Hybrid Hyrax Expanders Explained

Hybrid Hyrax Expanders Explained

Write short note on hyrax screw.
Answer. Full form of HYRAX is hygienic rapid expander.

• The tooth borne appliance use a special type of screw which is known as HYRAX.
• HYRAX screw is an expansion appliance.
• HYRAX screw consists of heavy gauge wire extension which is adapted in such a way that it follows the contour of palate.
• HYRAX screw is soldered to bands on molars and premolars.
• It is of two types, i.e. banded Hyrax appliance and bonded Hyrax appliance.

Banded Hyrax Appliance

• Hyrax screw is soldered to the bands over fist premolar and molar.
• It provides the advantage of hygiene due to less coverage of gingiva.
• Disadvantage of appliance is that chair side time enhances and wire banding as well as soldering should be done precisely.

Bonded Hyrax Appliance

• Arms of the Hyrax screw are attched to the acrylic cap splint on both sides.
• Acrylic cap splint covers the posterior teeth on both sides.
• Appliance is very popular because of ease of its cementation at mixed dentition period.
• Chair side time is very less and is completed in two appointments.
• Maintains good oral hygiene since coverage of appliance is 1 mm short of gingival margin.
• The appliance maintains overbite control.