Anterior Division Research Articles

Medication of the cervical spinal nerves for the treatment of equine cervical radiculopathy

SummaryBackgroundSeveral perineural injection techniques have been described to medicate the cervical spinal nerves of horses with suspected radiculopathy due to lesions at the intervertebral foramen (IVF). The technique and outcome have never been described in live, standing horses with suspected clinical disease.ObjectivesTo assess the safety and efficacy of medication of the ventral rami of the cervical spinal nerves (VRCSNs) for the treatment of cervical radiculopathy in horses.Study designCase series.MethodsHorses that underwent ultrasound‐guided perineural injection of the VRCSNs following radiographic and/or computed tomography (CT) evaluation of the cervical spine were included. Perineural injection with corticosteroids was performed using a standardised technique under ultrasound guidance as previously described. Outcome data were collected by clinical record review and unstructured follow‐up telephone conversations.ResultsForty‐seven injections of the VRCSNs were performed in 12 horses with only two self‐limiting adverse reactions noted. All horses that underwent CT examination had at least one site of IVF narrowing with the foramina at the C6/C7 articulation most frequently affected. Nine horses improved following medication of the VRCSNs with eight returning to their previous levels of exercise. All seven horses that underwent CT of the cervical spine had an initial improvement in clinical signs. Six horses were in full work and still performing at their intended level of exercise at a median of 21.5 months post injection.Main limitationsLack of definitive diagnosis of spinal nerve compression without histopathology of the spinal nerves which is not possible in the live horse.ConclusionsMedication of the VRCSNs is a safe treatment option which may provide benefit to horses with suspected spinal nerve compression but should be reserved for horses that have undergone a detailed clinical examination and CT evaluation of the cervical spine.

Extrauterine Causes of Severe and Concealed Postpartum Bleeding: Clinical Aspects and Challenges

Abstract Objective To describe the challenges in diagnosing concealed postpartum bleeding, a rare but potentially life-threatening condition, and to highlight key factors in identifying and managing this condition. Methods We reviewed clinical cases and diagnostic approaches where concealed postpartum bleeding was suspected, focusing on the role of imaging, serologic markers, and angiography. We examined instances of hemodynamic instability, the utility of pelvic space analysis via computed tomography, and the limitations of digital angiography, particularly in identifying bleeding sources in the posterior iliac internal artery division. Results Concealed postpartum bleeding often originates from venous damage or, less commonly, arterial injury. Hemodynamic instability was noted to occur periodically, despite negative findings on vaginal examination and ultrasound, leading to diagnostic delays. Digital angiography often yields negative results when the focus is limited to the anterior division of the internal iliac artery. Bleeding typically arises from damage to the vaginal muscular layer or levator ani muscle, both supplied by branches of the internal pudendal artery (posterior iliac division). In some cases, laparotomy also failed to locate the source due to the bleeding being in the subperitoneal spaces. Conclusion Concealed postpartum bleeding presents a diagnostic challenge due to intermittent hemodynamic instability and often negative imaging results. A detailed pelvic space analysis and awareness of posterior iliac internal artery involvement are crucial. Advanced expertise, along with serologic markers of hidden bleeding, is essential for timely diagnosis and management.

7996 Neuroanatomic Characterization of Mouse Kisspeptin Neurons in the Bed Nucleus of the Stria Terminalis

Abstract Disclosure: S.T. Zdon: None. M.S. Silva: None. V.M. Navarro: None. Kisspeptin (Kiss1) neurons are essential for reproductive function as they are strong regulators of the hypothalamic-pituitary-gonadal axis (HPG). Mammalian Kiss1 neurons are mainly located in the hypothalamus, controlling gonadotropin-releasing hormone (GnRH) secretion, where the anteroventral periventricular nucleus (AVPV) population is morphologically and functionally sexually differentiated. Kiss1 neurons are also found in limbic areas, such as the bed nucleus of the stria terminalis (BNST). This nucleus is involved in the integration of the HPG axis with sex-dependent social behaviors and metabolic functions. However, it remains unclear whether these populations show sexually dimorphic features. The present study focused on the neuroanatomical characterization of Kiss1BNST neurons in mice on both sexes. A Kiss1cre;salsa6f mouse strain carrying the expression of tdTomato specifically in Kiss1 neurons was used to study the distribution of Kiss1BNST neurons. The BNST is divided into the anterior division of the BNST (aBNST), and a more posterior division called the principal component of the BNST (prBNST). Results indicate that male mice have significantly more Kiss1prBNST neurons than females (Male: 139.4 ± 23.32 vs. Female: 43.70 ± 5.33 neurons; **P < 0.01). This sex-biased distribution was absent in Kiss1aBNST neurons. Additionally, stereotaxically injecting a Cre-dependent recombinant adenovirus carrying the expression of mCherry reporter into the aBNST or prBNST in adult mice was performed to observe neuronal projections. We observed fibers from aBNST-injected Kiss1 neurons projecting widely to areas that include the AVPV, medial preoptic area (MPO), lateral preoptic area (LPO), and periventricular hypothalamic nucleus (PVH). Moreover, fibers and cell bodies from male prBNST-injected Kiss1 neurons projected to dorsal lateral BNST (dlBNST), juxta-periventricular lateral hypothalamic area (JPLH), and the posterolateral stria terminalis (STMPL). This study observed a sexual dimorphic Kiss1 neuronal population in the prBNST, with males having more Kiss1prBNST neurons present and prospective postsynaptic areas in the brain where these neurons project to, helping to aid future studies on characterizing the functional role of these neurons. Presentation: 6/1/2024

Anterior Transfer of the Long Head of Triceps Nerve to the Terminal Part of the Anterior Division of the Axillary Nerve Through Two Incisions: A Cadaveric Feasibility Study.

Restoring shoulder function after axillary nerve injury is always a challenge. Transferring a branch of the radial nerve destined to the triceps onto the anterior division of the axillary nerve has become the preferred technique. However, this is not always possible, especially when the axillary nerve is severely injured around the posterior part of the humeral neck. The purpose of this cadaver study was to assess the feasibility of transferring the nerve of the long head of the triceps through an anterior and lateral humeral neck tunnel, directly onto the branch of the anterior division of the distal axillary nerve where it enters the deltoid fibers, by two surgical approaches. This anatomical study was performed using 6 fresh cadavers (12 shoulders). A medial brachial approach was used to locate the radial nerve and its first branch, innervating the long head of the triceps. Then a second, transdeltoid approach was made to locate the end of the anterior branch near where it enters the deltoid fibers. The long head of the triceps nerve was transected as close as possible to the muscle, to provide the longest length possible. Then an anterior and lateral subdeltoid tunnel was made to retrieve this branch through the transdeltoid approach. The long head of the triceps nerve could always be sutured to the anterior branch of the axillary nerve. Given the 7-12 mm surplus length (mean, 8.8 mm), tensionless suturing was possible in an anatomical region amenable to easier microsurgery. Transfer of the long head of the triceps to the anterior branch of the axillary nerve through an axillary or posterior approach remains the preferred method for reinnervating the deltoid. However, in some patients, the axillary nerve is injured at or beyond the typical microsurgical suturing zone, which means that transfer cannot be accomplished under optimal conditions. For this reason, we suggest making the transfer more distally, using a dual approach that allows direct suturing of the long head of the triceps nerve onto the anterior terminal branch, which shortens the distance between the sutured nerve and the deltoid, and should improve outcome.

Cadaveric study of the ultrasound-guided inter-transversospinalis plane block in dogs for the cervical epaxial musculature region.

Blockage of the dorsal rami of the spinal nerves (DRSN) provides analgesia to the epaxial musculature area in dogs. However, techniques to block the DRSN at the cervical level in dogs haven't yet been investigated. This study aimed to study the anatomy of the cervical area, and to describe a new ultrasound (US)-guided inter-transversospinalis plane (ITP) block technique at the 5th cervical vertebrae (C5). Fourteen adult canine's cadavers were used in this blinded, cadaveric, experimental study. One cadaver for cryo-section, one for anatomical research and twelve to do an ITP injection using 0.3 mL/kg (HV) or 0.15 mL/kg (LV) of dye/contrast solution in each lateral at C5, followed by a computed tomography and anatomical dissection.The HV and LV groups stained a median (range) of 4.67 (3-6) and 3.67 (2-5) DRSN into the ITP, respectively (P<0.017). Stained DRSN in the splenius plane were found in nine (75%) HV and five (41.66%) LV injections, respectively. Spread in the epidural space was found in two dogs using LV. One of them was injected into the ITP (4.33 %) while the other one was done accidentally outside of this plane. The paravertebral spread was found in one injection of each group. There was no dye of the ventral rami of the spinal nerves. The US-guided ITP injection is feasible in dog cadavers. The LV injected just after the medial surface of the semispinalis capitis muscle is recommended to avoid a possible extensive epidural spread.

Reappraisal of the Variations in the Origin of the Obturator Artery With Clinical and Developmental Perspectives: A Cadaveric Analysis.

Background The obturator artery (OA), typically originating from the anterior division of the internal iliac artery (ADIIA), shows significant variability in its origin. Such variations can present clinical challenges during pelvic surgeries, potentially causing unnoticed bleeding and complicating effective treatment. This study aims to thoroughly document the diverse anatomical variations of the OA and explore their implications for surgical practice. Materials and methods Forty-eight hemipelvis specimens from adult human cadavers were dissected. The origin of each OA was meticulously documented, photographed, and analyzed descriptively. Results In 38 specimens (79.2%), the OA originated from the IIA. It branched off at various levels from either the ADIIA or the posterior division of the IIA (PDIIA), either individually or in combination with other named branches. In nine cases (18.8%), the OA originated directly from the external iliac artery (EIA), either as a distinct branch or alongside the inferior epigastric artery (IEA). Additionally, one specimen (2%) exhibited a dual origin involving both the ADIIA and the IEA. Conclusion These findings highlight the frequent anatomical variations in the origin and pathway of the OA. Understanding these variations is crucial for accurately assessing pelvic anatomical relationships, which is essential for effective surgical planning and ensuring procedural safety. This knowledge is particularly important during vascular and surgical procedures, as it can impact the risk of bleeding and the effectiveness of treatment strategies.

Clinico-anatomical insight into the unusual course, branching pattern and connections of ulnar nerve: A narrative review.

Ulnar nerve originates from the lower trunk as a branch from anterior division, continuing as a branch from medial cord of the brachial plexus. It receives fibres from anterior rami of cervical nerve root 8 and the first thoracic nerve root. Ulnar nerve injury accounts for being the most common vessel of upper limb that results in hospitalisation. Knowing the variability in the anatomical pattern of ulnar nerve and its communication with various branches of nerves in the vicinity can have implications. The current narrative review comprised literature search on Google, Google Scholar and PubMed databases for articles published between 2015 and 2023 on the subject. The insight and understanding of the related ulnar nerve anatomy is likely to be of prodigious help to anatomists, surgeons, physicians and radiologists in preventing unexpected outcomes in the future.

Anatomical assessments of injectate spread stratified by the volume of the intertransverse process block at the T2 level

BackgroundThis cadaveric study aimed to analyze injectate spread to target nerves during a single-injection, ultrasound-guided intertransverse process block.MethodsAn ultrasound-guided intertransverse process block with three different injectate volumes was administered to...

Kinked again! From congenital brachial plexus palsy to adult neurogenic thoracic outlet syndrome: Case Report.

Neurogenic thoracic outlet syndrome (nTOS) is a chronic, focal lesion of the lower trunk of the brachial plexus or of the T1 and C8 anterior primary rami, often arising due to distortion of neural structures by a fibrous congenital band extending from a C7 transverse process or cervical rib. Accordingly, patients present with chronic weakness or atrophy of the hand, most prominently of the thenar eminence, which receives most innervation from the T1 root. We present clinical, electrophysiologic, and imaging findings in a case of nTOS presenting in an adult with a history most suggestive of congenital brachial plexus palsy (CBPP), another pathology sharing the mechanism of nerve compression or injury within the supracostoclavicular space. The patient had new right thenar eminence atrophy and a lifelong history of medial forearm sensory deficit and she improved after first rib resection. The convergence of two disorders in the same patient arising in different phases of life illustrates how anatomic or structural variation in this space can predispose to lower brachial plexus injury.

Erector spinae plane infiltration and anterior rami of spinal nerve: a cadaveric study

BackgroundThe erector spinae plane block (ESP block) is frequently employed for thoracic, abdominal, and spinal surgeries, yet its precise mechanism of action remains a subject of debate. While initially postulated...

НОВЫЕ ДАННЫЕ ПО ПОЗДНЕДЕВОНСКИМ ПЛОУРДОСТЕИДАМ (ПАНЦИРНЫЕ РЫБЫ) ИЗ МИХАЙЛОВСКОГО РУДНИКА КУРСКОЙ ОБЛАСТИ

New data on the placoderm fish Plourdosteus livonicus (Eastman, 1896) from the Lower Frasnian deposits of the Mikhaylovsky Mine in the Kursk Region is described. These remains are currently housed at the Earth Science Museum of Lomonosov Moscow State University. The medio-dorsal plate from this locality allows reconstructing its form and proportion, as also early unknown anterior division of the bone. Only small fragments of medio-dorsal plates were formerly described and figured for P. livonicus from this and other localities in European Russia. So, the new data from the Mikhaylovsky Mine adds to the morphology information of this species. The medio-dorsals are of diagnostic significance and distinguish in the plourdosteids. The specimen from the Earth Science Museum’s collection is compared with the medio-dorsal plates of other Frasnian Plourdosteus species from the East-European platform.

Origin and distribution of the brachial plexus in red-necked wallaby (Notamacropus rufogriseus, Marsupialia: Macropodidae).

Notamacropus rufogriseus (red-necked wallaby) are in the family Macropodidae, which is the second largest family of marsupials after the family Didelphidae. This study was conducted with the aim of providing a detailed description of the origin and distribution of the brachial plexus in N. rufogriseus. Two-year-old male and 3-year-old female red-necked wallabies were used for the study. The brachial plexus was formed by ventral rami of C4, C5, C6, C7, C8, and T1 spinal nerves. It is composed of three trunks that give rise to 12 principal nerves. The cranial trunk is formed by the combination of the rami C4-C7; the middle trunk is formed by the combination of the rami C6 and C7; and the caudal trunk is formed by the combination of the rami C8 and T1. Differences between left and right side of the plexus brachialis were not observed. C6 ventral spinal rami contribute the most to brachial plexus nerve formation, while C4 contributes the least. The formation and distribution of the plexus in N. rufogriseus exhibited more resemblance to the patterns observed in marsupial animals rather than placental mammals. Marsupial mammals demonstrate the involvement of C4 in the development of the brachial plexus. The formation and branching of the brachial plexus sequentially adapt in accordance with changes in their thoracic limb activities and innervation points. Anatomical data from brachial plexus studies optimizes thoracic limb clinical and surgical treatments. This work can provide baseline data for future marsupial brachial plexus studies and fill gaps in the scarce literature.

Morphology of the obturator nerve, an anatomical study with emphasis on its clinical implications

Background The goal of this cadaveric cross sectional study was to analyse the branching pattern of the obturator nerve morphologically and to determine its dimensions in embalmed cadavers. Methods In this cross sectional study, we examined 50 embalmed adult cadaveric lower limbs. Sex was not taken into consideration in the analysis; however, a side-based comparison was performed. The measurements were performed using a digital Vernier caliper. Results The branching of obturator nerve was observed at the pelvic cavity in 28 specimens (56%) and inside the obturator canal in 12 specimens (24%). The division of obturator nerve wasn’t observed in 10 specimens (20%). The length, width and thickness of the trunk of obturator nerve was 108.26 ± 9.53 mm, 2.84 ± 0.88 mm and 1.11 ± 0.35 mm. The width and thickness of the anterior and posterior divisions of obturator nerve measured 2.19 ± 0.82 mm, 0.9 ± 0.1 mm, 0.99 ± 0.6 mm and 0.71 ± 0.26 mm. The topography of branching of obturator nerve from the superior and inferior border of the obturator foramen was located at 1.48 ± 0.58 mm and 3.07 ± 1.1 mm away. The length of anterior division of the obturator nerve measured 110.88 ± 12.02 mm over the right side and 107.13 ± 7.81 mm over the left side. The width of the main trunk of obturator nerve was 2.87 ± 0.64 mm over the right side and 2.82 ± 0.64 mm over the left side. Conclusions We believe that morphometric data of the obturator nerve will be enlightening to the operating surgeon during procedures such as obturator nerve block, nerve transplantation, and obturator nerve repair. The dimensions of the obturator nerve observed in the present study can be utilized as a morphological database for our sample population.

Exploring the Topography of the Obturator Artery and Corona Mortis: a Detailed Analysis with Surgical Implications

Introduction and HypothesisThe obturator artery (ObA) is described as a branch of the anterior division of the internal iliac artery. It arises close to the origin of the umbilical artery, where it is crossed by the ureter. The main goal of the present study was to create an anatomical map of the ObA demonstrating the most frequent locations of the vessel’s origin and course.MethodsIn May 2022, an evaluation of the findings from 75 consecutive patients who underwent computed tomography angiography studies of the abdomen and pelvis was performed.ResultsThe presented results are based on a total of 138 arteries. Mostly, ObA originated from the anterior trunk of the internal iliac artery (79 out of 138; 57.2%). The median ObA diameter at its origin was found to be 3.34 mm (lower quartile [LQ] = 3.00; upper quartile [UQ] = 3.87). The median cross-sectional area of the ObA at its origin was found to be 6.31 mm2 (LQ = 5.43; UQ = 7.32).ConclusionsOur study developed a unique arterial anatomical map of the ObA, showcasing its origin and course. Moreover, we have provided more data for straightforward intraoperative identification of the corona mortis through simple anatomical landmarks, including the pubic symphysis. Interestingly, a statistically significant difference (p < 0.05) between the morphometric properties of the aberrant ObAs and the “normal” ObAs originating from the internal iliac artery was found. It is hoped that our study may aid in reducing the risk of serious hemorrhagic complications during various surgical procedures in the pelvic region.

Middle meningeal artery patency after surgical evacuation for chronic subdural hematoma.

Chronic subdural hematoma (CSDH) often requires surgical evacuation, but recurrence rates remain high. Middle meningeal artery (MMA) embolization (MMAE) has been proposed as an alternative or adjunct treatment. There is concern that prior surgery might limit patency, access, penetration, and efficacy of MMAE, such that some recent trials excluded patients with prior craniotomy. However, the impact of prior open surgery on MMA patency has not been studied. A retrospective analysis was conducted on patients who underwent MMAE for cSDH (2019-2022), after prior surgical evacuation or not. MMA patency was assessed using a six-point grading scale. Of the 109 MMAEs (84 patients, median age 72 years, 20.2% females), 58.7% were upfront MMAEs, while 41.3% were after prior surgery (20 craniotomies, 25 burr holes). Median hematoma thickness was 14mm and midline shift 3mm. Hematoma thickness reduction, surgical rescue, and functional outcome did not differ between MMAE subgroups and were not affected by MMA patency or total area of craniotomy or burr-holes. MMA patency was reduced in the craniotomy group only, specifically in the distal portion of the anterior division (p = 0.005), and correlated with craniotomy area (p < 0.001). MMA remains relatively patent after burr-hole evacuation of cSDH, while craniotomy typically only affects the frontal-distal division. However, MMA patency, evacuation method, and total area do not affect outcomes. These findings support the use of MMAE regardless of prior surgery and may influence future trial inclusion/exclusion criteria. Further studies are needed to optimize the timing and techniques for MMAE in cSDH management.

Possible anastomoses between the long branches of the brachial plexus and their clinical significance.

The brachial plexus consists of nerves that supply the upper limb and some nerves of the back, torso, and neck. It is formed by the ventral rami of C5 to T1 (in some cases, C4 or T2 also contribute). The anterior rami of the spinal nerves unite to the roots, trunks, divisions, cords, and terminal branches that innervate muscles and skin. An example is associated with terminal branches of the long nerves. Knowledge of this variation is necessary for enabling surgeons, orthopedists, and neurologists to avoid injury during surgical exploration in the arm or axilla region, and for achieving correct diagnoses, because such variability can evoke nonspecific responses. Awareness of this anastomosis is also mandatory for anesthetists performing anesthesia in the upper limb region. The aim of this article is to describe anastomoses between long nerves from the brachial plexus and to consider their clinical significance.

408 Nerve to Subclavius for Neurotization Procedures: An Anatomical Feasibility Study

INTRODUCTION: Injuries to the inferior trunk (IT) of the brachial plexus and its components can be debilitating. As such injuries are prioritized by surgeons during repair, an additional nerve transfer is considered. METHODS: 13 adult cadavers (26 sides) underwent dissection of the nerve to subclavius and proximal brachial plexus. Once the nerve was isolated from origin to termination, the C8 and T1 roots and IT were identified. The distal end of the nerve to subclavius was transected and swung to these roots and the IT. Once the nerves to subclavius were transposed and in a tension-free manner, the length of excess nerve following being brought to each of these nerves was measured. RESULTS: A nerve to subclavius originated from the superior trunk and traveled anterior to the middle and inferior trunks on all sides. The mean diameter of the nerve to subclavius was 0.8 mm and the mean length was 57 mm. After cutting the nerve to subclavius at its entrance into the subclavius muscle, the distal nerve could be transferred tension free to the IT of the brachial plexus and T1 ventral ramus on all sides. The distal nerve to subclavius reached the T1 ventral ramus with an average of 18 mm of additional length and to the C8 ventral ramus with an average of 19 mm. The nerve also could be transferred to the IT of the brachial plexus with an average of 20 mm of additional length. The nerve to subclavius was found to have approximately 3,000 axons. CONCLUSIONS: To our knowledge, use of the nerve to subclavius has previously not been used for nerve transfer procedures. Based on our cadaveric study, this often-overlooked nerve can be easily transposed to other regional nerves such as the IT of the brachial plexus.

Pathways of dye spread after injections in the paraspinal spaces-A cadaveric study.

The erector spinae plane (ESP) block is the most sought-after block since its inception. However, it is more of dorsal rami block with unpredictable ventral diffusion to the paravertebral area. We injected dye in ESP and other paraspinal spaces to study and compare the dye diffusion pattern along the neuroaxis and paraspinal region in human cadavers. In six soft-embalmed cadavers (12 specimens), 20 mL methylene blue dye (erector spinae plane and paravertebral space) or indocyanine green dye (inter-ligament space) was injected bilaterally using an in-plane ultrasound-guided technique at the level of the costotransverse junction of fourth thoracic vertebrae. Dye spread was evaluated bilaterally in the coronal plane in the paravertebral and intercostal spaces from the 1st and the 12th rib. Axial and sagittal sections were performed at the level of the 4th thoracic vertebrae. After cross sections, the extent of dye spread was investigated in ESP, inter-ligament, and paravertebral spaces. The staining of the ventral and dorsal rami and spread into the intercostal spaces was evaluated. ESP injection was mainly restricted dorsal to the costotransverse foramen and did not spread anteriorly to the paravertebral space. The paravertebral injection involved the origin of the spinal nerve and spread laterally to the intercostal space. The inter-ligament space injection showed an extensive anterior and posterior dye spread involving the ventral and dorsal rami. Following ESP injection, there was no spread of the dye anteriorly to the paravertebral space and it only involved the dorsal rami. Inter-ligamentous space injection appears to be the most promising block as dye spread both anteriorly to paravertebral space and posteriorly toward ESP.

Anatomic evaluation to compare the dye spread with ultrasound-guided pericapsular nerve group (PENG) injection with or without an additional suprainguinal fascia iliaca (SIFI) injection in soft embalmed cadavers.

Novel interfascial plane blocks like PEricapsular Nerve Group (PENG) and SupraInguinal Fascia Iliaca (SIFI) blocks are effective for management of hip fracture pain. We compared the difference in the distribution of the dye injected and nerves stained by the addition of the SIFI block to the PENG block. A total of 24 designated dye injections were performed in eight soft-embalmed cadavers. Under ultrasound guidance 20ml green ink injected bilaterally in PENG block and 30ml methylene blue dye was injected in the SIFI block on the right side. The cadavers were dissected 24h later to assess the extent of dye spread. Extensive spread of dyes was seen on both side of iliacus muscle on the right side, but blue dye was not visible medial to the psoas tendon. The subcostal and iliohypogastric nerves were stained green in the infra-inguinal region. On the left side (PENG alone), the anterior division of the obturator, femoral and saphenous nerve (7/8) and iliohypogastric nerves (3/8) were stained in the infrainguinal region. In the suprainguinal region, the femoral nerve (5/8), accessory obturator nerve (3/8), lateral femoral cutaneous (1/8) and nerve to rectus femoris (4/8) were stained. The main obturator nerve trunk was spared with both injections while its anterior branch and accessory obturator nerve were stained with the PENG injection. The study findings indicate that combined PENG + SIFI injections lead to an extensive craniocaudal and longitudinal spread along the iliacus muscle. We perceive that the combination of these two injections will have a superior clinical outcome.

Topography of the mandibular canal in male human skulls originating from different time periods.

Dynamic advances in dentistry, especially in implantology has inspired researchers to carry out many studies investigating the topography of the mandibular canal and its ethnic differences. The aim of the study was a comparative analysis of variations in the position and topography of the mandibular canal based on radiographic images of human mandibles originating from modern and medieval skulls. Morphometric examination of 126 radiographs of skulls (92 modern and 34 medieval skulls) was included. The age and sex of individuals were determined based on the morphology of the skull, the obliteration of cranial sutures, and the degree of tooth wear. To define the topography of the mandibular canal on X-ray images, we took 8 anthropometric measurements. We observed significant differences in several parameters. The distance between the base of the mandible and the bottom of the mandibular canal, the distance between the top of the mandibular canal and the crest of the alveolar arch, and the height of the mandibular body. Significant asymmetry was found for two parameters of mandibles from modern skulls: the distance between the top of the mandibular canal and the crest of the alveolar arch at the level of the second molar (p < 0.05), and the distance between the mandibular foramen and the margin of the anterior mandibular ramus (p < 0.007). There were no significant differences between measurements taken on the right and left sides of the medieval skulls. Our study revealed differences in the position of the mandibular canal between modern and medieval skulls, confirming the presence of geographical and chronological differences between populations. Knowledge of variability in the position of the mandibular canal between different local populations is fundamental for the correct interpretation of findings from diagnostic radiological studies used in dental practice and in forensic odontology or analysis of archaeological bone materials.