An in-vitro analysis of the accuracy of different guided surgery systems - They are not all the same.

OBJECTIVES: Different static computer-assisted implant surgery (sCAIS) systems are available that are based on different design concepts. The objective was to assess seven different systems in a controlled environment. MATERIALS AND METHODS: Each n = 20 implants were placed in identical mandible replicas (total n = 140). The systems utilized either drill-handles (group S and B), drill-body guidance (group Z and C), had the key attached to the drill (group D and V), or combined different design concepts (group N). The achieved final implant position was digitized utilizing cone-beam tomography and compared with the planned position. The angular deviation was defined as the primary outcome parameter. The means, standard deviation, and 95%-confidence intervals were analyzed statistically with 1-way ANOVA. A linear regression model was applied with the angle deviation as predictor and the sleeve height as response. RESULTS: The overall angular deviation was 1.94 ± 1.51°, the 3D-deviation at the crest 0.54 ± 0.28 mm, and at the implant tip 0.67 ± 0.40 mm, respectively. Significant differences were found between the tested sCAIS systems. The angular deviation ranged between 0.88 ± 0.41° (S) and 3.97 ± 2.01° (C) (p < .01). Sleeve heights ≤4 mm are correlated with higher angle deviations, sleeve heights ≥5 mm with lower deviations from the planned implant position. CONCLUSIONS: Significant differences were found among the seven tested sCAIS systems. Systems that use drill-handles achieved the highest accuracy, followed by the systems that attach the key to the drill. The sleeve height appears to impact the accuracy.

Precision and trueness of computer-assisted implant placement using static surgical guides with open and closed sleeves: An in vitro analysis.

OBJECTIVES: The aim of this in vitro study was to determine accuracy defined by trueness and precision of computer-assisted implant surgery comparing two guided surgery kits designed for either closed sleeves or open sleeves with a lateral window. MATERIAL AND METHODS: Each n=20 implants were placed fully guided (sleeve-bone distance of 2 or 4 mm) in identical replicas using a surgical guide with both closed sleeve or an open sleeve, partially guided, or free hand. The achieved implant position was digitized and compared with the planned position. Trueness and precision were determined. The angular deviation was defined as the primary outcome parameter. The means, standard deviation, and 95%-confidence intervals were analyzed statistically with 1-way ANOVA and the Scheffé procedure. RESULTS: The accuracy of guided implant placement using closed and open sleeves was comparable when the sleeve-bone distance was 2 mm. Accuracy decreased when the sleeve-bone distance increased in both fully guided groups, more so in the open than in the closed sleeve group. The least accurate method was the free-hand group. Partially guided implant surgery was more accurate than free-hand placement, but less accurate than the fully guided groups with 2-mm sleeve-bone distance. CONCLUSIONS: The closer the sleeve to the bone, the more accurate and precise is computer-assisted implant surgery using a closed system and a system using open sleeves. Partially guided implant surgery using only the static guide for the pilot drill is less accurate than both fully guided approaches, but more accurate than free-hand surgery.

Open-sleeve technique: A new approach for aortic valve leaflet reconstruction in small children.

A boy was diagnosed with a unicuspid aortic valve with severe stenosis at birth. Percutaneous balloon aortic valvuloplasty was performed four times; however, he had severe heart and growth failure. Thus, aortic valve repair was performed at age 2 years and 6 months. He weighed 6.6 kg. The aortic valve annulus diameter was 9.8 mm (z value = 0.43). We report on a small toddler with congenital aortic stenosis who was successfully treated with autologous pericardial aortic valve leaflet reconstruction using the open-sleeve technique.