My Piriform Rim Pet Peeve

A while back, I wrote a blog article titled “The Piriform Rim: Pearls and Pitfalls“. This article highlights the technique of engaging the piriform rim during AOX surgery and some of the risks, benefits, and misunderstandings of this technique.

Today, I wanted to revisit this topic. I received some questions regarding the use of the piriform rim in AOX surgery after my lecture this past weekend in Chicago. I have received similar questions on a recurring basis.

These questions have left me with some cause for concern.

I wanted to both share and expand on my response to these questions, as I think many could benefit from this discussion.

I was asked (and have been asked before) the following question:

“How come you are not engaging the piriform rim with all of your maxillary implants? I have been taught that I am doing the surgery incorrectly if I am not engaging the piriform rim with every implant.”

My Response:

1. I do NOT engage the piriform rim with all of my maxillary implants, all of the time.

For a routine arch, I utilize the Inverted-V configuration. By angling the midline implants subtly at 17 degrees I gain significant surgical and prosthetic benefits, all of which you can read about in the article highlighted above. While I will often get close to the piriform rim region with this configuration, my goal is not necessarily to engage it. This extra step simply isn’t needed most of the time.

2. In atrophic maxillas or low density maxillas, I will utilize a more traditional “V-4” approach, which includes extension of the maxillary anterior implants into the nasal crest.

This anatomic region is a component of the piriform rim, HOWEVER, my goal is simply to extend my implants into the 3-5 mm cortical nasal crest – not through it into the nasal cavity. Ideally, I will engage the nasal crest without perforation into the nasal cavity.

While there are times my anterior implants extend slightly into the nasal housing, to be transparent, this is often not on purpose. I am able to generate sufficient torque when required by engaging the nasal crest, without perforating through it.

3. I perform a true *bicortical engagement of the piriform rim very RARELY with my posterior implants.

I would say that “on purpose”, strategic engagement is done on <5 out of every 100 arches. I would also say with honesty, that this occurs an additional 2-4 times per 100 arches unintentionally. The remaining arches ~90+/100 do not have any posterior implant extension into or through the lateral piriform rim. It is simply not necessary as a means of generating adequate torque.

*Bicortical refers to the engagement of two cortices. One being the alveolar crest and one being the piriform rim. The piriform rim is thin. Engaging it, especially laterally, will often (in theory) require a slight (emphasis on slight) extension of the implant apex through the cortex of the bony nasal housing.

4. When I do STRATEGICALLY engage the piriform rim, I always attempt to do so with care and caution and attempt to have MINIMAL extension beyond the rim into the nasal cavity – with an added emphasis on maintaining the integrity of the nasal membrane.

If you do not do this, you are asking for complications. I have been referred, seen, and heard of these complications. The most notable of which I have managed – chronic oral-nasal communications. Not oral-antral…oral-nasal. A non-healing wound between the nose and mouth.

5. Why don’t I use this style of implant more often?

The majority of the time, it simply isn’t necessary. I consistently generate 45-60+ N-cm of torque in my “traditional” implants without the need to extend into and/or through the piriform rim.

Furthermore, I am aware that doing so carries increased risks of surgical complications. The risks do not outweigh the benefits for routine use.

I do feel that engagement of the piriform rim by a skilled and experienced surgeon can be, and is, a useful asset to their full-arch toolbox.

But it should not be one that is needed constantly. A skilled surgeon should be able to consistently generate torque (most of the time) simply through strategic osteotomy preparation and implant selection.

I also want to clarify that often what I see as being touted for “piriform rim” engagement, is simply an implant sticking into the nose. I will admit, I have some of those too. But this is more embarrassing for me as a surgeon than anything else. This is not a display of skill.

I want to clearly state that I am not against piriform rim implants by any means.

I utilize them as well. I advocate for and teach this technique.

BUT, I utilize them and feel that they should be utilized rarely, only when truly strategically required.

And, I attempt to do so with precision and surgical care.

Furthermore, when I am specifically engaging the nasal crest, I am doing so with the intent of never perforating through the bone into the nasal cavity. I do not always achieve this, but this is the goal. This is because I know that complications are lurking just on the other side.

I challenge those of you learning and/or operating otherwise, to proceed with caution and to focus on improving your ability to optimize osteotomy preparation and implant selection before simply placing implants into the nose.

Here’s to being a little less nosey…

“Simplicity is the ultimate sophistication.”

Leonardo da Vinci

Q & A with Dr. K