A to Z. ORTHODONTICS. Volume: 15. Dr. Mohammad Khursheed Alam. BDS,
PGT, PhD ... (10) Dento-alveolar disproportion: Sometimes no disproportion.
A to Z ORTHODONTICS Volume: 15
CLASS II MALOCCLUSION 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: 978-967-0486-04-8 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. CLASS II DIV 1 MO …..…….....................................3-7 2. CLASS II DIV 2 MO …..……….................................8-9 3. Differences b/w class II div 1 and 2….......................10 4. Deep bite......................................................................11-13 5. Differences b/w Complete and Incomplete over bite ..14
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OCCLUSAL FEATURES OF CLASS II DIV 1 MO Intra oral (1) Incisor & molar relationship: class II div 1 incisor relationship and angles class II molar relation. (2) SK. pattern: usually class II but may be class 1 or even mild class III rare. (3) Soft tissue morphology & behavior: lips-usually incompetent and habitually apart. May also have potentially competent lips. Active lower lop line is usually low, upper lip short and often protrude over lower lip. Swallowing may be normal, or atypical tooth apart with or without a certain amount of anterior tongue thrust. Tongue there may have tongue to lower lip contact. Tongue may also have forward thrust. Lower lip of ten acts like sling in expressive behavior. (4) Upper incisors: Usually proclaimed, may be crowned or spaced. May occasionally be in normal or even slightly retroclined. (5) Lower incisors: May be normal, proclined or retroclined depending upon the soft tissue morphology and behavior and early loss. May be crowned or spaced depending on dento-alvelar disproportion. (6) Overjet: increased.
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(7) Over bite: Usually --- complete or incomplete. May also have reduced over bite or even open bite. (8) Cross bite: Occasionally seen may be unilateral or bilateral or even open bite. (9) Dental arch: maxillary arch may be narrow especially in canine region. Arches are usually rather short anteroposteriorly. (10)
Dento-alveolar
disproportion:
Sometimes
no
disproportion.
Sometimes adverse and more frequent crowding is lower arch. (11) For plane angle: Usually average to high or may be low. (12) Mandibular posture & path of closure: May be endogenous or often forward posture [sunday face] and path of closure may be simple hinge [from endogenous] or upoards and back words [from forward posture] or interoclusal clearance is usually normal. (13) Family history: usually have strong family history. Extra oral: 1) Convex profile. 2) Short upper lip. 3) Ineompetent lips. 4) Everted lower lips. 5) Deep mentolabial stucus.
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6) Hyperactive mentalis.
Rx of class II Div 1 M.O Main objective * Alignment and retraction of upper labial segment to acceptable asthetic position where they will be stable. * Rx & stable end result depend on soft tissue morphology and behaviour. (A) Retracting of canines. Lower arch Rx confined to relief of crowding & alignment of teeth where necessary. Crowding of a degree Ex ---- & canine retracted to align the incisor. Appliance [usually fixed) may be use for this alignment. Upper arch The upper buccal segments are retracted untill they are in normal relationship i lower arch. Ex --- to retract ---- [i no lower ex] accepting the class Ii post. Occlusion. Instead of ---, --- may also be ex, where less space is required. In sever class II i marked crowding and over jet Ex ----- will not provide enough space to retract ---- into class I relation. Such cases are difficult to Rx but necessary to move the upper buccal segment.
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Distal movement of upper buccal teeth i or tout ex of ------- where the space required small. When ---- are present and there is stacking of the 2nd & 3rd molars the ex. of ----- provide sufficient space. Distal movement of upper buccal teeth carried out by removable appliance or fixed appliance involving the extra oral anchorage or inter Mx anchorage. Reduction of over bite Over bite deep & complete, the lower incisor will prevent lingual movement of the upper incisors. Therefore over bite reduce by depressing lower incisor by a flat anterior bite platfrom. [F.A may be used] If over bite is not adequately reduced the overjet reduced only moving the upper incisal not apex labially. Reduction of over jet: The goal here lies in moving the upper incisor so for lingually that the will come under the control of the lower lip and thus prevent relapse. Oj not too great – tipping movement of incisor Reduce oj. If inter-incisal angle become too large, overbite will deepen – such cases treated by suitable fixed appliance so instead of tipping movement,
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bodily traction of incisors or retraction of crowns i apical control may be achieved. Intra maxillary inters MX or extra oral anchorage may be providing during the reduction of OB. Selective class II div 1 Rx by myofunctional appliance such as Andersen appliance & frankest appliance, besides the conventional removable appliance. Residual space closure: Some space in the extraction sites – close naturally. Class II traction i upper & lower F.A used to reduce the oj & to close the lower arch spacing by moving the lower post, teeth forward [Fig – 118 E] Following retraction the upper incisor position should be retained for about 6 months or so to allow readjustment of the supporting tissue around the teeth.
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Rx of class II div 2 Planning of Rx The main object of treatment is to align the upper incisors and to make some reduction in overbite where possible or positively necessary. Very mild case – Should left untreated unless they are aesthetically displeasing or overbite is traumatic. Lower arch: Planning of treatment should start with lower arch. Slight degree of crowding – may be accepted as extraction in lower arch often over bite. When more crowding – Treated by buccal extraction usually --- and then to retract ---- and align lower labial segment. (accepting the labiolingual position of lower labial segment) Usually some residual spacing is describable other and of Rx. In some sever cases – Lingual collapse of lower labial segment is prevented by moving the buccal segment forward in contact i lower labial segment. Upper arch:
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In majority cases ----- position and OB may be accepted and upper canine retracted after ex of ----- or after distal movement of upper buccal segment i external traction. If normal axial inclination is to be produced – there should be favourable soft tissue pattern & growth of face- otherwise there will be problem. Multiband technique is necessary to depress both the upper & lower labial segment in their respective base – it will – OB & the control of cower lip over the upper incisor. Proclination of incisors may be possible in some case.
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Differences b/w class II div 1 and 2: Convexity/straight 1.
Profile
Convex
Competent
2.
Lips
Incompetent
Normal
3.
Mentalis
Hyperavtive
muscles 4.
Decreased
Lower facial
Increase/normal
Square/U shaped
height
V shaped
Normal
5.
Arch form
Deep
CI retroclind &
6.
Palate
Proclined
LI proclined
7.
Incisors
Decreased Increased
Closed Backward
8.
Overjet
Deep
9.
Overbite
Normal
10.
Path of closure
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DEEP BITE / INCREASED OVER BITE Definition: When overlapping of lower incisors by the upper incisor is more than normal. It may be complete or incomplete. Broadly classified two types – (1) skeletal deep bite (2) Dental deep bite on den to alveolar deep bite. Etiology: It is a combination of: a. Skeletal factor. b. Dental factor. c. Soft tissue factor. Skeletalfactor: 1.Decreased lower facial height 2. Increased normal height. 3. Low maxillomandibular plane angle. Dental factor –1.Increased interincisal angle 2. Supra eruption of anterior teeth. 3. under eruption of posteriors. Soft tissue factor –1. Lateral spreading lower tongue posture interferes – normal eruption of posterior teeth. 2. High lip line.
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TREATMENT Diagnosis: a. Clinical examination b. Study models. c. Radiographs – full mouth intra oral periapical radiograph, orthopantomogram and lateral cephalogram. Theoretically: this can be treated by – • Intrusion of upper and / or lower labial segment or • Extrusion of buccal teeth or both. Then correction of upper and lower incisor relation, it is important to avoid relapse. But practically: • Upper labial segment is not intruded as it may be away from the control of lower lip. • Lower labial segment is more usually depressed. • In case of class II Div-2 cases – Intrusion of upper labial segment can be done. Methods: A) Removal appliance
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i) Bite plane – This cause relative depression of lower labial segment [as described above] along – a) Proclination of lower labial segment. b) Proclination of upper labial segment, due to pressure of the plate on up incisors. c) Increase in mxillo-Mandibular Angle [Temporary] ii) Andresen appliance. B) Fixed appliance – True correlative depression can be achieved with fixed appliances by incorporating the following in the arch wire: i) Anchorage bends or tip-back bends – This may procline labial segment. ii) Reverse curve of spee. iii) Arch wire with “U” or “L” loops.
DEEP BITE: Before and after
treatment C) Surgery – Segmental surgery to reposition upper and lower labial segment in their respective basal bone. In growing children, when deep bite is associated with decreased lower facial height, low FMA angle, and the anterior bite plane is the appliance of choice.
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Differences b/w Complete over bite and Incomplete over bite
Complete over bite
Incomplete over bite
Relationship in which the lower Fail to occlude either the upper incisor
contacts
the
palatal incisions or the hucosa of the
surface of the upper incisor son palate. the palatal tissue. over bite within normal
more than normal
This when
relationship teeth
are
is in
obtained When the teeth are occluded centric
occlusion. There is a contact.
No contact
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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
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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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