A Novel Guided Zygomatic and Pterygoid Implant Surgery System: A Human Cadaver Study on Accuracy

Abstract

The aim of this human cadaver study was to assess the accuracy of zygomatic/pterygoid implant placement using custom-made bone-supported laser sintered titanium templates. For this purpose, pre-surgical planning was done on computed tomography scans of each cadaver. Surgical guides were printed using direct metal laser sintering technology. Four zygomatic and two pterygoid implants were inserted in each case using the guided protocol and related tools. Post-operative computed tomography (CT) scans were obtained to evaluate deviations between the planned and inserted implants. Accuracy was measured by overlaying the real position in the post-operative CT on the virtual presurgical placement of the implant in a CT image. Descriptive and bivariate analyses of the data were performed. As a result, a total of 40 zygomatic and 20 pterygoid implants were inserted in 10 cadavers. The mean deviations between the planned and the placed zygomatic and pterygoid implants were respectively (mean ± SD): 1.69° ± 1.12° and 4.15° ± 3.53° for angular deviation. Linear distance deviations: 0.93 mm ± 1.23 mm and 1.35 mm ± 1.45 mm at platform depth, 1.35 mm ± 0.78 mm and 1.81 mm ± 1.47 mm at apical plane, 1.07 mm ± 1.47 mm and 1.22 mm ± 1.44 mm for apical depth. In conclusion, the surgical guide system showed accuracy for all the variables studied and allowed acceptable and accurate implant placement regardless of the case complexity.

The Accuracy of Zygomatic Implant Placement Assisted by Dynamic Computer-Aided Surgery: A Systematic Review and Meta-Analysis

“…After removing duplicates ( n = 56), 51 articles were screened using title-abstract-keyword reading, leaving 35 reports eligible (substantial agreement, κ = 0.95). After full-text reading and a subsequent search for relevant citations, 14 studies were included in this systematic review [ 8 , 10 , 11 , 12 , 13 , 14 , 15 , 19 , 32 , 33 , 34 , 35 , 36 , 37 ] (100% of agreement among the reviewers) ( Figure 1 ). One current retrospective study from Wu included [ 19 ], and other fives studies from the same team (Shanghai Jiaotong University) were excluded due to the same population were collected in Wu’s publication [ 19 ].…”

“…The main characteristics of the included studies are described in Table 1 according to guidance approach, system, number of examinations, ZI characteristics, and conclusions. A total of 14 studies [ 8 , 10 , 11 , 12 , 13 , 14 , 15 , 19 , 32 , 33 , 34 , 35 , 36 , 37 ], including one RCT [ 32 ], two retrospective studies [ 15 , 19 ], five prospective studies [ 12 , 13 , 33 , 34 , 37 ], six cadaver studies with one comparative analysis [ 8 , 10 , 11 , 14 , 35 , 36 ], were retrieved from the search. Those reported ZI planned/placed accuracy in 144 patients (77 male and 67 female) and 35 cadavers with total of 511 ZIs (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179); six studies used 35 cadavers with 118 ZIs.…”

“…In the navigation group [ 19 , 32 , 33 ], 57 patients were treated via the classic approach, 35 patients via the quad zygoma approach, and in ten patients ZIs were placed in cases of deficient maxilla. In the static guide group [ 8 , 10 , 11 , 12 , 13 , 14 , 15 , 34 , 35 , 36 ], nine patients and six cadavers were treated via the classic approach, 18 patients and 24 patients via the quad zygoma approach, and in 11 patients and five cadavers, ZIs were used for maxillary defect cases. In the freehand group [ 10 , 37 ], one patient was treated with the classic approach, and three patients and ten cadavers received a quad zygoma approach.…”

“…This guide was supported by the bone in three studies and supported by the mucosal tissue in one study. Six studies used a modified surgical guide with double or extra-long sleeves designs [ 10 , 11 , 12 , 13 , 14 , 15 ]. The modified surgical guides were larger than conventional ones and were fixed with multiple screws to the bone.…”

“…In 2016, a modified surgical guide with double sleeves, designed to stabilize the long drill and to overcome the deviation, was introduced [ 9 ]. Later, studies focused on utilizing this modified guide concept to assist in ZI placement with increased intra-operative safety and accuracy [ 10 , 11 , 12 , 13 , 14 , 15 ]. Gecchi et al demonstrated that the accuracy of ZI placement with a modified surgical guide was superior to the free-hand approach, particularly at the level of the zygomatic bone [ 10 ].…”