MANAGEMENT OF CLASS I

MALOCCLUSION

PRESENTED BY: HAFSA SARA ZUBAIRBDS

OBJECTIVES:• OCCLUSION• CLASS I OCCLUSION• CLASS I MALOCCLUSION• LINE OF OCCLUSION• CAUSES OF CLASS I

MALOCCLUSION• BIMAXILLARY PROTRUSION• FEATURES OF BIMAXILLARY

PROTRUSION• FEATURES OF CLASS I

MALOCCLUSION• DIAGNOSIS• MANAGEMENT OF CLASS I

MALOCCLUSION

WHAT IS OCCLUSION ?

“ Occlusion is the relationship of the maxillary and mandibular teeth when the jaws are in fully closed position.”

CLASS I OCCLUSION

CLASS I MALOCCLUSION

• Normal relationship of the molars, but line of occlusion incorrect

o Malposed teetho Rotationso Others

LINE OF OCCLUSION FOR UPPER ARCH :

Smooth curve passing through the central fossa of each upper molar and across the cingulum of upper canine and incisor teeth.

oFOR LOWER ARCH:• The same line runs along the buccal cusp and incisal edges of lower teeth.

CAUSES OF CLASS I MALOCCLUSION

DEVELOPMENTAL GENETIC ENVIRONMENTA

L

DEVELOPMENTAL CAUSESINCLUDES: Congenitally missing teeth. Malformed teeth. Supernumerary teeth. Impacted teeth Ectopic eruption

GENETIC CAUSES:

Plays major role for malocclusion where there is discrepancy between the size of jaws and size of teeth.

ENVIRONMENTAL CAUSES

CAUSED BY: Injuries which has two types:

BIRTH INJURIES:

› Fetal moulding› Trauma during birth from usage of

forceps.

CONT…. INJURIES THROUGHOUT LIFE:

Trauma to teeth can lead to:

Damage to permanent tooth bud.

Premature loss of primary teeth leads to permanent tooth movement.

Direct injury to permanent teeth.

MOST COMMON FORM :

• BIMAXILLARY PROTRUSION

WHAT IS BIMAXILLARY PROTRUSION ??

The patient exhibits a normal class I molar relationship but the dentition of both the upper and lower arches are forwardly placed in relation to facial profile.

FEATURES

FEATURES OF BIMAXILLARY PROTRUSION

EXTRAORAL FEATURES

CEPHALOMETRIC FINDINGS

INTRAORAL FEATURES

EXTRAORAL FEATURES Decreased

nasolabial angle due to proclined maxillary anteriors.

oShallow mentolabial sulcus due to proclined mandibular anteriors.

oLips may be incompetent.

oConvex facial profile.

CONT…

INTRAORAL FREATUES

Maxillary and mandibular anterior proclination.

Class I molar relationship (2)

CONT…. Class I canine

relationship (may be)

CONT… Spacing

between teeth. (may be)

CEPHALOMATRIC FINDINGS Decreased

interincisal angle.

Increased incisor mandibular plane angle

CONT….. Increased SNA and SNB, if

there is prognathism of jaws.

FEATURES OF CLASS I MALOCCLUSION

INTRAORALEXTRAORAL

EXTRAORAL FEATURES: Straight profile.

Harmonious face

INTAORAL FEATURES: Class I molar

relationship (2)

Class I canine relationship (3)

CONT… Class I incisor

relationship

Spacing

CONT… Crowding

Bimaxillary protrusion

CONT… Cross bite

Open bite

CONT…. Deep bite

Rotations

DIAGNOSIS:• HISTORY• CLINICAL EXAMINATION• STUDY MODELSRADIOGRAPHS:• OPG• LATERAL CEPHALOGRAM

DIAGNOSIS:• HISTORY• CLINICAL EXAMINATION• STUDY MODELS

RADIOGRAPHS• OPG• LATERAL CEPHALOGRAM

MANAGEMENT OF CLASS I MALOCCLUSION

MANAGEMENT :AIMED AT CORRECTION OF DISTURBANCE IN LINE OF OCCLUSION LEADING TO

• CROWDING• SPACING• OPEN BITE• CROSS BITE• DEEP BITE• ROTATIONS• BIMAXILLARY PROCLINATION

‘’CROWDING’’

CROWDING:‘Is defined as malalignment of teeth caused by

inadequate space.’

• Occurs due to GENETIC or ENVIRONMENTAL factors.

• Classified as: Mild crowding --- less than 4mm per arch. Moderate crowding --- 5 to 9mm per arch. Severe crowding --- 10mm or more per

arch.

Before carrying out treatment, following aspects should be considered. Degree of crowding. Site and position of crowding. Patient’s age.

• MILD CROWDING• Resolves without extraction.• Proximal stripping• Alignment of teeth by labial bow or z-

spring.

MODERATE CROWDING

• Arch expansion (quad helix applaince)• Distalization of molars.

SEVERE CROWDING• Extraction of all 1st premolar• Retract canine by canine retractor• Align anteriors by labial bow.• Retention by hawley’s retainer.

SPACINGLOCALIZEDGENERALIZED

SPACING:‘Gaps between two teeth or many

teeth’

• Can be:• Localized (space present in

localized regions or areas)

• Generalized (space present in entire arch)

GENERALIZED SPACING• Results from hypodontia along with small

teeth (microdontia) in well developed arches.

• IN CASE OF MICRODONTIA:

• Eliminate spaces between anteriors, leaving a space between canine and 1st premolar.

• Give prosthesis or implant.

LOCALIZED SPACING• It results from loss of tooth due to trauma, or

hypodontia or due to presence of midline diastema.

Intervention is required in cases with:Diastema greater than 3mm, no space for perm. lateral incisors to erupt. Permanent canines have erupted, diastema still present. Labial frenum has not migrated to labial attached mucosa. Congenitally missing incisors. Presence of supernumerary teeth.

INTERVENTIONS INCLUDE: Eliminate cause: i.e. high labial frenum

attachment.

Removable appliance• Finger spring• Finger spring with labial bow• Split labial bow

Frenectomy

Implants

Fixed appliances: Pin and tube appliance

CROSS BITE

CROSS BITE:

‘Refer to a condition where one or more teeth may be abnormally bucally or lingually with reference to the opposed tooth or teeth.’ (GRABER)

TYPES OF CROSS BITE:ANTERIOR

CROSS BITE

SINGLE TOOTH

MULTIPLE TEETH

POSTERIOR

CROSS BITESINGLE TOOTH

UNILATERAL

BILATERAL

MANAGEMENT: ANTERIOR CROSS BITE:

SINGLE TOOTH:• Z- spring

MULTIPLE TEETH:• Expansion screw

POSTERIOR CROSS BITE:

SINGE TOOTH:• Cross-elastics

CROSS ELASTICS

UNILATERAL CROSS BITE: Functional appliance

Quad helix W arch Coffin spring

QUAD HELIX

W- ARCH

COFFIN SPRING

BILATERAL CROSS BITE::• Quad helix• W arch• RME by hyrax screw

Hyrex screw

OPEN BITE

OPEN BITE‘ Open bite is the failure of a tooth or

teeth to meet antagonists in the opposite arch.’

TYPES OF OPEN BITE

SIMPLE ANTERIOR OPEN

BITE SIMPLE

POSTERIOR OPEN BITE

COMPLEX OR SKELETAL OPEN

BITE

MANAGEMENT• SIMPLE ANTERIOR OPEN BITE:

o Due to digital sucking.

o MIXED DENTITION:o Habit breaking by tongue spikeso Arch expansion

o LATE MIXED DETITION AND EARLY PERMENANT DENTITION:

oHabit breaking.

• SIMPLE POSTERIOR OPEN BITE: (RARE)o CAUSES:

o Ankylosed primary molarso Lateral tongue thurst

oEARLY TREATMENT:o Removal of ankylosed primary tooth.

• COMPLEX OR SKELETAL OPEN BITE:

o EARLY MANAGEMENT:o Bionatoro Frankel appliance

o ADULT SKELETAL OPEN BITE:

o Orthognathic surgery

DEEP BITE

DEEP BITE:

‘condition of excessive overbite, where the vertical measurement b/w maxillary and

mandibular incisal margins is excessive when the mandible is brought into centric occlusion.’

(GRABER)

MANAGEMENT• GROWING AGE:

o Anterior bite planes • INTRUDE ANTERIORS BY:o Fixed applianceo J. hooks vertical pull headgear• Erupt posterior

• NON GROWING AGE:

o ORTHOGNATHIC SURGERYo Lefort 1

BIMAXILLARY PROTRUSION

BIMAXILLARY PROTRUSIONMANAGEMENT

• Extract all 1st premolars.

• TREATMENT DEPENDS UPON ANGULATION OF CANINE:

o DISTALLY INCLINED CANINE:o Retract canine and align incisors using

retainer.o MESIALLY INCLINED CANINE:

o Fixed appliance

ROTATIONS

ROTATIONS:• SINGLE TOOTH:

• REMOVABLE APPLIANCES:• Double cantilever spring • Labial bow

• MULTIPLE ROTATIONS:• FIXED APPLIANCE

• SEMI- FIXED APPLIANCE:• High labial bow with t- spring

Double cantilever spring

High labial bow

T spring

REFERENCES:• CONTEMPORARY ORTHODONTICS BY

WILLIAM R. PROFFIT

• HANDBOOK OF ORTHODONTICS BY ROBERT E. MOYERS

• ORTHODONTICS PRINCIPLE AND PRACTICE BY BASAVARAJ PHULARI

• GOOGLE