The surgical anatomy of the inferior alveolar nerve: a meta-analysis with clinical implications.

BACKGROUND: The main goal of the present meta-analysis was to provide physicians, especially surgeons, with crucial data on the complete anatomy of the inferior alveolar nerve (IAN). It is hoped that our results may help reduce the rates of complications in procedures associated with this anatomical entity. MATERIALS AND METHODS: Major online medical databases such as PubMed, Embase, Scopus, Web of Science, Google Scholar, and Cochrane Library were searched to gather all studies on IAN anatomy, including topography, morphology, and variations. RESULTS: IAN mean thickness of the IAN in the mandibular angle area was set to 2.32 mm (LL: 1.82 ; HL: 2.78-). IAN mean thickness of the IAN in the mandibular body region was found to be 2.49 mm (LL: 2.02 ; HL: 2.98). The mean thickness of the IAN in the mental region was established at 1.70 mm (LL: 1.54 ; HL: 1.86). The mean distance from the IAN to the external (buccal) surface of the 1st molar was set to be 4.99 mm (LL: 3.84 ; HL: 6.13). CONCLUSIONS: In conclusion, this is the most up-to-date and thorough analysis of the complete anatomy of the IAN. We provided morphometric data that present the spatial relationship of the IAN with numerous anatomical landmarks in the mandibular region. These include the ramus of the mandible, the first, second, and third molars, and the body of the mandible, among others. It is hoped that the results of the present meta-analysis may be a helpful tool for physicians, especially surgeons, performing various oral and maxillofacial procedures, such as third molar removal or IAN block anesthesia.

A morphological study on the sphenoid bone ligaments' ossification pattern.

PURPOSE: The sphenoid bone (SB) extracranial ligaments (ECRLs) are the pterygoalar and pterygospinous ligaments (PTAL and PTSL) that are located at the SB lateral pterygoid plate, and inferior to the foramen ovale (FO). Their ossification may affect the mandibular nerve's distribution. The intracranial ligaments' (ICRLs) ossification (the caroticoclinoid ligament-CCLL, the anterior and posterior interclinoid ligaments-AICLL and PICLL) may impede the approaches to the sella. This study highlights the incidence of the ossified ECRLs and ICRLs location, their type (partial, or complete), considering laterality, gender, age, and ligaments' simultaneous presence. METHODS: The sample consisted of 156 Greek adult dried skulls of both genders and variable age. RESULTS: Ossified ligaments were identified in 57.05%, predominantly extracranially (42.31%, P = 0.003). ECRLs were predominantly identified unilaterally (30.13%, P < 0.001). The majority of the ossified ICRLs were predominantly identified in male skulls (31.1%, P = 0.048) and the majority of the ECRLs (52.8%, P = 0.028) were predominantly identified at the age of 60 years and above. The PTAL was the most ossified (32.69%), followed by the CCLL (24.36%), the PTSL (16.03%), the PICLL (6.41%), and the AICLL (4.49%). CONCLUSIONS: Detailed knowledge of the SB morphology and ligaments' ossification extent is essential to improve the technique of the FO percutaneous approach, and sellar approaches, to minimize complications.

Suture-like pattern formation in the pterygospinous bridge of the human sphenoid bone.

The paper presents an anatomical study involving rare variations in the pterygospinous bridges found in Mongolian skulls. These structures extend between the lateral pterygoid plate and the sphenoid spine. Particularly interesting is the division of these bridges into two distinct parts of the similar length. The junctions within these structures resemble morphological patterns characteristic for the plain and zigzag sutures, which articulate the cranial bones.

The venous plexus of Rektorzik - anatomo-clinical issues retrieved from the literature data.

The venous plexus of Rektorzik is a network of small veins, which enlace outside the wall of the internal carotid artery while it traverses the petrous part of the temporal bone. The anatomical and clinical issues related to the communication between the plexus of Rektorzik and other cranial venous structures were discussed in this paper.

Anatomical features of the mandibular canal and their clinical significance - review of literature.

The clinical issues related to the anatomical variation of the mandibular canal have been extensively analyzed since the 19th century. Evolving dentistry techniques and advancements in the prosthetics forced to collect detailed information about anatomical variations of the mandibular canal due to its neurovascular content. Therefore, its radiographic imaging became an essential part of the oral surgery, in order to avoid complications resulted from an accidental damage of the mandibular canal.

A case of early obliteration of the sagittal suture without effect on cranial deformation.

This paper describes a unique case of craniosynostosis in a female skull in which sagittal sutures were completely fused by adolescence. Despite sagittal synostosis, the skull was of normal shape and size. Regarding craniometric features, the synostotic normocephalic skull was markedly different than that of scaphocephalic skulls which typically result from premature obliteration of the sagittal suture.

Cranial diploic channels and their veins - a review of literature.

The current paper is a review of the results attained in the past and current anatomical studies, aimed at understanding the variability and function of the diploic venous system of the human skull. The diploic veins can serve as transit for infections from the scalp to the structures contained within the cranial cavity via the emissary veins, due to their interconnections with the pericranial veins, meningeal veins and dural sinuses. Thereby this clinical aspect has also been discussed.

A 3D model of the renal vasculature - a joined result of the corrosion casting technique, micro-CT imaging and rapid prototyping technology.

Three-dimensional (3D) printed model of the renal vasculature shows a high level of accuracy of subsequent divisions of both the arterial and the venous tree. However, minor artifacts appeared in the form of oval endings to the terminal branches of the vascular tree, contrary to the anticipated sharply pointed segments. Unfortunately, selective laser sintering process does not currently permit to present the arterial, venous and urinary systems in distinct colors, hence topographic relationship between the vascular and the pelvicalyceal systems is difficult to attain. Nonetheless, the 3D printed model can be used for educational purposes to demonstrate the vast renal vasculature and may also serve as a reference model whilst evaluating morphological anomalies of the intrarenal vasculature in a surgical setting.

Duplication of the inferior vena cava: evidence of a novel type IV.

Anatomical variations of the inferior vena cava, including the double inferior vena cava or isolated left inferior vena cava, are uncommon and of great clinical importance. Inferior vena cava variations signify predisposition to deep vein thrombosis and may complicate retroperitoneal surgeries including abdominal aortic surgery. Failure to recognize such variations may predispose a patient to life- threatening complications. This prospective anatomical study assessed 129 cadavers for variations of the inferior vena cava. One of the 129 cadavers (0.78%) possessed a double inferior vena cava and none (0%) possessed an isolated left inferior vena cava. The left-sided inferior vena cava was of a larger diameter than that of the right-sided inferior vena cava - opposite of what would be seen in a Type III duplication. Therefore, this observation expands the three-type classification system to include a Type IV duplication.

Contribution of 3D printing technology for craniofacial surgery.

This article summarizes technical aspects of preparing printable 3D anatomical models created from radiological data (CT, MRI) and discusses their usefulness in surgery of the human skull. Interdisciplinary approach to the capabilities of the 3D printers, and the materials used for manufacturing 3D objects oriented on replicating anatomical structures has created new possibilities for simulating and planning surgical procedures in clinical practice settings.

Bilateral absence of the musculocutaneous nerve: implications for humerus fracture and atypical median nerve palsy.

The absence of the musculocutaneous nerve represents a failure of the nerve to depart from the median nerve during early development. During a routine dissection of a 66-year-old white female cadaver, a bilateral absence of the musculocutaneous nerve was observed in the upper limbs. Muscles of the anterior flexor compartments of the arms including biceps brachii and brachialis were supplied by branches of the median nerve. The lateral cutaneous nerve of the forearm also branched from the median nerve. In a clinical case of a particularly high median nerve injury, a variation of an absent musculocutaneous nerve may not only result in typical median nerve palsy of the forearm and hand, but palsy in the arm that would manifest as deficiencies in both shoulder and elbow flexion as well as cutaneous sensory loss from the lateral forearm.

A concise survey on 3D modeling in the science of anatomy.

This report provides a concise overview of the rendering and utilization of three-dimensional models in the field of anatomy. Anatomical three-dimensional virtual models are widely used for educational purposes, preoperative planning, and surgical simulations because they simply allow for interactive three-dimensional navigation across the human organs or entire body. Virtual three-dimensional models have been recently fabricated as accurate replicas of the anatomical structures thanks to advances in rapid prototyping technology.

Sphenoid bone and its sinus - anatomo-clinical review of the literature including application to FESS.

Authors paid attention to anatomy and clinical implications which are associated with the variations of the sphenoid sinus. We discuss also anatomical structure of the sphenoid bone implementing clinical application of this bone to different invasive and miniinvasive procedures (i.e. FESS).

3 D printed replica of the human temporal bone intended for teaching gross anatomy.

The anatomy of the human temporal bone is complex and, therefore, poses unique challenges for students. Furthermore, temporal bones are frequently damaged from handling in educational settings due to their inherent fragility. This report details the production of a durable physical replica of the adult human temporal bone, manufactured using 3D printing technology. The physical replica was printed from a highly accurate virtual 3D model generated from CT scans of an isolated temporal bone. Both the virtual and physical 3D models accurately reproduced the surface anatomy of the temporal bone. Therefore, virtual and physical 3D models of the temporal bone can be used for educational purposes in order to supplant the use of damaged or otherwise fragile human temporal bones.

Fusion between the median and musculocutaneous nerve: A case study.

The musculocutaneous nerve (C5-C7) is a terminal branch of the lateral cord of the brachial plexus and provides motor innervation to the anterior compartment of arm muscles. Both the musculocutaneous and median nerve may show numerous anatomical variations. Keeping in mind possible aberrations in the course of the upper limb nerves may increase the safety and success rate of surgical procedures. The presented report is a detailed anatomical study of the fusion between the median and musculocutaneous nerve, supplemented by intraneural fascicular dissection. In the presented case, the musculocutaneous nerve was not found in its typical location in the axillary cavity and upper arm during the preliminary assessment. However, a careful intraneural fascicular dissection revealed that musculocutaneous nerve was fused with the median nerve and with its lateral root; Those nerves were surrounded by a common epineurium, however they were separable. The muscular branch to the biceps brachii muscle arose from the trunk (fascicular bundle) dissected out from the median nerve and corresponding to the musculocutaneous nerve. Such variation may be of utmost clinical importance, especially during reconstructions of the brachial plexus or its branches.

Bilateral duplication of the abducens nerve - case study.

The abducens nerve is characterized by a long intracranial course and complex topographical relationships. Anatomical knowledge may help to understand both the etiology and clinical symptoms of abducens nerve palsy. Typically, the single trunk of the abducens nerve travels on both sides. However, occasionally different variants of unilateral or bilateral duplications of the abducens nerve may be observed. The presented paper is a detailed anatomical description of bilateral duplication of the abducens nerve, with atypical appearance of the nerve in the cavernous sinus and normal distribution within the lateral rectus muscle on both sides of one cadaver. On the right side both trunks of the abducens nerve fused within the subarachnoid space and pierced the dura mater together. On the left side both trunks of the duplicated abducens nerve pierced the dura mater separately, entered the petrous apex separately and fused just below the petrosphenoidal ligament. Within the cavernous sinus the nerve divided once again into two filaments, which reunited into one trunk a er crossing the horizontal segment of the intracavernous part of internal carotid artery. The orbital segments of the abducens nerve showed a typical course on both sides. Duplication of the abducens nerve is anatomical variation which should be taken into account during diagnostic and surgical procedures performed within the petroclival region and cavernous sinus.

Rediscovered identity of the scaphocephalic skull housed in the museum of the Department of Anatomy of the Medical College of the Jagiellonian University.

A personal data referring to the scaphoid skull housed in the Department of Anatomy of the Jagiellonian University, Medical College was established thanks to reviewing 19th century literature performed by Dr. Soficaru. We received information that the skull had belonged to an adult man who was a carpenter, born at Cracow. The original anthropometrical study of this skull was performed by prof. Kopernicki 19th century.

Oval Window Size and Shape: a Micro-CT Anatomical Study With Considerations for Stapes Surgery.

BACKGROUND: The oval window is an important structure with regard to stapes surgeries, including stapedotomy for the treatment of otosclerosis. Recent study of perioperative imaging of the oval window has revealed that oval window niche height can indicate both operative difficulty and subjective discomfort during otosclerosis surgery. With regard to shape, structures incorporated into the oval window niche, such as cartilage grafts, must be compatible with the shape of the oval window. Despite the clinical importance of the oval window, there is little information regarding its size and shape. METHODS: This study assessed oval window size and shape via micro-computed tomography paired with modern morphometric methodology in the fetal, infant, child, and adult populations. Additionally, the study compared oval window size and shape between sexes and between left- and right-sided ears. RESULTS: No significant differences were found among traditional morphometric parameters among age groups, sides, or sexes. However, geometric morphometric methods revealed shape differences between age groups. Further, geometric morphometric methods provided the average oval window shape and most-likely shape variance. CONCLUSION: Beyond demonstrating oval window size and shape variation, the results of this report will aid in identifying patients among whom anatomical variation may contribute to surgical difficulty and surgeon discomfort, or otherwise warrant preoperative adaptations for the incorporation of materials into and around the oval window.

Printable 3D model of the sella turcica region including the interclinoid bridge.

The objective of the study was to create a printable 3D model of the sellar region of the sphenoid bone for demonstrating anatomical variant of the osseous bridging between anterior and posterior clinoid processes. Three-dimensional reconstruction of the middle cranial fossa along with 3D printed model, allow for accurate depicting position of the interclinoid bridge with reference to other basicranial structures.