Reliability of orbital volume measurements based on computed tomography segmentation: Validation of different algorithms in orbital trauma patients

PurposeTo compare the most common methods of segmentation for evaluation of the bony orbit in orbital trauma patients.Materials and methodsComputed tomography scans (before and after treatment) from 15 patients with unilateral blowout fractures and who underwent orbital reconstructions were randomly selected for this study. Orbital volume measurements, volume difference measurements, prolapsed soft tissue volumes, and bony defect areas were made using manual, semi-automated, and automated segmentation methods.ResultsVolume difference values between intact and damaged orbits after surgery using the manual mode were 0.5 ± 0.3 cm³, 0.5 ± 0.4 cm³ applying semi-automated method, and 0.76 ± 0.5 cm³, determined by automated segmentation (р = 0.216); the mean volumes (MVs) for prolapsed tissues were 3.0 ± 1.9 cm³, 3.0 ± 2.3 cm³, and 2.8 ± 3.9 cm³ (p = 0.152); and orbital wall defect areas were 4.7 ± 2.8 cm², 4.75 ± 3.1 cm², and 4.9 ± 3.3 cm² (p = 0.674), respectively.ConclusionsThe analyzed segmentation methods had the same accuracy in evaluation of volume differences between two orbits of the same patient, defect areas, and prolapsed soft tissue volumes but not in absolute values of the orbital volume due to the existing diversity in determination of anterior closing. The automated method is recommended for common clinical cases, as it is less time-consuming with high precision and reproducibility.     

Technical considerations of computer-aided planning in severe orbital trauma: A retrospective study

The aim of this study was to evaluate the clinical outcomes of linear and orbital volume measurements in severe orbital trauma. Patients with severe orbital trauma that involved more than two walls and entailed a marked degree of comminution were included in this retrospective analysis. However, patients with incomplete clinical records and a simple blowout or zygmatico-orbital fractures were excluded. All the cases underwent surgical correction guided by virtual surgical planning and 3D-printed templates. The measurement protocol depended on assessing orbital dimensions, orbital volumetry, and the zygomatic bone's position in the three-dimensional planes. All patients' preoperative 3D CT scans were obtained, and DICOM files were imported into a three-dimensional image processing software. Data were then converted for 3D reconstruction in the axial, coronal, and sagittal views. A total of 18 patients with a mean age was 39.28 ± 6.28 were included in this study. The results revealed a significant difference between the pre and postoperative differences in distances in relation to the FHP (Frankfurt Horizontal Plane) (P = 0.0014) and sagittal planes (P < 0.0001). The orbital width and height of the traumatized orbit were significantly decreased from 45.26 ± 6.72 mm and 45.30 ± 2.89 mm to 39.74 ± 3.91 mm (P = 0.0022), and 40.34 ± 0.86 mm (P < 0.0001), respectively. Clinically, there was a satisfactory degree of symmetry regarding the zygomatic bones' position and orbital dimensions postoperatively. Moreover, the mean orbital volume on the traumatized side decreased significantly from 23.16 ± 1.91 cm³ preoperatively to 20.7 ± 1.96 cm³ postoperatively (P < 0.0001). These findings were associated with a low incidence of complications. Within the limitations of the study it seems that the described methodology is a relevant addition to clinical treatment options. It incorporates all the latest technology to plan virtual reconstruction surgery in the treatment of complex orbital trauma and should be adapted accordingly in cases of severe displacement and comminution.     

Piezosurgery for orbital decompression surgery in thyroid associated orbitopathy

The purpose of this study was to assess a piezosurgical device as a novel tool for bony orbital decompression surgery.At a multidisciplinary orbital center, 62 surgeries were performed in 40 patients with thyroid associated orbitopathy (TAO). Within this retrospective case-series, we analyzed the medical records of these consecutive unselected patients. The reduction of proptosis was the main outcome measure.Indications for a two (n = 27, 44%) or three wall (35, 56%) decompression surgery were proptosis (n = 50 orbits, 81%) and optic neuropathy (n = 12, 19%). Piezosurgery enabled precise bone cuts without intraoperative complications. Proptosis decreased from 23.6 ± 2.8 mm (SD) by 3 mm (95% CI: −3.6 to −2.5 mm) after surgery and stayed stable at 3 months (−3 mm, 95% CI: −3.61 to −2.5 mm, p < 0.001, respectively). The effect was higher in those with preoperatively higher values (>24 mm versus ≤24 mm: −3.4 mm versus −2.81 mm before discharge from hospital and −4.1 mm versus −2.1 mm at 3 months: p < 0.001, respectively). After a mean long-term follow-up period of 14.6 ± 10.4 months proptosis decreased by further −0.7 ± 2.0 mm (p < 0.001). Signs of optic nerve compression improved after surgery. Infraorbital hypesthesia was present in 11 of 21 (52%) orbits 3 months after surgery.The piezosurgical device is a useful tool for orbital decompression surgery in TAO. By cutting bone selectively, it is precise and reduces the invasiveness of surgery. Nevertheless, no improvement in outcome or reduction in morbidity over conventional techniques has been shown so far.     

Accuracy of patient-specific implants and additive-manufactured surgical splints in orthognathic surgery — A three-dimensional retrospective study

IntroductionBecause of the many limitations of conventional surgery planning for the treatment of orthognathic deformities, as well as advancements in computer-assisted planning, there is an urgent need for technical devices that transfer the surgical plan into the operating theatre. In this regard, additive-manufactured, patient-specific implants (PSI) and additive-manufactured interocclusal splints represent promising approaches. The aim of this retrospective study was to compare the accuracy of these two devices, with regard to preoperative virtual treatment planning for maxillary Le-Fort I advancement surgery using IPS CaseDesigner^®, and based on a new analysis method without the use of landmarks.Materials and methodsA retrospective evaluation of 18 class III patients (n(PSI) = 9; n(splint) = 9), who had undergone virtually planned orthognathic surgery (including maxillary Le Fort I advancement), was performed. The preoperative treatment plan and the postoperative outcome were combined to calculate the translational and rotational discrepancies between the 3D planning and the actual surgical outcome.ResultsFor the PSI and splint groups the accuracy of left/right positioning was 0.51 mm ± 0.48 and 1.11 mm ± 1.32 respectively. The accuracy of anterior/posterior positioning was 0.39 mm ± 0.26 and 1.42 mm ± 0.87, and that of up/down-positioning was 0.44 mm ± 0.31 and 0.62 mm ± 0.47. The rotational discrepancies were less than 2° in both groups. Conclusion: The findings demonstrate that both PSI and splint approaches can accurately transfer the virtual planning into the operating theatre. However, PSIs show an overall higher accuracy, especially for anterior/posterior translational movement (p < 0.002).     

Critical appraisal of patient-specific implants for secondary post-traumatic orbital reconstruction

In orbital reconstruction, a patient-specific implant (PSI) may provide accurate reconstruction in complex cases, since the design can be tailored to the anatomy. Several design options may be embedded, for ease of positioning and precision of reconstruction. This study describes a cohort of 22 patients treated for secondary orbital reconstruction with a PSI; one patient received two PSI. The preoperative clinical characteristics and implant design options used are presented. When compared to preoperative characteristics, the postoperative clinical outcomes showed significant improvements in terms of enophthalmos (P < 0.001), diplopia (P < 0.001), and hypoglobus (P = 0.002). The implant position in all previous reconstructions was considered inadequate. Quantitative analysis after PSI reconstruction showed accurate positioning of the implant, with small median and 90th percentile deviations (roll: median 1.3°, 90th percentile 4.6°; pitch: median 1.4°, 90th percentile 3.9°; yaw: median 1.0°, 90th percentile 4.4°; translation: median 1.4 mm, 90th percentile 2.7 mm). Rim support proved to be a significant predictor of roll and rim extension for yaw. No significant relationship between design options or PSI position and clinical outcomes could be established. The results of this study show the benefits of PSI for the clinical outcomes in a large cohort of secondary post-traumatic orbital reconstructions.     

Anthropometric changes in the morphology of the lower eyelid after using three different approaches in patients with orbital fractures

PurposeThe aim of this prospective study was to address the anthropometric changes in the morphology of the lower eyelid and esthetic outcomes after performing subciliary, subtarsal, and transconjunctival approaches in patients with orbital and periorbital fractures.Patients and methodsA prospective randomized controlled clinical study was undertaken on patients with orbital floor and infraorbital rim fractures. These were equally divided into three groups: in group 1, the fractures were approached via a stepped subciliary approach; in group 2, they were approached via a subtarsal approach; in group 3, a retroseptal transconjunctival approach was performed. The patients were assessed for anthropometric changes in the morphology of the lower eyelid, esthetic outcomes, and postoperative lower eyelid complications (LLCs). A one-way ANOVA test was used to analyze differences between the operated and non-operated sides and the effect of the surgical approach on anthropometric measurements.ResultsA total of 45 patients were included in the study. All the surgical approaches provided adequate surgical exposure of the infraorbital rim and orbital floor. The subtarsal approach allowed rapid access to the field (10.5 ± 1.9 min). All incisions resulted in adequate postoperative esthetic outcomes. Anthropometric analysis revealed that there were no significant differences between the three approaches, except for measurements of the eye fissure index (EFI) and lower iris coverage (LIC). Mean EFI measurements increased on all operated sides. The subciliary approach showed the highest percentage of increased measurements of this variable (34.5 ± 4.6), followed by the subtarsal approach (32 ± 2.1), and then the transconjunctival approach (31.1 ± 3.7), with p = 0.046. Furthermore, the subciliary approach significantly decreased the measurements of LIC. This change was also bigger with the subciliary approach (1.09 ± 2.3) than with the subtarsal approach (2.1 ± 2.4) or transconjunctival approach (3.4 ± 2.6), with p = 0.048.ConclusionBased on the results of this study, the subtarsal approach is a minimally invasive incision that provides an adequate and direct approach to orbital floor and infraorbital rim fractures, with a favorable periorbital architecture and the lowest incidence of LLCs. Therefore, the subtarsal technique should be preferred over subciliary and transconjunctival approaches.     

Three-dimensional (3D) printing for post-traumatic orbital reconstruction,a systematic review and meta-analysis

The purpose of this study was to determine if three-dimensional (3D) printed orbit models and preoperative plate contouring provides benefit over traditional surgical reconstruction of orbit fractures. This systematic review and meta-analysis searched five databases to identify cases of 3D printing for orbital fracture reconstruction. Primary outcomes were resolution of diplopia and enophthalmos, orbital volume symmetry and operation duration. Meta-analyses were used to calculate log odds ratios (OR) for diplopia and enophthalmos and absolute mean difference for orbital volume. A total of 58 articles describing 906 patient cases were included. A single article for each of diplopia and enophthalmos compared 3D printing with traditional management, which prevented answering the primary research question. However, pre-post meta-analysis showed that postoperative groups were less likely to have diplopia (n = 747, log OR = ?2.35, 95%CI ?1.72 to ?2.98, p < 0.001, I² = 10.91%) and enophthalmos (n = 486, log OR = ?2.47, 95%CI ?1.95 to ?2.99, p < 0.001, I² = 11.33%) than preoperatively. Mean orbital volume did not differ between the repaired and uninjured orbits (n = 290, mean difference = ?0.13 cm³, 95%CI ?0.48 to 0.22, p = 0.472, I² = 9.48%). Pooled mean operation duration for orbital reconstruction with 3D printing was 67.70 minutes (standard error [SE] = 4.24 minutes). Orbital reconstruction combined with 3D printing adequately restores orbital volume symmetry and improves diplopia and enophthalmos. Due to a lack of controlled studies, it remains unclear what contribution 3D printing alone makes to these results. Three-dimensional printing is likely a safe, accurate and effective adjunct; however, further controlled studies are required.     

Accuracy of laser-melted patient-specific implants in genioplasty — A three-dimensional retrospective study

PurposeTo assess the accuracy of laser-melted patient-specific implants (PSI) with regard to a preoperative virtual treatment plan for genioplasty based on a new analysis method without the use of landmarks.Materials and methodsA retrospective evaluation of a cohort of Class II and Class III patients who had undergone virtually planned orthognathic surgery (including genioplasty) was carried out. The preoperative virtual treatment plan and the postoperative outcome were fused to calculate the translational and rotational discrepancies between the 3D planning and the actual surgical outcome.ResultsThe accuracy of left/right positioning was 0.25 ± 0.28 mm (p < 0.001), that of anterior/posterior positioning was 0.70 ± 0.64 mm (p < 0.001), and that of up/down-positioning was 0.45 ± 0.38 mm (p < 0.001). The rotational discrepancies were less than 2 deg. The virtually planned and postoperative positions of the chin differed significantly from each other (p < 0.001 for all rotational and translational discrepanices).ConclusionThe findings demonstrate that PSIs can transfer the planned virtual genioplasty into the operation theatre with small but significant deviations. However, since no conclusions can be drawn from the results regarding surgical success in terms of shaping the soft tissue profile as well as the esthetic result, no superiority of PSI over traditional plate osteosynthesis can be demonstrated.     

Surgical effects of various orbital decompression methods in thyroid-associated orbitopathy: Computed tomography-based comparative analysis

ObjectivesTo evaluate the surgical effects of orbital fat decompression and bony decompression in each orbital wall using computed tomography (CT) in thyroid-associated orbitopathy (TAO).MethodsIn 27 TAO patients (48 orbits) with exophthalmos who underwent orbital wall decompression combined with fatty decompression, we recorded the resected orbital fat volume intraoperatively and estimated the decompression volume of the orbital wall in the deep lateral, medial and inferior walls using postoperative orbit CT images. Then, the correlation between exophthalmos reduction by Hertel reading and decompression volume in each area was analyzed to validate the surgical predictability, surgical efficiency and contribution level to total exophthalmos reduction.ResultsThe decompression volume in orbital fat and the deep lateral wall showed relatively high correlation with exophthalmos reduction (surgical predictability) compared to medial and inferior wall. The surgical efficiency was highest at deep lateral wall (2.704 ± 0.835 mm/cm³), followed by medial wall (0.892 ± 0.527 mm/cm³), orbital fat (0.638 ± 0.178 mm/cm³) and inferior wall (0.405 ± 0.996 mm/cm³). The actual contribution level to total exophthalmos reduction was highest in fatty decompression, followed by deep lateral decompression.ConclusionIn TAO patients with exophthalmos, orbital fat and deep lateral orbital wall are more predictable and contributory surgical targets for postsurgical exophthalmos reduction.     

The advantages of advanced computer-assisted diagnostics and three-dimensional preoperative planning on implant position in orbital reconstruction

Objective

Advanced three-dimensional (3D) diagnostics and preoperative planning are the first steps in computer-assisted surgery (CAS). They are an integral part of the workflow, and allow the surgeon to adequately assess the fracture and to perform virtual surgery to find the optimal implant position. The goal of this study was to evaluate the accuracy and predictability of 3D diagnostics and preoperative virtual planning without intraoperative navigation in orbital reconstruction.

Orbital floor restoration with traction of the infraorbital nerve using a vessel loop in posterior orbital floor fractures

BackgroundThe authors retracted the infraorbital nerve (ION) using a vessel loop to explore the orbital floor fracture site and analysed when the traction of the ION was needed.MethodsIn ninety-one patients, the location of the fracture according to its position relative to the infraorbital groove, the location of the infraorbital groove from the midpoint of the orbital floor, and involvement of the ION in the fracture site were recorded retrospectively from computed tomography scans. An analysis of any associations between the traction of ION and the location of the fracture and ION passage was performed.ResultsTraction of the ION was performed in 14 cases, of which 10 cases had involvement of the ION in the fracture site and 4 cases did not. All of them were posterior fractures. In 51 cases with posterior fractures, the ION passage in patients who had ION traction was statistically located more medially (0.50 ± 1.19 mm) than in patients who had no traction (2.38 ± 1.12 mm) (p < 0.05).ConclusionThe ION may interfere with the exposure of the fracture site in a posterior orbital floor fracture with the involvement of the ION in the fracture site and a medially located ION passage.     

Prediction of surface area size in orbital floor and medial orbital wall fractures based on topographical subregions

ObjectiveThis retrospective study evaluates the occurrence and frequency of different fracture patterns in a series of computed tomography (CT) scans in terms of the AOCMF Trauma Classification (TC) orbit module and correlates the assigned defects with measurements of the fracture area in order to get an approximate guideline for fracture size predictions on the basis of the classification.Material and methodsCT scans of patients with orbital floor fractures were evaluated using the AOCMFTC to determine the topographical subregions. The coding consisted of: W = orbital wall, 1 = anterior orbit, 2 = midorbit, i = inferior, m = medial. The 3-dimensional surface area size of the fractures was quantified by the “defect body” method (Brainlab, Munich, Germany). The fracture area size and its confidence and prediction interval within each topographical subregion was estimated by regression analysis.ResultsA total of 137 CT scans exhibited 145 orbital floor fractures, which were combined with 34 medial orbital wall fractures in 31 patients. The floor fractures – W1(i)2(i) (n = 86) and W1(i) (n = 19) were the most frequent patterns. Combined floor and medial wall fractures most frequently corresponded to the pattern W1 (im)2 (im) (n = 15) ahead of W1 (im) 2(i) (n = 10). The surface area size ranged from 0.11 cm² to 6.09 cm² for orbital floor and from 0.29 cm² to 5.43 cm² for medial wall fractures.The prediction values of the mean fracture area size within the subregions were computed as follows: W1(i) = 2.25 cm², W2(i) = 1.64 cm², W1(i)2(i) = 3.10 cm², W1(m) = 1.36 cm², W2(m) = 1.65 cm², W1(m)2(m) = 2.98 cm², W1 (im) = 3.35 cm², W1 (im) 2(i) = 4.63 cm², W1 (im)2(m) = 4.06 cm² and W1 (im)2 (im) = 7.16 cm².ConclusionThe AOCMFTC orbital module offers a suitable framework for topographical allocation of fracture patterns inside the infero-medial orbital cavity. The involvement of the subregions is of predictive value providing estimations of the mean 3-D fracture area size.     

Efficacy of tissue engineered bone grafts containing mesenchymal stromal cells for cleft alveolar osteoplasty in a rat model

The development of sufficient tissue engineered bone grafts for alveolar cleft osteoplasty could reduce the necessity of autogenous bone grafts and its donor site morbidity. The aim of the study was to evaluate tissue engineered bone grafts in an artificially created bone defect.Bone grafts were created in vitro colonizing a synthetic hydroxyapatite–tricalciumphosphate scaffold (BONITmatrix^®) with either undifferentiated mesenchymal stromal cells (group 1) or osteogenic differentiated mesenchymal stromal cells (group 2). Cells were multiplied from bone marrow of donor rats. Unmodified scaffolds (group 3) and the tissue engineered bone grafts were inserted into artificial maxillary defects of 54 Lewis rats. In 18 animals the defects remained unfilled (control). After one, three and six weeks the rats were sacrificed. The defect was evaluated radiologically and histologically with regard to the remaining defect volume and diameter. Statistical analysis followed.The bone grafts led to a specific bone formation at the defect margin. No complete reunion of any defect was observed within the healing time. After six weeks, the remaining defect volume was 6.86 ± 3.21 mm³ (control), 4.08 ± 1.36 mm³ (group 1), 5.00 ± 0.84 mm³ (group 2) 5.50 ± 1.05 mm³ (group 3). The remaining defect diameter measured 2.63 ± 0.52 mm (control), 2.39 ± 0.23 mm (group 1), 2.53 ± 0.22 mm (group 2) and 2.70 ± 0.66 mm (group 3). In all experimental groups the defect volume and diameter decreased over time, which was significant for group 1 (p = 0.014), group 2 (p = 0.025) and group 3 (p = 0.048). The defect volume and width was significantly reduced for bone grafts containing undifferentiated cells compared to control (p = 0.035) or scaffolds only (p = 0.05).ConclusionTissue engineered bone grafts induce a pronounced bone formation in artificial bone defects compared to unfilled controls or scaffolds only.     

Virtual surgery simulation in orbital wall reconstruction: Integration of surgical navigation and stereolithographic models

PurposeCorrection of post traumatic orbital and zygomatic deformity is a challenge for maxillofacial surgeons. Integration of different technologies, such as software planning, surgical navigation and stereolithographic models, opens new horizons in terms of the surgeons' ability to tailor reconstruction to individual patients. The purpose of this study was to analyze surgical results, in order to verify the suitability, effectiveness and reproducibility of this new protocol.MethodsEleven patients were included in the study. Inclusion criteria were: unilateral orbital pathology; associated diplopia and enophthalmos or exophthalmos, and zygomatic deformities. Syndromic patients were excluded. Pre-surgical planning was performed with iPlan 3.0 CMF software and we used Vector Vision II (BrainLab, Feldkirchen, Germany) for surgical navigation. We used 1:1 skull stereolithographic models for all the patients. Orbital reconstructions were performed with a titanium orbital mesh. The results refer to: correction of the deformities, exophthalmos, enophthalmos and diplopia; correspondence between reconstruction mesh positioning and preoperative planning mirroring; and the difference between the reconstructed orbital volume and the healthy orbital volume.ResultsCorrespondence between the post-operative reconstruction mesh position and the presurgical virtual planning has an average margin of error of less than 1.3 mm. In terms of en- and exophthalmos corrections, we have always had an adequate clinical outcome with a significant change in the projection of the eyeball. In all cases treated, there was a complete resolution of diplopia. The calculation of orbital volume highlighted that the volume of the reconstructed orbit, in most cases, was equal to the healthy orbital volume, with a positive or negative variation of less than 1 cm³.ConclusionThe proposed protocol incorporates all the latest technologies to plan the virtual reconstruction surgery in detail. The results obtained from our experience are very encouraging and lead us to pursue this path.     

Presentation and short-term evaluation of an all-in-one patient-specific implant for cranial reconstruction: A randomized controlled trial

Cranial reconstruction after bone graft harvesting remains a challenge. A patient-specific implant (PSI) to guide harvesting and reconstruction was evaluated and compared with the use of a free-hand procedure with calcium phosphate cement (C). Patients were randomized to either the PSI or C group. The outcome was measured clinically and radiographically as the primary endpoint. Secondary endpoints were ease of application, patient and surgeon satisfaction, and the complication rate. Twenty patients were randomized to the PSI (n = 10) and C (n = 10) groups. Two PSI patients were switched to the cement group due to a poor fit of the PSI. There was a non-significant trend towards more successful outcomes in the PSI group. Two PSI patients presented palpable screws, and one cement patient had a palpable dimple. Cone beam computed tomography showed a significantly lower median volume discrepancy in the PSI group (P < 0.0001). The total surgical manipulation time was significantly higher in the PSI group. At 10 days postoperative, three PSI and two C patients presented with minor postoperative complications. There was no significant difference in patient or surgeon satisfaction. PSIs are a reliable alternative to cement. This PSI is novel as it also serves as a guide for harvesting the bone blocks required for reconstructive purposes.     

Clinical outcome of patients with orbital fractures treated with patient specific CAD/CAM ceramic implants – A retrospective study

The aim of this study was to determine whether patients benefit from a secondary reconstruction since it carries the risks of no improvement or worsening of their current situation.Patients treated with individual computer-aided-design/computer-aided-manufacturing (CAD/CAM) ceramic implants were reviewed. To ascertain changes throughout the secondary reconstruction, the study investigators reviewed ophthalmological examinations, took volumetric measurements of the orbits and asked the patients for evaluation of their situation before and after the reconstruction. Points addressed were double vision, visual acuity, field of vision, limitations in daily life and aesthetic considerations.A total of 14 patients were reviewed and 11 answered the questionnaire. Ophthalmological examinations showed that the physical integrity of the eye was maintained. Volumetric measurements preopeatively (33.94 ± 3.24 cm³) and postoperatively (30.67 ± 2.07 cm³) showed that a statistically significant overcorrection of orbital volume leads to good functional and aesthetic outcomes. Patients’ subjective opinions were that they greatly benefitted, especially concerning limitations in daily life, which improved by 4.4 ± 2.8 points out of 10 possible points, and aesthetics, with an improvement of 5.9 ± 1.78 points.Based on these findings, we conclude that secondary reconstructions contribute to improvement of the patients’ quality of life and therefore should be considered as an option to improve patients’ condition.     

A new modification of the individually designed polymer implant visible in X-ray for orbital reconstruction

Orbital reconstruction makes higher demands on symmetry and axial precision than other parts of the skull, because the position of the eye globe determines proper vision. The aim of this study is to evaluate titanium surface marking of polymers (UHMW-PE and PA6) to check implants position in CT examination and clinical application of such modified individual implant.One hundred and twenty-four polymer blocks were prepared. New method of ultrasounds welding to connect the titanium markers to the polymer surface was developed and tested. Titanium marked polymer blocks were examined by CT to evaluate the quality of the cover. Then, two modified UHMW-PE individual implants were applied clinically and implant position was checked by CT.The biggest titanium cover was in PA6 [25 ± 18% of processed surface] and for UHMW-PE [19 ± 12%] without significance [p = 0.14]. Both covers were visible in CT. Clinical application revealed proper reconstruction, uneventful post-operational outcome and well visible surface of the implants in CT.The conducted tests make it possible to determine the suitability of ultrasonic technology for the deposition of titanium markers in polymer. The clinical use of modified individual implants allows to confirm the correct position of the implants because they are accurate visible in CT.     

Accuracy of splint vs splintless technique for virtually planned orthognathic surgery: A voxel-based three-dimensional analysis

PurposeThis study compared two transferring methods for virtually planned orthognathic surgery — the CAD/CAM intermediate splint and the customized surgical guide with fixation plates.MethodsThis was a prospective clinical study in which participants were consecutively recruited and underwent bimaxillary orthognathic surgery. They were divided into two groups based on the transferring method used. The pre- and postoperative CBCTs were aligned using voxel-based landmark-free registration, and the discrepancies for selected points were compared with the planned displacement of the virtually planned surgery. The maxilla and mandible were analyzed separately, and translation and rotation movements were considered.ResultsA total of 16 patients, divided into two groups of eight patients each, were included in this study. The splintless group was significantly more accurate for the translation movement along the x-axes for points A (p = 0.008; mean absolute error 0.527 ± 0.387 for the splint group and 0.137 ± 0.067 for the splintless group) and Ans (p = 0.045; mean absolute error 0.535 ± 0.446 for the splint group and 0.156 ± 0.002 for the splintless group). For the mandible there was a significant difference in accuracy along the x-axes for points B (p = 0.049; mean absolute errors 1.728 ± 1.181 and 0.697 ± 0.519 for the splint and splintless groups, respectively), LL3 (p = 0.049; mean absolute error 1.629 ± 0.912 and 0.851 ± 0.797 for the splint and splintless groups, respectively), LR3 (p = 0.049; mean absolute error 1.711 ± 0.906 and 0.844 ± 0.780 for the splint and splintless groups, respectively), with the splintless group being more accurate. For the rotation the splintless group was significantly more accurate along the y-axes (p = 0.04; mean absolute error 1.62 ± 0.78 and 0.49 ± 0.31 for the splint and splintless groups, respectively) and z-axes (p = 0.04; mean absolute error 0.63 ± 0.45 and 0.17 ± 0.05 for the splint and splintless groups, respectively) for the maxilla, while no significant difference was found for the mandible.ConclusionsOverall, the customized fixation plate system is more accurate than the intermediate CAD/CAM splint for transferring the virtual plan into the operation room.     

Evaluation of effectiveness of three-dimensional printed ear splint therapy following ear elevation surgery in microtia patients: A randomized controlled trial

AimThis study aimed to compare the effectiveness of a 3D-printed ear splint with that of a conventional thermoplastic ear splint after microtia reconstruction.MethodsPatients who underwent ear elevation surgery with postauricular fascia coverage between October 2017 and October 2018 were included. They were randomly divided into the experimental group (3D-printed ear splint) and the control group (thermoplastic ear splint) and underwent routine postoperative rehabilitation and antiscar therapy. Splint therapy was initiated 4 weeks postoperatively and continued until 24 weeks postoperatively. The evaluated indices were the Vancouver scar scale score (VSS score), cranioauricular distance, patient compliance, complications (dermatitis, skin ulcers, skin necrosis), and patient satisfaction. A two-group t-test was carried out to compare all variables except patient satisfaction, which was compared using the Mann–Whitney U-test; p < 0.05 was considered significant.ResultsTwenty patients were included in each group. At 4 weeks postoperatively, the VSS score (p = 0.748) and cranioauricular distance (p = 0.647) showed no significant differences between the groups. At 24 weeks postoperatively, the mean VSS scores were 4.85 ± 1.46 and 6.25 ± 1.74 (p = 0.009), the mean cranioauricular distances were 15.80 ± 1.82 mm and 13.95 ± 1.93 mm (p = 0.004), and the patient satisfaction scores were 4.5 ± 0.51 and 3.7 ± 0.47 (p < 0.001) in the experimental group and the control group, respectively, all showing significant differences. Two patients in each group exhibited skin irritation or skin ulcers, which resolved after 6 months of follow-up.ConclusionThe application of 3D-printed ear splints provides better inhibition of scar contracture, better maintenance of ear projection and higher patient satisfaction than conventional ear splints following ear elevation surgery in microtia patients. Therefore, 3D-printed ear splints should be preferred over conventional ear splints whenever possible.     

Preoperative and postoperative assessment of temporal and masseter muscle size with magnetic resonance imaging in patients undergoing unilateral temporomandibular joint surgery

The aim of this study was to assess any change between the preoperative and postoperative sizes of temporal and masseter muscles with magnetic resonance imaging (MRI) in patients undergoing unilateral temporomandibular joint surgery.This study was designed and implemented retrospectively. For clinical evaluation, a visual analog scale (VAS) and maximum mouth opening (MMO) were used. In order to make a preoperative diagnosis and perform a 6-month control, muscle size was measured in millimeters (mm) on T1 axial sections in MRI. Statistical analyses were performed using the SPSS 23.0 software package. Numeric variables were compared between two dependent groups using the Wilcoxon signed rank test. Statistical significance was set at p < 0.05.Twelve patients who underwent unilateral discectomy plus dermis-fat grafting, with classical preauricular inverse L incision, were included in the study, and data for eleven female patients were evaluated. The difference in size between the operated and non-operated sides was found to be statistically insignificant at the preoperative stage for both masseter muscle (operated side m^M: 13.264 ± 1.822 mm; non-operated side m^M: 13.264 ± 2.315 mm; p^M = 0.929) and temporal muscle (operated side m^T: 20.345 ± 2.609 mm; non-operated side m^T: 20.582 ± 2.366 mm; p^T = 0.594). There was a significant size reduction in the masseter muscle on the operated side in the postoperative period (preop m^M: 13.264 ± 1.822 mm; postop m^M: 12.036 ± 1.728 mm; p^M = 0.018). Although there was also a size reduction in the operated side of the temporal muscle in the postoperative period, that difference did not reach statistical significance (preop m^T: 20.345 ± 2.609 mm; postop m^T: 19.445 ± 1.603 mm; p^T = 0.182). On the non-operated side, there were no significant postoperative changes in the sizes of either the masseter muscle (preop m^M: 13.264 ± 2.315 mm; postop m^M: 12.682 ± 2.059 mm; p^M = 0.248) or the temporal muscle (preop m^T: 20.582 ± 2.366; postop m^T: 19.891 ± 3.487 mm; p^T = 0.625).Considering the study findings as a whole, a size reduction was observed in the operated side of the masseter muscle after TMJ surgery. The etiology of this change may be surgical trauma to the temporal and masseter muscles, skeletal alteration resulting from condylar change secondary to discectomy, and patients restraining themselves from application of maximum bite force as a result of a self-protection mechanism due to postoperative pain.