Read this before the workflow chapters. It is the part of the documentation that describes what the software is for, what it does not do, and where responsibility sits — none of which is obvious from using it.
What the system is for
GuideMia is a software interface that turns DICOM images from CT scanners into 3D models; an image segmentation system for creating dental anatomies from those images; and pre-operative software for simulating and evaluating dental implant placement and surgical treatment options. It includes a surgical guide design tool that transfers the treatment plan into geometric models wherever possible.
The stated purpose of that last part is worth reading twice, because it is the reason guided surgery exists:
This eliminates or reduces the risks that treatment plans are not correctly conveyed by the surgical guides.
The software runs on standard personal computer hardware under Windows.
What the measurements mean
The measurement features — dimensions and angles — are guaranteed to errors smaller than 0.01 mm or 0.05 degree.
That figure describes the software's arithmetic, not your case. Every deviation between a digital measurement and the physical anatomy depends on the accuracy of the data you put in:
Please refer to the specs of your CT and optical scanners for their accuracy information. GuideMia has no impact on the input data.
A plan is no more accurate than the scan it was built from.
Who may plan a case
Implant treatment planning should be performed only by practitioners or lab technicians who are trained to do so. Necessary training includes Implant Dentistry, CT Imaging Concepts, and GuideMia training courses.
The software does not substitute for any of that. It also expects the study work to have been done: adequate examination of the anatomic structures, and assessment of the biomechanical, functional and aesthetic requirements of each case. Radiographs or other diagnostic review should establish the position and topography of the maxillary sinus, nasal cavities, inferior alveolar nerve, mental foramen, natural tooth positions, and anything else bearing on placement or prognosis.
Consultation between surgeon, restorative dentist and dental laboratory is described as essential to success, not advisable.
Scanning, and what can go wrong before you start
The software can only be used when patients have been scanned according to specific protocols and procedures, with study models made and scanned where necessary.
Where a case uses a radiographic guide, its placement during the CT scan is itself a risk:
Improper placement of the radiographic guide during CT scan can cause serious errors and pose great risk to the surgery.
Contraindications
Implants should not be placed wherever there are general contraindications associated with elective oral surgery. The absolute and relative contraindications include, but are not limited to: cardiac and vascular disease, bleeding disorders, psychological disorders, uncontrolled diabetes mellitus, mineral, bone or connective tissue disorders, renal disease, hepatic disease, auto-immune disorders, decreased immune function through disease or medication, infectious disorders, and adverse conditions caused by medications. Further relative contraindications include poor oral hygiene, bruxism, malnutrition, alcoholism, tobacco use, and a history of radiation therapy.
Beyond the patient's general health, the site has to carry the plan: there must be adequate residual bone volume for implants of sufficient size and number to support the functional loads the patient will place on them. Narrow implants and angled abutments are not intended for use in the posterior region.
The risks of getting placement wrong
All implants must be placed with sufficient clearance between implants, teeth and nerve structures. The documented risks of improper placement and restoration include, but are not limited to: infection, implant failure, loss of bone and soft tissue, unfavourable aesthetic result, anaesthesia, dysaesthesia and paraesthesia in the oral and facial areas, sinus infection, dislodgement of implants and instruments into surrounding structures, damage to adjacent teeth, non-restorable implants, fracture of implants or restorative components, and loosening of implants or restorative components.
Implant systems measure differently
Each implant system has its own measuring characteristics for seating the implant to the intended depth, and they do not agree with one another:
In some instances, drill length reference lines measure longer than the stated length of the implant.
The surgeon is expected to be thoroughly familiar with the measurement system in use. This is the same concern that runs through placing the implant, where the surgical kit, sleeve diameter and drilling depth are set — and through the report, whose drilling instructions are what reaches the operating room.
Mixing systems
Each implant system also has its own design characteristics for mating implants, abutments, prosthetic components and instrumentation, surgical kits included.
Combining instruments, surgical kits, and components that are not configured or dimensioned for correct mating can lead to mechanical failure of components, damage to tissue, or unsatisfactory aesthetic results.
This is the clinical reason the software ties the guide to a named kit in placing the implant, and why customising a kit is a deliberate, documented operation rather than a convenience.
What guided surgery does not guarantee
One-hundred percent success cannot be guaranteed no matter a treatment is planned with software or physical models.
Inadequate quantity or quality of remaining bone, infection, inadequate surgical technique, poor oral hygiene and generalised disease are all potential causes of failed osseointegration — either immediately after surgery or after integration has initially been achieved. Pre-operative hard or soft tissue deficits may yield a compromised aesthetic result or unfavourable implant angulation.
For children, routine treatment is not recommended until completion of alveolar growth has been verified.
Procedural precautions for surgery
This section is about the physical object the software produces, and it is the part of the documentation most likely to be skipped and most costly to skip.
The guide is not a finished device.
The surgical guide model created by GuideMia is not intended for direct clinical use. The users must finish the surgical guide with additional drilling sleeves.
The software exports geometry. Sleeves are fitted afterwards, and the guide is not usable until they are.
Verify the guide before the surgery. The applicability of every guide must be verified beforehand, and quality assurance effort must be made to confirm it was made according to the designed model and to the treatment plan. That means trying it on diagnostic models, and on the patient's anatomy.
If a guide is found not fit properly on the patient's anatomy, or cannot be properly secured, it must not be used for the treatment.
Guides should also be visually inspected and evaluated, and any structure that could cause stress concentration identified and adjusted.
Minimise damage to the host tissue. Particular attention goes to thermal and surgical trauma, and to eliminating contaminants and sources of infection. The procedure requires a high degree of precision and care:
Any divergence from the principle of least possible trauma at implant installation increases the risk of failure to establish osseointegration.
Drilling. All drilling should be performed at a maximum of 1000-2000 RPM — or per the manufacturer's instructions — with copious irrigation. That holds with or without a guide designed by the system, and with or without a manufacturer's surgical kit. Essential to it are sharp drills, sufficient irrigation, an in-and-out drilling motion, short cutting cycles, waiting for the bone to cool, and pilot drills in successively increasing sizes.
This is the clinical basis for the irrigation windows described in step 10. A guide covers the site it drills through and a sleeve wraps the drill closely, which is exactly what obstructs the coolant this precaution requires.
An appropriate follow-up protocol should be followed.
Caution
The use of this device is restricted to, or by the order of, licensed physicians or dentists, and per the prescriptions of licensed physicians or dentists only.
Regulatory
The GuideMia Software System, model GuideMia-001, holds FDA 510(k) number K121466, approved 31 May 2012, and carries CE marking under notified body 1023.
Manufactured by GuideMia Technologies, LLC, Cypress, California, USA.
Where responsibility sits
The report each case produces carries a disclaimer and a signature line for the prescribing doctor, and it says this plainly: examination and diagnosis of the patient, and the determination and preparation of a medically sound treatment plan, are the prescribing doctor's alone.
The software plans. It does not diagnose, and it does not decide.