Influence of the volume of soft tissue herniation on clinical symptoms of patients with orbital floor fractures

Isolated traumatic orbital floor fracture: An analysis of the National Trauma Data Bank

Objectives

To date, no study provides a comprehensive analysis of traumatic orbital floor fractures across the United States. We aimed to characterize patient demographics, injury-related variables, and operative management in this population.

Method

The National Trauma Data Bank was queried for open or closed orbital floor fractures from 2008 to 2016. Clinical data were extracted.

Results

Overall, 148,592 orbital floor fractures were identified, with 142,577 (95.9%) closed- and 6158 (4.1%) open-type fractures. A total of 106,243 (71.5%) patients were male and the median patient age was 41 years. The majority of patients (79.2%) had abbreviated injury scale scores of ≤2, indicating minor/moderate injury. Fracture mechanism of injury (MOI) differed by gender, with the most frequent being unarmed fights in men (34.3%) and falls in women (14.0%). There were 29,600 patients (19.9%) with isolated orbital floor (I-OF) fractures. The MOI most strongly associated with operative intervention of with I-OF fractures were penetrating injuries caused by a firearm (odds ratio [OR]: 2.91; 95% confidence interval [CI]: 1.62-5.20) and cuttings/piercings (OR: 2.17; 95% CI: 1.29-3.65).

Conclusion

This large epidemiological study reveals that orbital floor fractures tend to present with minor or moderate injuries and are more likely to require operative intervention in setting of firearm or cut/pierce injuries.

Quantitative analysis of diplopia following orbital fracture repair

Orbital fractures can result in devastating functional complications to sight and well-being, yet our understanding of functional sequelae post reconstruction is not well understood in the literature. This research retrospectively analysed the activity of a specialist orbital surgeon over five years to evaluate the incidence of, and risk factors for, debilitating complications such as diplopia and restriction of extraocular movement. Orbital fracture cases repaired between 1 January 2015 and 31 December 2019 were retrospectively analysed. Demographics, orthoptic assessment, injury classification, timing, operative details, outcomes, and complications were recorded. Preoperative and postoperative binocular single vision scores (BSV) were recorded to calculate the effect of orbital repair on residual diplopia. Of 582 patients undergoing orbital access, 472 cases of orbital wall reconstruction satisfied the inclusion criteria, of which 162 (34%) were Jaquiéry 4 or 5. Overall, 10.6% had complications, 4.9% had diplopia, and 5.7% were returned to theatre. All those with residual diplopia had had it preoperatively, and had evidence of an improvement in BSV score. Time to surgery, material, and pure orbital fractures had a significant impact on the incidence of diplopia. Defect size did not. Whilst complication rates were low we conclude that strict adherence to a defined surgical protocol, postoperative imaging, and objective assessment of postoperative function are central to maintaining these standards. Objective orthoptic analysis of patients before and after orbital repair is critical to our understanding of this pathology. Whilst preoperative prediction of the persistence of long-term diplopia currently eludes us, further research should target it.

Prospective Evaluation of Intraorbital Soft Tissue Atrophy after Posttraumatic Bone Reconstruction: A Risk Factor for Enophthalmos

Orbital fractures are a common finding in facial trauma, and serious complications may arise when orbital reconstruction is not performed properly. The virtual planning can be used to print stereolithographic models or to manufacture patient-specific titanium orbital implants (PSIs) through the process of selective laser melting. This method is currently considered the most accurate technique for orbital reconstruction. Even with the most accurate techniques of bone reconstruction, there are still situations where enophthalmos is present postoperatively, and it may be produced by intraorbital soft tissue atrophy. The aim of this paper was to evaluate the orbital soft tissue after posttraumatic reconstruction of the orbital walls’ fractures. Ten patients diagnosed and treated for unilateral orbital fractures were included in this prospective study. A postoperative CT scan of the head region with thin slices (0.6 mm) and soft and bone tissue windows was performed after at least 6 months. After data processing, the STL files were exported, and the bony volume, intraorbital fat tissue volume, and the muscular tissue volume were measured. The volumes of the reconstructed orbit tissues were compared with the volumes of the healthy orbit tissues for each patient. Our findings conclude that a higher or a lower grade of fat and muscular tissue loss is present in all cases of reconstructed orbital fractures. This can stand as a guide for primary or secondary soft tissue augmentation in orbital reconstruction.

Is Surgery Needed for Diplopia after Blowout Fractures? A Clarified Algorithm to Assist Decision-making

Diplopia is a common symptom after blowout fractures, with an incidence of 43.6%–83%. Although there is some consensus toward surgical correction, diplopia is not always resolved by surgery. Thus, there is a clinical dilemma for surgeons with regard to performing surgery at a specific time. This review aimed to create an algorithm to support accurate and effective decision-making.

Anatomical and volumetric analysis of fibro-osseous lesions of the craniofacial skeleton

PURPOSE

Our study aimed to provide volumetric data relating to fibro-osseous lesions of the craniofacial skeleton, in order to highlight risk factors due to the different entities, and to guide clinical decisions for jeopardized patients.

METHODS

Volumetric measurements of osteomas and ossifying fibromas were performed by applying the open-source software ITK-Snap to cone-beam computed tomography images. DICOM datasets were imported, identified, and delineated using semiautomatic segmentation; this was then verified using manual segmentation. The volumes of the lesions were computed automatically in cubic millimeters using the program. For statistical investigations, descriptive statistics and independent Student t-tests were performed. Additionally, Pearson's correlation was applied as a bivariate analysis. Values of p < 0.05 were considered significant.

RESULTS

45 patients (11 male and 34 female) were included in this study. The mean volumes were 10.02 ± 18.79 cm³ for osteomas and 4.80 ± 5.71 cm³ for ossifying fibromas (p = 0.016). Males (12.81 ± 20.38 cm³) presented significantly larger volumes than females (5.43 ± 10.32 cm³) (p = 0.042). With regard to shape, morphology, and affection of surrounding anatomical structures, irregular shape (p = 0.001; p = 0.037), multilocular morphology (p = 0.001; p = 0.037), nerve affection (p = 0.001; p = 0.002), tooth affection (p = 0.001; p = 0.594), cortical bone exceedance (p = 0.033; p = 0.001), and clinically visible symptoms (p = 0.004; p = 0.001) were statistically significantly associated with a larger volume of both entities.

CONCLUSION

Volumetric analysis revealed that osteomas significantly exceeded the mean size of ossifying fibromas, supporting the argument that special attention should be paid to this entity. In cases of difficult histopathological examination, lesions with irregular shape, multilocular morphology, nerve and tooth affection, cortical bone exceedance, and clinically visible symptoms should be considered for close clinico-radiological follow-up, irrespective of the entity.

A Volumetric and Morphological Analysis of Recurrent Odontogenic Keratocysts by Semiautomatic Segmentation

PURPOSE

The authors conducted this study to provide morphological and volumetric data of recurrent odontogenic keratocysts of the upper and lower jaw to emphasize risk factors in accordance with their radiological appearance and guide clinical decisions for jeopardized patients.

METHODS

By applying the open-source software "ITK-Snap" on cone-beam computed tomography images, volumetric measurements of histopathologically diagnosed recurrent odontogenic keratocysts could be performed. For statistical investigations, descriptive statistics and independent Student t test were performed. The intraclass correlation coefficient was used to assess intra- and inter-rater reliabilities. P values P < 0.05 were considered significant.

RESULTS

Forty patients (24 male and 16 female) were included in this study. Recurrent odontogenic keratocysts had a mean maximum diameter of 28.91 mm ± 12.00 mm and a mean volume of 4.48 cm3 ± 4.29 cm3. According to morphology, irregular shape (P = 0.001; P = 0.005), unclear margin (P = 0.001; P = 0.001), multilocular morphology (P = 0.001; P = 0.001), and cortical bone exceedance (P = 0.001; P = 0.007) are statistically significantly associated with a larger cyst diameter and volume. Furthermore, significant differences by diameter and volume could be shown between patients with and without iliac crest graft reconstruction (P = 0.001; P = 0.001).

CONCLUSIONS

Volumetric analysis reveals that recurrent odontogenic keratocysts show large diametric and volumetric extension that leads to complex reconstruction by iliac crest grafts, adding an argument that special attention should be paid to this entity and its recurrence. In case of difficult histopathological examination, lesions with irregular shape and margin, multilocular morphology, cortical bone exceedance, and clinically visible symptoms should be considered for close morphological and volumetric clinico-radiological follow-up.

A Functional Radiological and Soft Tissue Classification to Predict Outcomes in Orbital Fracture Surgery in a Multidisciplinary "Real-World" Setting

Purpose: The decision for open reduction and internal fixation (ORIF) of orbital fractures is usually based on clinical severity and soft tissue and bony findings. This study aimed to identify prognostic factors for a successful surgical outcome.

Materials and Methods: We included all orbital fractures treated by ORIF referred to the Ophthalmology clinic for assessment over a 12-year period. A successful outcome was defined as (i) a single operation, (ii) improved diplopia and globe position at 6 months, (iii) no surgical complications, and (iv) patient satisfaction. Data was collected on presenting symptoms, orthoptic measurements, time interval from injury to surgery, fracture geometry and involvement of internal, and external bony landmarks. Univariate and multivariate regression was used to identify predictive factors for success.

Results: There were 143 cases with median age 35.4 years and 81.8% (117/143) male. 51% (73/143) were complex fractures involving multiple orbital walls. 63.6% (91/143) achieved significant improvement in both enophthalmos and diplopia at 6 months. 15.3% (22/143) had significant preoperative soft tissue or neurogenic injury. 11.8% (17/143) required orbital plate repositioning or removal. 1.4% (2/143) developed orbital haematoma and 4.2% (6/143) had cicatricial entropion. Pre-operative nerve or muscle damage (OR 0.05, p = 0.01) and infraorbital fissure fracture (OR 0.38, p = 0.04) were associated with poor outcomes, whereas an intact posterior ledge was associated with successful outcomes (OR 3.03, p = 0.02).

Conclusion: Careful ocular motility evaluation to ascertain neurogenic injury and muscle compartment syndrome, and radiological analysis of the integrity of the posterior ledge and the inferior orbital fissure can facilitate management and expectations of ORIF surgery.

Volumetric and Morphological Analysis of Mandibular Condyles of Angle Class 2 and 3 Malocclusion Patients

ABSTRACT

This study was conducted to provide diametric and volumetric data of mandibular condyles from patients with Angle class 2 and 3 malocclusions by semiautomatic segmentation based upon cone-beam computed tomography.Cone-beam computed tomography images of 79 patients were analyzed. By using the open-source software "ITK-SNAP", diametric and volumetric measurements of 158 mandibular condyles were performed. Descriptive statistics were calculated for all normally distributed variables. Correlations between patients with Angle class 2 and 3 were calculated with the independent Student t test. P values P < 0.05 were considered significant.Irrespective of the side, patients with class 2 malocclusion showed smaller mandibular condyles (right: 1.128 ± 0.504 cm3; left: 1.222 ± 0.596 cm3) than patients with class 3 (right: 1.504 ± 0.361 cm3; left: 1.493 ± 0.335 cm3). These results were reproducible also in accordance with the diametric measurement (class 2 right: 16.75 ± 2.72 mm; left: 17.04 ± 3.01 mm) (class 3 right: 18.24 ± 2.54 mm; left: 18.32 ± 2.13 mm). However, volumetric differences were highly statistically significant (right: P = 0.001; left: P = 0.018) while diametric differences were slightly significant for the right and not significant for the left side (right: P = 0.042; left: P = 0.053).Diametric and volumetric analyses offer important additional information based on 3D images of cone-beam computed tomography technology. Significant differences in diameter and volume of mandibular condyles could be assessed between different classes of malocclusion.

Outcomes in Orbital Floor Trauma: A Comparison of Isolated and Zygomaticomaxillary-Associated Fractures

ABSTRACT

Orbital floor fractures are common sequalae of trauma to the orbit. These fractures present as an isolated orbital floor (I-OF) fracture or with other midface fractures, typically the zygomaticomaxillary complex. The authors sought to better understand the differences in patient presentation, surgical decision-making, and outcomes in I-OF fractures compared with those associated with zygomaticomaxillary complex fractures (Z-OF). A retrospective review of patients with orbital floor fractures was conducted to generate an I-OF fracture group and a Z-OF fracture group. Demographics, preoperative symptoms, surgical choices, and postoperative complications were assessed. Complications were assessed individually and as 2 composite groups consisting of orbital complications and eyelid complications. There were 156 patients that met inclusion criteria with 75 I-OF fractures and 81 Z-OF fractures. The most common mechanism of injury for I-OF fractures was assault (34.7%) and motor vehicle accidents (39.5%) for Z-OF fractures. The I-OF group presented more often with diplopia (P = 0.01) whereas the Z-OF group had more trauma symptoms (P = 0.01), which included subconjunctival hemorrhages, retrobulbar hemorrhages, and relative afferent pupillary defects. I-OF fractures had longer preoperative observational periods (P < 0.001). Postoperatively, I-OF fractures had more motility restrictions (P = 0.002) but Z-OF fractures had higher risk for eyelid complications (P = 0.03). There was no significant difference in reoperation rates (P = 0.93). Multivariate analysis showed Z-OF fractures had reduced a rate of postoperative motility defects by 72% (P = 0.03) but had 2.6 times higher risk of eyelid complications (P = 0.04). Z-OF fractures present differently, vary in surgical management, and have complications that differ from an I-OF fracture.

Orbital anatomy magnetic resonance imaging in diplopic versus non-diplopic patients after glaucoma drainage device placement

PURPOSE

New-onset persistent diplopia has become a common complication after glaucoma drainage device (GDD) placement. Understanding the orbital anatomy of such patients may provide information regarding risk of diplopia, GDD selection, and post-operative management. The purpose of this study was to examine the orbital anatomic differences in diplopic and non-diplopic patients after GDD implantation using high-resolution MRI.

METHODS

Seven eyes (N = 4 with diplopia and N = 3 without diplopia after GDD placement) of seven patients that had undergone placement of Baerveldt 250 (B250), Baerveldt 350 (B350), or Ahmed FP7 (FP7) GDD were prospectively enrolled at a single institution. All patients underwent a 3.0T orbital MRI with 3D volumetric T1 and T2 weighted sequence. Images were analyzed for orbital volume, axial length, orbital distances, presence of superior rectus-lateral rectus (SR-LR) band, position of GDD, and SR-LR angles.

RESULTS

Patients with diplopia had smaller mean ± SD orbital axial (911.5 ± 111.8 mm³ vs 931.7 ± 79.7 mm³) and coronal volumes (1162.5 ± 145.5 mm³ vs 1180 ± 34.6 mm³) compared to non-diplopic patients. Average orbital rim distances were larger for the diplopic group. The SR-LR displacement angle for diplopic patients was larger (101.6° ± 8.1 vs 94.7° ± 17.6) while the SR-LR quadrantic angle (86.6° ± 4.2 vs 89.1° ± 4.3) was smaller. SR-LR band was present and intact in all patients. GDD malpositioning was not evident in any patient.

CONCLUSION

The decreased orbital axial and coronal volumes as well as increased orbital rim distances in diplopic patients suggests the need for further studies to understand the role of orbital anatomy in occurrence of diplopia. Dynamic MRI imaging may be helpful in identifying differences in extraocular muscle function that reveal an etiology of diplopia in patients with GDD implantation.

Bisphosphonate application and volumetric effects on MRONJ lesions

The purpose of this investigation was to analyze the volume of medication-related osteonecrosis of the jaw (MRONJ) lesions by semi-automatic segmentation of cone-beam computed tomography images, and correlate the results with the underlying diseases and applied medication. MRONJ lesions detected in cone-beam computed tomography images were assessed. The open-source software ITK-Snap enabled volumetric measurements of MRONJ lesions based on semi-automatic segmentation. Results were analyzed according to necrosis volume, localization, and gender. In addition, the underlying disease and the type of application of antiresorptive medication were investigated. Cone-beam computed tomography images of 66 patients were studied. 34 male and 32 female patients were included, with ages ranging from 50 to 93 years at the time of diagnosis. The mean volume was 993.24 ± 620.94 mm³: 484.73 ± 230.97 mm³ for the upper jaw and 1084.04 ± 625.74 mm³ for the lower jaw. The results indicated statistically significant differences between lesions of the upper and lower jaw, regardless of gender (p = 0.003). The analysis of differences between males and females did not show any significant results (p = 0.464), although males presented slightly larger lesions than females. With regard to the underlying disease, patients with osteoporosis presented larger volumes, whereas patients with malignant tumors presented smaller volumes. Nevertheless, no statistically significant differences according to the underlying disease (p = 0.313) were detected. However, patients with intravenous (iv) application showed statistically significantly larger lesions than patients who underwent oral or subcutaneous (s.c.) applications (p = 0.004). It seems that the osteonecrosis volume correlates with the applied antiresorptive agents. Larger MRONJ lesions should be expected in patients who receive intravenous antiresorptive therapy.

Anatomical and Volumetric Analysis of the Sphenoid Sinus by Semiautomatic Segmentation of Cone Beam Computed Tomography

This investigation was performed to analyze and evaluate anatomical and volumetric data of the sphenoid sinus by semiautomatic segmentation of cone beam computed tomography (CBCT) datasets.This analysis was carried out on cone beam computed tomography images of 100 patients. By using the discretionary software "ITK-Snap", the volumetric investigation of 197 sphenoid sinuses was conducted. The statistical analyses were carried out by using the paired and independent Student t-test. In addition, the Pearsons chi-square test was performed. P values P < 0.05 were considered significant.The volumetric mean was 4.438 ± 2.434 cm for the right and 4.809 ± 3.000 for the left side. Results did not indicate statistically significant differences according to the side, irrespective of gender (P > 0.05). The further investigation of differences between male and female patients did assess significant results (P < 0.05), males (10.477 ± 3.851 cm) present a larger total sinus volume than females (8.219 ± 3.574 cm). In accordance to patients' age (median 54 years), smaller volumes were related to younger patients and larger volumes to older ones. But, no statistically significant results in accordance to age could be detected (χ = 1.258; P > 0.05).Endoscopic sinus surgery of the vulnerable and intricate anatomy of the sphenoid sinus requires an explicit knowledge and orientation about the anatomical variations such as septums and volumetric capacity. Concerning this matter, semiautomatic segmentation of CBCT images can aid the surgeon in preoperative planning. Our investigation shows that a small sinus volume, that is, affecting female patients and a complex sinus anatomy by the occurrence of a septum, especially located close to neurovascular structures could essentially aggravate endoscopic sphenoid sinus surgery. In this regard, volumetric analysis of the sphenoid sinus by CBCT images can provide presurgical information and facilitates an individualized treatment.

Influence of Radiographic Soft Tissue Findings on Clinical Entrapment in Patients With Orbital Fractures

INTRODUCTION

Radiographic assessment of facial fractures with computed tomography (CT) scanning has become standard of care. As imaging resolution has improved, findings such as herniation of extraocular muscles (EOM) have become a means of diagnosing conditions like orbital entrapment. However, the sensitivity and specificity of these findings has not been well-studied. We sought to evaluate the value of radiographic findings such as fat herniation, EOM contour irregularity, and EOM herniation in predicting orbital entrapment after orbital fracture. Secondary endpoints include diplopia, abnormal EOM motility, and the need for surgical fixation.

METHODS

A single institution, retrospective review at a regional level 1 trauma center was conducted. Patients with orbital fractures were identified by International Classification of Disease (ICD) codes and CT reports were queried for the terms "herniation," "herniated," "entrapped," and "entrapment." Four hundred records were analyzed.

RESULTS

Sixty-seven percent of radiology reports mentioned "entrapped" or "entrapment," while the incidence of clinical entrapment was 2.8%. The odds of entrapment, diplopia, and abnormal EOM motility were higher in those with EOM herniation; however, EOM herniation had a positive predictive value of 7.9% for clinical entrapment. Fat herniation alone and EOM contour irregularity had positive predictive values of 4.2% and 4.8%, respectively.

CONCLUSIONS

While the odds of entrapment appear higher in patients with EOM herniation, this imaging finding is not predictive of clinical entrapment. Fat herniation and EOM contour irregularity did not have higher odds of entrapment, nor were they predictive. Diagnosis of orbital entrapment should be based primarily on physical exam, with CT as an adjunct only. The assumption that radiographic findings indicate orbital emergencies may result in unnecessary interfacility transfers, subspecialist consultations, and emergency operative procedures.

Assesing Intraoperative Virtual Navigation on My Craniofacial Surgery Fellowship for Orbital Fractures Repair: Is it Useful?

ABSTRACT

Orbital fractures pose specific challenge in its surgical management. One of the greatest challenges is to obtain satisfactory restoration of normal orbital volume and globe projection following traumatic injury, due to the inability of the surgeon to gain adequate visibility and to verify proper implant position and placement during the operation. Surgical navigation is a very helpful tool when dealing with the reconstruction of such orbital fractures. During the training of the craniofacial fellowship learning to recognize the orbital floor boundaries is essential for the correct implant placement for reconstruction, their identification is a critical step, which may be assisted by intraoperative virtual navigation. Six patients were surgically treated for orbital floor fracture with intraoperative virtual navigation. The clinical evaluation showed no complications such as enophtalmos, exophtalmos or dystopia in all the patients 2 months post operatively and a correct implant/graft position.During surgery, navigation provides exact determination of transverse, cranio-caudal and postero-anterior dimensions within the orbit and precise control of the position of implants/bone grafts.This tool aids consistently on the craniofacial surgery fellow's formation, as it facilitates the identification of the bony floor boundaries and verifies the correct placement of the implants/bone grafts. It is routinely use could help to avoid implants/bone grafts misplacement not only for craniofacial surgeon's fellow, but for all the orbital surgeons.

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

OBJECTIVE

This 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 METHODS

CT 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.

RESULTS

A 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.

CONCLUSION

The 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.

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.

An accurate interactive segmentation and volume calculation of orbital soft tissue for orbital reconstruction after enucleation

Background

Accurate measurement and reconstruction of orbital soft tissue is important to diagnosis and treatment of orbital diseases. This study applied an interactive graph cut method to orbital soft tissue precise segmentation and calculation in computerized tomography (CT) images, and to estimate its application in orbital reconstruction.

Methods

The interactive graph cut method was introduced to segment extraocular muscle and intraorbital fat in CT images. Intra- and inter-observer variability of tissue volume measured by graph cut segmentation was validated. Accuracy and reliability of the method was accessed by comparing with manual delineation and commercial medical image software. Intraorbital structure of 10 patients after enucleation surgery was reconstructed based on graph cut segmentation and soft tissue volume were compared within two different surgical techniques.

Results

Both muscle and fat tissue segmentation results of graph cut method showed good consistency with ground truth in phantom data. There were no significant differences in muscle calculations between observers or segmental methods (p > 0.05). Graph cut results of fat tissue had coincidental variable trend with ground truth which could identify 0.1cm³ variation. The mean performance time of graph cut segmentation was significantly shorter than manual delineation and commercial software (p < 0.001). Jaccard similarity and Dice coefficient of graph cut method were 0.767 ± 0.045 and 0.836 ± 0.032 for human normal extraocular muscle segmentation. The measurements of fat tissue were significantly better in graph cut than those in commercial software (p < 0.05). Orbital soft tissue volume was decreased in post-enucleation orbit than that in normal orbit (p < 0.05).

Conclusion

The graph cut method was validated to have good accuracy, reliability and efficiency in orbit soft tissue segmentation. It could discern minor volume changes of soft tissue. The interactive segmenting technique would be a valuable tool for dynamic analysis and prediction of therapeutic effect and orbital reconstruction.

Volumetric analysis of MRONJ lesions by semiautomatic segmentation of CBCT images

PURPOSE

The purpose of this study was to evaluate potential differences in volumes of areas of osteolysis caused by medication-related osteonecrosis of the jaw (MRONJ) between the upper and lower jaw. We aim to analyze the clinical relevance of volumetric measurement of osteolytic lesions for surgical planning of MRONJ patients.

METHODS

Sixty-seven patients who were clinically and histopathologically diagnosed with MRONJ were retrospectively included in this study. Cone beam computed tomography (CBCT) images were evaluated according to localization, affected anatomical structures, and volumetric measurement of osteolytic lesions caused by MRONJ in appliance of CBCT datasets by using ITK-SNAP.

RESULTS

The most frequently affected localization is the mandible, whereas female patients show significantly more often lesions of the maxilla. The cortical bone was predominantly affected. Furthermore, the affection of teeth, sinus floor, inferior alveolar nerve canal, or even a pathological fracture of the mandible are infrequently existing. The volumetric measurements revealed a statistically significant greater absolute osteolysis volume in males.

CONCLUSIONS

Image analysis and volumetric measurements of osteolytic lesions of MRONJ patients is a helpful tool to further understand the clinical appearance and identify compromised anatomic landmarks. Volumetric analysis aids in pre-surgical planning and visualizes the individual extent of the disease for each patient.

Clinical outcome after orbital floor fracture reduction with special regard to patient's satisfaction

PURPOSE

Primary reconstruction via transconjunctival approach is a standardized treatment option for orbital floor fractures. The aim of this study was to compare the findings of specific ophthalmologic assessment with the patient's complaints after fracture reduction.

METHODS

A retrospective medical chart analysis was performed on patients who had undergone transconjunctival orbital floor fracture reduction for fracture therapy with resorbable foil (ethisorb sheet or polydioxanone foil). A follow-up assessment including ophthalmological evaluation regarding visual acuity (eye chart projector), binocular visual field screening (Bagolini striated glasses test) and diplopia (cover test, Hess screen test) was conducted. Additionally, a questionnaire was performed to assess patients' satisfaction.

RESULTS

A total of 53 patients with a mean follow-up of 23 months (ranging from 11 to 72) after surgical therapy were included. Diplopia was present preoperatively in 23 (43.4%) and reduced in follow-up examination (n = 12, 22.6%). Limitations in ocular motility reduced from 37.7% to 7.5%. The questionnaire about the patient's satisfaction revealed excellent outcomes in relation to the functional and esthetical parameters.

CONCLUSION

Transconjunctival approach is a safe approach for orbital fracture therapy. Postoperative diplopia is nearly never perceptible for the individual and differs to pathologic findings in the ophthalmic assessment.

Image segmentation-based volume approximation-volume as a factor in the clinical management of osteolytic jaw lesions

OBJECTIVE

Size characterization of osteolytic jaw lesions (OJL), in particular of neoplastic nature, is heterogeneously performed and lacks standardization in the medical literature and clinical practice. An OJL's volume holds promise as a surrogate for treatment response and prognosis. We comparatively evaluate various methods for size characterization of odontogenic OJLs.

METHODS

We retrospectively performed semiautomatic image segmentation of CBCT data sets for volume approximation of neoplastic (51) and non-neoplastic odontogenic OJLs (100). We assessed the three greatest orthogonal diameters and calculated the volume using the cuboid- and ellipsoid-formula. Image segmentation was carried out using ITK-SNAP. Image segmentation-based volume approximation served as reference. Intra- and inter-rater variability were evaluated at hand of Bland-Altman-Analysis and dice similarity coefficient (DSC).

RESULTS

Concerning the intrarater variability, we found the DSC to be highest for image segmentation-based volume approximation, simultaneously showing the tightest limits of agreement and greatest reliability. The cuboid formula showed consistent overestimation of the lesion's volume with a percent mean difference of -52 % (upper and lower limits of agreement +8.57 %  and -112.63%, respectively). In mean, the ellipsoid formula underestimated the lesion's volume by 10.1% (upper and lower limits of agreement +76.8%  and -56.6%, respectively). Inter rater variability was higher for formula-based volume approximation. Volume and multilocularity (p = 0.001) correlate with aggressiveness and growth potential.

CONCLUSIONS

Segmentation-based volume approximation holds great promise for patient individualized treatment planning and clinical management. The data suggest that maximum tumour diameter-based size characterization, especially the cuboid-formula and the maximum diameter alone, should not be recommended.

Factors Influencing Postsurgical Diplopia in Orbital Floor Fractures and Prevalence of Other Complications in a Series of Cases

PURPOSE

We conducted a review of orbital fractures treated in our hospital over a period of 4 years. We reviewed several complications of such fractures, especially the relationship of postsurgical diplopia with different presurgical variables: age, gender, type of fracture, fracture area, coronal and sagittal diameter of fracture, fractured floor area, time to surgery, presence of muscle herniation, and presence of muscle entrapment.

PATIENTS AND METHODS

Fractures involving the orbital floor remain a controversial issue in terms of surgical treatment and the time from trauma to surgery. Surgical indications are divided into esthetic and functional, and they greatly differ from one medical center to another. We observed that the variables that influence postoperative complications varied in the different studies reviewed. Postsurgical diplopia is one of the most important complications, and its relationship with presurgical variables was the focus of this study. For the purpose of this study, we performed bivariate and multivariate analyses, accepting P < .05 as significant.

RESULTS

According to the multivariate analysis, postsurgical diplopia was only associated with trapdoor fractures, regardless of all other variables, especially if these fractures were operated on after 48 hours. In addition, the bivariate analysis showed that fractures involving muscle herniation resulted in less diplopia and a better prognosis if operated on before 48 hours. However, these results were not statistically significant.

CONCLUSIONS

Surgery performed within 48 hours of trauma statistically improves fractures with true muscle entrapment and also, fractures with muscle hernation (although in this fractures, the improvement is not statistically significant).

Is there more to the clinical outcome in posttraumatic reconstruction of the inferior and medial orbital walls than accuracy of implant placement and implant surface contouring? A prospective multicenter study to identify predictors of clinical outcome

PURPOSE

Reconstruction of orbital wall fractures is demanding and has improved dramatically with the implementation of new technologies. True-to-original accuracy of reconstruction has been deemed essential for good clinical outcome, and reasons for unfavorable clinical outcome have been researched extensively. However, no detailed analysis on the influence of plate position and surface contour on clinical outcome has yet been published.

MATERIALS AND METHODS

Data from a previous study were used for an ad-hoc analysis to identify predictors for unfavorable outcome, defined as diplopia or differences in globe height and/or globe projection of >2 mm. Presumed predictors were implant surface contour, aberrant implant dimension or position, accuracy of reconstructed orbital volume, and anatomical fracture topography according to the current AO classification.

RESULTS

Neither in univariable nor in multivariable regression models were unfavorable clinical outcomes associated with any of the presumed radiological predictors, and no association of the type of implant, i.e., standard preformed, CAD-based individualized and non-CAD-based individualized with its surface contour could be shown.

CONCLUSION

These data suggest that the influence of accurate mechanical reconstruction on clinical outcomes may be less predictable than previously believed, while the role of soft-tissue-related factors may have been underestimated.

Volumetric analysis of keratocystic odontogenic tumors and non-neoplastic jaw cysts - Comparison and its clinical relevance

The keratocystic odontogenic tumor (KCOT) is capable of causing vast osseous destruction. Histopathological examination is pivotal for diagnosis. The diagnostic process can sometimes be hindered by tissue inflammation of KCOTs with loss of defining criteria, resulting in misdiagnosis as an odontogenic jaw cyst. We discuss the possible merits of volumetric analysis when facing this particular diagnostic dilemma and for pathophysiological characterization of KCOTs. We included 114 patients, of whom 27 were histopathologically diagnosed with a KCOT and 87 with dentigerous (n = 41) and periapical cyst (n = 46). Semiautomatic segmentation and radiological analysis of preoperative cone beam computed tomography (CBCT) image data was carried out using ITK-SNAP. The mean volumetric extent of KCOTs is significantly higher compared to non-neoplastic odontogenic jaw cysts (p = 0.001). The mean volume and standard deviation for KCOTs and non-neoplastic odontogenic jaw cysts was 10381 mm³ ± 6410 and 5813 mm³ ± 4425, respectively. Volumetric analysis reveals that KCOTs significantly exceed the mean size of non-neoplastic odontogenic jaw cysts, adding an argument in favor of the neoplastic nature of KCOTs. In the case of difficult histopathological examination, lesions with a size exceeding a value of about 3000 mm³ could be considered for close clinico-radiologic follow-up.

Size distribution and clinicoradiological signs of aggressiveness in odontogenic myxoma-three-dimensional analysis and systematic review

OBJECTIVES

Therapeutic assessment of odontogenic myxoma (OM) is poorly standardized. Unidimensional size criteria have shown to be unreliable in therapeutic decision-making. We evaluate the size distribution of OM and scan for associated clinicoradiological signs of aggressiveness. Additionally, we evaluate three-dimensional size delineation of OM aiming to improve future therapeutic assessment of this destructive neoplasm.

METHODS

Primarily, we reviewed the database "PubMed" for data concerning the size of OMs as radiologically determined. Afterwards, the impact of age, sex, locularity and location on the size was investigated by χ² test, Student's t-test and regression analysis. Furthermore, we statistically evaluated the impact of size on the occurrence of clinicoradiological signs of aggressiveness. Secondly, we approximated the volume of five unpublished cases of OM by semi-automatic image segmentation of cone-beam CT images.

RESULTS

Multilocular OMs were significantly larger than unilocular ones (p < 0.002). Age (0.042) and multilocularity (<0.002) significantly impacted size. Size was significantly associated with cortical perforation (0.032) and multilocularity (<0.002), further regression analysis revealed tooth resorption (0.019), cortical perforation (0.005) and multilocularity (<0.002) as significant predictors of size. Employing the volume as a mean of comparison, we found that the biggest OM (38.42 ml; multilocular) was 124 times larger than the smallest (0.31 ml; unilocular). However, using the maximum diameter (cm) as a surrogate for size, the biggest lesion (6.3) was only 5.25 times larger than the smallest (1.2).

CONCLUSIONS

Locularity and volumetric size characterization might help in therapeutic decision-making and could help to improve our understanding of OM.