Best way to restore three buccally angled implants in the maxilla?

Was this meant to be an all-on-4 and the distal implant that is missing failed? I don't really rely on all-on-4 in the maxilla. 6 implants would be better. The 2 mesial implants seem irrestorable even with 30 degree multiunits. For a bar OVD the distal implant that is missing is important and the mesial implants disturb the vestibule part of the denture so I would do an upper wax up, determine if the 1st quadrant distal implant is salvageable with a multiunit and remove the mesial ones, place additional 3 implants for a bar OVD os 5 more and at least a hybrid full arch on 6 implants. Even better after the wax up remove the 3 implants and place the new ones in the correct position or refer to someone you know that can place them in the desired position.

With only 3 implants your not looking at a fixed approach even with 1 more thats stretching the all on 4 concept due to positioning. What i would do is wax up a full arch on this case then do a vacuform stent over it take that to the soft tissue model without heads on the analogs and see where the implants lay in relation to where the teeth need to be. I think on the centrals you have two options #1 explant them as they are too buccal to be used for fixed and may even be too buccal to be used for a bar overdenture with the bar lingual to these implants or #2 sleep them, place cover screws on them and cover them and let the gingiva cover them then place proper implants in the adjacent sites that are restoratively placed. Did the patient indicate were these placed by a GP or a periodontist or an OS?

Yes, what Greg described is how the case should be started in the first place, with a wax up. You are inheriting a case that has very little chance of a positive outcome from the appearance of the photographs. These cases were not uncommon 20 years ago but today we should not see this kind of implant placement with proper training. Just saying. Personally I would explant and start from the beginning with proper diagnostics and planning. You will save everyone an immense amount of frustration and expense this way.

Personally, I would remove them and start over ie. NIke slogan do it right do it once! Otherwise, its putting lipstick on a pig if you cant remove bury them and place others the distal single implant MAY be usable hard to tell but minimally have 5 implants for an "all-on-4 if one fails you have an all on 4 there is no such thing as an all on 3 actually there is its called a denture!

Remove implants. After 6 weeks contour bone graft and new implants.

Remove or bury the two front vestibularly placed implants and do an All-On-4. Use Zygos in back if needed.

I agree that the implant placement is not the greatest, and that a diagnostic wax-up for ideal placement of the final restoration should be how any forward momentum should begin. If extracting and repositioning the implants are not a favourable choice, maybe consider custom locator abutments and a removable CUD with Co/Cr mesh reinforcement? You did mention that an all-on-four restoration was the original treatment plan.

A CT would be helpful as we have no idea where the remaining bone is .As everyone has said it is obviously a case that was not planned . Unfortunately I see way too many of these and usually its a dentist with not much experience .I like to ask the patient why they selected that particular dentist and often I hear the price was lower