The last part introduced the relatively easy skills of using the mouth mirror in the lower left posterior area (for doctors who are accustomed to right-handed operation). This chapter will take you to the more challenging practice of the lower right dental arch. I believe you are ready for the last part of the dental microscope practice~
Basic skills of mandibular dental arch mouth mirror
Practice time: 80 minutes
Materials to be prepared:
- Dental surgery microscope
- Teeth model (28 teeth)
- Medium-sized phones
- Crown preparation emery bur
- Ergonomic doctor chair
Goals to be achieved by the exercise:
- Further practice oral mirror skills in the lower right posterior area under the field of view of 2x-12x magnification
- Learn how to solve the problem of declining vision of the mouth mirror
Working position of the lower right posterior area
Dental chair: The dental chair is slightly raised and adjusted so that the patient’s jaw plane is parallel to the ground plane, the patient’s mouth is at the same level as the elbow, and the backrest is at a 40° angle to the ground plane.
Doctor: From 7 to 9 o’clock.
Nurse: From 3 o’clock to 4 o’clock, use your ring finger to support the patient’s frequency. Use the tip of a strong straw to gently press down on the patient’s tongue.
Microscope: Increase the angle between the axis and the root canal.
Patient: Lie on his back, slightly to the left.
The above picture shows the recommended positions of physicians, nurses and patients during micro-root canal treatment in the lower right posterior area (pictures are demonstrations of positions, and rubber dams are recommended in actual treatment)
Observation of No. 30 tooth with 9 o’clock position
When finishing the left side of No. 30 tooth, you will find it easier to operate the left side of the lower right tooth area. When the mouth mirror is at 9 o’clock, it is necessary to isolate the tongue. At this time, a rubber dam or other isolator can come in handy.
Figure (1) highlights that the mouth mirror is correctly placed at the 9 o’clock position of tooth 30.
Figure (2) The correct 9 o’clock mouth mirror shows the No. 30 tooth, and the tongue needs to be blocked.
Figure (3) This photo shows the direct and indirect images of the needle and the indirect images of the mobile phone.
Observation of No. 30 teeth with 7 o’clock
When the mouth mirror moves to the 7 o’clock direction, the left side and longitudinal images of the teeth begin to appear in the mouth mirror. As shown in Figure 4, by moving the mouth mirror along a continuous track, you can observe the various orientations of the target tooth.
Figure (4) highlights the 7 o’clock position of the mouth mirror to observe No. 30 tooth.
Figure (5) The correct 7 o’clock position of the mouth mirror shows the 30th tooth.
Figure (6), like Figure 5, shows tooth 30 at the 7 o’clock position of the mouth mirror, but after high magnification by the microscope, only the image in the mouth mirror appears in the field of view.
Figure (7) shows tooth 30 at 9 o’clock.
Figure (8) shows tooth 30 at 9 o’clock under the microscope.
Figure (9) shows tooth 30 at 7 o’clock.
Figure (10) shows tooth 30 at 7 o’clock under the microscope.
3 o’clock mouth mirror observation of No. 30 tooth
When finishing the right side of No. 30 tooth, in order to show the right side of tooth, the mouth mirror should be placed at 5 o’clock and 3 o’clock. At this time, the finger fulcrum will lose its function again and force the forearm to support and move. Sometimes it is more useful to observe directly with the eyes, but this makes it more difficult to focus and change the field of view.
Figure (11) highlights the 3 o’clock position of the mouth mirror to observe No. 30 tooth.
Figure (12) The correct 3 o’clock mouth mirror shows the No. 30 tooth.
Figure (13) shows tooth 30 at 3 o’clock under the microscope.
Observation of No. 30 tooth with 5 o’clock position
As with 3 o’clock, when practicing at 5 o’clock, the fulcrum of the finger will be restricted. Supporting the operator’s forearm with a microscopist chair can alleviate this discomfort.
Figure (14) highlights the 5 o’clock position of the mouth mirror to observe No. 30 tooth.
Figure (15) The mouth mirror shows the No. 30 tooth at 5 o’clock. When the finger loses the fulcrum, the forearm can be supported by the dental chair.
Figure (16) The No. 30 tooth shown by the 5 o’clock position under the microscope.
Figure (17) 3 o’clock mouth mirror shows tooth 30.
Figure (18) shows tooth 30 at 3 o’clock under the microscope.
Figure (19) 5 o’clock mouth mirror shows tooth 30.
Figure (20) shows tooth 30 at 5 o’clock under the microscope.
On the problem of oval mirror
The elliptical mirror in Figure 21 is the image of the circular lens in the microscope. The angle of the mirror obviously affects the display area of the mirror. This situation may occur in the upper and lower arches, but it will appear more frequently in the lower arches. The solution is to adjust the mandibular plane to be close to 90 degrees to the horizontal plane, and then adjust the mouth mirror to the angle of the maximum display area, as shown in Figure 22.
Figure (21) The mouth mirror shows a small area
Figure (22) The dental arch is at 90 degrees to the vertical, making the display surface of the mouth mirror round
After completing the exercises of each dental zone, it takes more time to complete similar exercises. Only through repeated exercises can you fully master this skill.
The additional exercises are best completed within two consecutive days, and the brain activity at night can strengthen the memory of the exercise effect. The frequency of additional exercises can be gradually reduced, and you can also focus on the most difficult parts for strengthening exercises.
In the additional exercises, you can follow the sequence shown in Figure 23-27 from the preparation of class I holes, class II holes, 3/4 crowns, and full crowns, and arrange your own exercises flexibly according to your proficient dental tools.
Figure (23) Microscopy mandibular face prepared with No. 170 split drill
Figure (24) No. 170 crack drill enlarged hole shape
Figure (25) Preparation of standard type II holes
Figure (26) Hole shape preparation of cast onlay
Figure (27) Full crown preparation
The references for this article are taken from:
Rick Schmidt, Martin Boudro, “The Dental Microscope”