Date post: | 12-Jan-2017 |
Category: |
Health & Medicine |
Upload: | ahmed-baattiah |
View: | 383 times |
Download: | 13 times |
CLASS II DIV 2 MALOCCLUSION
Presented by: Ahmed Saeed Baattiah
Under supervision of: Prof. Maher Fouda
Mansoura UniversityFaculty of Dentistry
Orthodontics Department
Father of modern orthodontics
Born on a farm in Pennsylvania on June 1 , 1855 - fifth of seven children.
Marked ability to improve & create mechanical equipment on the farm.
Apprenticed him self to a dentist at his mothers request.
Graduated from Pennsylvania college of Dentistry – 1878.
Classified malocclusion – 1899.
Established orthodontics as a separate branch of dentistry.
Established Angle School Of Orthodontics in 1900.
Founded American Society Of Orthodontics in 1901.
Developed different orthodontic appliances.
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
INTRODUCTION Orthodontic specialty deals with various malocclusions. Malocclusion is the study of its cause or causes. Development of normal dentition and occlusion depends on number of interrelated factors that include the dentoalveolar, skeletal and neuromuscular factor .
CLASS II DIVISION 2 MALOCCLUSION
CLASS II DIVISION 2
DEFINITION
INTRODUCTION
Class II division 2 malocclusion is a type of class II malocclusion, defined by Angle in 1899.
It represents 5 to 10 % of all malocclusion ( Sassouni 1971 ).
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Shape of the head : brachycephalic
Facial profile: convex
Chin: prominent
Lower lip: Everted ( lower lip line is high relative to the upper incisors)
Upper lip: Positioned high inrespect to the upper anteriors (Gummy smile)
Mentolabial sulcus: Deep
Mentalis: Hyperactive
Retrusive lips
Facial features
Gummy smile
Prominent chinHyper active mentalis
Facial profile of class II division 2
The lips are usually thin and there is a lack of vertical development of the face below the nose.
The masseter and temporalis muscles are wide.
Mild mandibular retrognathia, with a pronounced chin point and reduced lower anterior face height.
High lower lip line
Some features of Class II division 2 malocclusion
Retroclined maxillary central incisors and deep overbite.
Profile of a class II division 2 boy. A round face, backwardly held mandible with thick chin button and thin lips.
Dental features
Class II molar and canine relationship
Deep traumatic bite Retroclined upper four incisors or
retroclined centrals with labial inclination of the laterals.
The tooth size may be small, and upper
incisors may have decreased collum angle between the crown and the root.
Decrease over jet
Shorter root and longer crown.
gingival recession
Canine relationship
Molar relationship
Angle class II division 2 malocclusion
Deep bite : overclosure ( closed bite ) Class II div 2 with posterior open bite
The lower teeth are shifted backward compared to the upper teeth (red arrow)
The green arrows indicate a bone loss problem (periodontics).
The upper left canine is longer than the right canine (blue line) and will have to be levelled individually to avoid causing inclination of the anterior occlusal plane.
Class II division 2, mandibular retrognathia and supraocclusion
Initial facial and intraoral photographs
Initial facial and intraoral photographs
Cephalometric features
Class ll/division 2 malocclusions have a shorter or normal mandibular length with its sagittal position retruded.
The chin being prominent and posterior facial height definitely increased.
The mandibular growth vector is horizontally oriented, with a flat mandibular plane, giving the appearance of a hypodivergent facial pattern.
The gonial angle is acute.
The lower incisors have a normal inclination relative to the mandibular plane but are retroclined relative to various facial planes.
Interincisal angle is obtuse, overbite is deep.
Airway restriction at the oropharynx level
Backward shift of the lower jaw
Upper incisor too vertical
Cephalometric features
Cephalometric features
Proclined lateral incisor
Retroclined central incisor
Flat mandibular plane, anticlockwise rotation
Increase in posterior face height
Class II division 2 incisors have a shorter root, a longer crown
Cephalometric features
Anthropometric method used in determination of gonial angle
GONIAL ANGLE
GONIAL ANGLE
Reduced gonial angle
Orthopantomograph (OPG) of Class II division 2 malocclusion. Well developed ramus in width with short gonial angle
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Diagnosis
Class II division 2 Extra and intra oral photographs
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Angle’s classification
Angle’s classification
British standards classification
Von - Der - Linden classification
Type A:*Maxillary central incisors and laterals are retroclined.*Degree of retroclination is less severe in nature.
Von - Der - Linden classification
Type B:Maxillary lateral incisors are overlapping the retroclined maxillary central incisors.
Von - Der - Linden classification
Type C:*Maxillary central and lateral incisors are retroclined and are overlapped by the maxillary canines.
Von - Der - Linden classification
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Muscular pattern Class II Division 2 TMJ Problems
Strong muscular pattern may not permit the bite opening with the vertical increase of the buccal segment in adult patients.
Abnormal intercuspal masticatory articulations
physiologic changes at any postural level require compensatory neuromuscular accommodation. Clinical evidence has consistently shown the occlusal signs and muscular symptoms that occur over time when teeth are not able to take their optimal physiologic place (position) within the oral cavity. Various musculoskeletal problems will occur.
Class II Division 2 TMJ Problems
Note: No gonial angle notching, nor extra boney growth exists with this 18 year old male. Normal vertical dimension of teeth supporting healthy musculature with no muscle tenderness or TMD symptoms. Normal mandibular range of motion is exhibited with no clicking or popping joints.
Normal mandibular range of motion is exhibited with no clicking or popping joints.
Because of these compressing forces the mandible retrudes while the masticatory muscles strain and skew the underlying bony structures of the cranium, mandibular condyles, cervical neck bones and downward.
Every TMD patient is a walking example of the ill effects of the mal alignment of the postural system beginning with vertically under developed (or under erupted) molars and bicuspids. this contributes to narrowing of dental arches, insufficient room for the tongue and further results in a downward cascading effect of jaw collapse, abnormal head posturing, and degeneration on the temporomandibular joints (due to abnormal forces (lack of sufficient vertical occlusal support).
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Class II division 2 malocclusion arise from a number of interrelated dental, skeletal, soft tissue and genetic factors.
Most of class II/2 malocclusion are caused by an underlying skeletal discrepancy, and few have a normal skeletal jaw relationship.
Etiology
Soft tissues
Skeletal pattern
Dental factors
Etiology
Etiology
Dental class II division 2
Normal maxilla-mandibular skeletal relationship. Steiner : SNA,SNB,ANB = Normal
Mainly occurs due to mesial drift of the maxillary first molar . As a result of
a) Loss of mesial proximal contact with the primary 2nd molar - premature extraction/loss of primary 2nd molar. - congenitally missing primary 2nd molar.
b) inter-arch tooth size discrepancy - small or congenitally missing maxillary permanent teeth (2nd premolar) results in a class II molar relation.
c) Maxillary canine or 2nd premolar impaction or displacement out of the arch - inadequate space in the dental arch class II molar
Dental class II division 2
Dental class II division 2
Soft tissues
Skeletal pattern
Dental factors
Etiology
Etiology
Skeletal class II division 2 Result from a discrepancy in the maxillary-mandibular skeletal relationship.
It might be either due to: 1) Mandibular deficiency 2) Maxillary excess 3) or a combination of both
Skeletal class II division 2 Mandibular deficiency
It is a skeletal class II relationship resulting from a mandibular that is either small or retruded relative to the maxilla.
Mandibular deficiency
size Position (Small mandible) ( Retrusion of a normal
sized mandible)
OR
(Combination of both in severe cases )
Skeletal class II division 2 Mandibular deficiency
Class II div 2 with a small mandible the decreased size is localized more to the mandibular body ( Mandibular Ramus is of normal length ).
Skeletal class II division 2 Mandibular deficiency
Mandibular deficiency may result from the retrusion ( distal positioning ) of a normal – sized mandible.
Skeletal class II division 2 Mandibular deficiency
Cephalometric analysis showed a skeletal class II relationship : ANB angle = 9SNA = 82B point was retruded, SNB angle = 74
Skeletal class II division 2 Maxillary excess
Skeletal class II division 2 Maxillary excess
Vertical maxillary excess may be localized only to the posterior area Open bite and incompetent lips ( normal vertical display of maxillary incisors in repose and during smiling ).
0verall maxillary excess includes both the anterior and the posterior area resulting in an excessive vertical display of the maxillary incisors in repose and during smiling (high smile line )
Gummy smile and incompetent lips.
In these 2 conditions of maxillary excess Mandible is rotated downward and posteriorly (clockwise) resulting in a class II skeletal relationship.
Skeletal class II division 2 Maxillary excess
Class II /2 with an overall vertical maxillary excess:
Skeletal class II division 2 Maxillary excess
Maxillary excess in Ant-Post Dimension is characterized by a protrusion of the entire midface including : 1) Nose 2) infra orbital area 3) upper lip
Skeletal class II division 2 combination
Skeletal class II division 2 might be a combination of both mandibular deficiency and maxillary excess.
Which will add to the severity of the Ant-post skeletal problem
A patient with maxillary vertical excess and mandibular deficiency
Skeletal class II division 2
Soft tissues
Skeletal pattern
Dental factors
Etiology
Etiology
Soft tissues
If the lower facial height is reduced
the lower lip line will effectively be higher relative to the crown of the upper incisors (more than the normal one-third coverage.
A high lower lip line will tend to retrocline the upper incisors
High lip line cause retroclination to incisors
Soft tissues
Patient with bimaxillary retroclination due to lip action Soft tissues
In some cases the upper lateral incisors, which have a shorter crown length, will escape the action of the lower lip and therefore lie at an average inclination, whereas the central incisors are retroclined.
Soft tissues
INTRODUCTION
ETIOLOGY
CLASSIFICATION
FEATURES
TREATMENT
DIAGNOSIS
CONTENETS
MUSCULAR PATTERN
Treatment of Class II Division 2
Treatment option for dental Class II Division 2
For a dental Class II/2 malocclusion:
Treatment option for skeletal Class II Division 2
Treatment for skeletal Class II Division 2
The goal of growth modification is to enhance the unacceptable skeletal relationship by modifying remaining facial growth pattern of the jaws.
Optimum timing : pre-pubertal growth spurt ( active growth period)
Treatment for skeletal Class II Division 2
Treatment for skeletal Class II Division 2
High pull headgear ( parietal )
Distal and intrusive forces on the maxillary molar.
Extra-oral force is directed superior and posterior.
A-p and vertical maxillary excess ( decreased V.D).
High pull headgear ( parietal )
Treatment option for skeletal Class II Division 2Treatment for skeletal Class II Division 2
Low pull headgear ( cervical )
Distal and extrusive forces on maxillary molars.
Posterior and inferior extra-oral force
Increases vertical dimension
Used in A-P maxillary excess with flat mand.plane
Low pull headgear ( cervical )
Medium pull headgear ( occipital )
Headgear to upper part of the Twin block
J-hook headgear
J-hook High-Pull Headgear
Treatment for skeletal Class II Division 2
REMOVABLE FUNCTIONAL APPLIANCES
ACTIVATORBIONATOR
TWIN BLOCK
FRANKYL II
FIXED FUNCTIONAL APPLIANCES
Herbst appliance Jasper jumper
Treatment for skeletal Class II Division 2
Adult patient with nearly full-cusp Class II molar relationship. Note inclination of incisors, 100% deep bite, and discrepancy in gingival margins between canines and incisors.
Biomechanical Considerations
Treatment of Class II, Division 2 Malocclusion in Adults by dental camouflage
Intrusion arch produces anterior tipback moment and intrusive force along with extrusive force on molars.
Force system and ligation points of intrusion arch in Class II, division 2 malocclusion.
Canine retraction generates extrusive effect on incisors. To counteract this tendency, intrusion arch is tied anteriorly.
Canine retraction with .016" × .022" stainless steel base arch and overlay intrusion arch for anchorage and incisor control.
Moment at molar counteracts mesial reactive force in anchor unit.
A. Mushroom-loop archwire without preactivation bends. B. Archwire with gable bends mesial and distal to archwire. C. 3mm preactivation of loop
017" × .025" CNA mushroom-loop archwire after intraoral activation
A. Mushroom-loop archwire with spaces closed. Wire is left in place for another six weeks to allow residual moments to deliver proper axial root inclinations.
B. Same patient with ideal axial inclinations
B. After initial intrusion phase (note incisor level and molar tipback), .016" × .022" stainless steel base arch is used with short .017" × .025" nickel titanium intrusion arch to retract canines.
C. Canines fully retracted into Class I positions. Note intrusion, overbite, and anchorage control without elastic wear.
017" × .025" mushroom-loop archwire with preactivation bends activated about 4mm for translatory incisor retraction. Archwire was not reactivated for about 10 weeks.
Finished occlusion, showing excellent anchorage control, overbite correction, and anterior incisor angulation.
re REFERENCES
ORTHODONTICS CURRENT PRINCIPLES AND TECHNIQUES 5TH EDITION (GRABER ).
CONTEMPORARY ORTHODONTICS (WILLIAM R.PROFFIT )
SCIENCE DIRECT DATABASE
TEXTBOOK OF ORTHODONTICS ( SAMIR BISHARA )
HANDBOOK OF ORTHODONTICS (ROBERT MOYERS )