Subperiosteal surgical kit, which comprises: - a subperiosteal implant fixable to the maxillary or mandibular bone of a patient and comprising a first frame, which is arranged to rest on an external surface of the patient's maxillary or mandibular bone and is provided with several through fixing holes, each fixing hole is provided with a corresponding first axis and is arranged to receive a corresponding bone screw to fix said subperiosteal implant to the patient's maxillary or mandibular bone; wherein said first frame is counter-shaped to said maxillary or mandibular bone of the patient on which said first frame must rest; - at least one surgical template, which comprises: • a second frame, which is arranged to rest on the external surface of the patient's maxillary or mandibular bone, and which is counter-shaped to said maxillary or mandibular bone of the patient on which said second frame must rest; and • several guide bushings fixed to said second frame and each internally defining a corresponding guide channel, which is provided with a corresponding second axis and is arranged to receive and guide a surgical drill to make a corresponding mounting hole in the patient's maxillary or mandibular bone; wherein each said guide channel is a through channel, which extends along the corresponding said guide bushing, along an extension direction, coinciding with said second axis, between an upper insertion opening and a lower outlet opening, opposite said insertion opening; the second axes of the guide channels of said at least one surgical template having the same spatial distribution as the first axes of corresponding said fixing holes of said subperiosteal implant to fix the bone screws of said subperiosteal implant on corresponding said mounting holes. - a subperiosteal implant fixable to the maxillary or mandibular bone of a patient and comprising a first frame, which is arranged to rest on an external surface of the patient's maxillary or mandibular bone and is provided with several through fixing holes, each fixing hole is provided with a corresponding first axis and is arranged to receive a corresponding bone screw to fix said subperiosteal implant to the patient's maxillary or mandibular bone; wherein said first frame is counter-shaped to said maxillary or mandibular bone of the patient on which said first frame must rest; - at least one surgical template, which comprises: • a second frame, which is arranged to rest on the external surface of the patient's maxillary or mandibular bone, and which is counter-shaped to said maxillary or mandibular bone of the patient on which said second frame must rest; and • several guide bushings fixed to said second frame and each internally defining a corresponding guide channel, which is provided with a corresponding second axis and is arranged to receive and guide a surgical drill to make a corresponding mounting hole in the patient's maxillary or mandibular bone; • a second frame, which is arranged to rest on the external surface of the patient's maxillary or mandibular bone, and which is counter-shaped to said maxillary or mandibular bone of the patient on which said second frame must rest; and • several guide bushings fixed to said second frame and each internally defining a corresponding guide channel, which is provided with a corresponding second axis and is arranged to receive and guide a surgical drill to make a corresponding mounting hole in the patient's maxillary or mandibular bone; wherein each said guide channel is a through channel, which extends along the corresponding said guide bushing, along an extension direction, coinciding with said second axis, between an upper insertion opening and a lower outlet opening, opposite said insertion opening; the second axes of the guide channels of said at least one surgical template having the same spatial distribution as the first axes of corresponding said fixing holes of said subperiosteal implant to fix the bone screws of said subperiosteal implant on corresponding said mounting holes.