Infraorbital canal variants and its clinical and surgical implications. A systematic review.

BACKGROUND: Recent literature highlights anomalous cranial nerves in the sinonasal region, notably in the sphenoid and maxillary sinuses, linked to anatomical factors. However, data on the suspended infraorbital canal (IOC) variant is scarce in cross-sectional imaging. Anatomical variations in the sphenoid sinuses, including optic, maxillary, and vidian nerves, raise interest among specialists involved in advanced sinonasal procedures. The infraorbital nerve's (ION) course along the orbital floor and its abnormal positioning within the orbital and maxillary sinus region pose risks of iatrogenic complications. A comprehensive radiological assessment is crucial before sinonasal surgeries. Cone-beam computed tomography (CBCT) is preferred for its spatial resolution and reduced radiation exposure. OBJECTIVE: The aim of this study was to describe the prevalence of anatomical variants of the infraorbital canal (IOC) and report its association with clinical condition or surgical implication. METHODS: We searched Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to June 2023. Two authors independently performed the search, study selection, data extraction, and assessed the methodological quality with assurance tool for anatomical studies (AQUA). Finally, the pooled prevalence was estimated using a random effects model. RESULTS: Preliminary results show that three types are prevalent, type 1: the IOC does not bulge into the maxillary sinus (MS); therefore, the infraorbital foramen through the anterior wall of MS could be used for identification of the ION. Type 2: the IOC divided the orbital floor into medial and lateral aspects. Type 3: the IOC hangs in the MS and the entire orbital floor lying above the IOC. From which the clinical implications where mainly surgical, in type 1 the infraorbital foramen through the anterior wall of MS could be used for identification of the ION, while in type 2, since the lateral orbital floor could not be directly accessed an inferiorly transposition of ION is helpful to expose the lateral orbital wall directly with a 0 scope; or using angled endoscopes and instruments, however, the authors opinion is that direct exposure potentially facilitates the visualization and management in complex situations such as residual or recurrent mass, foreign body, and fracture located at the lateral aspect of the canal. Lastly, in type 3, the ION it's easily exposed with a 0° scope. CONCLUSIONS: This systematic review identified four IOC variants: Type 1, within or below the MS roof; Type 2, partially protruding into the sinus; Type 3, fully protruding into the sinus or suspended from the roof; and Type 4, in the orbital floor. Clinical recommendations aim to prevent nerve injuries and enhance preoperative assessments. However, the lack of consistent statistical methods limits robust associations between IOC variants and clinical outcomes. Data heterogeneity and the absence of standardized reporting impede meta-analysis. Future research should prioritize detailed reporting, objective measurements, and statistical approaches for a comprehensive understanding of IOC variants and their clinical implications. Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/UGYFZ .

Abordaje transconjuntival en comparación con abordaje subciliar para el tratamiento de fracturas orbitarias / Transconjunctival versus subciliary approach for the treatment of orbital fractures

RESUMEN: Introducción: Los abordajes transconjuntival preseptal y subciliar han sido ampliamente utilizados para el manejo quirúrgico de las fracturas orbitarias. Sin embargo, aún existe incertidumbre sobre las complicaciones asociadas a cada uno de estos abordajes. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios. Realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos seis revisiones sistemáticas que en conjunto incluyeron 21 estudios primarios, de los cuales cuatro corresponden a ensayos aleatorizados. Concluimos que el abordaje transconjuntival preseptal podría disminuir tanto la incidencia de ectropión como de un resultado estético insatisfactorio, pero la certeza de la evidencia es baja. Además, este abordaje probablemente disminuye el riesgo de complicaciones intra y postoperatorias, tales como diplopía, parestesia transitoria, equimosis, exposición escleral, laceración del plato tarsal y laceración palpebral inferior. Por otro lado, el abordaje transconjuntival podría aumentar el riesgo de entropión, pero la certeza de la evidencia también es baja.

ABSTRACT: Introduction: The preseptal transconjunctival and subciliary approach have been widely used for the surgical management of orbital fractures. However, there is still uncertainty about the complications associated with each of these approaches. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified six systematic reviews that included 21 primary studies, four of which correspond to randomized trials. We conclude that the preseptal transconjunctival approach could decrease the incidence of ectropion and an unsatisfactory aesthetic result, but the certainty of the evidence is low. Furthermore, this approach probably decreases the risk of intra and postoperative complications, such as diplopia, transient paresthesia, ecchymosis, scleral show, tarsal plate laceration and lower palpebral laceration. On the other hand, the transconjunctival approach could increase the risk of entropion, but the certainty of the evidence is also low.

Tercer molar heterotópico en el reborde orbitario: Reporte de un caso y revisión de literatura / Heterotopic third molar in the orbital rim: Report of a case and literature review

Los terceros molares heterotópicos son órganos dentarios que se encuentran en un sitio anatómico fuera de lo habitual, pueden ser supernumerarios, deciduos o un diente permanente, el cual ha sido reportado en diferentes posiciones, incluyendo la región coronoidea, cavidad nasal, seno maxilar, región orbitaria, palatina, cóndilo mandibular. La etiología de la erupción heterotópica/ectópica es desconocida, aunque hay varias teorías como la discrepancia óseo-dentaria por la evolución. Los órganos dentarios heterotópicos/ectópicos son comunes en la mandíbula y en el género femenino y pueden ocurrir en ambas denticiones. Algunos terceros molares heterotópicos/ectópicos son asintomáticos durante el periodo de vida y son usualmente detectados en hallazgos clínicos y radiográficos de manera incidental. Existen casos documentados desde 1887 hasta la actualidad cuya localización es en el reborde orbitario. En el presente artículo se expone un caso clínico de una extracción quirúrgica de un tercer molar superior heterotópico en el reborde orbitario descrita bajo el protocolo de las retenciones dentales. Dicho caso fue establecido en el Hospital Regional «General Ignacio Zaragoza¼ del ISSSTE en la Ciudad de México, con el que se obtuvieron resultados favorables, fue el primer reporte de la literatura en México. Se realizó una revisión aleatoria de la literatura en páginas como PubMed, ScienceDirect y Springer, Cochrane Library y se desarrolló el reporte de caso clínico de una paciente con un tercer molar superior heterotópico ubicado en el piso de órbita derecho (AU)

Heterotopic third molars are dental organs that are in an anatomical site out of the ordinary, can be supernumerary, deciduous or a permanent tooth, which has been reported in different positions, including the coronoid region, nasal cavity, maxillary sinus, orbital region, palatal, mandibular condyle. The etiology of the heterotopic/ectopic eruption is unknown, although there are several theories such as bone-dental discrepancy due to evolution. The heterotopic/ectopic teeth are common in the jaw and in the female gender and can occur in both dentitions. Some heterotopic/ectopic third molars are asymptomatic during the lifetime and are usually found incidentally in clinical and radiographic findings. There are documented cases from 1887 to the present that its location is in the orbital rim. In the present article we present a clinical case of a surgical extraction of a third upper molar heterotopic in the orbital rim and that is described under the dental retention protocol established in the Regional Hospital «General Ignacio Zaragoza¼ of the ISSSTE in the City of Mexico, with which they obtain favorable results, first report of the literature in Mexico. A randomized review of the literature was made on pages such as PubMed, ScienceDirect and Springer, Cochrane Library and the clinical case report of a patient with a heterotopic upper third molar located on the floor of the right orbit was developed (AU)

Differentiation between Posterior Sinuses Using the Medial Orbital Floor as a Landmark.

Objectives This study aims to evaluate the difference in height between the floors of the posterior ethmoid and sphenoid sinuses with respect to the medial orbital floor (MOF) to confirm this difference as a landmark for identification of the posterior sinuses. It also aims to describe this difference regarding the type of pneumatization of the sphenoid sinus (conchal, presellar, and sellar). Design A cross-sectional study was conducted. Study Center The study was conducted at the Department of Radiology of Hospital de Clínicas de Porto Alegre, a tertiary care university hospital in Southern Brazil. Materials and Methods A standardized and computerized analysis of 100 tomography scans of sinuses (200 sides), in patients older than 18 years, was carried out. Results Mean vertical distance (height) from the MOF to the floor of the posterior ethmoid and sphenoid sinuses was 0.72 ± 1.85 mm and 9.48 ± 3.81 mm, respectively. There was no statistically significant difference as compared with sex and side. We found conchal-type sphenoid sinus pneumatization in 1.5% (n = 3), presellar in 13.5% (n = 27), and sellar in 85% (n = 170), whereas the vertical distance between the MOF and the floor of the sphenoid sinus was 2.04 ± 0.81 in the conchal-type sinuses, 5.71 ± 2.49 in the presellar sinuses, and 10.21 ± 3.52 in the sellar sinuses. No sphenoid sinus showed its floor above the MOF, regardless of the type of pneumatization. Discussion and Conclusion The present study demonstrates that there is a difference between the floor of the posterior sphenoid and ethmoid sinuses in adults, which is more evident when the sphenoid sinus is well pneumatized. These data suggest that the difference in height between the floors of the sinus investigated in our study may be considered during endoscopic sinus surgery to guide adequate localization, but the surgeon should be aware of the type of pneumatization of the sphenoid sinus to use this landmark.

[Bone cement implant as an alternative for orbital floor reconstruction: A case report]. / Implante de cemento óseo como alternativa para la reconstrucción de piso orbitario: reporte de caso.

BACKGROUND: The management of orbitary fractures is one of the most challenging in facial trauma; the variety of reconstruction materials for its treatment is broad and is constantly improving, but despite this there is no consensus for its use or literature that sustains it. OBJECTIVE: To present the use and design of a preformed bone implant as an alternative for the reconstruction of orbital floor fractures in the pediatric age group. CLINICAL CASE: A 7-year old male who suffered a right hemifacial contusion trauma with clinical and tomographic diagnosis of right pure blowout type orbital floor fracture with inferior rectus muscle entrapment and right post-traumatic palpebral ptosis. Successful surgical reconstruction was performed 7 days later with a pre-constructed bone cement implant. Eight weeks after surgery the patient presented with mild residual palpebral ptosis, no ocular movement limitations and no diplopia. CONCLUSIONS: The use of a bone cement implant can be considered appropriate for the reconstruction of these fractures, as another alternative to be used by the ophthalmologist among the variety of all the other materials used for this purpose. We consider that our optimism based on the results obtained in this case obligates us to increase the number of patients treated in order to gather more evidence and do larger follow up.

Reconstruction of orbital floor defects assisted by transantral endoscopy.

PURPOSE: The goal of orbital reconstruction is to restore anatomy, volume, and function. In extensive orbital floor defects, the visualization of the posterior area is limited through inferior eyelid incisions. The use of endoscope may improve the treatment; however, it is a high-sensitivity technique. The aim of this case series is to describe the combination of inferior eyelid incision with transantral endoscopy for treatment of extensive orbital floor defects. METHODS: Three patients were submitted to orbital reconstruction, and the postoperative CT scans were evaluated to analyze the orbital volume and anteroposterior globe position. Surgical treatment was performed using subciliary inferior palpebral approach to explore the orbital floor and placement of the titanium mesh and an intraoral antrostomy for endoscopy to magnification of the surgical field and adaptation of the mesh. RESULTS: Postoperative CT scan analysis shows that all treatments restored orbital volume and globe position without compression or damage of the optical nerve. CONCLUSION: The use of endoscope allowed the precise visualization of the posterior region of the orbit and adaptation of the titanium mesh.

Reconstrução orbitária com implantes Medpor®: estudo histomorfológico e imunohistoquímico / Reconstruction of the orbital floor with Medpor®: histomorphological and immunohistochemical analysis in rats

Entre os materiais aloplásticos, o Medpor® apresentou um aumento consideravel no uso de 17% a 30%, portanto o objetivo desse trabalho foi avaliar a utilização do Medpor® na reconstrução do assoalho orbitário. Foram utilizados 18 ratos que sofreram trauma cirúrgico no assoalho orbitário, simulando uma fratura tipo "blow-out". O lado direito do animal recebeu implante de Medpor® e o lado esquerdo não recebeu qualquer tipo de material. Nos períodos de 15, 40 e 90 dias foram realizadas as eutanásias e obtenção das peças para processamento histológico e imunohistoquímico. Os cortes obtidos foram corados com hematoxilina e eosina, tricrômico de Masson e marcação imunohistoquímica nos períodos de 15, 40 e 90 dias com a osteocalcina e RUNX2. O processo de reparo no lado controle finalizou com neoformação óssea aos 40 dias e perda do contorno ósseo inicial, criando um defeito no assoalho de órbita. O grupo tratado mostrou prevalência de tecido conjuntivo em contato com o implante de Medpor®, tanto em sua periferia quanto no seu interior. Não houve processo inflamatório intenso e ou agudo junto ao material. A imunomarcação mostrou escores intensos de OC após 15 dias de pósoperatórios e manteve expressão moderada após 40 e 90 dias pós-operatório, a RUNX2 foi moderadamente expressa em todos os períodos avaliados. Concluimos que o polietileno poroso (Medpor®) é um biomaterial bionert seguro e eficaz, a sua presença levou ao reparo ósseo local e compensou a ausência de tecido ósseo na sustentação do globo ocular(AU)

The aim of this research was to assessed histological and immunohistochemi cal properties in the use of porous polyethylene (Medpor®) for orbital floor reconstruction. Under general anesthesia 18 male rats (Rattus, norvegicus, albinus, Wistar) underwent bilateral surgical defect, simulating blowout fracture and infraorbital rim. Groups were divided as follow: GI control group and GII surgical defects were reconstructed with Medpor®. After 15, 40, and 90 days animals were euthanized with anesthetic overdose. Orbital specimens were laboratorial process, coronal slices were stained in Hematoxylin and Eosin and Masson trichrome. Immunohistochemical assess of osteocalcin (OC) and Corebinding factor alpha1 (Cbfa1) were performed. Bone repair at the control group was achieved after 40 days with loss of the orbital rim and lack of ocular support. Immunolabeling showed intense scores of OC after 15 days post-operative and maintain moderate expression after 40 and 90 days postoperative, Cbfa1 was moderately express within all the periods evaluated. Medpor® group showed fibrous tissue in contact with the implant in the inner and outer surface, without newbone formation and without intense inflammatory infiltrate nearby the biomaterial, the Medpor® gave enough support for the ocularglobe(AU)