Maloccluison

Nasir Al-Hamlan BDS, Cert.AEGD FDS RCSEd, MPH, MSc, MOrth RCSEd, FICD
Saudi Arabia
Malocclusion
@nhalhamlan
@saudibraces
nasiralhamlan
@nasiralhamlan

Learning Outcomes:
• To understand the definition of Occlusion and Malocclusion
• To review the historical development of Malocclusion’s Classification,
• To understand the Common used of Malocclusion's Classifications,
• To learn how to classify the malocclusions,
• To understand the common Features of Malocclusions,
• To review some of Prevalence of Malocclusion.

History: Orthodontics
• Historians claim that two different men deserve the title of
being called "The Father of Orthodontics.“
• One man was Norman W. Kingsley, a dentist, writer, artist, and
sculptor, who wrote his "Treatise on Oral Deformities" in 1880.
• The second man who deserves credit was a dentist named J. N.
Farrar who wrote two volumes entitled "A Treatise on the
Irregularities of the Teeth and Their Corrections". Farrar was very
good at designing brace appliances.
Norman W. Kingsley

• Edward H. Angle (1855-1930) devised the first simple
classification system for malocclusions, which is still in use today.
• In 1901, Angle started the first school of orthodontics.
• He is father of Modern Orthodontics.
Edward H. Angle
History: Orthodontics

• OCCLUSION

• IDEAL OCCLUSION

• NORMAL OCCLUSION

• MALOCCLUSION

Occlusion:
• The relation of the Maxillary and Mandibular teeth when the jaws are:

- Closed in centric relation

- Without strain of musculature or displacement of condyles in their Fossa.

Ideal Occlusion:
Hypothetical concept or a standardized goal (The Perfect Occlusion).

Normal Occlusion:
Implies to the variations around an average mean value.
It is a theoretical concept based on the ideal teeth position and
arches relationships. It is rarely, if ever, found in nature. However, it
provides a standard by which all other occlusions may be judged.

Ideal occlusion
- A coincident mid-line

- No (crowding/spacing/rotations)

- Overjet = 2-3mm

- Correct crown angulation and inclination

- Class I molar & canine relationship

- A ﬂat or slightly upwards curve of Spee
Normal occlusion
Is one which shows:

- Some deviation from that of the ideal but
is aesthetically acceptable and
functionally stable for the individual.

- The upper and lower teeth ﬁt nicely and
evenly together with the least amount of
destructive interferences

• MALOCCLUSION:

- A condition where there is departure from the normal relation of the teeth to
other teeth in the same dental arch and/or to teeth in the opposing arch.

* The term was coined by Edward H Angle, the "father of modern orthodontics“.

* It is a condition that reﬂects an expression of normal biologic variability in the way
the maxilla and mandible teeth occlude. (BISHARA)

* An occlusion in which there is a malrelationship between the arches in any of the
planes of the spaces or in which there are anomalies in tooth position beyond the
limit of normal. (Walther & Huston)

HISTORICAL REVIEW
• (1829) Samuel S Fitch - described in his book‘ A System of Dental Surgery’ first
classified into 4 states of irregularity.

• (1836) Christopher kneisel - ‘The oblique position of teeth’classified –general
obliqueness & paritial obliqueness.

• (1839) Jean Nicolas Marjolin - differentiated obliqueness of teeth and anomalies of
dental arch.

• (1842) George Carabelli - coined the term edge-to-edge bite and overbite.

• (1880) Norman Kingsely - classified into 2 broad categories based on etiology
Developmental malocclusion and Accidental malocclusion.

• Edward H Angle ( 1899, 1900, 1906.1907) – detailed description of malocclusion into
3 Classes

• (1905-1921)- Calvin case -anatomical groups- grouped into 5 classes- treatment
standpoint of view.

• (1912) Lischer– terms distocclusion and mesiocclusion.

• (1915) Martin Dewey–modified Angles classes.

• (1920) Paul Simon-based on the gnathostatics and canine law

• (1964) Ballard and Wayman- British classification based on incisor overjet

• (1969) Ackerman and proffit - based on venn diagram

• (1992) Katz- based on premolar as a reference landmark

• The World Health Organization (1987), had included malocclusion under the heading
of Handicapping Dento Facial Anomaly, defined as an anomaly which causes
disfigurement or which impedes function, and requiring treatment “if the disfigurement
or functional defect was likely to be an obstacle to the patient’s physical or emotional
well-being.

What is a Classification System?
A classification system is a grouping of clinical cases of similar
appearance for ease in handling and discussion; it is not a
system of diagnosis , method for determining prognosis ,or a
way of defining treatment (Robert E.Moyers).

Why we need a Classiﬁcation for Malocclusion?
Acquire a better understanding of the many deviations from normal occlusion

๏To describe the dental deviation from the norm,
๏Divide the wide range into small groups.

๏Describe the salient features.

๏Provide a verbal and mental picture.

๏Simplify the documentations

๏Unify the communications

๏Give clue about the etiology

๏Help to select treatment modality

๏Thinking of possible treatment modalities that may be needed in a particular case

Why occlusion is important?
-Mastication
-Speech
-Appearance
-Stability

Is Malocclusion disease?
i,e. Malocclusion is an appreciable deviation from the ideal/normal
occlusion.
Malocclusion is a developmental condition. In most instances,
malocclusion and dentofacial deformity are caused, not by some
pathologic process, but by moderate distortions of normal
development.

•Etiology of Malocclusion
o Specific causes of malocclusion
. Disturbances in embryologic development
. Skeletal growth disturbances
. Muscle dysfunction
. Acromegaly and Hemimandibular Hypertrophy
. Disturbances of dental development
o Genetic influences
o Environmental influences
Known
Cause
5%

Classification of Malocclusions:
-Depends

TYPES OF MALOCCLUSION depends on

๏ INTRAARCH
๏ INTERARCH
๏ SKELETAL
✴ INTRAARCH: Includes variation in individual tooth position & a group of teeth
within in a arch

- Abnormal inclination

- Abnormal Displacements

- Spacing and crowding within the same arch

✴ INTERARCH: Abnormal relationship between two teeth or group of teeth of one
arch to the other.

Types:

- Sagittal plane malocclusions

- Vertical plane malocclusions

- Transverse plane malocclusions

✴ SKELETAL: Malrelation of the apical bases.

Malrelation of the upper and lower apical bases is due to:

- Abnormal size

- Abnormal shape

- Abnormal relation to the skull

- Abnormal relation to each other.

Commonly Used
•Angle’s Classification:
- First Permanent Molar
•British Standards Institute Classification:
- Incisor’s classification

Angle’s Classification: Molar Relationship

In 1890 Edward H. Angle published the first classification of malocclusion.
The classifications are based on the relationship of the mesiobuccal cusp of the maxillary
first molar and the buccal groove of the mandibular first molar!
• Class I Malocclusion:
• Class II Malocclusion:
- Class II div 1
- Class II div 2
- Class II division 1 Subdivision
- Class II division 2 Subdivision
• Class III Malocclusion:
- True Class III
- Pseudo Class III
- Class III Subdivision

Normal Occlusion:
The mesiobuccal cusp of the maxillary ﬁrst molar is aligned with the
buccal groove of the mandibular ﬁrst molar. Teeth on line of occlusion,
and there is normal overbite and overjet and coincident maxillary and
mandibular midlines. (No Crowding, No Spacing…No etc.)


•Class I Malocclusion:
A normal molar relationship exists but there is at least one feature
such as crowding or crossbites, etc.

•Class II Malocclusion:
A malocclusion where the molar relationship shows the buccal
groove of the mandibular first molar distally positioned when in
occlusion with the mesiobuccal cusp of the maxillary first molar.
Class II Malocclusion has two divisions
to describe the position of the
maxillary anterior teeth.
•Class II Division 1 is when the maxillary
central incisors are proclined or of
average inclination (Overjet usually
increases)
•Class II Division 2 is where the
m a x i l l a r y c e n t r a l i n c i s o r s a r e
retroclined (Overbite usually increases)

•Class II Division 1 Malocclusion:

•Class II Division 2 Malocclusion:

• Class III Malocclusion:
A malocclusion where the molar relationship shows the buccal groove
of the mandibular first molar mesially positioned to the mesiobuccal
cusp of the maxillary first molar when the teeth are in occlusion.

Class III Malocclusion:
2 types:
• True class ІІІ malocclusion (Skeletal)
• Pseudo class ІІІ (FALSE or postural)
True Class III causes:
- Genetic in origin
- Excessively large mandible
- Smaller than normal maxilla
- Retropositioned maxilla
Pseudo Class ІІІ: Forward movement of mandible during jaw closure
- Occlusal prematurities
- Premature loss of deciduous posteriors
- Enlarged adenoids

Class I Malocclusion

Class II Division 1 Malocclusion

Class II Division 2 Malocclusion

Class III Malocclusion

Angle classification
Subdivision

Angle classification
UNIT = Cusp

ANGLE classification:
Advantages:
• First comprehensive classification- most widely accepted

• Simple

• Easy to use

• Most POPULAR

• Easy to Communicate

Disadvantages:
• Considers malocclusion only in anteroposterior plane not in
transverse/vertical

• Considered 1st molar as fixed point – skull

• Deciduous dentition

• 1st molar extracted

• Doesn't distinguish between skeletal and dental
malocclusion

• Doesn’t highlight etiology

• Individual tooth positions

Incisor’s classification

Classification of Malocclusions: Incisor Classification
Class I: the lower incisor edges occlude with or
lie immediate below the cingulum plateau of the
upper central incisors
Class II: the lower incisor edge lie posterior to
the cingulum plateau of the upper central
incisors
Class II Division 1: the upper central incisors are
proclined or of average inclination (Overjet usually
increases)
Class III Division 2: the upper central incisors are
retroclined (Overbite usually increases)
Class III: the lower incisor edge lie anterior to
the cingulum plateau of the upper central
incisors (Overjet is reduced or reverse)

Class I

Class II Division 1

Class II Division 2

Class III

Canine’s Classification/Relationship

Canine classification
The canine relationship also provides a useful anteroposterior
occlusal classification:
Class I: the maxillary permanent canine should occlude directly in the
embrasure between mandibular canine and first premolar.
Class II: the maxillary permanent canine occludes in front of the
Class III: the maxillary permanent canine occludes behind the

Class I
Classification of Malocclusions: Canine Classification

Class II

Class III

Unit

Skeletal (Jaw) Classification
Class I Class II Class III
Skeletal PatternsSkeletal (Jaw) Classification
Class I Class II Class III

Cephalometric analyses reveal to the orthodontist
the skeletal component of the patient’s
malocclusion.
Skeletal Patterns can classified :
• Class I Skeletal Pattern
• Class II Skeletal Pattern
• Class III Skeletal Pattern
These patterns often correspond with the Angle/
Incisor Classifications but not necessarily all the
time.
Conclusions: The incisal classification had a significant association with WITS appraisal, whereas with
ANB the association was marginally significant (alhamlan et.al., 2015)

Increase Overjet
Reverse Overjet
Other Malocclusion Features

Deep Overbite
Openbite

O v e r j e t : H o r i z o n t a l
relationship between upper
and lower anterior teeth
(2-3mm + 1).
Overbite: Vertical relationship
between upper and lower
anterior teeth (1-2mm).
Openbite: the condition where
the upper teeth fail to
overlap the lower teeth
when the mandible is
brought into full occlusion
(Anterior & Posterior)

Crossbite: a discrepancy in the
buccolingual relationship of the upper and
lower teeth.
- Buccal Crossbite: the buccal cusps of
the lower teeth occlude buccal to the
buccal cusps of upper teeth,
- Lingual Crossbite (Scissors bite): the
buccal cusps of the lower teeth occlude
lingual to the lingual cusps of the upper
teeth.

Types of Crossbite:
•Anterior Crossbites: At least one of the upper
incisors is in linguo-occlusion (Reverse Overjet)
• Posterior Crossbites: At least one tooth per
quadrant is affected.
It can be
• Dental and Skeletal,
• Anterior & Posterior,
• Buccal & and Lingual,
• Localized & Segmental,
• Unilateral & Bilateral
Crossbite

Crowding/Irregularity
Spacing

Missing Teeth

Impacted Teeth

What is Orthodontics?
- Orthodontics was the first specialists discipline in dentistry in the
world, followed by many others.
- Orthodontics concerns itself with the arrangement and alignment
of the teeth and jaws.
- And as Orthodontist, We are mostly occupied in correction of
problems of function and aesthetics of the teeth.

Orthodontic Treatment Goals
Static Occlusion
•(Andrews’ Six Keys)
Functional Occlusion
•Condylar Position/Disc Position
• Intercuspal position (ICP) & Retruded Contact Position (RCP)
• Non-working side contacts
• Canine guidance and Group guidance

• Andrews' Six Keys (1972) to normal (or optimal) are a widely quoted
set of static occlusal goals for tooth relationships in the intercuspal
position:
1. Correct interarch relationships
2. Correct crown angulation (tip)
3. Correct crown inclination (torque)
4. No rotations
5. Tight contact points
6. Flat curve of Spee (0.0 - 2.5 mm)
7. Correct tooth size (Bennett & McLaughlin, 1993)
Static Occlusion

Static Occlusion
Six significant occlusal characteristics identified & first
reported in 1972 by Lawrence F. Andrews “The six keys to
Normal Occlusion”

These six keys were found to be consistently present in a
collection of 120 models of teeth with natural excellent
occlusion (“nonorthdontic normal” models).

- The distal surface of the distal marginal ridge of the upper
first permanent molar contacts and occludes with the
mesial surface of the mesial marginal ridge of the lower
second molar.

- The mesio-buccal cusp of the upper first permanent molar
falls within the groove between the mesial and middle
cusps of the lower first permanent molar. The mesio-lingual
cusp of the upper first molar seats in the central fossa of
the lower first.

- The premolars enjoy a cusp-embrasure relationship
buccally, and a cusp fossa relationship lingually.

- Maxillary Canine has a cusp-embrasure relationship with
Mandibular Canine & 1st Premolar. The cusp tip is slightly
mesial to embrasure Maxillary Incisors overlap Mandibular
Incisors & midlines of arches match.
Andrews' Six Keys
Key 1 – Interach Relationships

+50 +50 +80+80 +60+60
Key 2 – Crown Angulation Relation

• Crown angulation (tip) Facial axis of the clinical crown (FACC) Best viewed from the labial or buccal
perspective. For all teeth except molars, is located at the middevelopmental ridge that runs vertically
and is the most prominent portion in the central area of the labial or buccal surface. The facial axis of
molar crowns is identiﬁed by the dominant vertical groove on the buccal surface.

• Crown angulation (tip). Viewed from mesial or distal perspective, the FACC is represented by a line that
is parallel to the middevelopmental ridge (or with molars, the dominant groove), and tangent to the
middle of the clinical crown on the labial or buccal surface

• Crown angulation (tip) refers to angulation (or tip) of the long axis of the crown, not to angulation of the
long axis of the entire tooth.

• Crown Angulation or Crown tip. The degree of crown tip is the angle formed by the FACC and a line
perpendicular to the occlusal plane. A “+ reading" when the gingival portion of the FACC is distal to
the incisal portion. A “- reading" when the gingival portion of the FACC is mesial to the incisal portion.

• Crown angulation (tip) Each normal model had a distal inclination of the gingival portion of each crown,
It varied with each tooth type, but within each type the tip pattern was consistent from individual to
individual.

• Crown angulation (tip) Normal occlusion is dependent upon proper distal crown tip, especially of the
upper ant. teeth ( longest crowns). Degree of tip of incisors, determines the amount of MD space they
consume & has a considerable eﬀect on post. occlusion as well as ant. esthetics.
Andrews' Six Keys

+
Lingual
Root
Torque
-
Buccal
Root
Torque
Key 3 – Crown Inclination Relation
Inclination (Torque)

Andrews' Six Keys
• Crown inclination angle formed by a line which bears 90°to the occlusal plane and FACC (as
viewed from the mesial or distal). A + reading is given if the gingival portion of the tangent line (or
of the crown) is lingual to the incisal portion, A - reading is recorded when the gingival portion of
the tangent line (or of the crown) is labial to the incisal portion.

• ANTERIOR CROWN INCLINATION. In upper incisors + crown inclination. In lower incisors -
crown inclination The average inter-incisal crown angle - 174°.

• Properly inclined anterior crowns contribute to normal overbite and posterior occlusion, when
too straight-up and -down they lose their functional harmony and overeruption results.

• If the inclination of the anterior crowns is not suﬃcient, space, in treated cases, is often
incorrectly blamed on tooth size discrepancy.

• POSTERIOR CROWN INCLINATION— UPPER. A minus crown inclination for each crown from
the U canine through the U-2nd PM. A slightly more negative crown inclination existed in the
U-1st & 2nd molars.

• POSTERIOR CROWN INCLINATION— LOWER. A progressively greater "minus" crown
inclination existed from the lower canines through the lower second molars.

• As the anterior portion of an upper rectangular arch wire is lingually torqued, a proportional
amount of mesial tip of the anterior crowns occurs. The ratio is approximately 4:1. For every 4°
of lingual crown torque, there is 1 ° of mesial convergence of the gingival portion of the central
and lateral crowns.

Andrews' Six Keys
Key 4 – Rotation
• Teeth should be free of undesirable rotations. Rotated molar, would occupy
more space than normal, creating a situation unreceptive to normal occlusion.

Andrews' Six Keys
Key 5 – Tight Contacts
• Contact points should be tight (no spaces). Persons who have genuine
tooth-size discrepancies pose special problems.

• Serious tooth-size discrepancies should be corrected with jackets or
crowns, so the orthodontist will not have to close spaces at the expense
of good occlusion.

Key 6 - Curve of Spee Contacts

Andrews' Six Keys
Key 6 – Flat Curve of Spee
• Occlusal plane (curve of spee), depth of curve of Spee ranges from flat plane to slight
concave surface (0- 2.5 mm). A flat plane should be a treatment goal as a form of over
treatment. There is a natural tendency for the curve of Spee to deepen with time.

• Lower jaw's growth downward and forward sometimes is faster and continues longer
than that of the upper jaw. This causes the Lower Anterior teeth to be forced back and
up, crowded lower anterior teeth and/or a deeper overbite and deeper curve of Spee.

• At the molar end of the lower dentition, the 3 rd molars are pushing forward, even after
growth has stopped, creating essentially the same results. If the Lower Anterior teeth
can be held until after growth has stopped and the 3rd molar threat has been eliminated
by eruption or extraction, All should remain stable, assuming that treatment has
otherwise been proper.

• Intercuspation of teeth is best when the plane of occlusion is relatively flat There is a
tendency for the c.o.s to deepen after treatment.

• Treatment the plane of occlusion until it is somewhat flat or reverse to allow for this
tendency.

• A deep curve of Spee results in a more contained area for the Upper teeth, making
normal occlusion impossible. Only the Upper1st Premolar is properly intercuspally
placed. The remaining upper teeth, Anterior & Posterior to the 1st PM, are progressively
in error.

• A reverse c.o.s is an extreme form of over treatment, allowing excessive space for each
tooth to be intercuspally placed www.indiandentalacademy.com

Key 7 – Correct tooth size (Bennett & McLaughlin, 1993)
• Correct tooth size Bennett & McLaughlin. If Andrews’ non orthodontic models
have shown tooth size discrepancy, it would have resulted in either spacing or
crowding in either of arches, until compensated by tip & torque in anterior
segment Prior to treatment by Bolton analysis.

• Discrepancy may exist prior to treatment but frequently not noticed until the
ﬁnishing stage. The potential need for interproximal reduction to ↓ tooth size in
one arch or restorative procedure to ↑tooth size in opposite arch should be
discussed with patient/parents before treatment.

Angle’s Classification:

Children and Youth American
30% Normal Occlusion
50-55% Class I Malocclusion
15% Class II Malocclusion
1% Class III Malocclusion
Adult Dental Health, London
60% Class I Malocclusion
25-30% Class II Malocclusion
5% Class III Malocclusion

Prevalence of Malocclusion

Europe
More Class II Malocclusion

Oriental
More Class III Malocclusion

African
Class III Malocclusion with Openbite

Prevalence of Malocclusion

Maloccluison

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