Infraorbital Groove Research Articles

Morphometric Analysis of the Infraorbital Canal, Groove, and Foramen in the Indian Population: A Retrospective Analytical Study

Morphometric Analysis of the Infraorbital Canal, Groove, and Foramen in the Indian Population: A Retrospective Analytical Study

Clinical Significance of the Inferomedial Orbital Strut in Orbital Blowout Fractures: Incidence of Symptomatic Diplopia in a Fractured vs. Intact Strut.

Background/Objectives: This study aims to compare the clinical findings, particularly symptomatic diplopia, associated with an inferomedial orbital strut fracture versus intact strut and to determine the clinical significance of the inferomedial orbital strut in patients with orbital floor and medial orbital wall fractures. Methods: A 10-year retrospective observational study involving orbital blowout fracture cases was conducted in our institution. Patients with fractures of the orbital floor medial to the infraorbital groove and medial orbital wall, as seen on computed tomography (CT) scans, were included in this study. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. Fracture of the inferomedial orbital strut was diagnosed via coronal CT images and patients were classified into those with an inferomedial orbital strut fracture and those without. Results: A total of 231 orbits from 230 patients was included in the study (fractured strut on 78 sides and intact strut on 153 sides). Approximately 2/3 of patients in both groups had the field of binocular single vision in primary position upon first examination (p = 0.717). Patients with strut fractures demonstrated only comminuted or open fractures, while those without strut fractures showed diverse fracture patterns (p < 0.001). Conclusions: Inferomedial orbital strut fracture does not automatically result in diplopia in patients with orbital blowout fractures. The integrity of the orbital periosteum plays a more essential role in hampering extraocular muscle displacement, thereby preventing symptomatic diplopia in these patients.

A New Approach in Management of Orbital Adherence Syndrome.

Orbital walls are one of the most common sites of midface fractures and account for ~40% of traumatic injuries in this region. These fractures are often associated with changes in the anatomy of the orbital cavity and frequently affect the orbital inferior wall, infraorbital groove and canal, and medial orbital wall, which leads to changes in its pattern and volume as well. Generally, the forces required for brake superior and lateral walls are greater than those required for thin medial and inferior walls. Disruption of any of these structures leads to the expansion of orbital volume that brings to the appearance of enophthalmos, diplopia, and impaired ocular mobility. The gold standard in the treatment of orbital wall fractures is surgical reconstruction, that includes fracture site exposure, freeing tissue prolapsed into the fracture site, and re-approximating the orbital wall support, usually with an orbital implant. It usually could be achieved by the usage of such as transconjunctival, subciliary, and coronal approaches and implementation of graft and reconstructive materials, including bones, cartilage, titanium, and resorbable mesh. Today, the gold standard in orbital floor reconstruction is the application of titanium mesh orbital plates. However, their implementation could be associated with a number of postoperative complications, such as mispositioning and orbital adherence syndrome. Orbital adherence syndrome is a poorly described and understood phenomenon and appears to occur after the use of large-pored titanium mesh for orbital reconstruction. It usually appears as limited eye movement that appears 1 to 2 weeks after reconstructive procedure. Prevention is possible through careful patient selection and the placement of a smooth interface medium in the initial surgery. The aim of the current study is to present the outcomes of orbital reconstruction done by both orbital mesh and customized ​​smooth-surfaced titanium orbital implants.

Incidence of Pure Orbital Fractures with Concomitant Lacrimal Drainage System Injury in the Japanese Population: A Retrospective Study

ABSTRACT Purpose This study aims to determine the incidence of pure orbital fractures with concomitant lacrimal drainage system injuries. Methods A retrospective observational study involving 956 sides from 940 pure orbital blowout fracture patients was conducted in our institution. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. Results A total of 13 sides (1.4%) from 13 patients were included in the study. Canalicular laceration, bony nasolacrimal canal fracture, and lacrimal sac wall laceration were found in 9, 4, and 1 patients, respectively (one overlapping). Majority of the injuries resulted from either sports or falls. Inferomedial orbital strut fracture (23.1% vs. 7.6%; p = .075) and orbital floor fracture occurring lateral to the infraorbital groove (30.8% vs. 9.9%; p = .035) tended to be higher in patients with lacrimal drainage system injuries. Conclusion There is a 1.4% incidence rate of pure orbital fractures with concomitant lacrimal drainage system injuries among the Japanese population included in this study. Inferomedial orbital strut fractures and orbital floor fracture lateral to the infraorbital groove were found to have higher association with lacrimal drainage system injuries.

A morphological study and the variability in the number of infraorbital foramina in the African green monkey (Grivet) (Chlorocebus aethiops) using microcomputed tomography.

Knowledge of the nonhuman primate morphology and anatomy related to craniofacial mechanoreception is essential for a fundamental understanding of the incidents that have occurred during the evolution of craniofacial features. The present study focuses on the variability in the number of infraorbital foramina and associated anatomical structures such as the infraorbital canal (IOC) and the infraorbital groove (IOG), as they are considered to play an important role in the behavioral ecology of these animals. A total of 19 skulls of Chlorocebus aethiops were analyzed. The number of infraorbital foramina was assessed macroscopically using a magnifying glass and a small diameter probe. Three dimensional(3D) projections and morphometric analysis of the infraorbital foramina, IOCs, and IOGs were performed using microcomputed tomography (micro-CT) for two skulls that represent one of the most common morphological types. Regardless of sex and body side, the most common morphological type observed in the studied species is the presence of three infraorbital foramina. The IOC takes a funnel or pinched shape. 3D projections were made to assess the course of the infraorbital vascular and nerve bundles in selected individuals. The results indicate a high morphological diversity within the species, although there appears to be a consistent distribution pattern of infraorbital neurovascular bundles in species of the Cercopithecidae family. The use of X-ray micro-CT allowed 3D visualization of the maxillary region to determine the variability of the infraorbital foramina and to track the division of the infraorbital neurovascular bundle in the case of the most common macroscopic expression of the number of the infraorbital foramen in C. aethiops, as well as the morphometric of the IOCs and IOGs which are related to mechanoreception of the primate's snout.

Morphometry of the Bony Orbit and Periorbital Structures: Personal Perspectives From Decades of Related Research.

The author introduces his personal perspectives on the bony orbit, nerves, arteries, and ligaments relating to orbital re- construction surgery. A supraorbital fissure was 40.0 ± 2.5 mm from the supraorbital notch. Posterior ethmoidal foramen was 31.7 ± 3.0 mm from the anterior lacrimal crest. The infraorbital fissure, where the infraorbital groove started, was 26.4 ± 2.6 mm from the infraorbital foramen. The supraorbital fissure was 34.3 ± 2.7 mm from the frontozygomatic suture. The medial palpebral ligament consisted of 2 layers. The superficial layer of the palpebral ligament (SMPL) was from the anterior lacrimal crest to the upper and lower tarsal plates. The deep layer of the palpebral ligament (DMPL) lay from the anterior lacrimal crest to the posterior lacrimal crest, covering the lacrimal sac. Horner muscle was at the posterior lacrimal crest just lateral to the attachment of the DLPL and ran laterally to the tarsal plate deep to the SLPL. Three components of the lateral canthal area are: (1) lateral palpebral raphe, (2) superficial lateral palpebral ligament (SLPL), and (3) deep lateral palpebral ligament (DLPL). The lateral ends of superior and inferior orbicularis oculi muscles interlaced at the lateral commissure and formed the lateral palpebral raphe. The superficial lateral palpebral ligament extended from the lateral ends of the tarsal plate to the periosteum of the lateral orbital rim. The lateral palpebral ligament extended from the lateral ends of the tarsal plate deep to the origin of SLPL to the Whitnall tu- bercle on the zygomatic bone. The palpebral branch of the in- fraorbital artery emerged from the infraorbital foramen and ran superior and lateral to the orbital septum. After passing through the orbital septum, distributed to the orbital fat.

Morphological and Morphometric Relations of Infraorbital Foramen in North Indian Population.

Introduction The evidence regarding the anatomy of the infraorbital foramen in the Indian population is limited. It mainly focuses on its shape, size, and incidence in the Indian population. The current study aimed to evaluate morphometric parameters of infraorbital foramen that can help clinicians during surgery and procedures around it. Methods We evaluated 90 dry adult humanhemi-skulls. The morphological parameters studied included the assessment of the shape of the infraorbital foramen, its horizontal and vertical diameters, and its relation to the teeth of the upper jaw. In addition, we measured the distance of the infraorbital foramen from the anterior nasal spine, nasion, infraorbital margin, and the lower extent of the alveolar margin. The lengthof the infraorbital canal till the inferior orbital fissure and the infraorbital groove and the infraorbital canal orientation angles in different planes were also measured. The measurement values were compared between the right and left side hemi-skulls. Results The oval-shaped infraorbital foramen was most commonly noticed. The mean vertical and transverse diameters were 3.8 mm and 2.6 mm, respectively, on the right side. The left side's mean vertical and transverse diameters were 3.9 mm and 2.5 mm, respectively. The most common location of infraorbital foramen was in line with the maxillary second premolar tooth. The distances of infraorbital foramen from the alveolar margin were 29.6 mm and 29 mm on the right and left sides, respectively. The distances of the infraorbital foramen from the anterior nasal spine were 34.3 mm and 34.2 mm on the right and left sides, respectively. The distances of infraorbital foramen from the nasion were 42.3 mm and 42.2 mm on the right and left sides, respectively. The distances of infraorbital foramen from the inferior orbital margin were 5.8 mm and 6.2 mm on the right and left sides, respectively. The distances between the inferior orbital margin and infraorbital groove were 12.7 mm and 12.7 mm on the right and left sides, respectively. The distances between the inferior orbital margin and inferior orbital fissure were 27.5 mm and 27.1 mm on the right and left sides, respectively. The orientation angles of infraorbital foramen were 48.31° in the horizontal plane, 34.07° in the Frankfurt plane, and 14.4° in the parasagittal plane. Conclusion Our findings suggest that the location of the infraorbital foramen is difficult to standardize, considering the wide interindividual variations in the foramen relations.Further research should be performed to investigate the parameters related to the distance and orientation of the infraorbital foramen in relation to nearby bony landmarks that are least affected by individual variations in skull morphology.

Investigating the relationship between infraorbital canal morphology and maxillary sinus size.

The purpose of the current study was to investigate relationships between maxillary sinus (MS) dimensions and the bony structures associated with the infraorbital nerve (ION). Computed tomographic scans of 87 adult crania (174 sides) from four morphologically diverse groups (West Africans, East Africans, North Asians, Europeans) were utilized. Seven primary variables were collected: infraorbital canal (IOC) type; infraorbital foramen (IOF) shape; distance from the foramen rotundum to IOF (FR-IOF); distance from the posterior wall of the infraorbital groove to IOF (IOG-IOF); and MS length, breadth, and height. Chi-square analyses indicated a significant association between IOC-type and IOF-shape (Pearson chi-square=12.710; p-value=.013), with the most common pattern being oval IOFs and Type-I IOCs (45.68% of the sample; 74/162 sides). Analysis of covariance indicated a significant effect of ancestry (F=8.333; p < .001) and MS length (F=15.406; p < .001) on IOG-IOF distance. Ordinal regression analyses indicated that MS length (Wald chi-square=7.103; p=.008) also maintained a significant effect on IOC-type, while multinominal regression analyses indicated that none of the measured parameters had a significant effect on IOF-shape. These results have clinical implications: recognizing IOC-type and IOF-shape relative to the MS is important to avoid ION damage during medical procedures. Overall, this study found most individuals possess Type-I IOCs (housed in the maxillary sinus roof) and oval-shaped IOFs. Most aspects of the ION pathway, including IOC-type and IOF-shape, were not influenced by ancestry or sex. However, antero-posteriorly longer MSs tend to possess Type-III IOCs protruding into the sinus, which could lead to surgical complications.

Transantral intraseptal sinuous canal

The sinuous canal is an anatomically well-defined intramural canal of the maxillary sinus (MS) folded within the antral walls. Commonly, its first, infraorbital part, courses within the antral roof, while its second, transverse facial part courses below the infraorbital foramen within the anterior antral wall. While retrospective files of patients that were scanned in cone-beam computed tomography (CBCT) for different dental medical purposes were observed randomly, a peculiar variant of the sinuous canal was noticed and further documented. The respective canal origin was far posterior in the infraorbital groove and the canal coursed through the MS embedded within an incomplete oblique septum dividing the antrum into anterosuperior and posteroinferior chambers. Then the sinuous canal continued with the transverse facial segment. As the sinuous canal contains the superior anterior alveolar nerve and artery, major suppliers of the frontal teeth, it is recommended to document in CBCT a possible transantral, and not intramural, course of it, especially when surgical or endoscopic corridors through the MS are planned.

Anatomical implication of less occurrence of inferior oblique muscle entrapment in orbital floor trapdoor fracture

To examine the anatomy of the inferior oblique (IO) muscle and its surrounding structures to clarify why IO muscle entrapment develops less in orbital floor trapdoor fractures. Computed tomographic (CT) images on the unaffected sides were obtained from 64 patients with unilateral orbital fractures. On coronal planes, presence or absence of an infraorbital groove below the IO muscle was confirmed. At the level of the medial margin of the infraorbital groove/canal, the distance from the orbital floor to the IO muscle (IO-floor distance), the thickness of the orbital floor, and the shortest distance from the inferior rectus (IR) muscle to the orbital floor (shortest IR-floor distance) were measured. On quasi-sagittal planes, the distances from the inferior orbital rim to the inferior margin of the IO muscle (IO-rim distance) and the most anterior point of the infraorbital groove (groove-rim distance) were measured. The infraorbital groove was found below the IO muscle in eight patients (12.5%), and the IO-rim and IO-floor distances were significantly longer than the groove-rim and shortest IR-floor distances, respectively (p < 0.001). The orbital floor below the IO muscle was significantly thicker than that below the IR muscle (p < 0.001). Although the medial margin of the infraorbital groove is the most common fracture site, the IO muscle was not located above the groove in most cases. A longer IO-floor distance and thicker orbital floor below the IO muscle may also contribute to less occurrence of IO muscle entrapment in orbital floor trapdoor fractures.

Novel technique for infraorbital groove correction using multiple twisted polydioxanone thread.

The infraorbital groove can be corrected by lower blepharoplasty, microfat grafting, and soft tissue filler injection. Recently, multiple twisted polydioxanone threads were developed for facial rejuvenation. This study aimed to examine the efficacy and associated risks of the use of new synthetic threads for infraorbital groove correction. From March 2018 to June 2019, 40 patients (mean age: 43.4years; range: 25-56years) underwent transcutaneous multiple twisted thread insertion to correct the infraorbital groove. Three threads were inserted along the infraorbital groove on each side. The outcomes were assessed based on a comparison between preprocedure and postprocedure findings. Barton's grading and Global Aesthetic Improvement Scale scores were assessed by two physicians. Patient satisfaction with the aesthetic outcome of the procedure was evaluated at the end of the procedure and after 3months. Ultrasonographic evaluation was performed to confirm that the threads had been properly placed. The anatomical layer in which the threads were placed was evaluated in a cadaveric study. The mean Barton grade improved significantly (P<.001) without decline throughout the 12-week period. Improvement was found in all patients who were designated with a score >2 ("improved"). More than 77.5% of the patients were satisfied with the outcomes, and the rest of the patients reported some extent of correction with little satisfaction. The findings indicate the benefits of the multiple twisted polydioxanone thread insertion in the treatment of patients with infraorbital groove without septal protrusion. This evaluation raised no major safety concerns.

Infraorbital groove correction by microfat injection after lower blepharoplasty

Blepharoplasty alone cannot completely correct deep infraorbital grooves because of its limited ability to improve anatomical volume loss. As the concept of resolving periorbital fat atrophy to improve the infraorbital groove was introduced, several methods to properly fill the groove have been attempted. The purpose of this study was to present a new technique, involving the use of autologous fat from periorbital compartments, for infraorbital groove correction after lower blepharoplasty. Fifty patients (mean age, 55.9 years; range, 41-75 years) underwent transcutaneous lower blepharoplasty between December 2016 and August 2018. Infraorbital septal fat was harvested during the operation; after lower blepharoplasty, transcutaneous microfat was injected into the infraorbital groove. One month after the procedure, 46 patients were satisfied or very satisfied with the results. One patient complained of an unsolved prominent infraorbital groove; additional microfat graft harvesting was performed from the abdomen after 6 months. Two patients complained of remnant septal bulging; additional transconjunctival fat was removed after 6 months. Five patients developed mild ectropion and recovered without any additional treatments. None of the patients developed infection, hematoma, lid retraction or any other complications. Microfat injection after lower blepharoplasty has become popular. The method described in this study has certain advantages: the amount of correction is accurate, there is no donor-site morbidity and both subcutaneous and submuscular layers can be corrected simultaneously.

Morphometric evaluation and surgical implications of the infraorbital groove, canal and foramen on cone-beam computed tomography and a review of literature.

The purpose of this study is to evaluate the anatomy, morphometry, and variations of infraorbital groove (IOG), infraorbital canal (IOC) and infraorbital foramen (IOF) on the cone-beam computed tomography (CBCT) images and to investigate their relations with surrounding structures. IOG, IOC and IOF were evaluated retrospectively in CBCT images of 75 female (F) and 75 male (M) cases with a range of 18-65 years (F: 37.62 ± ± 13.55, M: 37.53 ± 15.87) by Planmeca Romexis programme. IOG, IOC and IOF were examined bilaterally (300 sides) in the cases. The 13 parameters were measured on these images in axial, sagittal and coronal planes. There was a very weak positive correlation between the age and the angle between IOC and IOG (p = 0.015, r = 0.198), there was a weak positive correlation between the age and skin thickness (p = 0.001, r = 0.281), and there was no correlation between the age and other parameters. A total of 21 (7%) IOCs were detected in maxillary sinus, bilaterally in 6 cases and unilaterally in 9 cases (5 on the left, 4 on the right). In 1 case, bilaterally, IOC was separated 2 canals while running anteriorly in the maxillary sinus. The larger one was directed to IOF in its normal course and the smaller one was directed to lateral wall of nasal cavity and opened to the inferior nasal meatus in front of the opening of nasolacrimal duct. We suggest that the parameters found in the present study may facilitate prediction of the location of the infraorbital nerve. Knowledge of this exact position in relation to easily measurable parameters may decrease the risk of infraorbital nerve injury during surgical approaches directed to this region and might serve as a guide during local anaesthetic interventions for dentistry, ophthalmology, plastic surgery, rhinology, neurosurgery and dermatology.

Characteristics and dimensions of the infraorbital canal: a radiographic analysis using cone beam computed tomography (CBCT).

To analyze morphological characteristics and dimensions of the infraorbital canal-groove complex using cone beam computed tomography (CBCT), and to evaluate its relationship with adjacent anatomical structures. This retrospective study included CBCT scans of 100 patients taken between January and May 2014. Linear measurements of the infraorbital canal (IOC), the infraorbital groove (IOG) and the infraorbital canal-groove complex (IOC/G) were performed. Morphological variants of the IOC related to the maxillary sinus were classified into three types depending on the extent of protrusion of the canal into the sinus. Angles between the IOC and specific landmarks were measured to determine the direction of the IOC relative to the axial (A-ant) and sagittal (A-horiz) planes. A total of 127 IOCs were analyzed. The mean length of the IOC/G was 29 ± 3.0mm. This value comprised the mean distances of the IOC (24.4 ± 2.9mm) and the IOG (4.6 ± 1.7mm). For the different types of IOC morphology, Type 1 (IOC embedded in maxillary sinus roof) was the most common (n = 87, 68.5%). The mean angles of A-ant and A-horiz measured 48.9° ± 7.5° and 20.3° ± 7.9°, respectively. Knowledge of the IOC/G morphology and its variants is important for the prevention of infraorbital nerve injury due to anesthesia or surgical interventions in this area. The presented data of anatomical characteristics of the IOC/G could be helpful for the planning of surgeries in the maxillary region by means of CBCT imaging.

Extended Transconjunctival Lower Eyelid Blepharoplasty with Release of the Tear Trough Ligament and Fat Redistribution

Sir: In the August of 2017 issue of Plastic and Reconstructive Surgery, Wong and Mendelson published an interesting article in which the authors described in detail their methods of subtotally releasing the tear trough ligament and the orbicularis retaining ligament and redistributing the free orbital fat for the correction of the tear trough (lacrimal groove, nasojugal crease) and palpebromalar groove (lid-cheek junction) through the transconjunctival approach.1 Because the authors and we have similar treatment subjects (mainly Asians), and the periorbital rejuvenation is a subject on which we have worked intensively, we would like to share our thoughts about this technique. Wong and Mendelson have been consistently committed to studies of the anatomy of the periorbital region and midcheek and the antiaging treatments of the middle face.1–4 Their research achievements and surgical techniques of course contribute to better understanding the structures of these regions and choosing the optimum surgical procedure. The tear trough deformity is considered to be directly associated with the tear trough ligament, and the formation of the palpebromalar groove is mainly attributable to the orbicularis retaining ligament.2 It is also well known that the degree of infraorbital groove depends on the status of the tissue above (i.e., eye protrusion, prominence of the orbital fat pads, and looseness of the orbicularis oculi muscle and skin) and below (i.e., atrophy and descent of the malar fat pad and retrusion of maxillary) this furrow. Once the groove is seen, does it have to deal with the region? Everyone has the structure of the tear trough ligament (although it may be fragile and thus invisible), and almost all of the patients with eye bags have different degrees of prominence of the nasojugal crease. With these factors in mind, it is important for us to classify the tear trough deformity according to the morphologic features of the lacrimal groove and the situations of the surrounding tissue (because of the limit of article length, this section is not described here in detail). In other words, a judgment of which factor (i.e., the tear trough ligament, the surrounding tissues, or a combination of them) plays the major role in increasing the prominence of the tear trough must be correctly made preoperatively. In the article by Wong and Mendelson,1 the extended transconjunctival lower eyelid blepharoplasty with ligament release was performed on the patient (shown in Fig. 11) who had a mild eye bag and a slight tear trough even when smiling on the frontal view. According to our experience, we usually attribute the formation of this type of crease to the protruded orbital fat compartment. We do believe that transconjunctival blepharoplasty only with orbital fat removal can achieve a similar effect. The tear trough deformity that is visible in the static condition should be treated by ligament release, as shown in Figures 6 through 10. However, the surgical approach should be appropriately selected based on the laxity of the orbicularis oculi muscle and skin. Thus, we think that a transcutaneous approach may be preferential for the patient shown in Figure 10. Skin removal and tightening/suspending the orbicularis oculi can be performed simultaneously for better cosmetic outcome. It has been widely accepted that lifting is an essential step after releasing the tear trough ligament and orbicularis retaining ligament for treatment of the aging middle face, and that tissue suspension or repositioning seems unnecessary following the release of the two ligaments when aiming at correcting the periorbital groove. Although releasing the ligament does not lead to tissue ptosis in young patients or in short-term follow-up (as most of the cases presented in previously published articles), it is uncertain whether such a release procedure without suspension or repositioning will contribute to tissue ptosis over a long observation period such as 10 or 20 years. After all, a ligament, although it may create a depression or a crease/groove, may play a role in balancing the related tissue and preventing ptosis of tissue. DISCLOSURE The authors declare no potential conflicts of interest with the respect to the research, authorship, or publication. Qianwen Wang, M.D., Ph.D.Jiaqi Wang, M.D.Head & Neck Cosmetic Surgery CenterPlastic Surgery HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, People’s Republic of China

Branching Variants of the Infraorbital Nerve

The aim of the present work was to identify variants of the distribution and branching of the infraorbital nerve (ION) in the infraorbital canal. The Vorob’ev macromicroscopic method was used to prepare the heads of 23 people (11 male and 12 female) aged from neonatal to 74 years. The ION could divide into branches at the level of the inferior orbital fissure, at the beginning of the infraorbital groove, the infraorbital canal, the infraorbital foramen, and after emerging from the infraorbital foramen. Some preparations showed accessory infraorbital foramina though which branches of the ION passed. The nerve in 15 preparations consisted of one stem and divided into branches at the infraorbital foramen or 3–6 mm distal to it (magistral branching). Accessory foramina in most cases were round or flattened-round in shape. Data are presented on the different variants of the structure and topography of accessory infraorbital foramina.

An anatomical study of the orbital floor in relation to the infraorbital groove: implications of predisposition to orbital floor fracture site.

To examine the anatomy of the orbital floor in relation to the infraorbital groove. Twenty-two Japanese cadavers aged 86.9 ± 6.0years at death were used. We examined whether the bony overhang on the infraorbital nerve extending laterally was connected to the segment medial to the infraorbital groove. The bone thicknesses at 1, 2, and 3mm anterior to the junction between the infraorbital groove and the inferior orbital fissure were measured along the groove. We examined the angle between the infraorbital groove and the orbital floor, both at the medial and lateral margins, at the thinnest point in the above three measurement points. We used the measurement values examined in the left orbits to prevent doubling the number of the orbits. The bony overhang was not connected to the medial segment in 19 (86.4%) orbits. The thickness at the thinnest point was thinner in the medial portion (1.02 ± 1.20mm) than in the lateral portion (2.60 ± 1.82mm; p = 0.001). The angle between the medial margin and the orbital floor was obtuse (156.5° ± 12.3°), compared with that of the lateral margin (104.0° ± 17.0°; p < 0.001). The results of this study imply that the medial portion has an anatomical weakness and few supportive structures. Although these findings were obtained only from Japanese cadavers, there may be associated with frequent occurrences of an orbital floor fracture just medial to the infraorbital groove.

Morphometric analysis of the infraorbital foramen, canal and groove using cone beam CT: considerations for creating artificial organs.

The aim of this study was to examine the anatomy and variations of the infraorbital foramen and its surroundings via morphometric measurements using cone beam computed tomography (CBCT) scans derived from a 3D volumetric rendering program. 354 sides of CBCT scans from 177 patients were examined in this study. DICOM data from these images were exported to Maxilim® software in order to generate 3D surface models. The morphometric measurements were done for infraorbital foramen (IOF), infraorbital groove (IOG) and infraorbital canal (IOC). All images were evaluated by 1 radiologist. To assess intra-observer reliability, the Wilcoxon matched-pairs signed rank test was used. Differences between sex, side, age and measurements were evaluated using chi-square and paired t-test and measurements were evaluated using 1-way ANOVA tests. Differences were considered significant when p<0.05. The most common shape was oval for IOF and parallel for IOC without any accessory foramen. The results showed that females have smaller dimensions for the measurements between the two foramen rotundum (FR), FR-IOF, sella-FR, center of the IOF (cIOF)-nasion (N), cIOF-NB (nasion-B) (p>0.05). No significant difference was found according to age groups (p>0.05). These results provide detailed knowledge of the anatomical characteristics in this particular area. CBCT imaging with lower radiation dose and thin slices can be a powerful tool for anesthesia procedures like infra orbital nerve blocks, for surgical approaches like osteotomies and neurectomies and also for generating artificial prostheses.

Redesign and treatment planning orbital floor reconstruction using computer analysis anatomical landmarks.

Orbital floor fractures are one of the most commonly encountered maxillofacial fractures due to their weak anatomical structure. Restoration of the orbital floor following a traumatic injury or a tumor surgery is often difficult due to inadequate visibility and lack of knowledge on its anatomical details. The aim of this study is to investigate the locations of the inferior orbital fissure (IOF), infraorbital groove (G), and infraorbital foramen (Fo) and their relationship with the orbital floor using a software. Measurements from the inferior orbital rim (IOR) using the Fo, the IOF, G, and the optic canal (OC) were calculated in 268 orbits as reference points. The surgical landmarks from the G and the OC, the G and the IOF, the G and the intersection point were measured as 31.6±6, 12.9±4, and 12±5mm, respectively. The mean distances between the G and the IOR, the Fo and the IOF, and the Fo and the OC were found as 8.3±2.1, 28.7±3.5, and 53.6±5.9mm, respectively. The mean angles were calculated as OC-IOF-G 68.1°±16.4°; intersection-G-IOF as 61.4°±15.8°; IOF-OC-G as 19°±5.5°; OC-G-intersection as 31.5°±11.9°, G-intersection-OC as 129.5°, IOF-intersection-G as 50.5°. Furthermore, variable bony changes on the orbital floor which may lead to the differences at intersection point of the G and Fo were determined. In 28 specimens (20.9%), unilateral accessory Fo (AcFo) was present. In 27 specimens, AcFo was situated supermaedially (96.4%) on the main aperture. In one specimen, two intraorbital canals and Fo emerged from different points and coursed into different apertures. The measured mean distances of the AcFo-IOR and the AcFo-Fo were as 7±2 and 7.3±3.2mm, respectively. The primary principle in the oculoplastic treatment of orbital floor reconstructions must be repositioning the herniated orbital aperture by maintaining the infraorbital artery and the nerve in the orbital floor. The IOF and the G were recommended as the more reliable oculoplastic surgical landmarks for identifying the orbital floor. To avoid pinching of the orbital floor structures, the triangle (IS-G-IOF) should be equilateral with an exigence of a 70° angle within it. Among each distance of the intersection-IOF, IOF-G, G-intersection should be equal. With the help of certain software, this study made possible to investigate the variability of the orbital floor structures, observe the variety in measurements and calculate the parameters which are crucial in implementing personalized reconstruction and implanting support.

Infraorbital groove localisation for the endoscopic decompression of the orbit in Graves' disease.

The aim of our study was to determine the localisation of the inferior margin of the optic canal in relation to the infraorbital canal/groove complex (IOC/G complex) and zygomaticoorbitale (ZO) as the potential useful landmarks for reducing dangerous complications following surgical and invasive procedures. Sixty-four orbits of thirty-two human skulls were investigated. The distances between: the inferior margin of the optic canal and the posterior margin of the infraorbital groove measured at its medial border (OC-S); the inferior margin of the optic canal and the posterior margin of the roof of the infraorbital canal (OC-C); the inferior margin of the optic canal and the zygomaticoorbitale (OC-ZO) - were measured. The left/ /right symmetry ratio and the asymmetry index were counted. The symmetry between the contralateral measurements was analysed and statistical analysis was performed. On the right side the mean distance from the inferior margin of the optic canal to: the posterior margin of the infraorbital groove measured at its medial border; to the posterior margin of the roof of the infraorbital canal; and to the zygomaticoorbitale were: 23.41 ± 3.10 mm; 34.44 ± 5.30 mm; and 47.53 ± 4.13 mm, respectively. On the left side the mean distance from the inferior margin of the optic canal to: the posterior margin of the infraorbital groove measured at its medial border; to the posterior margin of the roof of the infraorbital canal; to the zygomaticoorbitale were 23.69 ± 2.80 mm; 36.75 ± 5.10 mm; 46.84 ± 3.24 mm, respectively. The presented measurements may be particularly helpful for endoscopic decompression in patients with the thyroid ophthalmopathy to avoid the complications.