This document discusses the classification of malocclusions. It describes three main skeletal patterns - Class I, Class II, and Class III - which are determined through cephalometric analyses and often correspond to Angle's classification. It also describes two skeletal divergence patterns - hypodivergent, characterized by a low mandibular plane angle, and hyperdivergent, characterized by a steep mandibular plane angle. Additional classifications and terms discussed include overjet, crossbites, the British Standards Institute classification of incisor relationships, and canine occlusion classification. Understanding the skeletal pattern and classification is essential for determining proper orthodontic treatment.
41. Skeletal Patterns
Cephalometric analyses reveal to the
orthodontist
the skeletal component of the
patient’s malocclusion.
We can classify patients as a :
Class I Skeletal Pattern
Class II Skeletal Pattern
Class III Skeletal Pattern
These patterns often correspond with
the Angle
Classification but not necessarily all the
time.
Understanding the skeletal pattern is
essential for choosing the proper
treatment mechanics
47. Hypodivergent Skeletal Pattern
A skeletal pattern in
which the skeletal planes
are more parallel to each
other.
Characterized by a low
mandibular plane angle,
short lower facial height
and is often as
sociated
with Class II Division 2
malocclusions.
48. Hyperdivergent Skeletal Pattern
A skeletal pattern that
deviates from the norm in
that there is an excessive
divergence of the skeletal
planes (determined by the
analysis used.)
Characterized by a steep
mandibular plane angle, a
long anterior lower face
height with open bite
tendency, lip incompetence
and often associated with
Class II malocclusion.
66. Overjet is a term used to
Describe HORIZONTAL distance
between the
labial surfaces of the mandibular
incisors and the incisal edge of the
maxillary incisors.
67.
68. Anterior Crossbite is a
malrelation between the maxillary
and mandibular teeth when they
occlude with the antagonistic
tooth in the opposite relation to
normal.
69.
70. Crossbites: Deviation from
normal buccolingual relationship
A Posterior Crossbite is present
when posterior teeth occlude in an abnormal
buccolingual relation with the antagonistic
teeth. Posterior Crossbites can be the result
of either malposition of a tooth or teeth,
and/or the skeleton.
71.
72.
73.
74.
75.
76.
77. The British Standards Institute classify the
incisor relationship as Class I, Class II
division I or division II, and Class III
78. Class I
The lower incisal edges
occlude with or lie
immediately below the
cingulum of the upper
incisors.
Class II division I
The lower incisal edge
occludes behind the
cingulum of the upper
central incisors and the
upper incisors are
proclined.
79. Class II division II
The lower incisal edge occludes
behind the cingulum of the upper
central incisors, and the upper incisors
are retroclined (the lateral incisors may
be proclined).
Class III
The lower incisal edge occludes in front
of the cingulum of the upper incisors.
80.
81. If the upper canine is positioned in
the embrasure between the lower
canine and first premolar, the canine
occlusion is called Cl I. If the upper
canine is positioned mesial to the
embrasure between the lower
canine and first premolar, the canine
occlusion is called Class II. If the
upper canine is positioned in the
embrasure between the lower
canine and first premolar, the canine
occlusion is called Class III.
CANINE CLASSIFICATION
