Palatal Microsurgery

Автор: Dr. Lloyd P. Nattkemper
D.D.S. AMED Charter Member

Статья опубликована в журнале AMED Vision News | vol 4 issue 3


Periodontists using microscopes for their surgical procedures face numerous challenges. Among these:
• skepticism on the part of other periodontists and many dentists (is this really necessary? do you use one of those because you’re blind or something?),
• overcoming the steep learning curve,
• fitting ‘scope procedures in the schedule
• and, particularly when you are “new” at use of the microscope, keeping your staff from lynching you because something they can’t
even see isn’t quite right.

Even when these problems are overcome, others can be formidable. Most entail figuring out patient/scope positions that allow direct vision, or how to incorporate your assistant to help retract and suction, or for them to hold a mirror. In my experience, unless a periodontist is particularly gifted and able to “think outside the box”, they would be wise to take a course in use of the operating microscope — one which addresses ergonomics, effciency, considerations for the staff and opertory set-up, and most important, use of the ‘scope in each area of the mouth. With instruction and subsequent practice, instead of feeling like a dope or generally lame, they will start feeling competent and even, yes, cool.

I am talking with my patient about what he is observing on the overhead screen. We have found that watching what we are doing is a terrific way of reducing “fear of the unknown” during surgery and getting patients excited about their periodontal treatment
We often supplement the microscope light with a standard opertory light for most flap procedures to improve the assistant’s visualization of the operating field

Here I would like to address use of the ‘scope for periodontists in one of the more problematic regions of the mouth: the palate. What I will offer here is based partly on what I have learned from mentors — including Dennis Shalelec, Peter Nordland, Rick Schmidt, Martin Boudro, Glen Van As and Wayne Remington — and mostly from twelve years’ practice using a microscope.
What I will offer here is not “how you should do it”. It’s how I do it, and my hope is that if you are frustrated with palatal surgery using the microscope, what I offer here might serve to help you past frustrations and along the road towards cool.

Connective Tissue Graft Harvest and Suturing

Because of the necessity for the operator to use both hands in manipulation of surgical instruments during graft harvest procedures, I have found it necessary to use direct vision. I will comment off the bat that a highly skilled assistant who is comfortable working totally from a video screen can suction and hold a mirror (usually a large, oblong mirror such as is used for intraoral photography) for you simultaneously — allowing indirect vision and simplified ergonomics.

Large monitor on movable arm allows the assistant excellent visualization of field

However, my assistants are not comfortable doing this. So I have learned to adjust patient and microscope to allow direct vision. This requires:

  1. Trendelenburg patient position (and head tilted back as far as possible).
  2. Patient’s head turned left (for left side harvest) or right (for right side).
  3. Microscope body tilted on “x” axis away from the operator for left side or toward the operator for right side harvest.
  4. In some cases, microscope body tilted on “z” axis to allow vision of palatal tissues without obstruction from maxillary incisiors (objective lens will be tilted to the left for right handed operators).
  5. An attempt, when possible, to align the objective lens with the slope of the palate, so as to maximize the field in focus and minimize need for refocusing during the procedure.
  6. Selection of magnification to allow reasonable depth-of-field and a wide enough field of view to allow suture tying without difficulty.
  7. In most cases, a 9 o’clock operator position (again, for right-handed operators); for certain right-side harvest cases, an 11 o’clock operator position will be necessary.
  8. Operator as close as possible to the patient to prevent a forward “lean” and allow reasonable comfort during the procedure, which can take several minutes.

I have found that harvest of grafts from the right palate is more problematic than the left when using the ‘scope, in that certain individuals have long or lingually inclined maxillary incisors which, even with quite a severe tilt to the ‘scope, block direct vision. As such, there are certain procedures in which you must default to unaided vision or use of loupes.

initial incision completed
with 15C blade
probe used
to assess length of incision
flap created
with 6915 blade

The technique I use for graft harvest involves a horizontal incision placed 2-3mm palatal from the teeth, with short (3-4mm) vertical incisions at either end. I try to avoid going distal to the first molar or mesial to the canine. A 6915 blade is used to gently dissect a flap, about 1 to 1.5mm thick, extending 5 to 6mm from the initial incision palatally. The same blade is then used to dissect the connective tissue graft, either away from the palatal bone (if a thin palate) or away from the periosteum. A fresh blade is used to carefully free the base of the graft away from the underlying and overlying connective tissue. The graft is stored in saline while the palate is sutured.

CT exposed,
beginning secondary incision
completing graft harvest;
note 1mm endo suction tip
suturing donor area

A continuous suture is placed, beginning just beyond the incision, with a loop about every 1.5-2mm. This technique allows primary closure of the site and I have not found it necessary, at least in the 12 years I have used this technique, to place a palatal stent. Currently I use a 6/0 or 7/0 polypropylene suture. This material is quite strong in spite of its tiny dimension and elicits virtually no infammatory reaction. Although patients frequently will request resorbable suture, I have found that these often lose strength before tissues have attained suffcient integrity and can lead to exposure of the underlying soft and hard tissue.

Sutured Left palate –
creating flap, 6915 blade
Left palate –
completing graft harvest

Palatal Flap Surgery

Virtually all flap (osseous) surgery I have performed since I was 35 has been done in a mirror. There are situations where I crane my neck and hunch over to see (almost always this will be when suturing something), but in all honesty, each of us “pay” for this sort of habit sooner or later. Neck and back problems are among the most common motivations students attending the course Jean and I teach in Newport share with us. While loupes with a long focal length used with a mirror offer good ergonomics when performing palatal surgery, the operating microscope used with a mirror offers excellent ergonomics, superior visual clarity and shadow-free illumination even on the distolingual aspect of maxillary second molars.

Palatal flap/distal wedge procedure: my assistant is helping to retract the patient’s lower lip and the palatal flap with a suction tip as I work on the distal aspect of #2 using a mirror
Palatal flap/distal wedge procedure: assistant is observing me work and prepared to retract or suction as needed

There are some simple keys I have found to minimizing frustration and maximizing effciency when using the ‘scope for palatal flap procedures. It is critical that your assistant is willing and able to aid in flap retraction and to work outside their usual “box”.

  1. Have the patient lean back far enough (if possible, Trendelenburg) so that the microscope body is vertical or close to it.
  2. Use a good quality mirror that is free of scratches.
    It is ideal to use a two-ended mirror to allow rapid transition from a fouled mirror to clean. We keep a heated cup of water on the surgical tray to minimize mirror fogging and allow rapid cleansing of the mirror.
  3. Have the patient turn their head just slightly.
    I have found it best when working on the left palate to have the patient turned just a bit to the right, and when working on the right palate to have the patient turned slightly left. Although this sounds contradictory, this will place your subject — the palatal aspect of the teeth you are working on — at a 90 degree angle to your mirror and yield the flattest field of view (and thus require the fewest microscope adjustments).
  4. Your assistant will usually need to help retract the flap for you.
    In most cases my assistants use a small surgical suction tip, held gently against the undersurface of the flap and a short distance away from where I am working. They usually also will place a saliva ejector behind the area (or we may use an Isolite). In other cases they will use a Shanelec or Prichard periosteal elevator to suspend the flap. When working in interproximal areas, you may not need the assistant to retract. I often will ask that they position their suction tip on the buccal aspect of the interdental area I am treating in order to efficiently remove any debris or fluids as I work.
  5. Begin with relatively low magnification (depending on the operator, this will vary between 3.5 and 8 power).
    Incisions, flap reflection, initial debridement with hand and then ultrasonic instruments is in my opinion best done under low power to allow you to move efficiently and minimize refocusing or movement of the microscope. Experience will allow you to do a sextant with only one ‘scope position, or a quadrant with two or at most three positions.
  6. Focusing is accomplished primarily by moving the mirror closer or farther from the subject.
    Particularly when any sort of aerosol is being created, it is wisest to keep the mirror as far from the surface you are working on as possible. It is important that the microscope and your patient are positioned close enough together to allow for this extra focal path (lens – to subject – to mirror – to lens). I will usually position the mirror just beyond the midpoint of the palate on the opposite side of the mouth for posterior procedures, and against the lower incisors for anterior procedures.
  7. I will usually use 5 to 8 power magnification for osseous contouring; as I transition to root instrumentation, I will change back and forth between roughly 8 and 12 (or, in some cases, higher) power.
  8. For my root instrumentation I have taken Tim Allen’s “Tool Time” guidance to heart – if there is a power tool to do the job you’ve traditionally done by hand, use it. I utilize the Kavo Parosonic Scaler with diamond-coated inserts and Piezosurgery diamond-coated inserts for almost all of my surgical root instrumentation. Both of these instruments have slender insert tips which are easy to see around (unlike a handpiece barrel). They produce a glassy smooth root surface rapidly and precisely without scratches and without “collateral instrumentation” of regions you’d rather leave alone. They also function beautifully for debridement of bony defects and act to reduce or eliminate bleeding from the bone and PDl.
  9. For suturing, I will usually change to low magnification – 2 to 5 power – or switch to my loupes.
    If at all possible it is best to position the patient so that you can, with the ‘scope, see the buccal aspect of the teeth with direct vision and the palate with your mirror or, when the patient turns far enough, with direct vision. Your assistant both suctions and retracts the patient’s cheek to allow you to use both hands as you work. If you have a cooperative patient, you can ask them to turn for you as you pass needle from buccal to lingual and back again, such that through use of needle holder and forceps there is almost no adjustment of the microscope, except to focus as you move distally.
Connective tissue graft harvest, left palate. The patient’s head is tilted back and to the left. Operator is close to the patient, arms close to sides, ‘scope tilted to allow direct vision
Suturing, right palate: note the ‘scope tilt, operator slightly to patient’s right. Patient is turned toward the operator and tilted back

I have found that suturing of posterior flap surgeries is one of the most challenging ‘scope procedures. Inevitably, if pressed for time, if the patient is less than ideally cooperative, if bleeding is an issue, I will, as I mentioned, revert to my loupes. However, especially for distal wedge areas and cases where regenerative materials have been placed which depend on precise closure, the microscope offers the best solution.

As a final thought, I would offer this suggestion, which I make to our students at NCoFI. Consider yourself a student of this discipline – mastery of the operating microscope – no matter what level of mastery you attain. Be patient with yourself and your staff. Don’t be in a rush. Break down the complex into manageable steps. And by all means, if you get frustrated, remember to breathe. If you get really frustrated, swing the ‘scope out of the way and put on your loupes. And come back and try it again tomorrow with a fresh approach.