PurposeThe　re-measurement　of　full-arch　implant　digital　impressions　is　an　important　step　in　denture　restoration.　This　paper　provides　an　efficient　oral　photogrammetry　technology　using　projective　invariant　marker,　applied　in　the　re-measurement　of　full-arch　implant　digital　impressions.MethodsWe　have　developed　a　self-recognizing　marker　with　projection　invariance,　along　with　its　detection　code.　The　marker　is　installed　on　the　scanning　body　and　used　for　photogrammetric　measurements.　Triangulation　is　utilized　to　determine　the　3D　coordinates　of　the　marker,　followed　by　a　series　of　post-processing　steps　to　obtain　more　accurate　3D　coordinates.ResultsThe　experimental　data　indicate　that　the　optimal　working　distance　is　between　200　and　250　mm,　with　a　minimum　measurement　error　of　less　than　0.05　mm　and　an　average　measurement　error　of　0.10　mm.　The　measurement　time　is　less　than　2　min.ConclusionsThe　experimental　results　show　that　the　photogrammetric　system　can　obtain　reliable　positions　of　full-arch　implants　with　efficient　photogrammetry,　without　the　need　to　enter　the　patient＇s　oral　cavity,　and　has　potential　clinical　application　value.