Intraoperative cone beam computed tomography in the management of facial fractures

Intraoperative Computed Tomography Use in Orbital Fracture Repair: A Systematic Review and Meta-Analysis

Background: Intraoperative computed tomography (CT) allows surgeons to make adjustments during orbital fracture repair that may impact postoperative outcomes. Learning/Study Objectives: To determine the impact of intraoperative CT use on intraoperative revision and surgical outcomes for orbital fracture repair. Methods: A systematic review was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines: the population was patients undergoing orbital fracture repair; intervention was use of intraoperative CT; comparison was patients not undergoing intraoperative CT; and outcomes were intraoperative revision rate, postoperative complications, and secondary revision surgeries. Meta-analysis was performed on the rate of intraoperative revision. Results: The search criteria yielded 790 articles, 377 were eligible for review, and 20 articles met criteria for analysis. In 19, intraoperative imaging led to immediate surgical corrections, with a random pooled effect size of 0.27 (0.20-0.35). Six studies reported secondary revision surgery rates (range 0-10.5%), and six studies reported postoperative complication rates (range 10-30%). Conclusions: Intraoperative imaging helps surgeons make precise, real-time adjustments in 27% of orbital fracture repair cases, which may improve surgical outcomes; however, more research is needed to investigate its impact on health care costs, operating time, and radiation exposure.

The Value of Intraoperative Computed Tomography in the Treatment of Zygomatic Complex Fractures

BACKGROUND

Due to the complex anatomical morphology and lack of anatomic markers on the surface of zygomatic complex (ZMC), the treatment results of ZMC fractures are often suboptimal.

PURPOSE

The study aimed to evaluate the effectiveness of intraoperative computed tomography (ICT) in the treatment of unilateral ZMC fractures, and further study the feasibility of ICT to replace early postoperative Computed Tomography (CT).

STUDY DESIGN, SETTING, AND SAMPLE

The investigators designed a retrospective cohort study. Adult patients who underwent surgery with unilateral ZMC fractures were enrolled.

PREDICTOR VARIABLE

According to whether intraoperative CT was used, the subjects were divided into the ICT group and the control group (without ICT).

MAIN OUTCOME VARIABLES

Five distances and 3 angles representing bilateral ZMC symmetry were main outcome variables. The differences of outcome variables were compared between the 2 groups and the indices of ICT group were further compared with their postoperative indices.

COVARIATES

Demographics (eg age), etiology (eg traffic injury), dysfunction (eg diplopia), and surgical approach (eg vestibular incision) were collected as covariates while we conducted clinical investigation, examination, and implementation.

ANALYSES

The data were analyzed using independent-samples t test, paired-samples t test, Mann-Whitney U test, and χ2 test. P value < .05 was considered statistically significant.

RESULTS

A total of 60 patients (18 to 59 years) were enrolled in this study. All median values of the measurements in the ICT group were smaller than those in the control group, and the differences of horizontal displacement distance (0.56 vs 1.02 mm), anteroposterior displacement distance (1.69 vs 2.34 mm, 0.90 vs 2.35 mm), horizontal angle of bilateral zygomatic arch (2.31 vs 4.19°), and horizontal angle of bilateral zygomatic process (1.77 vs 2.94°) were significantly different between the 2 groups with P value < .05. Moreover, there was no statistically significant difference in all indices between the intraoperatively and postoperatively injured sides in the ICT group.

CONCLUSIONS

ICT can improve the treatment outcomes of ZMC fractures by evaluating the fracture reduction adequacy during surgery. Moreover, ICT can replace early postoperative CT.

Cost-effective 3D scanning and printing technologies for outer ear reconstruction: current status

Current 3D scanning and printing technologies offer not only state-of-the-art developments in the field of medical imaging and bio-engineering, but also cost and time effective solutions for surgical reconstruction procedures. Besides tissue engineering, where living cells are used, bio-compatible polymers or synthetic resin can be applied. The combination of 3D handheld scanning devices or volumetric imaging, (open-source) image processing packages, and 3D printers form a complete workflow chain that is capable of effective rapid prototyping of outer ear replicas. This paper reviews current possibilities and latest use cases for 3D-scanning, data processing and printing of outer ear replicas with a focus on low-cost solutions for rehabilitation engineering.

Insight in to the Awareness of CBCT as an Imaging Modality in the Diagnosis and Management of ENT Disorders: A Cross Sectional Study

The advent of Cone-beam computed tomography (CBCT), has revolutionized 3D imaging in dentistry. CBCT has enormous potential to be used as an alternative imaging modality by Otolaryngologists. But their knowledge regarding CBCT is limited. The study aims to evaluate the awareness of CBCT as an imaging modality among Ear, nose and Throat (ENT) practitioners. The validated questionnaire was sent by email and the participants were asked to fill the google form through the link provided to record the responses. The participants were asked to answer 25 multiple choice questions regarding the general information and practice related to CBCT imaging. Data was evaluated according to the descriptive statistics and the Chi-square test was used to determine the test of significance. The response rate for this study was 84.4%. The mean age of the participants was 44.9 ± 11.3. 69% of the respondents were academicians,14.2% had exclusive clinical practice, and 16.8% had both clinical and academic exposure. Among the study population, 76.8% had never advised CBCT in their practice. Only 10.3% of the study participants were aware of the potential of CBCT in ENT disorders. The mean knowledge, attitude and practice scores were very low regarding the applications of CBCT. Most of the study participants advised CBCT for maxillofacial fractures (78.1%) and was statistically significant p < 0.05. The knowledge about various advantages and clinical applications of CBCT among Otolaryngologists is limited. However, continuing medical education and inclusion in the medical curriculum will increase the scope and awareness about CBCT among ENT fraternity.

Controversies and Contemporary Management of Orbital Floor Fractures

Substantial controversy exists regarding the timing of intervention and management of patients with orbital floor fractures. Recent advances in computer-aided technology, including the use of 3-dimensional printing, intraoperative navigational imaging, and the use of novel implants, have allowed for improvement in prospective management modalities. As such, this article aims to review the indications and timing of repair, surgical approaches, materials used for repair, and contemporary adjuncts to repair. Indications for orbital floor fracture repair remain controversial as many of these fractures heal without intervention or adverse sequelae. Intraoperative navigation and imaging, as well as endoscopic guidance, can improve visualization of defects mitigating implant positioning errors, thereby reducing the need for secondary corrective procedures. Patient-specific implants may be constructed to fit the individual patient's anatomy using the preoperative CT dataset and mirroring the contralateral unaffected side and have been shown to improve pre-operative efficiency and minimize postoperative complications. With increased data, we can hope to form evidence-based indications for using particular biomaterials and the criteria for orbital defect characteristics, which may be best addressed by a specific surgical approach.

Secondary Correction of Posttraumatic Enophthalmos

Posttraumatic enophthalmos (PE) arises when the ocular globe is displaced posteriorly and inferiorly in the orbital cavity due to a mismatch in orbital volume and orbital content. This most commonly happens after orbital fractures. The resulting disruptions to aesthetic form and ocular functions often necessitate surgical correction for reconstruction and restoration. The purpose of surgical management of PE is to reconstruct orbital shape and volume as well as to restore any herniated orbital content. This can be particularly challenging in cases involving large defects that require complex orbital reconstruction. Recent advancements in computer-aided surgery have introduced innovative and important tools to assist surgeons with these difficult cases. The ability to create customized, patient-specific implants can facilitate reconstruction involving complicated anatomy. Additionally, intraoperative imaging and intraoperative navigation can serve as useful guides for surgeons to more accurately place implants, especially in cases with limited visualization, in order to achieve optimal outcomes.

Intraoperative Computed Tomography Image Fusion for Orbital Blowout Fracture Reconstruction

Intraoperative computed tomography (CT) has been previously described and acknowledged for its use in orbital blowout fracture reconstructions. We described a clinical case series managed by this technique combined with intraoperative image fusion for accuracy in orbital implant position. In total, eight patients who sustained a total number of 19 orbital wall fractures were described. From the total number of 19 blowout orbital fracture reconstructions comprised of medial and inferior (floor) orbital fractures, malposition was identified in a total of four orbital implants by using image fusion. All cases of implant malposition were immediately revised intraoperatively. Subsequent fusion was carried out to confirm whether the revision was satisfactorily achieved. We found that the intraoperative image fusion technique utilised to determine orbital implant position, especially at the posterior ledge, further augmented the role of intraoperative CT scanning. Image fusion conceptually provides an immediate, real-time, and objective solution for intraoperative image analysis and potentially eliminates problems with misaligned CT images. It also reduces the need for the surgeon to ‘eye-ball’ the CT images acquired or the need for additional intraoperative time, since the patient’s head orientation is always axially at random during the acquisition of the CT. Conventional methods for CT image assessment are subjected to one’s own interpretation and may introduce inconsistent or longer intraoperative decision-making. The technique facilitates intraoperative decision-making and reduces the risk of orbital implant malposition in orbital blowout fracture reconstructions. Hence, surgical complication in relation to orbital implant malposition in orbital blowout fracture management could be minimised. In addition, no further postoperative imaging is required.

Impact of intraoperative cone beam computed tomography in the management of zygomatic fractures

AIM

To evaluate the impact of intraoperative cone beam computed tomography (CBCT) assessment for the surgical management of zygomatic bone fracture (ZF).

METHODS

A prospective study was conducted on patients operated on for unilateral ZF during a two-year period. Repositioning of the fractured zygoma was assessed intraoperatively by measuring the position of malar eminences in three dimensions on CBCT. A difference of more than 2 mm between both sides was considered significant and the reduction was judged inadequate. Surgical procedure was adapted to intraoperative imaging findings.

RESULTS

The surgical procedures of 47 patients treated for ZF were analyzed. In 15% of the cases (7 patients), the intraoperative CBCT showed an inadequate reduction while the morphological results seemed correct. Those patients benefited from an immediate correction of the reduction. From these 7 patients, reduction was optimized further without the need of osteosynthesis in one case, additional osteosynthesis was performed in 4 cases and 2 patients required both reduction and osteosynthesis revision.

CONCLUSION

Intraoperative CBCT control helps to achieve anatomic repositioning in case of ZF. It may reduce the risk of under-treatment and possible reoperation, and of over-treatment meaning systematic ORIF in all fractures.

Does Intraoperative Computed Tomography Scanning in Maxillofacial Trauma Surgery Affect the Revision Rate?

PURPOSE

The purpose of this study was to determine how intraoperative computed tomography affects the intraoperative revision rate and consequently the post-operative, secondary corrective surgery in maxillofacial trauma surgeries.

PATIENTS AND METHODS

A retrospective study composed of patients with facial fractures was conducted in Prince Sultan Military Medical City in Riyadh, Saudi Arabia. The predictor variables were age, gender, site of facial fracture, type of treatment, number of scans per patient, and discharge time. The primary outcome variable was immediate intraoperative revision rate. Secondary outcome variable was total scanning time (recorded from the moment surgery was halted until it was resumed after image acquisition). Descriptive statistics were used; numerical data presented as mean ± SD and categorical variables as frequency (%).

RESULTS

A total of 22 patients underwent 25 intraoperative scans while undergoing different maxillofacial surgeries. Eleven (50%) required intraoperative revisions after the scans, and 3 (13.6%) cases had another intraoperative scan after revision. Eighteen were men and 4 were women. The mean age was 30 years and age range was 19 to 76. Cases were categorized by fracture location and treatment preformed. The mean scanning time was 18.9 ± 4.6 minutes. The highest rate of revisions was seen in zygomaticomaxillary complex fractures (63.6%), they were also the only cases that required a second intraoperative scan after revision to confirm final reduction. No complications were seen postoperatively, and all patients recovered uneventfully. None of the patients required a secondary corrective surgery. All patients were discharged on the following day, except 1 case which was admitted under another service.

CONCLUSIONS

The use of intraoperative computed tomography imaging in treating maxillofacial fractures results in a higher rate of intraoperative revisions, which in turn leads to more accurate fracture reduction and consequently reduces the possibility of a postoperative, secondary corrective surgery.

Clinical outcome following intraoperative computed tomography-assisted secondary orbital reconstruction

BACKGROUND

Secondary post-traumatic orbital reconstructions are challenging. Portable computed tomography (CT) provides the option to acquire real-time, intraoperative images that help to detect the insufficient reconstruction of the orbit immediately. We retrospectively analyzed patients who received intraoperative CT imaging and analyzed the effect of intraoperative CT scans on revision rates and orbital volume changes before, during, and after surgery.

METHODS

From August 2014 to September 2016, eleven patients received intraoperative cone-beam CT scans to evaluate the results of secondary orbit reconstruction using Medpor + titanium implants. Patient demographics, surgical details, CT scanning protocol, and follow-up results were analyzed. 3D CT volumetry was used to analyze the orbital volume based on OsiriX MD software.

RESULTS

Based on intraoperative CT findings, seven cases required intraoperative revision to further augment the orbital cavity or adjust implants. The mean preoperative measured enophthalmos was 3.41±1.4 mm (range: 2-6 mm), which decreased to 0.73±0.4 mm (range: 0-1 mm) at postop assessment (p<0.0001). On the fracture side, there was a significant difference between preoperative vs. intraoperative and preoperative vs. postoperative volume measurements (p<0.01 for both subsets), but no significant difference between intraoperative vs. postoperative measurements.

CONCLUSION

Intraoperative CT is a valuable tool in secondary orbital reconstruction cases based on clinical enophthalmos evaluation and 3D CT volumetry. For these patients, the avoidance of another revision surgery may outweigh the disadvantage of increased operation time and additional radiation exposure.

Diagnostic performance of mobile cone beam computed tomography versus conventional multi-detector computed tomography in orbital floor fractures: a study on human specimens

The aim of this study was to evaluate the diagnostic accuracy of mobile cone beam computed tomography (MCBCT) versus multi-detector computed tomography (MDCT) in orbital floor fractures. Twenty-four fresh cadaver heads were used, and one orbital floor was fractured for each head by transconjunctival approach. MDCT and MCBCT were performed on each of the heads. The images obtained were then analysed independently by eight evaluators. The radiological characteristics of the orbital floor fractures were visualized with good interpretation agreement between the two images. The location of the fracture and enophthalmos were identified in a comparable manner with strong agreement (κ=0.93 and κ=0.85, respectively). Measurements of fatty hernias and bone defects showed a strong correlation between the two imaging modalities (Pearson coefficient between 0.64 and 0.71 and between 0.67 and 0.71, respectively). The fracture limits and the presence of bone fragments, an intrasinus fatty hernia, and a fracture of the associated medial orbital wall were visualized in both examinations with good agreement (κ=0.68, κ=0.51, κ=0.57, and κ=0.46, respectively). The soft tissue study showed superiority for MDCT, with a κ<0.0009. MCBCT showed good diagnostic performance in the study of orbital floor fracture characteristics.

Low-Dose Computed Tomographic Scans for Postoperative Evaluation of Craniomaxillofacial Fractures: A Pilot Clinical Study

Computed tomographic scans are frequently obtained following craniomaxillofacial fracture reconstruction. The additive radiation from such scans is not trivial; cumulative radiation exposure poses stochastic health risks. In this article, the authors postulate that a low-dose computed tomography protocol provides adequate image quality for postoperative evaluation of reconstructed craniomaxillofacial fractures. This study included patients for whom a computed tomographic scan was indicated following craniomaxillofacial fracture repair at a Level I trauma center. Postoperative craniomaxillofacial computed tomography was performed using a low-dose protocol, rather than standard protocols. A craniomaxillofacial surgeon and a radiologist interpreted the images to determine whether they were of sufficient quality. It was decided a priori that any inadequate low-dose computed tomography would require repeated scanning using standard protocols. The primary endpoint was the need for repeated computed tomography. In addition, the clarity of clinically significant anatomical landmarks on the images was graded on a five-point Likert scale. Twenty patients were scanned postoperatively using the low-dose protocol. Mean radiation dose (total dose-length product) from the low-dose protocol was 71 mGy · cm versus 532 mGy · cm for the preoperative computed tomographic scans that were obtained using conventional protocols (p < 0.001). All 20 low-dose computed tomographic scans were determined to provide satisfactory image quality. No patients required repeated computed tomography secondary to poor image quality. Low-dose computed tomography received high image-quality scores. A low-dose computed tomography protocol that delivers approximately 7.5-fold less radiation than the standard protocols was found to be adequate for postoperative evaluation of craniomaxillofacial fractures. Larger prospective studies may be warranted. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Does Intraoperative Computed Tomography Improve the Outcome in Zygomatico-Orbital Complex Fracture Reduction?

Purpose

Zygomatico-orbital (ZMO) fractures pose considerable difficulty in intraoperative assessment during open reduction and internal fixation (ORIF), and this can be attributed to its three-dimensional complex anatomy and articulations. Recent advancements in the form of intraoperative imaging and navigation have led to an adequate assessment and correct reduction of these fractures minimizing chances of any revision surgery. The purpose of this study was to evaluate the advantage of intraoperative computerized tomography (CT) scan in the management of ZMO/isolated orbital complex fracture and further to develop a protocol for managing such fractures.

Methods

Twenty-three cases of ZMO/isolated orbital fractures were managed with ORIF, followed by an intraoperative CT scan. The evaluation was focused on the articulations of the zygoma and orbital wall reconstruction. The score of 0 and 1 was given for inadequate and adequate reduction, respectively. Necessary corrections were performed in case of improper reduction followed by a repeat CT scan if required. The reduction score was statistically correlated with number of incisions.

Results

In 8 (35%) out of 23 patients, clinical judgment was inaccurate when radiologically assessed with an intraoperative CT scan. In 6 out of 8 cases, a repeat CT scan was done after revision of reduction. The reduction score improved with additional incision and revision in the second CT scan.

Conclusion

Intraoperative CT has an important role in assessing the accuracy of reduction and confirming implant position in ZMO/isolated orbital fractures. This can avoid the need for secondary corrective surgery and postoperative imaging. Intraoperative CT is an important tool to improve surgical outcomes in the management of ZMO orbital fractures.

Intraoperative Navigation and Cone Beam Computed Tomography for Restoring Orbital Dimensions: A Single-Center Experience

Background

Correction of post-traumatic orbital defects remains a challenge for the maxillofacial surgeon. We examined the added value of combined intraoperative (IO) navigation and IO cone beam computed tomography (CBCT).

Materials and Methods

A retrospective cohort study was performed in all consecutive patients requiring unilateral post-traumatic orbital surgery between January 2012 and December 2018. Patients were divided into 3 groups: IO navigation (NAV), IO-CBCT (CBCT), and IO navigation with IO-CBCT (NAV-CBCT). A detailed description of our workflow is provided. Volumetric comparison of the operated orbit to the contralateral orbit was made with Brainlab.

Results

Of the 81 cases, 22 patients were included (12 males/10 females) with a mean age of 51 years. Three patients were assigned to NAV, 6 to CBCT, and 13 to NAV-CBCT. The reconstructed orbital volume did not significantly differ from the contralateral orbital volume within the 3 groups. The mean difference between the contralateral and the operated orbit was 3.05 cm³, 3.72 cm³, and 1.47 cm³ for NAV, CBCT, and NAV-CBCT, respectively, where only NAV-CBCT showed a significant smaller volumetric difference in comparison to CBCT alone. Gender or age did not correlate with difference in orbital volume. Normal function and aesthetics was seen at 6 weeks postoperative in 0 of 3, 6of 6, and 6 of 13 patients of the NAV, CBCT, and NAV-CBCT, respectively.

Conclusion

Orbital defects can be treated effectively using IO navigation. Although our data could not demonstrate a significant added value of IO-CBCT in cases where IO navigation was used based on volumetric difference alone, the combination of IO-CBCT and IO navigation seems to give the best results considering both volumetric difference and postoperative function and aesthetics. Confirmation in a prospective, randomized trial with a larger sample size is required.

Intraoperative imaging and navigation with mobile cone-beam CT in maxillofacial surgery

INTRODUCTION

Intraoperative mobile Cone-Beam Computed Tomography (CBCT) trends to develop for the management of complex facial fractures. It allows a real-time imaging and surgical navigation.

AIM

Through the presentation of two clinical cases, we aimed at presenting the procedure of intra-operative CBCT and new applications in maxillofacial surgery.

RESULTS

A young patient with extended orbito-frontal fibrous dysplasia, and a child with the recurrence of a temporomandibular joint ankylosis secondary to mastoïditis, were operated using a intra-operative imaging control. In both cases, the intraoperative CBCT increased precision and safety of the bone resection. No surgical complication was noted and a good healing was obtained.

CONCLUSION

Intraoperative CBCT raises the problems of radiation exposure and increased operating time. However, it represents a useful imaging tool and a navigation system in complex situations as osseous dysplasia and surgery of the temporo-mandibular joint.

Intraoperative Computed Tomography Scan for Orbital Fracture Reconstruction

Orbital fractures pose specific challenge in its surgical management. One of the greatest challenges is to obtain satisfactory reconstruction by correct positioning of orbital implant. Intraoperative computed tomography (CT) scan may facilitate this procedure. The aim of this study was to describe the early use of intraoperative CT in orbital fractures repair in our center. The authors assessed the revision types and rates that have occurred with this technique. With the use of pre-surgical planning, optical intraoperative navigation, and intraoperative CT, the impact of intraoperative CT on the management of 5 cases involving a total number of 14 orbital wall fractures were described. There were 6 pure orbital blowout wall fractures reconstructed, involving both medial and inferior wall of the orbit fracturing the transition zone and 8 impure orbital wall fractures in orbitozygomaticomaxillary complex fracture. 4 patients underwent primary and 1 had delayed orbital reconstruction. Intraoperative CT resulted in intraoperative orbital implant revision, following final navigation planning position, in 40% (2/5) of patients or 14% (2/14) of the fractures. In revised cases, both implant repositioning was conducted at posterior ledge of orbit. Intraoperative CT confirmed true to original reconstruction of medial wall, inferior wall and transition zone of the orbit. Two selected cases were illustrated. In conclusion, intraoperative CT allows real-time assessment of fracture reduction and immediate orbital implant revision, especially at posterior ledge. As a result, no postoperative imaging was indicated in any of the patients. Long-term follow-ups for orbital fracture patients managed with intraoperative CT is suggested.

Dose reduction in CT imaging for facial bone trauma in adults: A narrative literature review

Trauma to the facial area accounts for a significant number of admissions to the emergency department. Diagnostic imaging is almost always required, and is critical in determining patient management. Multi‐detector computed tomography (MDCT) appears consistently in the literature as the gold‐standard imaging modality for facial bones, but results in a high radiation dose to the patient. This makes the application and advancement of dose reduction and dose optimisation methods vital. This narrative review presents a critical analysis of the literature concerning diagnostic imaging of facial bone trauma, with an emphasis on dose reduction methods for MDCT. Databases including Pubmed, Medline, Web of Science and Scopus were used to investigate this topic, with the key words: facial bone trauma, computed tomography (CT) imaging and dose reduction. Exclusion criteria included studies on nasal bone fracturing, dental imaging, elective surgeries and paediatric imaging. The literature shows overwhelming support for MDCT, given its accuracy, efficiency and ease of operation. Noise reducing reconstruction algorithms show promise as a successful method of dose reduction in facial bone imaging. Investigations of more innovative techniques also appear within the literature, including diagnostic cone‐beam CT (CBCT), intraoperative CBCT and dual‐source CT (DSCT), but further research is required to confirm their clinical value.

Indications of cone beam CT in head and neck imaging in children

For imaging of bony structures, especially for the anterior and lateral skull base in ORL medicine, cone beam computed tomography (CBCT) is an increasingly used alternative to CT, with a lower exposition to plain radiography that makes its use for imaging, particularly in children, very interesting. The aim of this study was to analyse possible indications and settings for CBCT in children and compare them to those of adults. A total of 554 patients (age range 0-18 years, mean age 10.36 years), who underwent CBCT between 01/2004-06/2013 in the ENT department at the university clinic of Marburg were enrolled in this retrospective analysis to evaluate technical parameters and indications. Data on CBCT of all children were compared with previously published data collected from 1730 adults who were diagnosed with the help of CBCT in the ENT department at the university clinic of Marburg, during the years 2012-2013. The most frequent indications of CBCT in children vs. adults were in the anterior skull base region: mid-facial trauma (60.4%) vs. chronic rhinosinusitis (54.8%), disturbed nasal breathing (13.9% vs. 13.0%) and chronic rhinosinusitis (12%) vs. mid-facial trauma (10.8%). For the lateral skull base the main indications were cholesteatoma (20.3%) vs. position control of cochlear implant (CI) electrode (31.2%), chronic otorrhoea (17.5%) vs. cholesteatoma (20.9%), and position control of CI electrode (11.8%) vs. chronic otitis media mesotympanalis (6.8%). CBCT is a suitable imaging modality for bony structures in adults and children. Settings mainly depend on the region of interest. One aim should also be to reduce exposure to radiation in both adults and children.

Coincidence of mandibular fractures with isolated posterior maxillary sinus fractures

BACKGROUND/AIM

There are no data available to show whether there is a relationship between mandibular fractures and isolated fractures of the posterior and/or lateral walls of the maxillary sinus. The aim of this study was to determine whether there is a coincidence between these fracture patterns.

METHODS

Four hundred large volume cone beam computed tomography scans (CBCT) of patients with a fracture of the mandible between 2008 and 2013 were analyzed retrospectively. Patients with multiple midfacial fractures were excluded. The radiographic findings were correlated with epidemiological and clinical data of the patients such as gender, age, treatment methods, or complications.

RESULTS

The most frequent fracture sites of the mandible were the jaw angle, the parasymphysis region, and the condyle. Nineteen of the 400 patients (4.75%) had an isolated fracture of the lateral and/or posterior maxillary sinus. Odds-ratio analysis revealed a high tendency for significant correlation of condylar process fractures with isolated maxillary sinus fractures. Chi-square test demonstrated a P-value near statistical significance (P=.054). No other fracture site of the mandible could be associated with an isolated fracture of the maxillary sinus.

CONCLUSION

A condylar process fracture of the mandible after trauma without any further injury of the midface may be associated with an isolated fracture of the lateral and/or posterior maxillary sinus.

Imaging modalities for midfacial fractures

The middle third of the facial skeleton is one of the most complex areas of the human body. A critical factor determining the successful treatment of midfacial fractures is an early and correct diagnosis. Assessment and management of the traumatized patient requires rapid evaluation and decision making. Imaging for the evaluation of patients with midfacial fractures has contributed to achieving an accurate diagnosis and a subsequent successful management. It requires a knowledge of those imaging modalities and projections that provide the most information with the least exposure of radiation to the patient. Conventional radiography has been used successfully for many years although advanced imaging methods such as—three-dimensional computed tomography, magnetic resonance imaging, and cone beam computed tomography have been applied more recently. In this article, we will take a relook at various modalities to image midfacial fractures, and discuss the rationale for selection of those procedures that offer the greatest diagnostic information.

Orbital reconstruction

PURPOSE OF REVIEW

Post-traumatic orbital reconstruction is a complex issue that involves both the soft tissue and bony injury. The current literature focuses primarily on bony reconstruction, with fewer investigators evaluating soft-tissue injuries. This article will review recent advances in orbital reconstruction, including presurgical planning software, intra-operative navigation, patient-specific implants, and intra-operative imaging.

RECENT FINDINGS

Traditional techniques for diagnosis and orbital injuries continue to be refined; however, advances in computer-aided surgery are allowing surgeons to significantly improve the anatomic accuracy of orbital reconstruction.

SUMMARY

While not all surgeons currently have access to computer-aided applications for orbital reconstruction, these techniques will continue to be refined, resulting in lower cost and greater access.

Virtual Surgical Planning for Orbital Reconstruction

The advent of computer-assisted technology has revolutionized planning for complex craniofacial operations, including orbital reconstruction. Orbital reconstruction is ideally suited for virtual planning, as it allows the surgeon to assess the bony anatomy and critical neurovascular structures within the orbit, and plan osteotomies, fracture reductions, and orbital implant placement with efficiency and predictability. In this article, we review the use of virtual surgical planning for orbital decompression, posttraumatic midface reconstruction, reconstruction of a two-wall orbital defect, and reconstruction of a large orbital floor defect with a custom implant. The surgeon managing orbital pathology and posttraumatic orbital deformities can benefit immensely from utilizing virtual planning for various types of orbital pathology.

A case series of rapid prototyping and intraoperative imaging in orbital reconstruction

In Christchurch Hospital, rapid prototyping (RP) and intraoperative imaging are the standard of care in orbital trauma and has been used since February 2013. RP allows the fabrication of an anatomical model to visualize complex anatomical structures which is dimensionally accurate and cost effective. This assists diagnosis, planning, and preoperative implant adaptation for orbital reconstruction. Intraoperative imaging involves a computed tomography scan during surgery to evaluate surgical implants and restored anatomy and allows the clinician to correct errors in implant positioning that may occur during the same procedure. This article aims to demonstrate the potential clinical and cost saving benefits when both these technologies are used in orbital reconstruction which minimize the need for revision surgery.

A Diagnosis of Maxillary Sinus Fracture with Cone-Beam CT: Case Report and Literature Review

The purpose of this article is to present the case of maxillofacial trauma patient with maxillary sinus fracture diagnosed with cone-beam computed tomography (CBCT) and to explore the applications of this technique in evaluating the maxillofacial region. A 23-year-old male patient attempted to our clinic who had an injury at midface with complaints of swelling, numbness. The patient was examined before in emergency center but any diagnosis was made about the maxillofacial trauma. The patient re-examined clinically and radiographically. A fracture on the frontal wall of maxillary sinus is determined with the aid of CBCT. The patient consulted with the department of maxillofacial surgery and it is decided that any surgical treatment was not necessary. The emerging technique CBCT would not be the primary choice of imaging maxillofacial trauma. Nevertheless, when advantages considered this imaging procedure could be the modality of choice according to the case.

Cone beam CT: a current overview of devices

The purpose of this study was to review and compare the properties of all the available cone beam CT (CBCT) devices offered on the market, while focusing especially on Europe. In this study, we included all the different commonly used CBCT devices currently available on the European market. Information about the properties of each device was obtained from the manufacturers' official available data, which was later confirmed by their representatives in cases where it was necessary. The main features of a total of 47 CBCT devices that are currently marketed by 20 companies were presented, compared and discussed in this study. All these CBCT devices differ in specific properties according to the companies that produce them. The summarized technical data from a large number of CBCT devices currently on the market offer a wide range of imaging possibilities in the oral and maxillofacial region.

Intraoperative Cone-Beam Computed Tomography and Multi-Slice Computed Tomography in Temporal Bone Imaging for Surgical Treatment

Objective

Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens.

Study Design

Cross-sectional study.

Setting

University tertiary care facility.

Subjects and Methods

Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures.

Results

CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus.

Conclusion

CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.