Bony Orbital Volume Research Articles

Patient-Specific Implant Customization for Treatment of Internal Orbital Fractures Using Office-Based Three-Dimensional Printing.

Three-dimensional (3D) modeling technology aids the reconstructive surgeon in designing and tailoring individualized implants for the reconstruction of complex craniofacial fractures. Three-dimensional modeling and printing have traditionally been outsourced to commercial vendors but can now be incorporated into both private and academic craniomaxillofacial practices. The goal of this report is to present a low-cost, standardized office-based workflow for restoring bony orbital volume in traumatic orbital fractures. Patients with internal orbital fractures requiring open repair were identified. After the virtual 3D models were created by iPlan 3.0 Cranial CMF software (Brainlab), the models were printed using an office-based 3D printer to shape and modify orbital plates to correctly fit the fracture defect. The accuracy of the anatomic reduction and the restored bony orbital volume measurements were determined using postoperative computed tomography images and iPlan software. Nine patients fulfilled the inclusion criteria: 8 patients had unilateral fractures and 1 patient had bilateral fractures. Average image processing and print time were 1.5 hours and 3 hours, respectively. The cost of the 3D printer was $2500 and the average material cost to print a single orbital model was $2. When compared with the uninjured side, the mean preoperative orbital volume increase and percent difference were 2.7 ± 1.3mL and 10.9 ± 5.3%, respectively. Postoperative absolute volume and percent volume difference between the orbits were -0.2 ± 0.4mL and -0.8 ± 1.7%, respectively. Office-based 3D printing can be routinely used in the repair of internal orbital fractures in an efficient and cost-effective manner to design the implant with satisfactory patient outcomes.

Revisiting bilateral bony orbital volumes comparison using 3D reconstruction in Korean adults: a reference study for orbital wall reconstruction, 3D printing, and navigation by mirroring

BackgroundOrbital wall fractures can result in changes to the bony orbital volume and soft tissue. Restoring the bony orbital and intraconal fat volumes is crucial to prevent posttraumatic enophthalmos and hypoglobus. We aimed to establish an evidence-based medical reference point for “mirroring” in orbital wall reconstruction, which incorporates three-dimensional (3D)-printing and navigation-assisted surgery, by comparing bilateral bony orbital volumes.MethodsWe retrospectively analyzed the data obtained from 100 Korean adults who did not have orbital wall fractures, categorized by age groups. The AVIEW Research software (Coreline Soft Inc., Seoul, South Korea) was used to generate 3D reformations of the bony orbital cavity, and bony orbital volumes were automatically calculated after selecting the region of interest on consecutive computed tomography slices.ResultsThe mean left and right orbital volume of males in their 20 s was 24.67 ± 2.58 mL and 24.70 ± 2.59 mL, respectively, with no significant difference in size (p = 0.98) and Pearson’s correlation coefficient of 0.977 (p < 0.001). No significant differences were found in orbital volumes in other age groups without fractures or in patients with nasal bone fractures (p = 0.84, Pearson’s correlation coefficient 0.970, p < 0.001). The interclass correlation coefficients (2,1) for inter- and intrarater reliability were 0.97 (p < 0.001) and 0.99 (p < 0.001), respectively.ConclusionsNo significant differences were found in the bilateral bony orbital volumes among males of any age. Thus, the uninjured orbit can be used as a volumetric reference point for the contralateral injured orbit during orbital wall reconstruction.

The Impact of Orbital Volume on Post-traumatic Enophthalmos: A Systematic Review and Meta-analysis.

Orbital volume increase has been previously linked with post-traumatic enophthalmos. However, this varies and some studies show no correlation. This systematic review and meta-analysis aimed to synthesize the correlation between orbital volume and enophthalmos and to determine if surgical intervention, enophthalmos measurement method, fracture location, or timing affect this correlation. Automation tools were used to assist in this review of 6 databases. Searches were performed across all dates. Included studies quantitatively reported orbital volume and enophthalmos following traumatic orbital wall fractures in at least 5 adult subjects. Correlational data were extracted or calculated. Random-effects meta-analysis was used with subgroup analyses for each of the secondary aims. Twenty-five articles describing 648 patients were included. The pooled correlation between orbital volume and enophthalmos was r =0.71 ( R2 =0.50, P <0.001). Operative status, enophthalmos measurement method, and fracture location did not affect pooled correlation. The delay between trauma or surgery and enophthalmos measurement was not shown to modulate correlation for unoperated patients ( R2 =0.05, P =0.22) but showed a negative relationship for postoperative patients ( z =-0.0281, SE=0.0128, R2 =0.63, P =0.03), but this was heavily influenced by a single article. All results had high residual heterogeneity. Studies were rated as moderate, low, or very low quality with few stating explicit hypotheses or limitations. Bony orbital volume expansion accounts for around 50% of post-traumatic enophthalmos. The other half is probably explained by soft tissue or geometric bony, rather than volumetric, changes.

Orbital Aging: A Computed Tomography-Based Study of 240 Orbits.

Previous studies have attempted to explain age-related changes to the orbit in isolation, often producing conflicting results. The authors used highly accurate imaging software to analyze computed tomographic scans to characterize changes related to age objectively. In this case-control study, patients seen in an ear, nose, and throat clinic were screened for study entry. Male and female participants were divided into two age groups (20 to 30 years and 60 to 75 years). Primary outcomes included measurement of bony orbital dimensions, volume of soft tissues (muscle and fat volume), and anterior globe position. Three-dimensional reconstructions were created of each orbit allowing these measurements. The generalized estimating equation was used so that both orbits from each patient could be included without any bias. The final sample included 240 orbits from 120 patients. There were 30 patients in each age group. Among female participants, the bony orbital volume ( p < 0.05), fat volume ( p < 0.01), and central width ( p < 0.001) of the bony orbit increased with age. The anterior globe position was significantly greater in older female participants ( p < 0.01). For male participants, the fat volume ( p < 0.0001) and central height ( p < 0.03) increased with age; the lateral rim moved posteriorly with age ( p < 0.007). The anterior globe position was not different between the age groups in male participants ( p = 0.56). The female bony orbit expands with age and is associated with a more anterior position of the globe; the male bony orbital volume remains the same and the lateral rim moves posteriorly.

Quantitative assessment of bony orbital volume symmetry: CT analysis in the uninjured caucasian population

There is a surprising lack of evidence documenting the volumetric symmetry of the bony orbit. This paper establishes reference values for orbital volume (OV) and symmetry in the 25 - 40 year old caucasian population. Secondarily, this paper sets a landmark for the tolerances in OV that can be expected when reconstructing the bony defects which may occur from trauma. A standardised method of quantitative OV measurement was developed using CT sinus examinations acquired for indications unrelated to orbital trauma. Sex, ethnicity, age, right and left OV were recorded. Data for 100 patients was obtained (50 male, 50 female). Mean left OV was 23.1cm3 and mean right OV was 23.3cm3. Left and right OV were strongly positively correlated (correlation coefficient: 0.96). Mean female OV was 21.6cm3 and mean male OV was 24.8cm3. On average, male OV is 3.2cm3 larger than female OV. The mean difference between left and right OV was 0.5cm3 in females and 0.6cm3 in males. The intra-class coefficient score between the two assessors was 0.973 (excellent). There is strong positive correlation between left and right OV in this study population. Previous work suggests that orbital volume loss less than 1cm3 would not lead to significant clinical symptoms of orbital fracture. When orbital reconstruction is undertaken, this study suggests that a volume symmetry difference of <0.5cm3 in females and <0.6cm3 in males would be consistent with the variation seen in the study population of uninjured caucasian 25-40 year olds and is therefore a reasonable goal of surgical management.

Aging of the Adult Bony Orbit.

Accurate quantitative data of the adult bony orbital volume and dimension are needed for treatment optimization. In the present study, the authors aim to evaluate adult orbital volume and corresponding linear dimensions according to age, volume, and individual symmetry. Seventy computerized tomography facial scans of adults were randomly chosen from an institutional database and 3-dimensionally reconstructed. Studies were excluded for orbital pathology or incomplete radiographic data. Anatomic landmarks were marked. Interval linear distances and orbital volumes were calculated. Data were analyzed using paired T-tests, independent T-tests, linear regression analysis, and 1-way analysis of variance. A total of 140 orbits from 70 patients were analyzed (female = 35, male = 35), ranging from 20 to 88 years of age. Orbital volume was similar between an individual's left and right side; however, a difference was observed in vertical orbital height, orbital width, inferior orbital rim position, orbital roof length, orbital width, and medial orbital wall length (0.45, 0.64, 0.4, 0.77, 0.97, and 5.1 mm, respectively; P < 0.05). In comparison to females, males averaged larger orbital volume by 3.07 cm (29.58 cm versus 26.51 cm, P = 0.0002), medial wall length by 2.66 mm (P < 0.05), and orbital width by 2.66 mm (P < 0.05). Orbital volume did not correlate with patient age, while lateral wall length was correlative. This accurate normative data of the adult bony orbit impacts key aspects of patient diagnosis and treatment and also suggest clinical signs of periorbital aging are not due to bony orbital changes.

Longitudinal Changes in Adult Bony Orbital Volume.

To our knowledge, no prior study has measured bony orbital volume in a group of subjects over time. This study evaluates longitudinal changes in bony orbital volume with age. A search was created for patients with digitized CT imaging studies of the orbit at least 8 years apart. Charts with a history of prior head trauma, head and neck tumors, sinus disease, head surgery, elevated intracranial pressure, thyroid eye disease, or conditions that could affect bone metabolism were excluded. Three outcome measures were used: orbital volume, medial orbital wall length, and lateral orbital wall length. Categorical data were summarized with frequency (%); normally distributed continuous data are summarized with mean (standard deviation), and non-normally distributed data were summarized with median. Normality was verified with Shapiro-Wilk Test. Paired t-tests were used to analyze the differences in the 3 outcome variables. One hundred and eighty-two subjects, 91 males and 91 females, were included. The median time between CT scans was 9.4 years. Orbital volume was significantly larger at the second scan than the first (p < 0.001). The average difference in orbital volume was 0.91 ml, an increase of 4.1%. Lateral orbital length was significantly shorter in the second scan than in the first (p = 0.046) though the difference was only 0.4 mm. There was no statistically significant change in medial orbital wall length. Bony orbital volume increases in individuals with age. This increase in orbital volume occurs in the context of soft tissue changes to contribute to the aging appearance of the periorbital region.

Comparison of Orbital Volume in Young Versus Senescent Human Skulls.

To compare bony orbital volumes in young skulls with those of older skulls to elucidate aging-associated changes of the orbit. One hundred Caucasian male skulls from the Hamann-Todd collection of the Cleveland Museum of Natural History were studied. There were 50 young skulls (age range, 19-33 years) and 50 senescent skulls (age range, 79-96 years). Volcanic sand was used to fill each orbit in an identical fashion and weighed as a proxy for volume. Digital calipers were used to perform linear measurements of the orbit. The relationship between orbit measures and skull size was assessed using Pearson's correlations and 95% CI, and statistical models to compare age groups adjusted for skull size. The volume of the orbits (P < 0.001), the horizontal diameter of the orbit (P = 0.015), and the orbital depth (P < 0.001) were significantly larger in the senescent group of skulls after adjusting for skull surface area. No significant differences were found in the vertical diameters of the orbit between the 2 groups. Skull size did not statistically differ between the age groups. Increases in the depth and horizontal dimensions of the orbit lead to increasing bony orbital volume with increasing age. These changes in size and shape of the orbit with age may contribute to phenotypic changes of aging and may affect disease processes and management.

Bony Orbital Volume Expansion in Thyroid Eye Disease.

To quantify changes to the bony orbital volume (BOV) in patients with thyroid eye disease (TED) relative to normal controls. In this case-control study, all patients affected with TED seen over a 2-year period were screened for study entry. Eligible participants were adults with clinical evidence of TED and CT scans of their orbits obtained during the course of their routine care. Exclusion criteria included the history of decompression surgery and/or medical or other ophthalmic conditions that could alter the orbital anatomy. The primary outcome was the measurement of the BOV. Secondary outcome measures included the relationships between BOV and muscle volume, fat volume, Hertel measurements, duration of the disease, and the occurrence of dysthyroid optic neuropathy in patients with TED. Three-dimensional reconstructions of the orbits were created to measure BOV, muscle volume, and fat volume. A total of 100 participants were included in the study, contributing 200 orbits. This sample was comprised of 50 patients with TED (37 female, 13 male) and 50 controls (37 female and 13 male). There were no differences between the control and patient groups in age or sex. Of the patients with TED, 14 were diagnosed with dysthyroid optic neuropathy (15 orbits, 1 case was bilateral). The mean (standard deviation [SD]) clinical activity score for males was 4.1 (2.29) and 4.35 (2.63) for females. The mean (SD) BOV for males in the TED group was 28.62 ml (3.47), while that of the control group was 24.59 ml (2.19). This difference was significant (p < 0.01). The mean (SD) BOV for females with TED was 24.33 ml (2.39), while that of the female control group was 20.97 ml (1.84). This was again significant (p < 0.01). There was a significant relationship between the BOV and fat volume (p <0.05). There were no significant relationships between BOV and: muscle volume, duration of disease (p = 0.705), Hertel measurements (p = 0.212), age (p = 0.9), and dysthyroid optic neuropathy (p = 0.12). This study found that the BOV is significantly greater in patients with TED, suggesting that TED is associated with widespread bony remodeling of the orbit.

Orbital fat expansion in thyroid eye disease is related to age.

To objectively measure the differential expansion of orbital fat and muscle volume in patients with thyroid eye disease. In this retrospective study, eligible participants were adults with clinical evidence of thyroid eye disease and high-resolution computed tomography scans of their orbits. Patients with a history of decompression surgery and/or medical or other conditions that could alter the orbital anatomy were excluded. Three dimensional reconstructions of the orbits allowed the calculation of the fat volume, muscle volume and bony orbital volume using the MIMICS imaging analysis tool. Both orbits from each patient were included without bias through the use of the generalized estimating equation. The primary outcome was the measurement of fat volume. Secondary outcome measures included the correlation of the muscle volume, bony orbital volume and exophthalmometry with age. Fifty patients with thyroid eye disease who were included contributed 100 orbits. The sample included 29 females (age 57, standard deviation = 14.8) and 21 males (age 52, standard deviation = 18.14). Mean (standard deviation) exophthalmometry measurement was 21.58 (4.01). Fat volume and exophthalmometry were negatively correlated with age (p = 0.00001 and p = 0.00001, respectively). Muscle volume (p = 0.985) and bony orbital volume (p = 0.484) did not correlate with age. Older patients with thyroid eye disease have less expansion of fat volume compared with younger patients. There are no associations between age and the bony orbital volume or muscle volume. These results support the growing body of evidence which suggests that the pathophysiology of TED is different in older patient.

VOLUME MEASUREMENTS OF NORMAL BONY ORBIT AND ORBITAL SOFT TISSUE IN CHILDREN BY COMPUTED TOMOGRAPHIC ANALYSIS

Objective: to study the volumetric data of the bone of the orbit and its soft tissues in children is normal. Material and methods. A research into CT scans of 50 children (80 orbits) without orbital abnormality was conducted. The computed tomography imaging was performed routinely, with both axial and frontal sections obtained. Section thickness measured 1.0 mm at intervals of 1.00 mm. Results. The article presents volume measurements for normal bony orbits and orbital soft tissue (extraocular muscle, retrobulbar tissue, optic nerve, and lacrimal gland) in children in vivo, with regard to age peculiarities. The orbital tissue volume ratios presented in the article allow for conclusions about age-specific changes in the anatomy and topography of the orbit in children. Conclusion. The growth of a child is accompanied by a continuous steady increase in the bony orbit and orbital soft tissue volume, which reaches 21.93 cm3 and 14.87 cm3 respectively by the age of 15 to 16 years. With age, the volume of orbital soft tissues shows a greater increase than the volume of the bony orbit, which leads to a change in topographic ratio of orbital tissues (the muscle “cone” widens, the eyeball protrudes forward).

Measurement of bony Orbital Volume with Computed Tomography (CT) in Healthy Eyes of Saudi Children

Purpose: To provide age and gender-specific reference values of bony orbital volume in normal healthy eyes of Saudi Arabian children. Methods: A retrospective review of health data was performed between October 2014 to May 2015. Healthy eyes of children aged 15 years or younger without orbital disease were included. Their computed tomography (CT) scans were reviewed. Orbital bony cavity volume (OV) was calculated by the 3D-semi-automated volumetric methods. Variation of OV by age and gender was analyzed. Results: CT scans of 374 children (197 males, 177 females) were reviewed. The mean OV of healthy Saudi children was 19.1 mm3 [95% confidence interval (CI):18.7 – 19.5]. OV was statistically significantly larger in males than females [(difference of mean=1.23 mm3 (95% CI: 0.7 – 1.8) P<0.0001]. There was a positive, statistically significantly association of OV to age (P<0.0001). Conclusion: OV of normal healthy eyes of Saudi Arabian children statistically significantly differed between gender and with age. The 3D volumetric method presents a reliable method for orbital volumetry. The rapid phase in orbital growth in Saudi males and females seems to end at 15 years and 11 years old respectively. Advances in Knowledge: Orbital volume (OV) of 374 Saudi children measured by semiautomatic method (CT scan) was 19.1 mm3. The OV of boys was larger than of girls. With increasing age, the OV increased but in different proportions in boys and girls.

Radiological evaluation of sphenozygomatic suture fixation for restoration of orbital volume: A retrospective study.

Lateral displacement of fracture zygomaticomaxillary complex (ZMC) can cause significant increase in orbital volume leading to enophthalmos. The aim of this study was to radiologically evaluate the efficacy of sphenozygomatic (SZ) suture fixation for restoration of orbital volume after elevation of the temporalis in cases of fracture ZMC where the fixation of zygomatic arch (ZA) was deemed necessary through latero-posterior approach. 43 operated cases of fracture ZMC using 4-point fixation were divided into two groups. Group I (n=24) cases had undergone reduction and fixation of SZ suture as fourth point of fixation by elevating temporalis muscle using hemicoronal approach. Group II (n=19) cases had undergone reduction and fixation of Infraorbital (IO) rim as fourth point of fixation using preseptal transconjunctival approach. Both the groups were analyzed separately and compared for restoring the increased orbital volume on CT. Difference in the pre-surgical orbital volume of both the groups was found to be statistically insignificant [p=.678]. In group I, the average bony orbital volume significantly reduced by 3.6cc from 25.5cc to 21.9cc [p=.000] post-surgically. In group II, the average bony orbital volume reduced by 1.5cc from 25.6cc to 24.1cc post-surgically There was a significant difference in the reduction of the increased orbital volume among the 2 groups (Group I: 3.6cc, group II: 1.5cc). The amount of reduction was more and statistically significant [p=.000] in the group I than group II. SZ suture fixation is reliable in reducing fractures ZMC and restoring the increased orbital volume where the fixation of zygomatic arch (ZA) was deemed necessary through latero-posterior approach.

Bony orbital maldevelopment after enucleation.

One common belief in ophthalmology is that enucleation at an early age will result in bony orbital maldevelopment and facial asymmetry. However, the age range in which enucleation is associated with risk of orbital maldevelopment and the extent of asymmetry remains controversial. In this study, patients who had undergone unilateral enucleation at different ages without orbital implantation were analysed to investigate bony orbital development after enucleation. A total of 87 Chinese adult patients were included. Their bony orbital volume and orbital aditus area were measured using three-dimensional reconstructive models based on patients' computer tomography scans. The ratio of the parameter values of the affected orbit to the unaffected orbit was calculated and described as the orbital symmetry index. The results showed that the bony orbit grew until approximately 18 years old. Enucleation after that age did not affect the orbit, whereas enucleation before that age led to significant orbital maldevelopment. The relative reduction ranged up to 20% in orbital volume and 17% in the orbital aditus area. The extent of orbital maldevelopment was correlated to the age ofenucleation. The symmetry index of orbital volume=-0.0003x(2) +0.0159x+0.8112 (x=the age of enucleation). The symmetry index of the orbital aditus area=-0.0002x(2) +0.0119x+0.8504 (x=the age ofenucleation). The regression formulae were used to predict the severity of orbital asymmetry after unilateral enucleation, and evaluate the necessity and efficacy of interventions following enucleation.

Dermis fat graft implantation after unilateral enucleation for retinoblastoma in pediatric patients.

To evaluate the efficacy of dermis fat graft (DFG) as a primary implant technique in pediatric patients requiring unilateral enucleation due to retinoblastoma. A retrospective chart review of 14 consecutive pediatric patients who underwent dermis fat graft implantation after unilateral enucleation for retinoblastoma by 1 surgeon (E.A.S.) was performed to evaluate graft efficacy with regard to orbital volume growth and any associated morbidity. Patients who received chemotherapy or external beam radiation were excluded. Demographic information was recorded. Serial MRIs were used to measure orbital volumes to compare the surgical and contralateral orbits over time. The main outcome measure was the difference in bony orbital volume between enucleated and contralateral, uninvolved orbits. Mann-Whitney U test was used to compare orbital volume measurements between surgical and nonsurgical orbits. Correlation testing was performed to determine the effect of age, sex, and follow-up time on the orbital volume changes. There was no statistical difference between the MRI volume measured for surgical and nonsurgical orbits over time. This was the case at all measured time points and for all ages and genders. All patients were under the age of 4 years at the time of surgery. The median difference in orbital volumes between surgical and nonsurgical orbits was -0.095 cm (range -1.26 to 1.01 cm; quartiles -0.32 to 0.07 cm; mean ± SD, -0.144 ± 0.0522 cm; 95% confidence interval, -0.247 to -0.0419 cm). The median follow-up time from surgery date to the most recent clinical examination was 38.5 months (range, 13 to 70 months; quartiles, 28.75 to 45.5 months; mean ± standard deviation [SD], 38.43 ± 17.21 months; 95% confidence interval, 29.41 to 47.45 months). In pediatric patients below 4 years of age with unilateral retinoblastoma treated with enucleation and primary dermis fat graft implantation, there was no statistically significant difference in bony orbital volume between the surgical and nonsurgical orbits during the follow-up period.

Reconstruction of orbital floor fracture using porous polyethylene mesh

Objective: Treatment of traumatic orbital injury has long been a formidable challenge to maxillofacial and oculoplastic surgeon. Significant complication can occur as a result of these injuries including enopthalmus, persistent diplopia, vertical dystopia and restriction of gaze. Surgical techniques have been more aggressive with primary surgical repair directed at restoring bony orbital volume and contour while repositioning the herniated tissues. The study was undertaken to assess the treatment results with alloplastic graft for reconstruction of orbital floor. Material and methods: It is a prospective randomized study during the period of January 2010 to December 2012 including the follow up of six months on ten orbital floor fractures. Results: Eyeball movement restriction and infraorbital nerve paresthesia improved in all patients. One patient who also had associated head injury and the fracture of supraorbital rim, frontal and temporal bone had persistent enopthalmus, vertical dystopia and diplopia postoperatively. Conclusion: We conclude that early exploration of orbital floor minimizes the morbity associated with late reconstruction due to the fibrosis of tissues entrapped. Use of prolene mesh reduces the operating time and donor site morbidity.

Change of the Orbital Volume Ratio in Pure Blow-out Fractures Depending on Fracture Location

The purposes of this study were to observe bony orbital volume (OV) changes in pure blow-out fractures according to fracture location using a facial computed tomographic scan and to investigate whether the OV measurements can be used as a quantitative value for the evaluation of the surgical results of the acute blow-out fracture.Forty-five patients with unilateral pure blow-out fracture were divided into 3 groups: inferior (group I), inferior medial (group IM), and medial (group M) orbital wall fracture. The OV and the orbital volume ratio (OVR) were prospectively measured before and 6 months after surgery with the use of 3-dimensional computed tomographic scans, and the Hertel scale was measured with a Hertel exothalmometer.The preoperative OVR increased to the greatest extent in group IM, and the mean preoperative OVR was 121.46. The mean preoperative OVR in group I was significantly higher than that of group M (P = 0.005). The OV and OVR revealed a statistically significant decrease after the surgery (P = 0.000). The Hertel scale improved from -1.04 mm before the surgery to -0.78 mm after the surgery, but no significant difference was observed (P = 0.051).The OVR was useful as a quantitative value to evaluate pure blow-out fractures, compared with that of the Hertel scale. Fracture location-associated OVR studies are needed to make volume guidelines of blow-out fracture surgery.

Measurement of Orbital Volume after Enucleation and Orbital Implantation

IntroductionThis article reports experience relating to the measurement of orbital volume by means of cone beam computed tomography (CBCT) and Cranioviewer program software in patients who have undergone enucleation and orbital implantation.Patients and MethodsCBCT scans were made in 30 cases, 10 of which were later excluded because of various technical problems. The study group therefore consisted of 20 patients (8 men and 12 women). The longest follow-up time was 7 years, and the shortest was 1 year. In all 20 cases, the orbital volume was measured with Cranioviewer orbital program software. Slices were made in the ventrodorsal direction at 4.8 mm intervals in the frontal plane, in both bony orbits (both that containing the orbital implant and the healthy one). Similar measurements were made in 20 patients with various dental problems. CBCT scans were recorded for the facial region of the skull, containing the orbital region. The Cranioviewer program can colour the area of the slices red, and it automatically measures the area in mm.ResultsIn 5 of the 20 cases, the first 4 or all 5 slices revealed that the volume of the operated orbit was significantly smaller than that of the healthy orbit, in 12 cases only from 1 to 3 of the slices indicated such a significant difference, and in 3 cases no differences were observed between the orbits. In the control group of patients with various dental problems, there was no significant difference between the two healthy orbits. The accuracy of the volume measurements was assessed statistically by means of the paired samples t-test.SummaryTo date, no appropriate method is avaliable for exact measurement of the bony orbital volume, which would be of particular importance in orbital injury reconstruction. However, the use of CBCT scans and Cranioviewer orbital program software appears to offer a reliable method for the measurement of changes in orbital volume.

Quantitative morphometry of the orbit in Chinese adults based on a three‐dimensional reconstruction method

The three-dimensional (3D) reconstruction technique serves as a practical tool in diagnosis, surgical planning, and outcome prediction of plastic and reconstructive surgery. In our study, the morphologic features of the Chinese adult orbit were described by 11 anatomic parameters using a 3D reconstruction technique. Sixty-four Chinese adults were selected randomly from patients who had undergone craniofacial computed tomography (CT) scans to diagnose conditions other than craniofacial or orbital deformations. The morphologic parameters of orbit such as bony orbital volume, orbital foramen area and orbital rim perimeter were measured on 3D models using this technique. Differences between the two orbits and between the two sexes were investigated. The method of measurement showed high reproducibility of results. No difference between the two orbits was found. There were significant differences between men and women in all anatomic parameters other than orbital height. In men and women, respectively, mean bony orbital volume was 26.02 and 23.32 mL, mean orbital foramen area 11.80 and 11.10 cm², mean orbital rim perimeter 12.65 and 12.20 cm, mean orbital height 33.35 and 33.22 mm, mean orbital width 40.02 and 38.00 mm; mean orbital floor length 47.93 and 46.18 mm, mean orbital roof length 52.93 and 50.89 mm, mean medial orbital wall length 46.43 and 44.41 mm, mean lateral orbital wall length 48.38 and 46.91 mm, mean intraorbital distance 27.18 and 25.11 mm, mean extra-orbital distance 98.77 and 93.69 mm. It is concluded that the measurements of these orbital parameters could be obtained from a 3D reconstruction method. The two orbits were symmetric based on orbital volume and other anatomic parameters. Orbital size was significantly smaller in women than in men; orbital height, however, was similar. The findings of the present study allow for quantification of the orbital features of Chinese adults and provide parameters for preoperative planning and prediction of postoperative outcome.

Computer-Aided Volumetric Comparison of Reconstructed Orbits for Blow-Out Fractures With Nonpreformed Versus 3-Dimensionally Preformed Titanium Mesh Plates

To compare and evaluate, using computer-aided volumetric measurements, the accuracy and reliability of nonpreformed mesh plates (NPMPs) versus 3-dimensionally preformed titanium mesh plates (PMPs) in posttraumatic orbital volume restoration. Facial coronal computed tomographic scan slices from 20 patients (10 in the NPMP and 10 in the PMP group) were used to measure bony orbital volume using OsiriX Medical Image software (version 3.3.2, www.osirix-viewer.com). The procedure was performed on both orbits; thereafter, the volume of the contralateral health orbit was used as a control for comparison in the 2 groups of patients. The difference in orbital volume between the 2 groups and between the reconstructed versus uninjured side in both groups have been statistically correlated. The mean orbital volume between the reconstructed (19.215 mL in NPMP and 21.791 mL in PMP) and the contralateral uninjured side (18.955 mL in NPMP and 21.710 mL in PMP) was not statistically significant (P > 0.05). The mean orbital volumes of the reconstructed orbits were 19.215 mL in the NPMP and 21.791 mL in the PMP group, with no statistically significant difference (P > 0.05). The volume data of the reconstructed orbit fitted that of the contralateral uninjured orbit with an accuracy of a maximum of 1.85 mL in the NPMP group and 2.5 mL in the PMP group. The current study demonstrated that there were no significant differences in the orbital volume restoration using either technique. In fact, both techniques allow for close reproduction of natural orbital volume and shape, and its use in posttraumatic orbital wall reconstruction was successful.