Hi, Jennifer:

12 mm Offset of this case is set up because of the narrow mesiodistal space and oblique axis of the neighboring teeth?  The proportion of drills in drilling sequence is accurate.  Because of 12 mm offset, there is no necessity to use 2.2x7.3, x8.5 mm drills?  There is no bone trimmer longer than 12 mm?  Thanks

To answer your first question, yes, 12mm offset has been set up due to narrow mesiodistal space and position of #16 leaning towards mesial.

Please refer to the picture below.

Secondly, No, for this time, there's sufficient bone in height, so there's no need to go for short drills such as 7.3 and 8.5mm (I mean as a final drill, Of course, those short drills are part of drilling sequence). And this case won't require sinus elevation therefore you can go with regular drilling sequence.

When I reviewed this case, the bone density was high compared to other upper molar cases. So, as we have agreed on our phone call, we will not go with undersized drilling this time and if there's lots of torque being applied, then you may also conduct tapping. 

As we know that the final drill would be 4.5 X 10mm to place 5.0 X 10.0mm implant. (Usually drill size is 0.5mm smaller than the actual implant size and you may have noticed it before on the guide kit)

And with 4.5 X 10.0mm drill, as we have raised the sleeve level to 12mm offset which is 3mm higher. So, your final drill would be 4.5 X 13.0mm.

When you take a look at the sequence I sent you, our final drill is 4.5 X 11.5mm that is because this case was designed to go with 1 size shorter drilling in length in order not to perforate sinus membrane.

Last question was for the bone trimmer. OFFSET 12mm bone trimmer  is the longest bone trimmer we have in our kit and I have not faced any case requires longer bone trimmer than that. So I think it will be enough length to trim the cortical bone for this case.

Hope this clarifies your confusion. If there's any other following questions, please let me know.