What is alar base Implant (prosthesis)? Range and limitations of treating oral depression

Alar base Implant (prosthesis) is a procedure that places artificial material into the depressed bone around the base of the alar (perinasal region) to support it from the front, making the recessed mouth area and shadow at the base less noticeable. Unlike nasal dorsum augmentation surgery, which aims to raise the bridge of the nose, its role is to supplement the "foundation" portion of the nose. However, comparative research specifically examining this site is limited, and the approach to materials and implantation layers is currently based on applying knowledge from nearby sites such as nasal dorsum Implant (prosthesis).[1].

Which area is filled? Depressions that are candidates for treatment

The candidates for treatment are bone depressions extending from the base of the alar to the front surface of the upper jaw. When this foundation is recessed, it can create a shadow on the side of the alar or make the entire mouth area appear to recede backward. The importance of this foundation has long been recognized in cleft lip and palate surgery (a condition where the lip or roof of the mouth is split from birth), and it is documented in the Japanese Society of Plastic Surgeons' guidelines that bone grafting to the jaw in the cleft area improves the depression at the base of the nasal passages and reduces asymmetry at the base of the alar.[2].

What changes? What is possible

Supporting the base forward reduces the shadow at the root and the recession of the mouth area. Textbooks also note that pushing forward the anterior surface of the nasal base (around the anterior nasal spine) makes the nasal tip appear more prominent and reduces tension when closing the columella (the pillar between the nostrils).[3], and it is explained that support of the base affects the impression of the entire nose. Additionally, apart from artificial materials, textbooks also describe a method of transplanting finely shredded cartilage from one's own tissue—approximately 1.5 cc per side (about one-third of a teaspoon)—into this area to fill in depressions.[4].

What cannot be done / What is difficult to change

On the other hand, there are limitations. In bone grafting for cleft areas, while the base of the ala (small nose wing) moves forward, many opinions hold that there are no clear changes in measured values such as the shape of the external nares (nostrils), and the guideline itself acknowledges variability in results.[2]. Even if you fill the base, the width of the ala and the shape of the nostrils may not change as desired—it is good to keep this in mind. If you want to narrow the width of the ala, it will be necessary to combine it with another surgery such as alar reduction.[3].

What material is used?

For artificial materials, silicone and others are used. In the field of augmentation rhinoplasty, a meta-analysis that synthesizes many studies has organized the trends in complications by material type.[1]。Long-term reports using silicone show that by accurately creating gaps (pockets) under the bone membrane (subperiosteal) sized to match the material, displacement and movement can be reduced and stability can be achieved[5]。When using one's own tissue, options include transplantation of shaved cartilage[4]or bone transplantation[2]。While hyaluronic acid injection is available as a non-surgical method, vascular embolism risks have been reported in areas with abundant blood vessels[6]、and the procedure differs significantly in nature from surgery.

How should we think about complications and risks?

Risks commonly known to be shared by artificial materials are infection and extrusion (the implanted material emerging from the skin).[1]。Additionally, if the pocket (gap) created for the material is inadequate, it can cause the material to shift or move.[5]。Furthermore, comparative studies point out that when infection or extrusion occurs, corrective surgery becomes difficult with artificial materials[7]。It is impossible to eliminate risk entirely. Being prepared includes receiving explanations about how to respond if problems occur.

What to confirm before undergoing the procedure

This treatment's starting point is determining "whether the cause of the indentation is in the bone structure." Since it is difficult to judge on your own whether the indentation is due to bone shape or lack of volume in soft tissues (skin and fat), have it examined during a consultation. Following that, we recommend receiving explanations about the reason for choosing the material, the layer and pocket-creation method, the plan if infection or extrusion occurs, and which features like the alar width will not change, and making your decision only after you are satisfied.