All-on-4 Dental Implants

The bite is a force-management system. I design it in this order. Every full-arch case I treat follows the same sequence. The order matters more than any single step, because each one protects the next.

A natural tooth sits in a tiny ligament that acts as a shock absorber and a nerve ending at the same time. It lets the tooth give a fraction of a millimetre under load, and it tells your brain, instantly, when you bite on something hard.

An implant is fused directly to the bone. It does not move, and it does not feel. Every force that lands on it goes straight through to the bone and the screws and the ceramic. That is why a bite that a natural mouth would shrug off can, on implants, quietly loosen screws, chip porcelain, fatigue the framework or remodel the bone around the implant, often without you noticing anything until something breaks.

Your mouth has a division of labour. When you close, the back teeth take the load, straight down their long axis, where they are strongest. When you slide your jaw forward or sideways, the front teeth take over and steer, and the back teeth separate so they are not dragged across each other. Each half protects the other.

These are not preferences. They follow from how force behaves on a rigid structure, and from thirty years of seeing what happens when one of them is skipped.

The single most important decision in the whole reconstruction, for both how it looks and how long it lasts, is the angle at which your lower front teeth slide against the backs of your upper front teeth.

When that slope is shallow and smooth, the back teeth separate the moment you move your jaw, the muscles relax, the joints are unloaded and very little force reaches the front teeth or the implants. When the slope is steep, as it is in many people with a deep bite, every sideways and forward movement rams the lower teeth into the uppers. The muscles work harder, the joints load more, and the result over time is chipped ceramic, loose screws and worn or fractured front teeth. There is a third pattern I see often, the “fenced” bite, where the upper front teeth overlap the lowers deeply but with almost no gap in front of them. The lower jaw is literally fenced in; it cannot move without hitting something.

Think of your lower jaw as a tripod standing on three points: the two jaw joints at the back and the front teeth, the idea Peter Dawson built his approach to occlusion around. All three have to be stable in the jaw's natural, relaxed, seated position, at the right height. If the front stop is weak or a back tooth is in the way, the tripod tips, and force concentrates where it should not.

No amount of planning on a model or a screen can tell me how your lips, tongue and muscles will respond. So nothing in the bite is made permanent until you have lived with it in a set of carefully made provisional teeth, for at least four weeks.

Implant surgery has become very good. Guided placement, immediate teeth, same-day smiles. What has not kept pace is the thinking before it: where the lip goes, where the seam will sit, whether the lip will still be supported, whether there is room for the materials chosen. Those are prosthodontic questions. They are decided by the person who designs the teeth, and they have to be decided first, because once the bone is shaped and the implants are in, the answers are fixed.

A prosthodontist is a dentist with specialist training in exactly this: planning the end result first and working backwards to the surgery. Fewer than two percent of dentists are prosthodontists. Dr. Reshad has been one for more than thirty years, in London and Beverly Hills. The classification on this page is his own work, published in the textbook surgeons train from, and he teaches it to clinicians in the United States, Europe, China and Australia. When you sit in his chair, the person who wrote the method is the person applying it to you.

The regret patients most often bring to Dr. Reshad after full-arch implants elsewhere is not pain or cost. It is a line across the smile, where pink ceramic meets their own gum, on show every time they laugh. Whether that happens to you is decided at the very first visit, by how far your lip lifts. Dr. Mamaly Reshad, a specialist prosthodontist in Beverly Hills, wrote the classification that surgeons use to read it. Here is what it means for you.

Full-arch implant teeth usually replace gum as well as teeth. The pink part is ceramic. Your own gum is above it. Where the two meet there is a seam, and no ceramist on earth can make living tissue and ceramic look like one thing. The seam cannot be masked. It can only be hidden under the lip.

So everything depends on one question that has to be answered before surgery: when you smile as hard as you can, where does your lip stop? If the seam ends up below that line, you will see it every time you laugh, and so will everyone else. By then the bone has been shaped, the implants are in, and the only ways out are a second operation or living with it.

Dr. Reshad regularly sees patients who arrive in exactly that position. That is why, in his practice, your lip is read before anything else is planned.

Everyone's lip lifts differently, and most people's lip rises further when they laugh with friends than when they pose for a photo. So your lip is not judged from a polite smile. That is the whole examination, and it is the one most patients never get. Without the denture, the lip shows where it really goes. If the gum ridge is visible at that moment, the seam of a fixed prosthesis will be visible too, because the seam sits on the ridge.

Dr. Reshad films it. The lip line used for planning is the highest position the lip reaches anywhere in that video, exaggerated smile and the E sound included. The design is then built so that the seam sits 2 to 3 millimetres above that line. Not at it. Above it, with a safety margin, because lips move more when people laugh with friends than when they sit in a dental chair.

Dr. Reshad first published his classification of the toothless upper jaw in the surgical textbook used to train oral and maxillofacial surgeons. In 2026 he rewrote it as the Lip-Line Classification: five classes, from the smile where a seam is easiest to hide, to the one where fixed teeth should not be promised at all. Every patient fits one. Knowing yours before surgery is what makes the result predictable.

Two thirds of the upper lip rests on the front teeth. Remove them and the lip has nothing behind it: it drops back, the profile flattens, and the face reads older. A denture props it up again with a flange, the thick pink rim under the lip. Fixed implant teeth have no flange, so before anyone promises you a fixed bridge, one question has to be answered: can the teeth alone hold the lip? Dr. Reshad answers it on your profile, with the teeth in and out, before surgery. For this patient, the answer was yes.

Fonseca's Oral and Maxillofacial Surgery is widely regarded as the gold-standard reference for oral and maxillofacial surgery teaching worldwide. Dr. Reshad's classification of the edentulous maxilla, the system that became the Lip-Line Classification, was published in its third edition, in the pages surgeons use to learn how to plan a full-arch case.

That matters to you for a simple reason. The surgeon placing your implants was very likely taught from this book. The prosthodontist who wrote the chapter on reading the lip is the one you can see in Beverly Hills.

One visit. Denture out, a short video, a trial of the lip with and without support, and a straight answer about what can be built in your mouth and what cannot. If you are planning full-arch implants, or you already have them and something shows that should not, start here.

You will hear the difference before you see it. A soft S on the phone. An F that will not land. The first week with a new set of teeth is often spent listening to your own voice. Dr. Mamaly Reshad teaches dentists why that happens and how to design teeth that speak. This section is that lecture, written for you.

In the lecture, Dr. Reshad shows dentists a cross-section through the front of the mouth: nose, upper lip, upper front tooth, lower lip, lower front tooth. Where that one edge sits decides three things at once: how your lip is supported, how your profile looks, and how you say F and S.

Speech problems after new teeth are rarely random. The sound points to the part of the prosthesis that needs changing. The numbers below match the numbers on the diagram.

Nothing is made permanent until you have lived with a trial set of teeth. Speech is one of the things that trial is for. These are the four rules he teaches, and applies to every full arch he makes.