How to achieve a perfect bite alignment when scanning with TRIOS

General guideline

Correct bite registration is a very important part of the scanning, especially if there will be any restorations done for the patient.

In general, the procedure for bite registration is described in:

• Trios User Manual (3.5-3.6);
• TRIOS Bite Info Pack;
• relevant video on Youtube.

According to the procedure, it is especially important:

• Follow instructions concerning all types of restorations as described in the Manual.
• During scanning - the bite should be taken in the optimal position - there should not be any movements, the jaws should be fully closed.
• During scanning - not to scan too much gingiva after the last molars.
• Trim the scans properly (trim artifacts and gingiva after the last molars).

NOTE: The reason for altered occlusion can be soft tissue after the last molars and untrimmed artifacts. It is important to clean up (trim) this area to minimize its influence:

Soft tissue and artifacts

• Scan enough - 3-4 teeth from the last molar - until the teeth are recognized by the software and the occlusion is identified.
• It's not recommended to scan front teeth in bite scan, unless it's the only teeth which are present on the jaw.
• Follow general guidelines (remove extra saliva, avoid direct external light, clean scan tip mirror and front tube glass, pre-heat the scanner to avoid fogging).
• For full arch scanning - it is mandatory to do both Bite 1 and Bite 2.

In most cases issues with bite registration are caused by not following the above-mentioned strategy:

• bad scan strategy (too short/way too long bite - on anterior area)
• patient changes occlusion between 1st and 2nd bite scan
• 1 bite scan for full arch cases
• insufficient trimming of scans leads to snap to soft tissue areas..

Most faced issues with bite registration

1. Live/automatic alignment does not work.
   Scan needs manual adjustment.
   When scanning Bite 2 (or both bite 1 and bite 2) - one of the jaws does not snap
   In some cases, automatic alignment will not work due to more complex anatomical shapes of the teeth, e.g. small teeth (child), very altered occlusion (deep bite) or not enough reference area for bite (edentulous).
    In such cases, use the manual bite alignment feature to align the bite.
   What to check?
   If that happens for many orders/patients -> inspect problematic orders by importing scan streams.
   The issue could be related to scanning technique and trimming.
   Test scanning on real patients.
2. Issue with contact points (penetration/no contact points) when doing bite.
   There is a special functionality in TRIOS software called Bite adjustment:

• when it's set to adjust for intersections, software is going to adjust a bit the positions of arches in order to avoid penetrations.
• when it's set to no adjustment, occlusion is not modified by the software.
  NOTE: Possible hard-biting of teeth may cause an effect of penetration. In this case ask the patient not to bite hard and try to smile during bite scanning -> it's not possible to bite hard when smiling.Details about using these functionalities are described in Bite Info pack. It is up to the doctor to decide what corresponds to his preferences.
• When doing bite registration on one side - the bite on the other side slightly opens up
   This is expected to happen, as when only bite 1 is done, software does not have enough scan data to create final/correct bite. After doing bite 2 - bite should correspond to the real occlusion.

If that happens on bite 2 -> check scan strategy and if there are no artifacts on the scans.

In case of any issues with bite registration, contact 3Shape support.