If every time you see your profile you think "my lips protrude" or "my chin recedes," it may be an E-line issue. But wait a moment――there is a way to resolve this concern without surgery, using just one injection. And if you're not satisfied, you can even reverse it.
"Is there really such a good thing?" you might wonder…
- 89.4% of people rated it as "improved"――what is the true identity of E-line (E-plane) formation?
- WhyHyaluronic acid injectionCan a single injection dramatically change your profile? The scientific mechanism behind it
- 6 months? 1 year? 18 months?――the 5 factors that determine how long results last
- Blindness, tissue necrosis…critical risks you need to know about, and 3 golden rules to avoid them
- Surgery vs. injection――which is truly right for your face?
"I don't want cosmetic surgery, but I'd like to change just my profile a little"――many people think this way but struggle to take the first step. But actually, you're not the only one with this concern. In this article, based on peer-reviewed papers in aesthetic medicine, we clearly explain the reality of E-line formation through hyaluronic acid injection into the chin and nasal tip.
However――we must also explain why you shouldn't take this lightly.
89.4% experienced improvement: What is the E-line――why does it determine the impression of your profile?
The "E-line" is an aesthetic guideline proposed by orthodontist Robert Ricketts, referring to the straight line (E-plane) connecting the nasal tip and the chin point. A state where the lips lie slightly inward relative to this line is recognized as a "balanced profile" in both Eastern and Western aesthetics.
Here is an important fact――
East Asians such as Japanese, Korean, and Chinese people tend to have lower noses and recessed chins due to skeletal structure, and in many cases the lips appear to protrude relatively forward. In other words, your dissatisfaction with your profile is definitely not "just your imagination."
And here's where it gets interesting…
Hyaluronic acid filler is an exceptionally compatible approach for this problem. By raising the nasal tip (nasal apex and nasal root) to move the front point of the E-line forward, and simultaneously adding volume to the chin to move the back point forward, adjusting these two points alone dramatically balances the profile without touching the lips.
"But does it really work?" ――it's natural to wonder. That's why we should look at the data.
Why does "one injection" change the E-line――the mechanism of filler rhinoplasty
Hyaluronic acid is a polysaccharide naturally present in skin and joints, with the property of attracting moisture and maintaining a gel-like state. By injecting this into the nasal root, bridge, tip, or chin, you can adjust projection without using a scalpel.
Now let me show you some remarkable data――
A prospective clinical study evaluating non-surgicalrhinoplastyin Asian noses found that89.4%of subjects who received hyaluronic acid filler injection rated it as "improved" or "greatly improved" on the Global Aesthetic Improvement Scale (GAIS) at 24 weeks. Additionally, patient satisfaction (PSAS) remained high throughout this period, demonstrating sufficient efficacy as a non-surgical technique.
But that's not all…
For chin injection, combining with the nose corrects the back point of the E-line. When hyaluronic acid is injected into the chin point, the projection of the chin increases without changing the skeleton, improving the distance relationship with the lips. This two-point combination approach is considered the most efficient method for improving profile balance.
Anatomical considerations specific to Asians
Here I must share an important warning――
Applying filler technology developed for Europeans directly to Asians is dangerous. Asian noses have weaker supporting structures of bone and cartilage, and thicker skin, so the same amount of filler tends to look artificial, and the pattern of blood vessel distribution differs.
Therefore…
The international consensus recommendations published by Trevidic et al. (2022) specifically for Asian patients strongly recommend considering anatomical differences by race in the choice of injection volume, injection plane, and injection site. In particular, the outdated technique of "injecting in a straight line from the nasal root to the nasal tip" is noted to increase overcorrection and complication risk, and staged, distributed injection is now standardized.
Technique――injection technique for safe and natural results
"How exactly do you inject?" "Does it hurt?" "Can it fail?" ――these questions naturally cross your mind.
Here we organize the main injection techniques used for E-line formation by area. While approaches differ by clinic, we explain based on evidence shown in peer-reviewed papers.
Nasal root and bridge injection
By injecting hyaluronic acid from the nasal root to the nasal bridge, the nose appears to have a well-defined profile from both frontal and profile views. According to the Trevidic et al. (2022) consensus, injection into the deep layer above the periosteum is recommended, and injection into the superficial layer (subcutaneous fat layer, dermal layer) is noted to increase the risk of blood vessel compression.
Regarding the injection volume of concern――
The injection volume is typically 0.2 to 0.5 mL at the nasal root, and injecting large amounts at once should be avoided. A careful layering approach with small amounts contributes to both natural results and safety.
Nasal tip injection
The nasal tip is the most important in E-line formation. As the nasal tip projects forward, the front point of the E-line advances, improving the relative positional relationship with the lips. Injection into the nasal tip must be done carefully along the shape of the major alar cartilage; excessive injection results in an unnatural appearance of a "ball-shaped nasal tip."
However, there is an important caveat here——
Chen et al. (2020) reviewed hyaluronic acid-based rhinoplasty in general,and reported that serious complications such as skin necrosis and blindness occur most frequently during injection into the nasal tip,concluding that anatomical knowledge and careful technique on the part of the surgeon are essential.
Injection into the chin
When injecting hyaluronic acid into the chin, the basic technique is to inject along the mental protuberance (the central bony projection of the chin) onto the periosteum. Since the thin-skinned chin tip can easily show irregularities with over-injection, small amounts are added layer by layer. By shaping with the fingers after injection, a more natural contour can be created.
But we're not doing this haphazardly——
Balance adjustment between the nasal tip and chin is recommended to be confirmed via simulation using lateral profile photographs before treatment. In a multi-center collaborative study by Rho et al. (2021), pre- and post-treatment changes were quantitatively evaluated using 3D image analysis, confirming a strong correlation between patient satisfaction and objective improvement.
Cannula vs. needle——which is safer?
"What kind of needle is used for injection?"——In fact, this too is a critical choice directly related to safety.
There are two types of injection instruments: the "needle (microcannula)" and the "cannula (blunt-tip tube)". The needle allows for precise injection but carries the risk of vascular puncture, while the cannula is easier to avoid blood vessels but may be difficult to deliver to specific sites.
And…
In the consensus by Trevidic et al. (2022), the use of cannula for the nasal bridge and nasal root, and fine-gauge needles for the nasal tip, are recommended, with instrument selection according to location being key to preventing complications. Cannula is often recommended for the chin as well, and choosing safety as a priority, especially in initial treatments, is important.
6 months? 18 months? Duration of effect——how long does the result last?
"If I'm going to undergo treatment, I naturally want to know how long the effect will last"——a reasonable question.
Because hyaluronic acid is gradually absorbed by the body, the effect is not permanent. The duration of filler used for E-line formation varies greatly depending on the product type, degree of cross-linking, injection site, and individual differences.
But we have concrete data——
Duration of effect shown in clinical trial data
In a long-term observational study by Liew et al. (2016) following hyaluronic acid injection into the nose in Asian patients,aesthetic improvement was maintained at the 24-week (approximately 6-month) timepoint,and the same study tracked subjects to 72 weeks (approximately 18 months), with the majority maintaining "a better state than baseline," and some patients showing sustained effects beyond 1.5 years.
And what is particularly interesting…
In a multi-center study by Rho et al. (2021), two types of different hyaluronic acid products (with different cross-linking densities) were compared, and the highly cross-linked product showed sustained significant improvement even at 48 weeks (12 months),whereas the low cross-linked product showed progression of absorption after 24 weeks. This demonstrates important evidence that product selection directly impacts duration of effect. Product selection directly impacts longevity.
Five factors affecting duration of effect
- Injection site: Areas with less movement such as the chin and nasal bridge tend to last longer than areas with more movement such as the perioral region
- Cross-linking degree of the product: Highly cross-linked hyaluronic acid tends to be absorbed slowly and have longer duration
- Injection volume: Moderate injection volumes may have longer duration of effect compared to minimal volumes
- Individual metabolic rate: There is large individual variation, and those with faster metabolism experience earlier absorption
- Repeated injections: Regular supplemental injections that build upon residual hyaluronic acid tend to stabilize sustained effects
As a general guideline, fillers intended for E-line formation are expected to last approximately6–18 monthsafter the initial treatment, and many patients undergo maintenance treatments about once per year.
Risks and Complications—What You Absolutely Must Know
Please do not skip this section. Are you thinking lightly about this as "it's just an injection, so it's safe" or "no downtime"?
Hyaluronic acid injection is often underestimated due to its image of "no downtime" and "non-invasive," but depending on the injection site, technique, and operator experience, serious complications can occur.
Minor adverse reactions (most are transient)
- Redness, swelling, and bruising at the injection site: typically resolve within a few days to 1 week
- Tenderness and discomfort: from immediately after injection for several days
- Hardening (nodules) at the injection site: may occur depending on product selection and injection technique
In the Liew et al. (2016) trial, the majority of adverse events were injection-site reactions (redness, swelling, pain, bruising),all of which resolved spontaneously within 14 daysaccording to their report.
However――the problem starts here.
Serious complications (low incidence but requiring careful attention)
Vascular occlusion and skin necrosis: the most critical complication to guard against. When filler is accidentally injected into a blood vessel or external compression of surrounding vessels occurs, blood flow to the skin is cut off, leading to necrosis. Chen et al. (2020) stated that,skin necrosis due to vascular occlusion is the most frequently reported serious complication following nasal filler proceduresand damage to arteries around the nasal tip and ala (lateral nasal artery, dorsal nasal artery) is particularly dangerous.
And, even more frightening…
Blindness and vision loss: Cases of permanent blindness caused by retrograde embolism to the ophthalmic artery or central retinal artery have been reported worldwide. According to Chen et al. (2020), blindness reports related to nasal fillers are more common than in other facial areas, with particularly high risk when injecting at the nasal root. Although rare, once it occurs, it is irreversible.
Infection and biofilm formation: If biofilm develops due to unhygienic conditions or repeated injections, chronic inflammation, swelling, and granulomas may result.
"I'm getting scared…"――you might think so. But there are appropriate preventive measures.
Three essential rules for preventing complications
In the Trevidic et al. (2022) consensus, the following are identified as fundamental for preventing complications in nasal filler injections in Asian patients:
- Aspiration test (needle aspiration): Before injection, pull back the syringe to confirm no blood reflux
- Small volume, slow injection: Do not inject large amounts at once; add small amounts while confirming effect
- Hyaluronidase immediate readiness: In case of suspected vascular occlusion, be prepared to immediately inject hyaluronidase (an enzyme that dissolves hyaluronic acid)
When undergoing treatment, we strongly recommend confirming in advance whether your physician has hyaluronidase on hand and whether they have the experience to immediately identify early signs of vascular occlusion (white patches, pain, dark purple discoloration).
Dissolvability is the greatest advantage of hyaluronic acid
Unlike chin and nose augmentation with Implant (prosthesis) (silicone implants), hyaluronic acid fillers can be rapidly broken down and eliminated with a dissolving agent (hyaluronidase). The ability to "redo" in both cases—when the shape is unsatisfactory and when complications occur—is a major reassurance of the non-surgical approach.
Is it right for you? Who is a good candidate――comparison with surgery
"In my case, is injection enough? Or would surgery be better?"――this decision is most important.
Hyaluronic acid injection is suitable for people who
- Have reservations about surgery and want to first try a lower-risk method
- Cannot afford much downtime
- Want to correct mild to moderate E-line irregularities rather than skeletal changes
- Want to "try out" the result or keep the option to redo
- Can tolerate regular maintenance
Cases where surgical intervention should be considered
- Significant skeletal retrusion of the chin exceeding the limits reachable by filler
- Structural problems such as nasal cartilage deformity or deviated nasal septum
- Desire for permanent results and wish to avoid the cost of regular injections
- Excessive filler accumulated from past injections, requiring dissolution treatment
Rho et al. (2021) stated that in patient selection for filler nose augmentation, "pre-treatment patient education and setting realistic expectations" contribute most to long-term satisfaction. Undergoing treatment under the misconception that "the result will be identical to surgery" leads to decreased satisfaction.
Treatment flow――what happens on the day
"If I actually underwent the procedure, what would it be like?" — We'll answer that question for you.
Consultation
Using a lateral profile photograph, the doctor will confirm the balance of your E-line with you. You will receive an explanation about which areas (nose or chin) to improve and to what extent, the products to be used, the expected duration of results, and possible risks.
Anesthesia
A topical anesthetic cream (such as EMLA) will be applied for 30–40 minutes, or you will wait for the lidocaine anesthesia contained in the product to take effect. For chin injections, local anesthetic injection may be used.
Injection
Hyaluronic acid will be injected into the nose and chin using either a needle or cannula. The total procedure time is typically 15–30 minutes. If skin discoloration or severe pain occurs during or after injection, it is important to inform the doctor immediately.
Post-procedure care
- Day of procedure: Avoid strenuous exercise, alcohol, and saunas
- One week: Do not touch the injection site forcefully; avoid sleeping face-down
- Swelling and bruising typically subside within a few days to one week
- Final results should be assessed 2 weeks or later after swelling has resolved
Understanding costs — Why we caution against "overly cheap procedures"
"I want to keep costs as low as possible" — we understand that feeling. But please wait a moment.
The cost of E-line formation (nose and chin hyaluronic acid) varies significantly among clinics, but procedures performed with appropriate technique, products, and safety protocols are not normally available at extremely low prices. Maintaining hyaluronidase on hand, continuous training in anatomical knowledge, and 3D analysis equipment are costs that ensure the safety and quality of the procedure.
The most important investment is in **the skill and experience of the surgeon**. As Chen et al. (2020) emphasize, most serious complications stem from technical errors, and receiving treatment from an experienced surgeon is the greatest risk-mitigation strategy.
If you're thinking "How should I actually approach my lateral profile?"
Book a free consultation
There is no high-pressure selling. You can simply show us the condition of your lateral profile.
8 Key Points: Summary of This Article
- 89.4% experienced improvement: The E-line is the straight line connecting the tip of the nose and the tip of the chin. A lateral profile where the lips lie slightly inside this line appears aesthetically balanced. East Asian people tend to have structurally disrupted E-lines.
- Scientifically supported: The efficacy of hyaluronic acid injection has been confirmed in multiple clinical trials. In filler injection to the Asian nose, 89.4% were rated as "improved or better" on the GAIS scale at 24 weeks.
- Lasts 6–18 months: Duration depends on the product, location, and individual variation, but cross-linked products have been reported to sustain effects for 12 months or longer. Generally, maintenance is recommended every 6–18 months.
- 3-level safety technique: Injection technique follows a staged, distributed injection protocol based on consensus for Asian patients. The nasal bridge is recommended for cannula use, and the nasal tip for fine-gauge needle.
- Blindness risk requires caution: The greatest risk is skin necrosis and blindness from vascular occlusion. Blindness related to nasal filler is reported more frequently than in other anatomical sites.
If you're wondering "What about my case?"
Book a free consultation
There is no high-pressure selling. Feel free to reach out.
References
- Liew S, Scamp T, de Maio M, et al. Efficacy and Safety of a Hyaluronic Acid Filler to Correct Aesthetically Detracting or Deficient Features of the Asian Nose: A Prospective, Open-Label, Long-Term Study. Aesthetic Surgery Journal. 2016DOI
- Rho N, Youn C, Youn S, et al. A comparison of the safety, efficacy, and longevity of two different hyaluronic acid fillers in filler rhinoplasty: A multicenter study. Dermatologic Therapy. 2021DOI
- Trevidic P, Kim H, Harb A, et al. Consensus Recommendations on the Use of Hyaluronic Acid–Based Fillers for Nonsurgical Nasal Augmentation in Asian Patients. Plastic & Reconstructive Surgery. 2022DOI
- Trevidic P, Kim H, Harb A, et al. Consensus Recommendations on the Use of Hyaluronic Acid–Based Fillers for Nonsurgical Nasal Augmentation in Asian Patients. Plastic & Reconstructive Surgery. 2022DOI
- Chen B, Ma L, Ji K, et al. Rhinoplasty With Hyaluronic Acid. Annals of Plastic Surgery. 2020DOI
About the Author of This Article
Hiromitsu NakamuraPhysician, Ginza Clinic
Zetith Beauty Clinic Ginza, Shinsaibashi Osaka, and Fukuoka Clinics
With a track record of presenting research at domestic and international academic conferences, he is involved in technical guidance and education across all Zetith Beauty Clinic locations. He specializes in precision aesthetic medicine based on anatomical science, pursuing natural results tailored to each individual's bone structure and tissue.