Breast Implants: Choosing Size, Shape, Profile and Placement
By Dr. Rushapol Sdawat, MD — Thai Board-certified Plastic and Reconstructive Surgeon, Medical Licence No. 17689
Last reviewed: 26 AUG 2026
You have probably already picked a number. Somewhere between the forums, the Instagram saves and a friend's result you admired, a figure like 350cc has lodged in your head, and you are now looking for a surgeon who will agree to it. I want to talk you out of that way of thinking before you get on a plane — not because your number is necessarily wrong, but because it is the wrong place to start.
I have been placing breast implants for over two decades at Intrarat Hospital in Bangkok, a large proportion of them in Australian and New Zealand patients. The consultations that go well begin with a tape measure and a pinch test, not a volume. The ones that go badly begin with a number the patient will not let go of. This article is the conversation I would have with you across the desk, including the parts that do not help me sell surgery.
Why your chest decides the base width before you do
Every implant has two defining dimensions: its base width — the diameter of its footprint on your chest — and its projection — how far it stands forward off the chest wall. Volume in cubic centimetres is simply what you get when you combine the two.
Here is the concept that clarifies almost every sizing decision: your base width is essentially fixed, and projection is the free variable. Your breast has a natural footprint, measured from its inner border to the anterior axillary line. An implant meaningfully wider than that footprint has nowhere legitimate to sit. Push past it and the implant drifts into the armpit, blunts your cleavage line, or produces the shelf-like upper pole that reads as "operated" from across a room. An implant much narrower than your footprint leaves the outer breast empty and the implant visible as a mound within a breast rather than a breast.
So when I measure a base width of, say, 12 centimetres, I am not restricting your choices — I am telling you which family of implants fits your skeleton. Within that family, projection is where your preference genuinely operates: a low-profile implant of that width might be 260cc and look like a subtle fullness; a high-profile implant of the same width might be 400cc and look emphatically augmented. Same footprint, very different result. That is the honest sense in which you choose your size.
What "profile" actually changes
Profile is simply the ratio of projection to base width. Manufacturers name the steps differently — moderate, moderate-plus, high, extra-high; Motiva uses "mini" through "corse" — but the principle is constant: as profile rises, the implant projects further forward from the same footprint.
Higher profile is not "better" and is not simply "bigger". On a broad chest, a high-profile implant can look narrow and bolted-on. On a petite frame with a narrow base width, high profile is often the only way to achieve meaningful volume without violating the footprint. The right profile is the one that delivers the look you have described within the width your chest dictates — which is why I ask patients to bring photographs of results they like on bodies shaped like theirs, not on bodies they wish they had.
Tissue-based planning versus "my friend got 350cc"
Your friend's 350cc sits on your friend's base width, under your friend's skin thickness, over your friend's chest wall shape. On you, the same implant can look smaller, larger, wider or frankly wrong. Chest wall curvature alone changes apparent projection: an implant on a convex chest throws forward; the same implant in a slightly sunken chest partially disappears.
Tissue-based planning works the other way around. I measure:
Base width of the existing breast, which sets the implant width range
Soft-tissue pinch thickness at the upper pole and lower pole, which tells me how much cover your tissue can provide
Skin stretch and nipple-to-fold distance, which tell me how much the envelope can accept and whether you need a lift rather than, or as well as, an implant
Existing asymmetry — almost every patient has some, and an implant magnifies whatever it sits behind
From those numbers comes a narrow range of implants that will fit you, and within that range we discuss taste. Patients sometimes hear this as the surgeon overriding their wishes. It is the opposite: it is the method most likely to produce the result you actually pictured, and it is the method most likely to still look right in ten years, because implants chosen beyond the tissue's capacity are the ones that thin the skin, drop, and ripple.
Smooth or textured — and what BIA-ALCL changed
Texturing was developed to help implants adhere to tissue and to reduce rotation of teardrop-shaped implants. Then came breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), an uncommon cancer of the immune system that develops in the fluid and capsule around an implant, typically years after surgery, most often announcing itself as a sudden swelling of one breast.
The evidence is now consistent on the central point: BIA-ALCL is overwhelmingly a disease of textured implants, particularly the high-surface-area macrotextured types, and to date no confirmed case has involved a woman exposed only to smooth implants. Risk estimates from confirmed cases and sales data give a lifetime risk between roughly 1 in 2,200 and 1 in 86,000 for textured implants, and Australian and New Zealand data — which are among the best in the world on this disease — put the risk for the highest-surface-area textured implants at approximately 1 in 2,800 to 1 in 7,000, versus about 1 in 35,000 for lower-surface-area textured surfaces. In 2019 Australia's TGA removed a number of macrotextured and polyurethane implant models from the market. Importantly, regulators and surgical societies on both sides of the ditch agree that women with textured implants and no symptoms do not need them removed; the absolute risk remains low and surgery has risks of its own.
In my practice the practical consequence is simple: for routine cosmetic augmentation I now use smooth or nanotextured-surface round implants. The Mentor and Motiva devices I offer both sit at the smooth end of the surface classifications regulators use. When a patient asks me for a macrotextured anatomical implant because a website from 2015 recommended one, I explain why I will not.
Over the muscle, under it, or dual plane?
Placement is decided mainly by two findings: your upper-pole pinch thickness and your degree of ptosis (droop).
If I can pinch more than about two centimetres of soft tissue at your upper pole, you have enough natural cover for the implant to sit in front of the muscle (subglandular) without visible edges or rippling. If you are lean — and many of the Australian patients I see are — that cover does not exist, and the implant belongs at least partly under the pectoralis major muscle, which adds a layer of padding exactly where the implant would otherwise show.
Dual plane splits the difference: the upper implant sits under muscle for cover, while the lower pole is released so the implant can expand the lower breast directly. It is my usual choice for lean patients and for those with mild ptosis or a slightly deflated lower pole after breastfeeding, because it lets the implant fill the loose lower envelope while keeping the upper edge concealed. Full submuscular placement gives maximal cover but can produce animation deformity — visible distortion when the pectoral muscle fires — which matters to women who lift weights seriously.
Which incision, and what each trades away
IncisionWhere the scar sitsAdvantagesTrade-offsInframammary (under the fold)In the crease under the breastBest visibility and control; lowest reported contracture and reoperation rates; my defaultScar on the breast itself, though hidden in the foldPeriareolar (around the nipple)Lower border of the areolaScar at a colour transition; useful when a small lift is combinedPasses through duct tissue — higher bacterial exposure, linked to higher capsular contracture rates; possible nipple sensation changeTransaxillary (armpit)In the axillary creaseNo scar on the breastLongest instrument path; less precise pocket control; harder revision
I use the inframammary incision for the large majority of augmentations because the evidence and my own revision workload both point the same way: the shortest, cleanest path to the pocket produces the fewest problems later.
What the Mentor–Motiva price gap actually buys
Patients see the price list and reasonably ask what an extra two thousand dollars purchases. Indicative prices in my practice, confirmed at booking:
ImplantIndicative price (AUD / THB)Round Gel (Mentor)A$5,500 / ฿125,000Silk Surface Plus (Motiva)A$6,400 / ฿145,000Round Ergonomix (Motiva)A$7,300 / ฿166,000Ergonomix V.2 (Motiva)A$10,900 / ฿250,000
Mentor's round gel is a thoroughly proven device from one of the two longest-studied manufacturers, with decades of core-study data behind it. It holds its round shape in all positions. Motiva's Ergonomix range uses a softer, more mobile gel designed to behave differently with gravity — rounder lying down, more teardrop standing — with a nanotextured surface and, in the V.2, further refinements to the gel and shell.
Here is the honest version: the price gap buys you a more naturally mobile gel and a more recently engineered surface. It does not buy you immunity from capsular contracture, rupture, malposition or reoperation, and it does not buy a visibly different result in every patient. In a woman with generous natural tissue cover choosing modest volumes, the Mentor implant is often the better clinical choice — her own tissue will dominate how the breast moves and feels, and the extra spend changes little. The Ergonomix earns its price mainly in lean patients with thin cover, where the implant itself contributes most of the breast's movement and feel, and in patients who strongly prioritise a soft, gravity-responsive look. I tell patients which category they fall into; I do not upsell the dearer device to someone whose tissues will hide the difference.
Implants are not lifetime devices
The US FDA's wording is the one I quote because it is blunt and correct: breast implants are not lifetime devices, and the longer you have them, the more likely you are to develop complications, some of which will need further surgery. Rupture, capsular contracture, malposition and simple changes in your own body — pregnancy, weight change, ageing — mean that a proportion of augmented women will face revision surgery at some point. There is no fixed replacement schedule; an intact, comfortable implant does not need swapping at year ten. But if you are twenty-eight and considering augmentation, you should budget — financially and emotionally — for at least one further operation in your lifetime. Any clinic that leaves this out of the consultation is not consulting; it is selling. The risks I go through with every augmentation patient include haematoma, seroma, infection, wound-healing problems, altered nipple sensation, asymmetry, rippling, capsular contracture, rupture, BIA-ALCL, anaesthetic risks, venous thromboembolism — and the result that is technically satisfactory but emotionally disappointing, which is real and deserves naming.
When to seek care
In Bangkok, in the first two weeks: a breast that becomes rapidly swollen, tight and much more painful than the other — especially within the first 48 hours — may be a haematoma and needs review the same day; contact me, do not wait for your scheduled appointment. Fever above 38°C, spreading redness, or discharge from the incision needs same-day review. Calf pain or swelling in one leg, breathlessness, or chest pain are emergencies — in any country, go directly to an emergency department, and on a plane, tell the crew.
Back home in Australia or New Zealand: sudden swelling of one breast months or years after surgery is not an emergency, but it is never something to ignore — it needs an ultrasound and, if fluid is found, aspiration with the fluid tested for BIA-ALCL. See your GP promptly and tell them you have implants, which brand, and which surface. New hardness, distortion or pain in a previously soft breast warrants specialist review within weeks. Remember that Medicare does not cover treatment overseas and your private insurer is unlikely to cover complications from surgery performed abroad — factor that into your planning, not into your delay in seeking care.
Questions worth asking any surgeon, including me
Ask what your base width is and how it constrained the recommendation. Ask why this profile and not one step lower. Ask which surface the implant has and how the surgeon responded to the BIA-ALCL evidence. Ask what the revision rate is for the operation proposed, and what a revision would cost you, in which country. A surgeon who answers those four questions specifically, with numbers where numbers exist and honesty where they do not, is telling you something more important than any before-and-after gallery ever could.
Dr. Rushapol Sdawat (known to international patients as Dr. Dominic) is a Thai Board-certified plastic and reconstructive surgeon practising at Intrarat Hospital, Bangkok, Medical Licence No. 17689. He holds Thai Board certification in General Surgery (Phramongkutklao Hospital) and in Plastic and Reconstructive Surgery (Ramathibodi Hospital, Mahidol University), has been a member of ISAPS since 2008 and is an international member of the American Society of Plastic Surgeons. Dr. Rushapol holds Thai specialist certification; he is not registered with Ahpra and does not hold Australian or New Zealand specialist registration. His registration can be verified on the Medical Council of Thailand register at checkmd.tmc.or.th.
This article is provided for general information and education. It is not medical advice and cannot substitute for individual assessment by a qualified practitioner who knows your history. Surgery carries risk, including risk of serious complications and of outcomes that do not meet expectations. Results vary between patients.
