how-to take an ear impression

WHAT KIND OF IMPRESSION DO YOU MAKE?

  • POOR IMPRESSION, NO CANAL,

    INSUFFICIENT CANAL DEPTH

    Your impression needs sufficient canal depth.

  • poor ear impression, small otoblock,blow-by

    DAM PLACEMENT & SIZE

    Inadequate dam placement results in under-filled canal; undersized otoblock results in blow-by.

  • POOR EAR IMPRESSION, NO HELIX, EAR NOT FILLED WITH IMPRESSION MATERIAL

    INSUFFICIENTLY FILLED

    The entire area must be filled to avoid pockets and ripples that result in a mold with a poor fit.

  • POOR EAR IMPRESSION,MATERIAL RIPPLED

    ICE CREAM EFFECT

    The ice cream effect is caused by either pulling back on the gun too rapidly, or moving the syringe while taking the ear impression.

  • GOOD EAR IMPRESSION

    GOOD IMPRESSION

    Sufficient canal depth

    Proper dam placement

    Full helix and cymba

preparation

Follow hygienic procedures:  Wash hands thoroughly. Wash specula, earlight tips, etc. thoroughly before immersing them in an antiseptic solution.  Caution: alcohol or other antiseptic injurious to plastics should be avoided. 

Ask the client if they have had any prior ear problems such as injury, surgery, infection, or currently have any irritation, swelling, or soreness in the ear.  It is inadvisable to take an impression of an ear that has been operated on within the last 90 days, and advise client to consult with a doctor if there is any apparent irritation, swelling, or soreness in the ear.

InSPECTION OF THE EAR

Always make a thorough inspection of the ear with an otoscope before taking an impression

  • A complete inspection with an otoscope will usually reveal any difficulties that might hinder the taking of the best possible impression. By taking the ‘pina’, or back of the ear, and extending it forward and up, the canal will straighten out for a thorough inspection.

  • Inspect for any discharge, infection or swelling, do not take the impression of an ear with discharge, infection or swelling, and advise any customer with these conditions to see their doctor.

  • Inspect for excessive wax. If the canal is entirely blocked or nearly blocked, do not take an impression, and advise the customer to see a physician to have the excess wax removed. Clearing the canal should also result in better hearing.

  • Inspect for foreign objects, resulting in a blockage that is not ear wax.

  • Inspect for any malformations and be sure they are shown clearly on the impression. Note these malformations on the earmold lab order form.

  • Check the texture of the ear to see if it is hard, medium, or very soft. You should be very careful in making an impression of a soft ear, not to stretch it out of shape. Many earmold problems are caused by pressing the material too hard into a soft ear, thus over-sizing and misshaping the impression.

THE OTOBLOCK

Always block the ear with an otoblock before taking an impression

The otoblock, whether cotton or foam, should be the same size, or slightly larger, than the canal area at the point where it is inserted.  Typically, otoblocks are placed just past the first bend of the ear canal.

The otoblock (dam) serves three important functions:

  • Stops the inward flow of impression material at the proper point

  • Prevents the impression material from penetrating too far into the ear canal

  • Improves impression detail, resulting in a better fit

Take your time with dam placement.  Inadequate dam placement results in an under-filled canal.

 

The Impression

  • Whether you are using a powder & liquid, or silicone impression material, follow the instructions for mixing. 

  • Place the material in a syringe.  Insert the tip of the syringe in the ear canal to a comfortable placement depth for your customer. 

  • Your impressions need sufficient canal depth.  Hold your hand steady and apply the impression material with even pressure, filling the ear canal first.  Then work around the conch bowl.  Make sure to fill the canal and the helix thoroughly.

  • When filling the ear, the entire area must be full and complete to avoid pockets and ripples that will result in a poor ear mold fit.

  • Wait the suggested amount of time for your material to set before removing.



Remove the Impression

  • To remove the impression, pull up on the pina to break the seal.  Using your index finger, remove the helix area first, then gently twist the impression forward.  Do not try to remove the impression using the otoblock thread.

  • The removal should be slow, to avoid stretching or tearing the canal portion, or forming a vacuum.  The dam should come out attached to the end of the canal section.  If the dam remains in the ear, remove it by using the attached thread.

  • Carefully inspect your impression, paying particular attention to the canal, helix, and conch areas, checking for fullness and any undesirable pockets or ripples.  If any areas are questionable, take a second impression.

 

Examine the Impression

1.  Does the canal position extend to the second bend?

2.  Is the helix area full and smooth?

3.  Is the impression smooth and complete?

4.  Is the tragus area covered by impression material?

5.  Are there bubbles of air in the impression?

6.  Are there mold marks resembling ripples, wrinkles and cracks?

You should answer questions 1, 2, 3, and 4 with "yes", and questions 5 and 6 with "no".

A properly fitted, comfortable, custom made earmold is just as important as any other component in the successful fitting of a hearing instrument. 

Since the custom earmold is a duplicate of the ear impression you make, it is extremely important to take a full and complete impression.

At Hocks, we do our best to work with all impressions. However, complete and full impressions are required at Hocks Hearing Healthcare Products to guarantee fit and comfort for all custom made earpieces.

  • The finished impression needs to meet the following criteria.

                           1. The concha is round and full

                           2. The canal is past the 2nd bend

                           3. The helix is filled in and complete

4. The impression fills the ear cavity, including the tragus, concha, and antihelix 

  • Please look each impression over carefully.

  • If an impression does not meet the above criteria, please take another impression.

  • Note any abnormalities in the impression, that are natural for your patient, on your order form.

  • Package your impressions for protection when shipping.  A small box is preferred.

Remakes

Whenever a remake or replacement mold is needed, send a new impression.  Full information should be furnished on the order form, including reason for the remake. Return the original mold with the new impression.

 

hocks earmold lab