To finish my Maltese question series before boarding a plane off the island, here is another question about [Latin inscriptions in tombstones in St. John's co-cathedral at Valletta](https://latin.stackexchange.com/q/6571/79).
In many tombs, including the one below, the inscription begins with the abbreviation "D. O. M." in a fashion very similar to Roman grave inscriptions starting with "D. M." much earlier.

What does this abbreviation mean?
I did not find any graves with this abbreviation expanded (starting with three words with initial letters DOM).
I assume it is a Christian counterpart of the Roman *Dis Manibus* and that the D stands for some form of *Deus*.
Is "D. O. M." related to "D. M." at all, or is the similarity a complete coincidence?

[![A tombstone in Latin](https://i.stack.imgur.com/eaNqu.jpg)](https://i.stack.imgur.com/eaNqu.jpg)