People often assume All-on-X is the same procedure whichever jaw it is done in. It is not. The upper and lower jaws differ in bone quality and anatomy, and those differences shape the number of implants used, the healing period and sometimes the recommendation itself.
Dr. Jin-Ho Cho at Shine Dental Newington — BDS (University of Sydney, 1987), more than 35 years in practice, over 9,000 implant fixtures placed — plans each arch on its own terms.
What makes the lower jaw different?
The mandible is generally the more favourable of the two for implants.
The bone is denser. The lower jaw has a thicker outer layer of cortical bone, which gives an implant better initial stability at the moment it is placed. That stability is what makes immediate provisional teeth possible in suitable cases.
Bone at the front is usually well preserved. The region between the mental foramina — where the nerve exits on each side — tends to retain volume even after long-term tooth loss. This is why full-arch lower cases are frequently achievable without extensive grafting.
The main anatomical constraint is the inferior alveolar nerve, which runs through the jaw and supplies sensation to the lip and chin. Implant positions must respect it, which is one of the reasons a CBCT scan is taken before planning rather than a standard x-ray.
The practical result is that lower full-arch cases often integrate predictably and are more frequently candidates for same-day provisional teeth.
What makes the upper jaw more demanding?
The maxilla presents a different set of conditions.
The bone is softer. The upper jaw has more spongy bone and a thinner cortical layer. Achieving the same initial stability is harder, which affects both implant selection and whether immediate loading is advisable.
The sinuses sit above the back teeth. After upper molars are lost, the sinus floor tends to move downward and the ridge resorbs from below, leaving limited height. This is why sinus lifts are common in the upper jaw and rare in the lower — our article on bone grafting explains the technique.
Resorption patterns differ. The upper ridge tends to shrink inward as well as downward, so over time the ridge sits further back relative to where the teeth used to be. That affects how the restoration must be designed to support the lip properly.
Aesthetic demands are higher. The upper teeth and the transition between the restoration and the gum are far more visible when you smile. This influences material choice and the design of the prosthesis.
Because of these factors, upper cases more often use additional implants to distribute load, may involve angled implants to make use of available bone, and may call for a longer healing period before the final restoration.
Does that mean more implants in the upper jaw?
Frequently, yes. Lower arches are often restored on four implants where conditions allow. Upper arches more commonly use five or six, precisely because the softer bone means load is better shared across more fixtures.
This is a general tendency, not a rule. The number for your case comes from your scan. Our article on how many implants All-on-X needs covers the reasoning.
What if I need both arches?
This is common, and there are two broad approaches.
Both arches together means one surgical episode, one recovery period and a single overall timeline. It is a bigger day and a more demanding recovery, but it is done once.
Staged, one arch at a time spreads the surgical load and the cost, and lets the first arch be assessed before proceeding. It also means two recovery periods and a longer overall span.
There is a clinical dimension too. When one arch is restored on implants and the other is a conventional denture, the fixed arch bites against a mobile one, which affects both comfort and the rate at which the denture-bearing ridge resorbs. Restoring an upper arch against a lower All-on-X, for instance, needs thought about what it is biting against.
Which route suits you depends on your health, your work and family commitments and your budget. It is a decision worth taking time over.
Does the daily experience differ?
Once the final restorations are fitted, most patients describe both arches as feeling similar — fixed teeth that stay put. Two practical differences are worth knowing.
An upper All-on-X bridge does not cover the palate, which is the change most former upper denture wearers notice first: taste and temperature return. Our article on switching from dentures covers that transition.
Cleaning technique is the same for both arches but access differs slightly, and the lower is generally easier to reach. Our cleaning guide sets out the routine, which matters for the long-term health of the implants — see also peri-implantitis.
What determines your own plan
Bone height and width at each proposed site, the position of the nerve and sinuses, your bite, your general health and habits. None of this can be judged from the outside, which is why planning starts with a CBCT scan taken on site.
Outcomes vary between individuals, and not everyone is a candidate for full-arch treatment in either jaw. Our guide on who is suitable for All-on-X is honest about the limits.
Arranging an assessment
You receive a written, itemised quote with item numbers before anything is booked. Consultations run in English or Korean. HICAPS on-the-spot claiming is available, and the practice is a CBHS and NIB preferred provider.
Call (02) 9748 4822, mobile 0430 442 018, or send an enquiry.