Anatomic characteristics of the infraorbital foramen: a cadaver study.

PURPOSE: The aim of this study was to document the variability in the position of the infraorbital foramen with relation to the facial midline, infraorbital rim, supraorbital notch, and maxillary teeth. MATERIALS AND METHODS: Forty-seven cadavers (94 sides) were dissected, exposing the infraorbital foramen, supraorbital foramen, and orbital floor bilaterally. Measurements made included (A) distance between the infraorbital foramen and inferior orbital rim; (B) distance of the infraorbital foramen from the facial midline; (C) distance of the supraorbital foramen from the facial midline; (D) distance between the infraorbital foramen and supraorbital foramen. Means, standard deviations, and ranges were determined, and statistical differences were calculated between the left and right orbits and sexes by use of an unpaired sample t-test (P < .05). RESULTS: In men, the mean distance between the infraorbital foramen and the inferior orbital rim was 8.5 +/- 2.2 mm. In women, this was 7.8 +/- 1.6 mm. The distance between the infraorbital foramen from the facial midline was 27.7 +/- 4.3 mm in males and 26.2 +/- 3.2 mm in females. The mean distance between the infraorbital foramen and supraorbital notch in males was 43.3 +/- 3.1 mm and in females was 42.2 +/- 2.4 mm. The average distance of the supraorbital notch from the midline was 26.5 +/- 3.5 mm in males and 26.3 +/- 3.3 mm in females. There were no statistically significant differences between the left and right sides or between sexes. The maxillary tooth most commonly found in the same vertical plane as the infraorbital foramen was the first premolar. Multiple ipsilateral foramina were found in 15% of cadavers. CONCLUSION: These anatomic characteristics may have important implications for surgical and local anesthetic planning.     

Anatomy of the lateral canthal tendon

OBJECTIVE: The purpose of this study was to clarify and describe the anatomy of the lateral canthal tendon. Knowledge of this anatomy is essential in selection of appropriate surgical procedures to restore orbital anatomy. STUDY DESIGN: Gross dissections were performed of the lateral orbital soft tissues from 21 preserved Caucasian cadaveric orbits. A block of the bony attachment of each lateral canthus was taken for histologic examination. After anatomical exposure, the following measurements of the lateral canthus were made: (1) the distance from the midpoint of insertion of the lateral canthus at the lateral orbit to the zygomaticofrontal suture; (2) the horizontal width of the lateral canthus, as measured from the lateral commissure to the lateral orbit; (3) the vertical difference in height between the medial canthal and lateral canthal insertions. RESULTS: The mean midpoint of the lateral canthus insertion was 10. 24 mm inferior to the zygomaticofrontal suture (range, 5-15 mm). The mean horizontal length of the lateral canthus from the lateral commissure to the lateral orbit was 7.52 mm (range, 2-12 mm). The mean vertical difference in height between the insertions of the medial canthus and the lateral canthus was 1.35 mm (range, -2-4 mm), the lateral canthus being at a more superior point. Histologic examination of hematoxylin-eosin-stained slides showed that the fibers of the lateral canthus inserted into the periosteum but not beyond it. CONCLUSIONS: The lateral canthal tendon attaches the upper and lower tarsal plates to Whitnall's tubercle inside the orbital rim deep to the septum. A precise knowledge of the periorbital anatomy will assist the surgeon in the selection of appropriate surgical techniques that will provide for restoration of this delicate anatomical configuration.     

Location and nature of retro-orbicularis oculus fat and suborbicularis oculi fat

The aim of this study is to elucidate the anatomic location and histologic nature of the retro-orbicularis oculus fat (ROOF) and suborbicularis oculi fat (SOOF) around the orbital area. Seventeen hemifaces of 12 Korean adult cadavers were used. ROOF and SOOF were observed in all specimens. ROOF was located in a supraorbital area within a range of between a medial +41 and a lateral -39 degrees to a vertical midpupillary line. The shape is crescent and almost symmetric when folded in half. The horizontal length of ROOF was approximately two thirds of a transverse orbital dimension. The height was approximately one third of a vertical orbital dimension. SOOF was located in the inferolateral side of the orbit within a range between a medial +15 and a lateral -89 degrees to a vertical midpupillary line. The SOOF looks like a hockey stick head. The SOOF is divided into two parts, horizontal and vertical. The length of the SOOF horizontal part is almost equal to a transverse orbital dimension (a). The height of the SOOF vertical part was approximately three fourths (bx3/4) of the vertical orbital dimension (b), and the width of vertical part was one fourth (a/4) of a transverse orbital dimension (a). Most of the SOOF vertical part was outside the lateral orbital rim, and the horizontal part was below the infraorbital rim. Histologically, ROOF and SOOF were situated deep to the orbicularis oculi muscle and superficial to the orbital septum and periosteum. ROOF and SOOF consisted more of fibrofatty tissue than the pure fatty nature of orbital fat. The findings in this study might be conducive to the practice of blepharoplasty and midface lift.     

A simple and reliable landmark for identification of the supraorbital nerve in surgery of the forehead: an in vivo anatomical study.

PURPOSE: In this in vivo study, we set out to determine the reliability of the medial margin of the iris as a landmark for the course of the supraorbital neurovascular bundle at the supraorbital rim. PATIENTS AND METHODS: Seventy-five patients (73 women and 2 men) undergoing endoscopic brow lift procedures were enrolled, for a total of 150 sides. With the patient focused on a distant point, a line was constructed preoperatively along the mid-sagittal plane, tangential to the medial iris. After general anesthesia and initial dissection, a 27-gauge needle was placed (without the aid of the endoscope) through this line, parallel to the mid-sagittal plane at the orbital rim. Measurements were then taken following creation of the optical cavity. Measurements were taken from the course of the deep (lateral) branch of the supraorbital nerve to the needle. In addition, measurements were taken from the course of the supraorbital nerve to the course of the supratrochlear nerve. RESULTS: In 84 sides, the needle was at the nerve; in 48 sides, the needle was less than 1 mm to the nerve; and in 18 sides, the needle was 2 mm from the edge of the nerve. Overall, the nerve was an average of 0.56 +/- 0.7 mm from the needle, and in no case was the nerve course greater than 3 mm from the landmark. The supratrochlear nerve was located medial to the supraorbital nerve an average of 9.0 +/- 1.0 mm. CONCLUSIONS: Based on our findings, the medial iris, as opposed to the mid-pupil line, serves as a reliable topographical landmark for the course of the supraorbital nerve at the supraorbital rim.     

The anatomy of the palpebral branch of the infraorbital artery relating to midface lift

The aim of this study was to elucidate a branch of the infraorbital artery (IOA) crossing the arcus marginalis into the orbit that might be vulnerable during a procedure of midface lift or fat sliding or a transposition in lower blepharoplasty.Eleven orbits of 6 Korean cadavers were dissected after injecting red latex into the external carotid artery. The IOA and nerve were identified. A branch of the IOA running upward was traced. In 28 cases of blow-out fracture, a branch of the IOA crossing the arcus marginalis into the orbit was identified, and the location was measured from each medial and lateral canthus.The palpebral branch of the IOA (PIOA) emerged from the infraorbital foramen and ran superior and lateral to the orbital septum. After passing through the orbital septum near the arcus marginalis, PIOA was distributed to the orbital fat. The palpebral branch of the IOA was identified in 21 (75.0%) of 28 fractured orbits. Twenty orbits had 1 PIOA, and 1 orbit had 2 PIOAs. The location of PIOA from the medial canthus (49.0%) was approximately half of the eye width in average. Most of the PIOAs (91%, 20 of 22 arteries found) were included in the range of 40% to 80% of the eye width from the medial canthus.Knowledge of the anatomic course of the PIOA crossing the arcus marginalis is conducive to cauterizing the vessels, as needed, in the subciliary or transconjunctival approach for lower blepharoplasty.     

Surgical anatomy of the orbit of Korean adults.

When operating in and around the orbit, the key to a successful result is precise anatomical localization. However, there is no precise study about the localization of vital orbital structures from reliable periorbital bony anatomy of the Korean adult. This study was constructed to give pertinent anatomical measurements to which the plastic and maxillofacial surgeon may refer. The 82 orbits obtained from 41 skulls of adult Koreans were measured with Vernier calipers and Marshac calipers. Superiorly, the supraorbital fissure was 40.0 +/- 2.5 mm from the supraorbital notch. Medially, the posterior ethmoidal foramen was 31.7 +/- 3.0 mm from the anterior lacrimal crest. Inferiorly, the infraorbital fissure where the infraorbital groove started was 26.4 +/- 2.6 mm from the infraorbital foramen. Laterally, the supraorbital fissure was 34.3 +/- 2.7 mm from the frontozygomatic suture. These distances are suggested as appropriate safe distances from each periorbital bony landmark. Dissection beyond that distance should be done with great caution.     

Pattern of the temporal branch of the facial nerve in the upper orbicularis oculi muscle

The purpose of this study is to clarify a pattern of the temporal branch of the facial nerve in the upper orbicularis oculi muscle (OOM) and an impact in exploiting the frontalis myofascial advancement flap. The authors investigated the pattern of the temporal branch of the facial nerve in the upper OOM in 20 cadavers. The highest and lowest level of the nerve coursing into the OOM were measured at three different sagittal/vertical planes through the lateral canthus, midpalpebral fissure, and medial canthus, respectively. The authors designate a hazard zone that delineates a circle with 1.0-cm diameter and its center located inferiorly and laterally in the direction of -15 degrees 7.5 cm from the lateral canthus. The highest level of the those twigs that entered OOM on the X-axis and Y-axis with the origin of lateral canthus is +2.51 +/- 0.23 cm, +2.70 +/- 0.35 cm, and the lowest is 0 cm, +2.68 +/- 0.32 cm, respectively. The highest level of the those twigs on the Y-axis with the origin of lateral canthus, mid-palpebral fissure, and medial canthus is +3.47 +/- 0.27 cm, +3.49 +/- 0.45 cm, and +2.97 +/- 0.35 cm, and the lowest is +1.62 +/- 0.12 cm, +1.82 +/- 0.17 cm, and +1.63 +/- 0.22 cm, respectively. Those twigs of the temporal branch of the facial nerve coursed horizontally along the fibers of OOM with interconnections but did not cross over the superior orbital rim. The authors describe details of the temporal branch of the facial nerve in the OOM and designate a hazard zone, wherein the temporal branch should be spared. They also assure that injury of the temporal branch of the facial nerve is inevitable in the procedure of the frontalis myofascial advancement flap.     

Anatomical variations of the supraorbital, infraorbital, and mental foramina related to gender and side.

PURPOSE: The aim of the study was to examine the different anatomical variations of the supraorbital, infraorbital, and mental foramina related to gender and side. MATERIALS AND METHODS: Measurements were made on 110 adult skulls without mandibles and isolated mandibles. Gender was determined for each skull. Parameters measured bilaterally included the distances from the supraorbital and mental foramina to midline, from the infraorbital foramen to the anterior nasal spine, from the infraorbital foramen to the inferior orbital rim, and from the mental foramen to the inferior rim of the mandible and the angle between the line linking the infraorbital foramen with the anterior nasal spine and horizontal plane. Comparisons were made between genders and sides and statistical analysis was done where appropriate using Student's t test. RESULTS: There were 70 male and 40 female crania. Nature of the 3 foramina was similar between sides and genders. The average distance from the left supraorbital foramen to midline in females was significantly lower than that in males (2.42+/-0.04 versus 2.56+/-0.05). The mean distances from the bilateral infraorbital foramina to anterior nasal spine in females were also significantly lower relative to those in males (3.28+/-0.03 versus 3.48+/-0.03 right and 3.31+/-0.03 versus 3.50+/-0.03 left). There were also considerable differences between sides in the average angle of the infraorbital foramen in both genders. CONCLUSIONS: Differences in several measurements suggest that gender and side should be considered when applying the anatomical variation data to an individual subject.     

The course of the temporal branch of the facial nerve in the periorbital region.

PURPOSE: This study identified the terminal temporal and zygomatic branches of the facial nerve as they enter the orbicularis oculi muscle and related these branches to identifiable surface markings. MATERIALS AND METHODS: The temporal and zygomatic branches of the facial nerve were dissected from 5 preserved cadavers (10 sides). The most superior temporal branch entering the orbicularis oculi muscle was identified and related to the lateral canthus of the eye. A vertical line was passed through this point so that the line was equidistant from the nasal tip and chin point. A line perpendicular to the vertical line through the lateral canthus served as the horizontal scale. Vertical and horizontal lines through the lateral canthus were used to establish the anatomic relationship between the lateral canthus and the branch of the temporal nerve entering the orbicularis oculi muscle. RESULTS: The temporal branch was an average of 2.85 +/- 0.69 cm superior to the lateral canthus and an average of 2.54 +/- 0.43 cm lateral to the lateral canthus as it courses into the orbicularis oculi muscle. At the lateral border of the orbicularis oculi muscle, where the temporal and zygomatic nerves insert into the muscle, the mean vertical distance between the temporal and zygomatic nerves was 1.72 +/- 0.62 cm. CONCLUSION: Incisions superior or inferior and parallel to the course of the facial nerve, can provide access to the fronto zygomatic suture and the superior and lateral orbit without damaging its branches.     

Location of supraorbital foramen/notch and infraorbital foramen with reference to soft- and hard-tissue landmarks

The purpose of the present study was to determine the locations of the supraorbital foramen (SOF) and the infraorbital foramen (IOF) relative to soft- and hard-tissue landmarks. It will provide more accurate data for dental and facial surgery. Twenty embalmed adult cadavers (40 sides; 16 men, 4 women) were dissected to expose the SOFs and IOFs, and another 46 skulls (92 sides) were also measured for further study. The locations of the SOFs and IOFs were evaluated with direct and photographic measurements. The data gained were analyzed by statistical method. The horizontal distances between the SOFs/IOFs and the medial canthus to the distance between the medial canthus and the lateral canthus ratios have been measured, and their confidence intervals are 0.22 to 0.31 and 0.34 to 0.49, respectively, and their linear regression equations are EF = 0.58 CF + 25.02 (unit: mm) and EF = 0.51 DG + 24.20 (unit: mm). The vertical distance between IOFs/SOFs and the medial/lateral canthi are 25.09 ± 3.36 mm/23.91 ± 3.31 mm and 25.75 ± 3.34 mm/26.93 ± 3.88 mm, respectively. The horizontal angle between IOFs/SOFs and the medial/lateral canthi are 72.54 ± 7.13 degrees, 66.77 ± 5.17 degrees, 47.45 ± 6.57 degrees, 54.69 ± 8.38 degrees, respectively. Based on the hard tissues, The SOF localized 20.55 ± 3.24 mm medial and 13.78 ± 2.60 mm superior to the zygomaticofrontal suture. And the horizontal angle between them is 56.04 ± 6.87 degrees. The IOF localized 18.52 ± 2.30 mm medial and 30.79 ± 3.29 inferior to the zygomaticofrontal suture. The horizontal angle between them is 31.06 ± 4.33 degrees. We also found that most (96.81%) of the IOFs were located below the middle line of the zygomatic arch. These results may provide more detailed information about the locations of SOF and IOF. And they will facilitate prediction of the locations of IOF and SOF in clinical procedure.     

Anatomy of the supraorbital region and the evaluation of it for the reconstruction of facial defects

Damaged supraorbital neurovascular bundle during anterior orbital approach, fronto-glabellar reconstruction flap, supraorbital injection, blepharospasm, and Graves disease surgery is an important complication reported with varying frequency. The origin, calibration, and branches of the supraorbital artery and its topographical relations were investigated by injection of the arterial bed with red-dyed latex in 38 forehead regions. The supraorbital artery with the supratrochlear artery arose from the orbit as two separate vessels in 33 out of 38 forehead sides (87%). The supraorbital artery entered the frontalis muscle between 20 and 30 mm in 20 cases (52.6%), and between 30 and 40 mm in 16 cases (42.1%). This artery was located approximately the subcutaneous tissues between 40 and 50 mm in 17 cases (44.7%), between 50 and 60 mm in 18 cases (47.4%). The transverse supraorbital vein coursed at the level of the orbital rim on 22 sides (58%) and between 6.1 and 11.2 mm (mean: 9.4 mm) above the supraorbital rim on 16 sides (42%). All branches of supraorbital nerve were located between 2.0 and 3.2 cm from the midline at the level of the orbital rim. In 23 cases (60%), the lateral branch of the supraorbital nerve exited the bone as two branches, usually one large and one much smaller, which can together run into the scalp without further branching. In the present anatomical study, special attention was paid to morphological details concerning the neurovascular relationship of the supraorbital region. A better understanding of the midline forehead neurovascularity should allow modification of reconstructive techniques, afford better localization of the supraorbital nerve during blepharoplasty and ptosis surgery, and reduce the incidence of postoperative hematomas and nerve injuries.     

Surgical anatomy of retaining ligaments in the periorbital area

The aim of this study was to elucidate an anatomic detail of ligamentous attachments in the periorbital areas of Korean cadavers. Sixty-one hemifaces of 35 Korean adult cadavers (age range, 43-101 years; 23 men and 9 women) were used. Fifty-five specimens were dissected, 12 used for tension measurement, and 6 for histologic study.Definite retaining ligaments were found in 42 (76.4%) of 55 dissected hemifaces. We named the retaining ligaments attached to the bony orbit periorbital ligament (PL). Periorbital ligament was in the medial and lateral orbital area. Medial PL (MPL) was curvilinear shaped and between an angle of +23.4 and -23.1 degrees on the horizontal at a midpupillary line. Lateral PL (LPL) was crescent shape and between an angle of +39.1 and -42.1 degrees. The MPL was vertical along the medical orbital rim just outer to the orbital septum. The width of MPL was 0.8 mm, and vertical length was 22.1 mm. The crescent-shaped LPL was located a few millimeters (up to 4 mm) lateral to the lateral orbital rim. The maximum width of LPL was 6.9 mm, and vertical length was 28.2 mm. The breaking strength of the LPL (14.2+/-11.1 N) was significantly higher (P=0.016) than that of the central lower eyelid (5.1+/-2.5 N). The breaking strength of the MPL (8.4+/-3.0 N) was also significantly higher (P=0.013) than that of the central lower eyelid. However, there was no significant difference between LPL and MPL (P=0.055).Knowledge of the retaining ligaments is conducive to performing the midfacial rejuvenating surgery.     

In situ fronto-orbital advancement with medial orbital osteotomies for trigonocephaly-associated hypotelorism

In treating trigonocephaly, the value of direct surgical correction of orbital hypotelorism is controversial. In many cases of hypotelorism, the distance between the orbits increases over time after traditional fronto-orbital advancement. Still, more severe hypotelorism is not fully corrected and may benefit from a more definitive surgical intervention. We describe an in situ fronto-orbital advancement that improves severe hypotelorism and simplifies the surgical treatment of trigonocephaly. The key modification to traditional fronto-orbital advancement is an in situ medial orbital osteotomy that extends along the medial orbit, posterior to the medial canthus, and then across the inferior orbital rim into the piriform aperture. The procedure is indicated only in patients with more severe hypotelorism on physical examination. Rather than creating a freely removable bandeau during the operation, the bone segment composed of the supraorbital bar and superior orbits remains attached at the medial canthi. A midline osteotomy allows the respective orbital segments to be independently mobilized with the medial canthi left attached, and the space between them widened with gentle lateral traction and placement of an interpositional bone graft. Concomitantly, the lateral orbits and lateral supraorbital bar are contoured, advanced, and fixed with resorbable plates and screws. Representative results are shown. In situ fronto-orbital advancement with medial orbital osteotomies is a safe, efficient, and relatively simple technique that results in immediate improvement of hypotelorism and may be a worthwhile maneuver to consider in selected cases.     

Innervation features of the extraocular muscles

Several transcranial surgical approaches such as frontoorbital, lateral, medial, central, inferolateral, and transmaxillary orbitotomy have been used for exposure of lesions within the orbit. During surgical approaches, detailed anatomic knowledge regarding neural, muscular, and neighboring structures for preservation of the neurovascular structures is important in avoiding traumatic retraction of the nerves of the extraocular muscles. For this study, a total of 22 formalin-fixed cadavers were dissected. Vascular structures were perfused with colored latex to facilitate their definition. In this study, the orbit was investigated in two divisions, superior and inferior. In the superior division, innervation features of the levator palpebrae superioris, the superior rectus, and superior oblique muscles were examined. In the inferior division, innervation features of the medial rectus, the lateral rectus, the inferior rectus, inferior oblique muscles, and ciliary ganglion were investigated. The diameter of the oculomotor nerve (CN3) within the superior orbital fissure was measured as 2.10 mm on the right and 2.09 mm on the left. The diameter of the superior division of the CN3 was on average 1.54 +/- 0.30 mm on the right and 1.65 +/- 0.30 on the left. The mean diameter of the inferior division was measured as 1.85 +/- 0.22 mm on the right and 1.94 +/- 0.20 on the left. In the lower wall of the orbit, different branching types of inferior division of CN3 were observed. The diameter of the trochlear nerve in the superior orbital fissure was on average 1.15 +/- 0.19 mm on the right and 1.21 +/- 0.21 mm on the left. The diameter of the abducens nerve in the superior orbital fissure was on average 1.54 +/- 0.24 mm on the right and 1.54 +/- 0.22 on the left. The number of small branches entering the muscle was on average three branches. Areas nervosa of the nerves were located in the middle one third of the muscles. In this study, detailed knowledge regarding the innervation features of extraocular muscles was attained. An understanding of the innervation features of extraocular muscles is important for the preservation of neural structures during intraorbital procedures.     

An anthropometric analysis of the key foramina for maxillofacial surgery.

PURPOSE: The study goal was to determine the location of important maxillofacial foramina relative to frequently encountered surgical landmarks. MATERIALS AND METHODS: Measurements (1,120) were made on 80 cadaveric heads of known race and gender to evaluate the position of the supraorbital, infraorbital, and mental foramina relative to surgical landmarks. RESULTS: Analysis of the data determined the supraorbital foramen to be an average of 2.5 cm lateral to the nasal midline and 2.6 cm medial to the temporal crest of the frontal bone. Of the supraorbital foramina, 92.5% were notches and not true foramen. The infraorbital foramen was an average of 2.7 cm lateral to the nasal midline, 0.64 cm caudad to the inferior orbital rim, and 0.03 cm medial to the zygomaticomaxillary suture. The mental foramen was an average of 2.2 cm lateral to the mandibular skeletal midline. The average position of the mental foramen, relative to adjacent teeth, was between the first and second premolars for whites and just posterior to the second premolar in blacks. CONCLUSION: The measurements show small but significant differences in foramen location between whites and blacks and males and females. The knowledge of the distances from surgically encountered anatomic landmarks may be of assistance in locating these important maxillofacial neurologic structures during many procedures. This information may play an even more important role as new techniques for minimally invasive surgery are developed. Understanding the location of these foramina will also assist the clinician in performing local anesthetic blocks.     

Cutaneous distribution of zygomaticofacial nerve

The aim of this study is to elucidate the cutaneous distribution of the zygomaticofacial nerve (ZFN). Twenty hemifaces of 10 adult Korean cadavers were dissected. ZFN-innervated limits were rectangular and each side was 18.8 +/- 4 mm and 15.8 +/- 3.4 mm. The center of the rectangle was located laterally at 17.3 +/- 5.5 mm from the lateral canthus and then inferiorly at 18.1 +/- 3.1 mm. The cutaneous area innervated by the ZFN was rectangular shaped having a horizontal side that was 9.3 +/- 4% to 27.3 +/- 7.5%of the line from the lateral canthus to the root of helix and a vertical side that was 13.9 +/- 5.8% to 35.7 +/- 5.4% of the line from the lateral canthus to the oral commissure level. Knowledge of ZFN innervation is available with an intraoral approach in maloplasty or midface lift.     

Triangulating the ledge: radiographic study of the floor of orbit and derivation of a novel template

In orbital floor reconstruction, the need for the orbital implant to reach the exact position of the posteromedial ledge is essential, but owing to the complex anatomy of the region, visualisation of the ledge may be difficult. Several morphometric studies, both radiographic and cadaveric, have calculated a mean length from the orbital rim to the ledge. However, those linear measurements are unreliable and possess a higher margin of error for intraoperative guidance. This study attempts to triangulate the position of the posterior ledge from three easily accessible and reproducible points on the orbit and tries to provide a better guideline. A total of 50 patients (25 male and 25 female) with no history of orbital trauma or orbital surgery were selected randomly for this study. Computed tomography (CT) of both orbits, was done from three anatomically consistent and reproducible points: the infraorbital rim just above the infraorbital foramen (point A), hamulus lacrimalis (point B), and the most anterior point of the inferior orbital fissure (point C). The distance from these landmarks to the posterior ledge was measured using DICOM imaging software. A polygonal template was fabricated using the data obtained, which was used for intraoperative guidance. The mean (SD) distance to the posterior ledge from point A was 32.99 (1.35) mm, from point B was 31.36 (1.31) mm, and from point C was 20.19 (1.40) mm. There were no significant differences between left and right orbit or between male and female subjects. The template guides the shape, size, and direction of the orbital implant, reducing the risk of undersized or misplaced implants.     

Horizontal branch of the supraorbital nerve and temporal branch of the facial nerve

The aim of this article is to describe anatomical detail of the course and territory of the horizontal branch of the supraorbital nerve, which connects with temporal branch of the facial nerve. Eighteen hemifaces of Korean cadavers (11 male, 7 female) fixed in 10% formaldehyde solution were dissected. All 18 specimens had horizontal branch of the supraorbital nerve. The horizontal branch emerges out of the supraorbital foramen, runs upward about 12 mm, and then turns laterally at an angle of 104.7 degrees toward the end of the eyebrow. The average number of horizontal branches was 1.7 +/- 0.8. The skin boundary supplied by the horizontal branch was a circle with a diameter of 30 mm. The center was located at 30 mm lateral to the supraorbital foramen and 12 mm above. Grossly, the horizontal branch of the supraorbital nerve connected with the temporal branch of the facial nerve in 8 of 18 (44%) specimens. Microscopically, both nerve branches had common epineurium, but the perineuria were separated. The horizontal branch of the supraorbital nerve is in touch with the temporal branch of the facial nerve, and there are actual connections between them in 44% of cases.     

Maximum forces applied to the orbital floor after fractures

ABSTRACT: The objective of this study was to measure the force on and displacement of completely detached intraorbital tissue from thebony orbit, as a worst-case scenario after orbital trauma, to preserve the maximum load and predict the necessary strength of reconstruction materials. Six fresh-frozen human heads were used, and orbital floor defects in the right and left orbits were created by the direct impact of 3.0 J onto the globe and infraorbital rim. The orbital floor defect sizes and displacements were evaluated after performing a Le Fort I osteotomy. In addition, after the repositioning of the completely detached intraorbital tissue, the forces and displacements were measured. The mean orbital floor defect sizes were 208.3 (SD, 33.4) mm for globe impacts and 221.8 (SD, 53.1) mm for infraorbital impacts. The mean intraorbital tissue displacement after the impact and before repositioning was 5.6 (SD, 1.0) mm for globe impacts and 2.8 (SD, 0.7) mm for infraorbital impacts. After repositioning, the displacements were 0.8 (SD, 0.5) mm and 1.1 (SD, 0.7) mm, respectively. The measured forces were 0.10519 (SD, 0.00958) N without the incorporation and approximately 0.11128 (SD, 0.003599) N with the incorporation of reconstruction materials. The maximum forces on the completely detached orbital tissue were minimal (～0.11 N) and suggest the use of collagen membranes as reconstruction materials for orbital floor defects, at least in medium-sized fractures.     

Communication of infraorbital nerve and facial nerve: anatomic and histologic study

The maxillary nerve, second division of the trigeminal nerve, is entirely sensory. It has been reported that drooling may occur later in the event of fracture of the zygoma in which hypesthesia prevails. The aim of the study is to elucidate additional detailed anatomy of the infraorbital plexus, consisting of the superior labial branch of the infraorbital nerve and facial nerve in the cheek. The authors dissected infraorbital nerves and facial nerves in 16 cadavers. Most terminals of the zygomatic branch of the facial nerve emerged from under the levator labii superiors and zygomatic muscle and infraorbital nerve. A hazardous zone of infraorbital plexus is found in a circle 36 mm in diameter. Its center is located 22 mm below the inferior orbital foramen. This hazardous zone of infraorbital plexus should be kept in mind when performing any procedures related to zygoma, maxilla, or deep cheek injuries.