Chapter 15

ORTHODONTICS

1

Orthodontics

The study dealing with prevention and correction of

abnormally positioned or misaligned teeth.

2

Orthodontist

Dentist specializing in causes and treatment of malocclusion.

3

Classifications of Malocclusion

1- Neutroclusion

2- Distoclusion

3- Mesioclusion

4

Neutroclusion

Class I condition

The antero-posterior occlusal or mesiodistal positions are

normal.

There are other malocclusion or positioning of individual teeth.

5

Distoclusion

Class II condition

Mesiobuccal cusp of maxillary first molar is anterior to the buccal

groove of mandibular first molar.

Having the appearance of retruded mandible.

6

Distoclusion

Division 1 : Maxillary incisors protruding with a V-shaped arch

instead of a U-shaped arch

Division 2 : Maxillary incisors having a lingual incline with an

excessive overbite and a wider than normal arch.

7

Mesioclusion

Class III condition

Mesiobuccal cusp of the maxillary first molar occludes in the

interdental space of the mandibular permanent first molar’s

distal cusp and the mesial cusp of mandibular second molar.

Having the appearance of a protruded mandible.

8

Causes of Malocclusion

Trauma

Poor mouth condition

Congenital factors ( supernumerary or ectopic

teeth)

9

Occlusal Problems

Open bite

Overjet

Vertical overbite

Cross bite

Underjet

End to end

10

Open bite

11

Overjet

12

Vertical Overbite

13

Cross Bite

14

Underjet

15

End To End

16

Types and Methods of Orthodontic Treatment

Preventive

Interceptive

Corrective

17

Movements in Corrective Orthodontics

Rotation

Translation

Tipping

Intrusion

Extrusion

Torque

18

Choices and Methods of Correction

Banding

Direct bonding

Invisalign

Lingual braces

19

Banding

20

Direct Bonding

21

Invisalign

22

Lingual Braces

23

Why Force Application?

Force stimulates osteoclast cells to resorb the alveolar bone.

When misaligned tooth moved into proper place and

retained, osteoblast cells deposit mineral salts to strengthen

the alveolar bone and make the movement permanent.

24

Extraoral Devices

25

Headgear

Device composed of facebow and traction for

applying external force.

26

Facebow

Stainless steel external archbow inserted into the fixed molar

tubes on the maxillary first molars.

Used to move the molars distal for more anterior space.

27

Traction Device

Fitted expandable device to be hooked onto a facebow after

placement on the head.

28

Cervical Device

Circles the patient’s neck and attaches to facebow.

Pull in parallel position to retract teeth.

29

Chin Device Incorporates high-pull and cervical forces.

Used to control mandible growth.

30

Specialized appliances and Retainers

31

Activator

Appliance designed to guide , change, or alter facial and jaw

functions for a more favorable occlusion position

32

Lingual Retainer

Mandibular lingual bar with cuspid-to-cuspid cemented unions

to maintain lower incisors in position.

If extended and attached to mandibular molar to molar areas ,

known as Lingual Arch Retainer.

33

Palatal Expander

RPE ( Rapid Palatal Expander)

Fixed appliance to maxillary molar with a spring in the palate

area which is activated by a key rotation to expand appliance,

apply force and expand midpalatal suture, therefore increasing

the size of maxilla.

34

Oral Shield

Device fitting into the vestibule space between teeth and lips.

Trains and maintains lip function.

35

Mouth Guard

Protects the teeth in sport activities

36

Orthodontic Instrumentation

37

Band-remover Pliers

For removing bands from teeth

38

Bird-beak Pliers

Used to bend and shape the wires

39

Loop-forming Pliers

Used to form and shape loops in wires

40

Three-prong Pliers

Used to close or adjust clasps

41

Contouring Pliers

Used to contour bands for concave and convex tilt

42

Bracket Tweezers

Small-ended tweezers used to place direct-bond brackets

43

Ligature Cutter

Used to cut ligature wire, intraorally or extraorally.

44

Distal End Cutter

Used to cut and hold arch wire that was inserted into the

buccal tube

45

Band Pusher

Used to push and seat bands onto the teeth.

46

Scaler

Used to remove excess cement from bands.

47

Boone Gauge

Measuring device for establishing the height of the

orthodontic bands.

48

Bitestick

Plastic or metal instrument with projecting serrated steel

area used to help “seat” posterior bands

49