Orthopedic Appliances Question And Answers

Orthopedic Appliances

Question 1. Write short note on orthopedic appliances.
Answer. Following are the commonly used orthodontic appliances.

• Headgear.
• Protraction face mask.
• Chin cup appliance.

Headgear

• Headgears are the most widely used extraoral orthopedic appliances.
• They are mainly used in the management of skeletal class 2 malocclusion by growth modification.
• They are also used for the distalization of maxillary molars, as well as for reinforcing intraoral anchorage.
• A typical headgear is attached to the teeth via a face bow and is anchored from the back of the head/neck by means of head cap/neck strap.

Read And Learn More: Orthodontics Question And Answers

Indications

• Growth modification: Headgears can be used to treat a variety of skeletal class II problems. However, ideal circumstances to use the extraoral orthopedic effect of headgears is when skeletal class 2 malocclusion is caused by maxillary protrusion (anteroposterior excess of maxilla) with normal mandibular skeletal and dental morphology, and when there is continued active mandibular growth in a forward direction.
• For distalization of maxillary molars.
• To reinforce intraoral anchorage.

Face Mask

• Face mask is also called as “reverse pull headgear or “protraction headgear”.
• Face mask has been used in the treatment of patients with class 3 malocclusion and a maxillary deficiency.
• It exerts a mesial force on the maxilla with an equal and opposite force on the chin and forehead, thereby causing a forward movement of maxilla.

Indications

• The face mask can be used in the treatment of mild to moderate skeletal class 3 malocclusions with a retrusive maxilla and a hypodivergent growth pattrn.
• It can even be used for selective rearrangement of the palatal shelves in clef patients.

Chin Cup

• Chin cup is an extraoral orthopedic orthodontic appliance used to treat skeletal class 3 malocclusions caused due to mandibular prognathism.
• It covers the chin and is connected to a headgear.
• Chin cup appliance is aimed at restraining the forward growth of the mandible.

Indications

Chin cup appliance is indicated in:

• Patients with a mild skeletal prognathism of the mandible.
• In the case of decreased facial height.
• Patients who has well aligned or protrusive, but not retroclined mandibular incisors.

Question 2. Write short note on face mask.
Answer. Face mask is also known as reverse pull headgear. Face mask is an extraoral traction appliance. It corrects the skeletal Class III malocclusion.

Components of Face mask

It consists of following components i.e.

• Chin cup
• Forehead cap
• Metal framework
• Intraoral splint/device
• Elastics.

Chin Cup

• It covers the chin and also derives the anchorage from chin so the protraction force is delivered to maxilla and delivers reciprocal force to chin to push it backwards.
• Chin cup restrain the forward growth of mandible by changing direction of growth from forward and downward to backward and downward.

Forehead Cap

• It rest against the forehead and delivers anchorage to the appliance from frontal bone.
• It gives reciprocal force to forehead with protraction on maxilla.

Metal Framework

• They are of different types in its design.
• Metal framework support as well as connect all the parts of face mask.
• It provide, attchment to rods by which elastic get attched from intraoral device.

Intraoral Device

• Intraoral device is a full banded fied appliance in which elastic is engaged from molars.
• Use of banded rapid maxillary expansion and bonded rapid maxillary expansion with hooks at premolar region for engaging the elastic should also be done.

Elastics

Heavy orthopedic elastics are used to provide traction force to maxilla.

Types of Face Mask

• Hickham reverse pull headgear: It has got a chin cup and forehead support. The framework consists of metal rods which run parallel to mandible and at angle of mandible, the rods turn upwards to run parallel to lateral border of face. Two arms engage the elastics.
• Delaire: This is very similar to Hickham, the diffrence is, it remains away from the face without touching it. It consists of hexagonal framework which has horizontal rod at lower third of face which run parallel to lip line for engaging elastics.
• Petit: Petit simplifies the Delaire’s face mask. It consists of central midline rod which has horizontal adjustable rods for engaging elastics. Horizontal rod can be made up and down as per need of practitioner. Midline rod gets curved at contour of face and extends from chin cup to forehead support.
• Turbinger: It is similar to Petit’s facemask but diffrence is there are two rods instead of midline rod. Rod run parallel from chin cup and in region of base of nose they turn medially to accommodate nose. Now rods turn parallel till forehead support. Horizontal rod should be present at lip level for engagement of elastic.

Effects of Face Mask

• It leads to forward movement of maxilla as well as maxillary teeth.
• It leads to proclination of maxillary anterior teeth.
• It leads to correction of anterior and posterior crossbite.
• It leads to downward and backward rotation of mandible.

Duration for Face Mask

It should be weared for 20 hours/day but after 6 months it is reduced to night time wear for retention. Active treatment takes 4 to 6 months.

Age for Treatment

Age of 10 years is best for the application. After 10 years of age response of appliance decreases.

Usage of Rapid Maxillary Expansion

Rapid maxillary expansion should be activated once daily before going for bed time for period of two weeks till desired expansion is gained.

Completion of Treatment

After treatment get completed positive overjet is gained and concave profie is improved.

Advantages of Face Mask

• It corrects the maxillary deficiency with rapid improvement and early results.
• As treatment with facemask is rapid, patient compliance is improved.

Question 3. Write short note on headgear.
Or
Write short note on components and types of headgear.
Answer. Headgears are the most widely used extraoral orthopedic appliances.

• They are mainly used in the management of skeletal class 2 malocclusion by growth modification.
• They are also used for the distalization of maxillary molars, as well as for reinforcing intraoral anchorage.
• A typical headgear is attached to the teeth via a face bow and is anchored from the back of the head/neck by means of head cap/neck strap.

Components of Headgear

Following are the components of a headgear:

• Force delivering unit i.e. Facebow or J hook
• Force generating unit
• Anchor unit, i.e. Head cap or neck strap

Force Delivering Unit

• Facebow: This is the handle through which the force of headgear is transmitted to jaws and dentition. Mainly this is the force delivery unit. Facebow is fabricated by heavy stainless steel gauge wire. It consists of two parts, i.e. outer bow and inner bow and a junction.
• J hook: Headgear can directly engaged to the loops on the arch wire of the fixed appliances. This is known as J hook headgear.

Force Generating Unit

• It is the force generating element of the assembly, which produces heavy forces to effect skeletal changes.
• Force generating unit also connects the facebow to the anchor unit (head cap or neck strap).
• Force generating unit may be in the form of springs, elastics or other stretchable material.
• Force thus produced is delivered to the teeth through the facebow and then to the underlying skeletal structures via teeth

Anchor Unit

• Headgear appliance derives anchorage from extraoral sites using the rigid bones of skull and / or the back of the neck.
• There are two basic types of extraoral attchments that provide anchorage for headgear:
  • Cervical attachment/ neck strap
  • Occipital attachment/ head cap
• A combination of cervical and occipital attachments may also be used to distribute the external forces over a wide surface area.

Types of Headgear

Following are the types of headgear according to site from which anchorage is obtained

Highpull or Occipital Headgear:

In this head cap is attched to back of the head in occipital region or junction of occipital and parietal region. This is indicated in high mandibular angle cases. This provides superior and distal force to both maxilla and maxillary dentition.

Straight or Medium Pull Headgear or Combination Pull Headgear:

Combination pull headgear has both occipital and cervical straps. It is indicated in normal or average mandible angle cases. If level of force of both the straps is equal, then there is distal and slight upward force on maxilla as well as teeth.

Cervical or Low Pull Headgear:

Its anchorage is from nape of the neck. It applies distal force and also exert extrusive component of force to maxillary molars. It is indicated in cases of Class 2 division 2 malocclusion.

Uses of Headgear

• For intrusion of molars and incisors by high pull headgear.
• For uprighting of molars
• For expansion or contraction of the arch
• For reducing the overjet
• For space maintenance and space regaining
• For retention of molar correction done by other techniques
• For reinforcement of anchorage during fixed appliance treatment.
• For distalization of maxillary first molars.