Three-dimensional study of the orbit-related structures according to sex, age and skeletal deformities

Objective: This study aimed to evaluate the relations between orbit-related structures and sex, age and skeletal deformities using cone-beam computed tomography (CBCT). Methods: This retrospective study evaluated 216 consecutive CBCT scans of patients, who were divided according to: sex (male, n=105; female, n=111), age (A1: 18-32 years, n=71; A2: 33-47 years, n=78; A3: 48-62 years, n=67), and skeletal deformities (Class I, n=70; Class II, n=75; Class III, n=71). The supraorbital foramen (SOF) location, volume of orbit, optic canal (OC) and infraorbital canal (IOC) were evaluated. Results were analyzed using the Gamma model test. The Tukey-Kramer post-hoc test was used to compare the variables with three factors (p<0.05). Results: The IOC volume showed higher values for male, A3 and class I patients. The SOF location and the orbital volume also showed higher values for male patients. Regarding the volume of CO, it showed higher values ​​for male and class I patients. Conclusions: According to our results, sex has been shown to have a significant influence on orbit-related structures. Age and skeletal deformities also influenced the volume of IOC and OC. These results eventually help the clinical practice, being useful for orbital reconstruction surgeries, anthropological studies, gender identification and identification of susceptibility to pathological conditions related to sexual dimorphism.

Incidence, Aetiology, and Associated Fracture Patterns of Infraorbital Nerve Injuries Following Zygomaticomaxillary Complex Fractures: A Retrospective Analysis of 272 Patients

Study Design: Retrospective study. Objective: Zygomaticomaxillary complex (ZMC) fractures are common facial injuries with heterogeneity regarding aetiologies, fracture types, infraorbital nerve (ION) involvement, and treatment methods. The aim of this study was to identify associations between aetiologies, fracture types, and neurological complications. Additionally, treatment methods and recovery time were investigated. Methods: Medical files of 272 patients with unilateral and bilateral ZMC fractures were reviewed, whose cases were managed from January 2014 to January 2019 at the Department of Oral and Maxillofacial Surgery, University hospitals Leuven, Belgium. History of ION sensory dysfunction and facial nerve motoric dysfunction were noted during follow-up. Results: ION hypoaesthesia incidence was 37.3%, with the main causes being fall accidents, road traffic accidents, and interpersonal violence. Significant predictors of ION hypoaesthesia were Zingg type B fractures ( P = 0.003), fracture line course through the infraorbital canal ( P < .001), orbital floor fracture ( P < 0.001), and ZMC dislocation or mobility ( P = 0.001). Conclusion: Of all ZMC fractures, 37.3% exhibited ION hypoaesthesia. Only ZMC Zingg type B fractures (74.0%) were significantly more associated with ION hypoaesthesia. ION hypoesthesia was more likely (OR = 2.707) when the fracture line course ran through the infraorbital canal, and was less dependent on the degree of displacement. Neuropathic pain symptoms developed after ZMC fractures in 2.2% patients, posing a treatment challenge. Neuropathic pain symptoms were slightly more common among women, and were associated only with type B or C fractures. No other parameters were found to predict the outcome of this post-traumatic neuropathic pain condition.

Comparison of three regional anaesthetic techniques for infraorbital or maxillary nerve block in cats: a cadaveric study

Objectives The maxillary nerve courses very close to the globe, rendering cats – with their large eyes – at risk of globe penetration during infraorbital or maxillary nerve blocks. Therefore, the goals of the study were to compare the distribution and potential complications of three infraorbital or maxillary regional injection techniques. Methods Twenty-three bilateral maxillae of cat cadavers were used in a randomised blinded trial. Each maxilla was injected with a 0.2 ml 1:1 mixture of lidocaine 2% and a contrast medium by one of three injection techniques: infraorbital foramen (IOF; n = 14); infraorbital canal (IOC; n = 16); or maxillary foramen (MF; transpalpebral approach; n = 16) using a 25 G 1.6 cm needle. CT imaging of each cadaver head was performed before and after injections. A radiologist scored injectate distribution (none [0], mild [1], moderate [2], large [3]) in four locations: rostral, central and caudal IOC, and at the MF, for which the distribution side was also determined. Comparisons were performed with ordinal logistic mixed effects ( P <0.05). Results The median (range) total distribution score of the IOC and MF technique were significantly higher compared with the IOF technique (6.5 [4–12], 4 [2–8] and 0 [0–10], respectively). The total IOC score was also significantly higher compared with the MF technique. Injectate distribution at the MF was significantly more central following IOC injection compared with MF injection, which distributed centrolaterally. None of the techniques resulted in intraocular injection. Conclusions and relevance The IOC and MF techniques produced a satisfactory spread of the mixture that could result in effective maxillary anaesthesia in cats. Further studies are required to determine the effectiveness and safety of these techniques.

Oxynoemacheilus amanos, a new nemacheilid loach from the Orontes River drainage (Teleostei: Nemacheilidae)

Oxynoemacheilus amanos, new species, is described from İncesu spring in the upper Hupnik drainage, a northern tributary of the lower Orontes in Turkey. It is distinguished from the other Oxynoemacheilus species in the Eastern Mediterranean Sea basin by possession of an incomplete lateral line with 23–45 pores, terminating between the vertical through the dorsal fin origin and the anus, 10–13 pores in the infraorbital canal, a deeply emarginate caudal fin, no suborbital groove in the male, and a series of irregularly shaped and set dark-brown bars on the flank, not connected to saddles on the back.

Cadaveric Evaluation of Injectate Distribution for Two Maxillary Nerve Block Techniques in Cats

Regional nerve blocks have been shown to decrease general anesthetic drug requirements and improve pain management in patients undergoing surgery. Regional nerve blocks are used routinely in patients undergoing oral surgery, such as dental extractions. There is little published information regarding the efficacy of feline maxillary and infraorbital nerve blocks. The goal of the study was to compare injectate distributions of the infraorbital foramen and percutaneous maxillary nerve block techniques in feline cadavers using a combined dye and radiopaque contrast media solution to simulate an injection. There was no significant difference in length of stained nerve between the two different techniques. It was not necessary to advance the needle into the infraorbital canal to achieve effective staining of the maxillary nerve. There was no significant difference in injectate distribution between two different injectate volumes, 0.2 and 0.4 ml, indicating that the smaller volume injected at the infraorbital foramen resulted in adequate nerve staining.

Iatrogenic ocular trauma associated with infraorbital block performed for rhinoscopy in a cat: case report and preliminary imaging findings

Objectives This paper describes a case of endophthalmitis in a feline patient caused by globe penetration during an infraorbital block performed to provide analgesia during rhinoscopy, and presents additional imaging and dissection data demonstrating risk of iatrogenic ocular trauma during infraorbital blocks in cats when the infraorbital canal is entered. Methods Case records and accompanying histopathologic reports were reviewed for the feline patient. Separately, two feline cadavers were imaged using CT following placement of 5/8" 25 G needles or 1" 22 G over the needle catheters in the infraorbital canal. Infraorbital blocks with injection of trypan blue dye followed by dissection were performed in two further feline cadavers to assess the potential for globe penetration and to provide preliminary information regarding the potential efficacy of infraorbital blocks for analgesia during rhinoscopy. Results Clinical and histopathologic findings support inadvertent globe penetration during infraorbital block as the cause for endophthalmitis in the feline patient described. CT imaging and dye injection studies further demonstrate the risks involved with this local anesthetic technique in cats. Conclusions and relevance Further study is needed to assess the safety and efficacy of infraorbital blocks performed for rhinoscopy in cats. Catheters may be safer anesthetic delivery devices than needles. Extreme caution should be used when entering the infraorbital canal in cats.

An Unusual Case of Perineural Infiltration and Orbital Invasion of Squamous Cell Carcinoma Associated with Actinic Keratosis

Actinic keratosis is considered a precancerous lesion, constituting a precursor to squamous cell carcinoma (SCC) formation. Perineural invasion has been observed in patients with cutaneous carcinoma due to local subcutaneous tissue destruction and primarily involves the trigeminal nerve due to rich innervation provided by the supraorbital nerve in addition to the facial nerve. An unusual case of perineural infiltration and orbital invasion of squamous cell carcinoma associated with actinic keratosis is presented. A 70-year-old Caucasian woman presented with complete left eye ophthalmoplegia, total left upper-eyelid ptosis, and facial pain with paresthesia. Computed tomography revealed a process of the soft tissues in the left cheek infiltrating the infraorbital canal, pterygopalatine fossa, inferior orbital fissure, and left cavernous sinus with periosteal adherence. Magnetic resonance imaging revealed pathological extension via the left infraorbital canal with a considerable area of necrosis. Treatment of facial actinic keratosis may not prevent malignant transformation and can delay diagnosis and treatment of SCC. A deep biopsy appears to be essential for a correct diagnosis. Perineural spread of cutaneous SCC may be characterized by insidious progression in the cranial trigeminal nerve, abnormal ocular motility, diplopia, or external ophthalmoplegia.

Ontogenetic and static allometry in the skull and cranial units of nine-banded armadillos (Cingulata: Dasypodidae: Dasypus novemcinctus)

A large part of extant and past mammalian morphological diversity is related to variation in size through allometric effects. Previous studies suggested that craniofacial allometry is the dominant pattern underlying mammalian skull shape variation, but cranial allometries were rarely characterized within cranial units such as individual bones. Here, we used 3D geometric morphometric methods to study allometric patterns of the whole skull (global) and of cranial units (local) in a postnatal developmental series of nine-banded armadillos (Dasypus novemcinctus ssp.). Analyses were conducted at the ontogenetic and static levels, and for successive developmental stages. Our results support craniofacial allometry as the global pattern along with more local allometric trends, such as the relative posterior elongation of the infraorbital canal, the tooth row reduction on the maxillary, and the marked development of nuchal crests on the supraoccipital with increasing skull size. Our study also reports allometric proportions of shape variation varying substantially among cranial units and across ontogenetic stages. The multi-scale approach advocated here allowed unveiling previously unnoticed allometric variations, indicating an untapped complexity of cranial allometric patterns to further explain mammalian morphological evolution.