London), MOrth
(Malaya), MOrth RCS( Edin), FRACPS.
School of Dental Science, Universiti Sains Malaysia.
Dr Kathiravan Purmal graduated from University Malaya 1993.
He has been in private practice for almost 20 years.
He is the first locally trained orthodontist in Malaysia with
international qualification. He has undergone extensive
training in the field of oral and maxillofacial surgery and
general dentistry.
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