Petrous Bone Research Articles (Page 5)

To evaluate the morphology of the mastoid process and its role in sex determination with the help of cone-beam computed tomography (CBCT). A retrospective study was conducted on 200 adults who were subjected to full FOV CBCT scans (100 males and 100 females). Eight parameters of the mastoid process were assessed for sex determination. The study measured eight parameters of the mastoid process, including mastoid length (ML), mastoid width, mastoid height (MH), intermastoidale distance (IMD), intermastoidale lateral surface distance (IMLSD), mastoid medial convergence angle, mastoid size (MS), and mastoid surface area (MSA). Data were recorded and statistically analyzed. Statistics revealed a significant value for MH (p < 0.001), IMD (p < 0.001), IMLSD (p < 0.001), MSA (p < 0.001), MS (p < 0.001), and ML (p = 0.032). A highly significant value was noted for MH (p < 0.001), IMD (p < 0.001), IMLSD (p < 0.001), MSA (p < 0.001), MS (p < 0.001), followed by ML, all of which were found to be greater in males. Out of the eight parameters, IMD was found to be the best sex determinant among all the eight parameters, with an accuracy of 70%. The study showed a significant difference between the mastoid process morphometric measurements for males and females. It can be concluded from the present study that IMD can be used as a good index for sex determination. The combined parameters that were found to be the most accurate were right MH, left ML, and IMLSD, with an accuracy of 75%. The three-dimensional imaging techniques can contribute significantly towards disaster victim identification and sex determination in the fields of forensic odontology and anthropology. For the recognition of victims, sex determination becomes one of the most difficult parameters to assess. In such events, the mastoid process can become an important anatomical landmark for the estimation of sex. This is due to the condensed nature of the petrous bone and its protected position in the skull. How to cite this article: Ahmed J, Saha A, Muralidharan A, et al. Efficacy of Mastoid Morphometry in Sex Determination Using Cone-beam Computed Tomography: A Retrospective Analysis in Dakshina Kannada Population. J Contemp Dent Pract 2024;25(5):453-458.

The petrous bone contains significantly higher amounts of DNA than any other human bone. Because of highly destructive sampling and because it is not always part of the recovered remains, the need for alternative sources of DNA is important. To identify additional optimal bone types, petrous bones were compared to femurs, tali, and calcanei sampled from 66 adult skeletons from two distinct modern-era Christian cemeteries. An extraction method employing full demineralization was used to obtain DNA, real-time PCR quantification to ascertain DNA quantity and degradation, and a commercial forensic short tandem repeats (STR) PCR amplification kit to determine genetic profiles. Statistical analysis was performed to explore the differences in DNA yield, DNA degradation, and success of STR amplification. A systematic studies exploring intra-skeletal variability in DNA preservation including various excavation sites differing by time period and geographical position are rare, and the second part of the investigation was based on a comparison of both archaeological sites, which allowed us to compare the effect of different post-mortem intervals and environmental conditions on DNA preservation. The older burial site in Črnomelj was active between the 13th and 18th century, whereas the more recent Polje burial was in use from the 16th to 19th century, creating different temporal and geographical environments. Results for the Črnomelj burial site revealed that the petrous bone outperformed all other bone types studied, except the calcaneus. At the Polje archeological site calcanei, tali, and femurs yielded the same STR typing success as petrous bones. The results obtained highlight the importance of careful bone sample selection for DNA analysis of aged skeletal remains. In addition to petrous bones, calcanei were found to be an alternative source of DNA when older burial sites are investigated. When more recent burial sites are processed, calcanei, tali, and femurs should be sampled besides petrous bones, not only because they exhibited good performance, but also because of easier sampling and easier grinding in the case of trabecular bones. This study contributes valuable insights into the potential use of various skeletal types as a source of DNA for investigation of aged skeletal remains, and it offers practical implications for forensic and archaeological investigations.

Cochlear neurodysplasia (CND) is recognized as a contributing factor to sensorineural hearing loss in children. This study aimed to investigate the relationship between modiolus density on high-resolution computed tomography (HRCT) and CND, and to evaluate its performance in diagnosing CND. This retrospective study collected HRCT images of 34 patients diagnosed with unilateral neurological hearing loss in the Children's Hospital of Chongqing Medical University from March 2018 to December 2023, who were also diagnosed with unilateral CND by computed tomography (CT) and magnetic resonance imaging (MRI) hydroimaging. CT values of the modiolus and petrous bone were measured on the affected and healthy sides, in addition to determining the width of cochlear nerve foramina and the width of internal auditory tract. The receiver operator characteristic (ROC) curve was used to evaluate the diagnostic performance of these features. Simultaneously, comparisons were conducted with parameters obtained from normal children. A total of 29 patients without CND were randomly selected as a control group. The unilateral sensorineural hearing loss group had 34 patients, comprising 18 males and 16 females, with a median age of 4.5 years, ranging from 0.7 to 11 years. The normal children group consisted of 20 males and 9 females, with a median age of 5.9 years, ranging from 0.5 to 12.0 years. Statistically significant differences were observed in the CT values of the modiolus, modiolus/petrous bone CT value ratio, width of cochlear nerve foramina, and width of internal auditory tract between the affected and healthy sides in patients with unilateral sensorineural hearing loss (P<0.05). The area under the ROC curve (AUC) of the modiolus CT value and the width of cochlear nerve foramina for the diagnosis of unilateral sensorineural hearing loss was 0.98 [95% confidence interval (CI): 0.95-1.00] and 0.99 (95% CI: 0.98-1.00), respectively. the modiolus density was significantly elevated in the affected sides in patients with unilateral CND. The optimal cut-off value of modiolus CT values was 983 Hounsfield unit (HU). The elevated density of the modiolus on HRCT holds significant value in diagnosing CND.

The petrous bone generally preserves ancient DNA better than other fossil bones. One reason for this is that the inner layer of the petrous bone of pigs and humans contains about three times as many osteocytes as other bones, and hence more DNA. A FIB-SEM study of modern pig petrous bones showed that the 3D structure of the thin inner layer is typical of woven bone that forms in the fetus, whereas the thicker outer layer has a lamellar structure. The lamellar structure is common in mammalian bones. Here we study human petrous bones that are about 2500 years old, obtained from three Phoenician sites in Sicily, Italy. A detailed FIB-SEM study of two of these bones, one well preserved and the other poorly preserved, shows that the 3D bone type structure of the human petrous inner layer is woven bone, and the outer layer is lamellar bone. These are the same bone type structures found in pig petrous bones. Furthermore, by comparing nine differently preserved petrous bones from the same archaeological region and age, we show that their collagen contents vary widely, implying that organic material can be significantly altered during diagenesis. The mineral crystals are better preserved and hence less crystalline in the inner layers compared to the outer layers. We therefore infer that the best-preserved DNA in fossil petrous bones should be found in the thin inner layers immediately adjacent to the otic cavity where much more DNA is initially present and the mineral phase tends to be better preserved.

The facial canal (FC) is an extensive bony canal that houses the facial nerve and occupies a central position in the petrous part of temporal bone. It is of utmost significance to otologists due to its dehiscence and relationship to the inner or middle ear components. The main objectives of current investigation are to detect variations in the reported values ​​of FC anatomy that may occur due to different methodology and to elucidate the influence of age and ethnic factors on the morphological features of FC. The methodology is adapted to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pooled weighted estimation was performed to calculate the mean length, angle, and prevalence of dehiscence. The cross-sectional shape of FC varied from circular to ellipsoid index and is 1.45 [95% CI, 0.86-2.6]. The mean length of the FC is 34.42mm [95% CI, 27.62-40.13mm] and the mean width or diameter is 1.35mm [95% CI, 1.013-1.63mm]. The length of the FC in fetuses and children is 21.79mm [95% CI, 18.44-25.15mm], and 26.92mm [95% CI, 23.3-28.3mm], respectively. In meta-regression, age is observed as a predictor and accounts for 36% of the heterogeneity. The prevalence of FC dehiscence in healthy temporal bones is 29% [95% CI, 20-40%]. The different segments of the FC exhibit significant variability and an unusually high incidence of dehiscence, which could potentially have clinical implications for the etiopathogenesis of facial nerve dysfunction.

Beyond qualitative evidence legitimizing endoscopic corridors through contralateral transmaxillary (CTM) and endonasal ipsilateral transpterygoid (ITP) corridors to the petrous apex and petroclival region, surgical feasibility by direct quantitative comparative anatomy is sparse. Our cadaveric study addresses this by performing the CTM approach followed by ITP extension to quantify the extent of petrous apex resection, instrument maneuverability, and working distance to petrous apex. Anatomic dissections were performed bilaterally on 5 latex-injected human cadaveric heads (10 petrous bones). After CTM dissections were quantified, the ITP approach was added enlarging initial exposure. Differences were measured with statistical significance when P values are < .05. The mean petrosectomy volume was 0.958 cm 3 with CTM and 1.987 cm 3 with CTM + ITP, corresponding to 14.53% and 30.52% petrous apex resection, respectively. Craniocaudal instrument mobility was more limited in the lateral extent of dissection compared with the midline for both CTM (8.062° vs 14.416°) and CTM + ITP (5.4° vs 14.4°). The CTM approach achieved the lateral-most dissection at the body of the petrous apex (15.936 mm), with lateralization more limited in the superior petroclival region (9.628 mm) and the inferior petroclival region (8.508 mm). Angle of surgical maneuverability increased superiorly vs inferiorly in the CTM approach (mean 12.596° vs 8.336°, respectively). The CTM approach offered the shortest mean working distance (88.624 mm) to the petroclival region compared with the bi-nares approach (100.5 mm). CTM + ITP achieved greater lateralization in the superior (21.237 mm) and inferior (22.087 mm) aspects of the petroclival region compared with the CTM approach. Operative considerations are discussed in accessing target neurovascular structures through the uniquely shaped corridors formed by the CTM or combined CTM + ITP. Allowing mobilization of the internal carotid artery laterally and eustachian tube inferiorly, addition of the ITP allowed for larger petrosectomy than CTM alone, especially in the inferior and lateral aspects of the petrous bone.

Abstract Aim IgG4-related disease (IgG4-RD) involving the temporal bone is an uncommon and underrecognized pathology often mistaken for malignancy. This systematic review is the first that aims to thoroughly analyse IgG4-RD of the temporal bone. Method The following databases (Ovid MEDLINE, EMBASE, Cochrane Library, and Google Scholar) were searched using the following keywords: "lgG4-RD," "skull," "skull base," "cranial," "temporal bone," "inner ear." The bibliographies of relevant articles were additionally manually searched. The JBI Critical Appraisal Checklist for Case Reports and Case Series was used to assess the risk of bias; because of the scarcity of the reports, data were available through limited case series and reports; thus, data synthesis was not possible. Results Seventeen studies with 22 cases of temporal bone involvement were included. The most common presenting symptoms were hearing loss, otalgia, and headache. The mastoid and petrous bone were the most affected anatomical areas. Both computed tomography and magnetic resonance imaging were used. Biopsies showed the characteristic lymphoplasmacytic infiltrate in all cases, with histopathology being the diagnostic modality that set the diagnosis. Most patients were treated with corticosteroids ± surgery or a combination of corticosteroids and immunosuppressants with 95.5% symptomatic response and disease control. Conclusions IgG4-RD of the temporal bone radiologically manifests as space-occupying, lytic lesions; clinically, it presents with vague otological symptoms. Diagnosis involves a thorough workup, with histopathology being crucial in setting a definite diagnosis. IgG4-RD tends to respond well to systemic corticosteroids, whereas surgery is mostly required for diagnostic purposes.

Abstract Introduction Even though pneumatic weapons rarely cause severe direct trauma, pellet embolisation can lead to unexpected, catastrophic events. Case Report A 13-year-old, previously healthy boy was injured by an accidentally fired pneumatic gun, while playing with his twin brother. He sustained a penetrating wound to left anterior chest wall and resultant bleeding was self-limiting. He was hospitalised within 15minutes. On admission, he was hemodynamically stable with normal Respiratory, Cardiovascular and Neurological system findings. Entry wound measuring 5*5 mm was present at 5th intercostal space just left to the sternum. No exit wound was detected. Initial chest radiograph and ultra-sound abdomen and chest were normal. 2D echocardiogram revealed only a very thin layer(3mm) of pericardial effusion. Four hours later, He developed a focal seizure followed by left sided hemiparesis. Urgent NCCT brain and carotid artery duplex showed a high dense pellet in right internal carotid artery at the level of petrous temporal bone and hypo-dense Middle Cerebral Artery (MCA) suggestive of right MCA thrombosis. He was transferred to a tertiary care centre. Interventional radiological and endo-vascular attempts of pellet retrieval have been failed. Ischemic stroke pursued with worsening cerebral oedema; thus decompression craniotomy was performed on day 3. He is currently being rehabilitated in a specialised centre. Conclusions High degree of suspicion should be maintained on the possibility of projectile embolisation, in pneumatic gun-shot injuries, especially in the absence of an exit wound. Extensive early investigations should be performed to localise the projectile and retrieval should be planned.

The leading cause of trigeminal neuralgia (TGN) relies on the microvascular conflict between the superior cerebellar artery (SCA) loop and the dorsal root entry zone of the trigeminal nerve (TN). However, lesions along the TN have been described as a possible cause of TGN for direct mass effect or indirect vascular transposition. Thus, the surgical approach to TGN in patients harboring cerebellopontine angle or Meckel's cave tumor should be methodically chosen. The retrosigmoid (RS) approach with suprameatal extension offers direct access to the TN in both its cisternal and Meckel's cave segment, allowing optimal TN decompression from vascular and tumoral components. Although the RS approach with suprameatal extension has been described in numerous studies,1-4 videos detailing its key steps in addressing a multicomponent TGN are lacking. In this video, we highlight the case of a 46 year-old woman with 6 months of medically refractory typical TGN with a right en plaque meningioma involving the petrous bone, petroclival junction, Meckel's cave, and tentorium. In addition, magnetic resonance imaging was suspicious for a compressive SCA loop over the dorsal root entry zone. The patient underwent a RS approach with suprameatal extension for subtotal resection of the tumor and microvascular decompression of the TGN. The patient recovered with no complications and TGN resolved.

Abstract The mandibular joint is a condyloid synovial joint, that is formed between the head of the mandible and the petrous temporal bone. Temporomandibular disorders (TMDs) occur in roughly one out of four people; they are degenerative musculoskeletal diseases that cause morphological and functional alterations, characterized by pain, restricted mouth opening, and clicking sounds. Basically, the causes of TMD are genetic predisposition, trauma, arthritis, and dental malocclusion. TMD is rooted in early Egypt manual therapy, Hippocrates, and early surgeons such as Annandale, Lanz, Pringle, and Wakeley. The National Institutes of Health sponsored an international workshop in 1994 to initiate the research and nevertheless consensus of TMD. The American Academy of Orofacial Pain has divided TMD into muscle TMD or myogenous and joint TMD or arthrogenous TMD. Studies are in agreement that orthodontic treatment may help in alleviating TMD. The systematic review showed that patients undergoing orthodontic treatment reported a decrease in their TMD symptoms and headaches. TMD treatment is generally carried out in two stages: Phase I, intraoral orthopedic appliances, phase II, occlusal adjustment, or further large case procedures. They include splints that are commonly used but produce negative effects whenever the splints are designed wrongly or used for an unusually long time. Fixed removable appliances such as stabilization and anterior positioning appliances are applied in treating TMD. Stabilization appliances deal primarily with muscle pain and parafunctional activities, while anterior positioning appliances are useful in cases of disc derangement disorders, they aid in the proper positioning of the condyle and disc. Their usage needs specific criteria to be fulfilled for them to be effective. Although there is continuing controversy and uncertainty about certain aspects of the results of studies for now, oral appliances belong to the most conservative type of TMD therapy. They afford relief from the symptoms and are akin to orthopedic braces without aiming at creating new occlusal erections. Further studies are required to provide more accreditation on treatment regimens and patients’ conditions.

Cochlear duct length (CDL) measurement plays a role in the context of individualized cochlear implant (CI) surgery regarding an individualized selection and implantation of the CI electrode carrier and an efficient postoperative anatomy-based fitting process. The level of detail of the preoperative temporal bone CT scan depends on the imaging modality with major impact on CDL measurements and CI electrode contact position determination. The aim of this study was to evaluate the accuracy of perioperative CDL measurements and electrode contact determination in photon-counting CT (PCCT). Ten human fresh-frozen petrous bone specimens were examined with a first-generation PCCT. A clinically applicable radiation dose of 27.1 mGy was used. Scans were acquired before and after CI insertion. Postoperative measurement of the CDL was conducted using an otological planning software and 3D-curved multiplanar reconstruction. Investigation of electrode contact position was performed by two respective observers. Measurements were compared with a conventional multislice CT and to a high-resolution flat-panel volume CT with secondary reconstructions. Pre- and postoperative CDL measurements in PCCT images showed no significant difference to high-resolution flat-panel volume CT. Postoperative CI electrode contact determination was also as precise as the flat-panel CT-based assessment. PCCT and flat-panel volume CT were equivalent concerning interobserver variability. CDL measurement with PCCT was equivalent to flat-panel volume CT with secondary reconstructions. PCCT enabled highly precise postoperative CI electrode contact determination with substantial advantages over conventional multislice CT scanners.

Fragments of two skulls of young cetotheriid baleen whales were described from the Fortep'yanka 2 locality (Russia, Republic of Adygea, Maikop district, Fortep'yanka River valley, Upper Miocene, Upper Sarmatian, Blinovskaya Formation). The finds were attributed to Kurdalagonus maicopicus (Spasskii, 1951) based on the morphology of the posterior (mastoid) process of the petrosal bone, the structure of the posterior edge of the temporal fossa, and the S-like shape of the supraoccipital ridges. The skull proportions and the degree of suture closure made it possible to determine the individual age of the whales within a year. New finds significantly complement the data on the structure of the sutures of the lateral wall of the skull and age-related variability of cranial morphology in representatives of the genus Kurdalagonus.

Surgical results for one-stage VII/VIII schwannoma resection and hemihypoglossal-facial neurorrhaphy

BACKGROUND Meningioma in the cerebellopontine angle (CPA) without dural attachment is extremely rare. We report a unique case of meningioma derived from the superior petrosal vein without dural attachment. CASE SUMMARY A 44-year-old right-handed woman presented with a two-month history of headache and tinnitus. Brain magnetic resonance imaging showed a well-defined contrast-enhancing lesion in the right CPA without a dural tail sign. Tumor resection was performed using a right retro sigmoid approach. A dural attachment was not seen at the tentorium or posterior surface of the petrous pyramid. The tumor was firmly adherent to the superior petrosal vein. The origin site was cauterized and resected with the preservation of the superior petrosal vein. A diagnosis of meningothelial meningioma was made. The patient’s headache and tinnitus gradually disappeared, and a recurrence was not observed five years after the surgery. CONCLUSION The rare occurrence of meningioma without dural attachment makes it difficult to determine dural attachment before surgery. The absence of dural attachment makes it easy to completely resect such tumors. Vessels related to tumors should be removed carefully, considering the possible presence of tumor stem cells in the microvessels.

Background and objectives Around 20-40% of trigeminal schwannomas (TS) are dumbbell shaped, spanning the middle and posterior cranial fossa The petrous apex is often truncated in these patients, aiding surgical resection of both compartments through the middle fossa approach. However, a less eroded petrous creates a blind spot, making total resection difficult. This study describes the feasibility of an approach combining expanded Meckel cave access with tailored petrous bone drilling to optimize tumor visualization and resection. Methods Eleven patients with dumbbell TS and minimal petrous apex erosion underwent the described surgery. Surgical steps included temporo-orbito-zygomatic craniotomy, middle fossa floor drilling, navigation aided (tailored) extradural petrous bone drilling and extra-arachnoidal tumor excision. Extent of resection and postoperative outcomes were recorded. Results Patients presented with trigeminal nerve dysfunction (n = 9; sensory −9 and motor − 5), headache(8/11), ataxia (7/11) and pseudobulbar palsy (3/11). Complete tumor resection was achieved in all patients. Postoperatively, 8 out of 9 patients had transient increase in facial hypoesthesia with conjunctival injection in 3. It improved within 3-6 months, except in four cases wherein mild hypoesthesia persisted. Motor symptoms improved in 2 of 5 patients. Two developed transient 6th nerve paresis, that resolved in 2 months. Cerebellar and brainstem pressure symptoms resolved in all. No patients developed new onset permanent neurological deficit. Two patients reported mild post-craniotomy masticatory difficulty. Conclusions The additional tailored petrous bony drilling enhances the surgeon’s view, allowing a higher chance of total resection with no major operative morbidity.

The term petrous bone cholesteatoma (PBC) refers to lesions extending deep to the bony labyrinth via superior, inferior, and posterior cell tracts. PBC is a rare incidence accounting for only 4-9% of petrous bone lesions. Lesions of petrous bone represent a real surgical challenge due to its complex relationship with critical neurovascular structures. To demonstrate our 40-plus years' experience in the management of PBC, depict the clinical features of PBC according to Sanna's Classification, evaluate the postoperative follow-up of surgically treated PBC patients, and determine the recurrence rate. Retrospective medical record review. Medical records of 298 PBC cases operated from the year 1983 to 2024 were thoroughly evaluated. A total of 298 PBC cases were surgically treated at our center. The average age at presentation in this series was 47 years. Males are more affected than females with a male-to-female ratio of 2.2:1. The most common presenting symptoms were hearing loss (84%), tinnitus (48%), and facial nerve paralysis (45%). Mixed hearing loss (41%) was the commonest audiometric pattern of hearing loss followed by conductive hearing loss (26%) and profound sensorineural hearing loss (4%) and a total of 86 (29%) had anacusis at presentation. On preoperative facial nerve function examination, 133(45%) of patients had various degrees of paresis and complete paralysis whereas 55% had normal HB-I function. The commonest degree of paresis noted was HB-III (18%) followed by HB-VI (5%). A total of 150 (50%) patients had previous otologic surgery and two-thirds of these cases had two or more prior otologic surgeries. According to Sanna's PBC Classification system, we identified that the supralabyrinthine class (44%) is the commonest of all classes followed by massive (33%), infralabyrinthine-apical (9%), infralabyrinthine(8%), and apical (5%) classes in that order. However, only ten patients had congenital type of PBC. Extension to clivus, sphenoid, nasopharynx, intradural space, and occipital condyle was found in 8, 2, 1, and 2 cases respectively. The most commonly used surgical approaches at our center were TO, MTCA with rerouting of the facial nerve, and TLAB with external auditory canal (EAC) closure. Postoperative complications were minimal and the duration of follow-up ranged from one to 458 months with a mean duration of 65 months. Residual lesions were evident in 11 cases (3.7%), with the surgical cavity, middle and posterior fossa dura, and jugular bulb being the commonest sites. Petrous bone cholesteatoma represents diagnostically and surgically challenging lesions of temporal bone which are usually frustrating to the treating surgeon. A high index of clinical suspicion, thorough clinical evaluation examination, and preoperative radiologic evaluation make the diagnosis easier. Preoperative anatomic classification of the lesion enables the physician to choose the appropriate surgical approach. Sanna's classification is widely used to classify PBC in relation to the labyrinthine block. Radical disease removal should always come before hearing preservation. Cavity obliteration is the solution to the problems related to a large cavity. Finally, advancements in lateral skull base approaches create adequate surgical access for the complete removal of the lesion with excellent control of critical neurovascular structures.

Idiopathic facial paralysis is the most common type of facial nerve injury, accounting for approximately 70% of peripheral facial paralysis cases. This disease can not only lead to a change in facial expression but also greatly impact the psychology of patients. In severe cases, it can affect the normal work and life of patients. Therefore, the research on facial nerve injury repair has important clinical significance. In order to study the mechanism of this disease, it is necessary to carry out relevant animal experiments, among which the most important task is to establish an animal model with the same pathogenesis as human disease. The compression of the facial nerve within the petrous bone, especially the nerve trunk at the junction of the distal end of the internal auditory canal and the labyrinthine segment, is the pathogenesis of idiopathic facial paralysis. In order to simulate this common disease, a compression injury model of the main extracranial segment of the facial nerve was established in this study. The neurological damage was evaluated by behavioral, neuroelectrophysiological, and histological examination. Finally, 50 g constant force and 90 s clamp injury were selected as the injury parameters to construct a stable idiopathic facial paralysis model.

Bones and teeth represent a common finding in ancient DNA studies and in forensic casework, even after a long burial. Genetic typing is the gold standard for the personal identification of skeletal remains, but there are two main factors involved in the successful DNA typing of such samples: (1) the set-up of an efficient DNA extraction method; (2) the identification of the most suitable skeletal element for the downstream genetic analyses. In this paper, a protocol based on the processing of 0.5 g of bone powder decalcified using Na2EDTA proved to be suitable for a semi-automated DNA extraction workflow using the Maxwell® FSC DNA IQ™ Casework Kit (Promega, Madison, WI, USA). The performance of this method in terms of DNA recovery and quality was compared with a full demineralisation extraction protocol based on Qiagen technology and kits. No statistically significant differences were scored according to the DNA recovery and DNA degradation index (p-values ≥ 0.176; r ≥ 0.907). This new DNA extraction protocol was applied to 88 bone samples (41 femurs, 19 petrous bones, 12 metacarpals and 16 molars) allegedly belonging to 27 World War II Italian soldiers found in a mass grave on the isle of Cres (Croatia). The results of the qPCR performed by the Quantifiler Human DNA Quantification kit showed values above the lowest Limit of Quantification (lLOQ; 23 pg/µL) for all petrous bones, whereas other bone types showed, in most cases, lower amounts of DNA. Replicate STR-CE analyses showed successful typing (that is, >12 markers) in all tests on the petrous bones, followed by the metacarpals (83.3%), femurs (52.2%) and teeth (20.0%). Full profiles (22/22 autosomal markers) were achieved mainly in the petrous bones (84.2%), followed by the metacarpals (41.7%). Stochastic amplification artefacts such as drop-outs or drop-ins occurred with a frequency of 1.9% in the petrous bones, whereas they were higher when the DNA recovered from other bone elements was amplified (up to 13.9% in the femurs). Overall, the results of this study confirm that petrous bone outperforms other bone elements in terms of the quantity and quality of the recovered DNA; for this reason, if available, it should always be preferred for genetic testing. In addition, our results highlight the need for accurate planning of the DVI operation, which should be carried out by a multi-disciplinary team, and the tricky issue of identifying other suitable skeletal elements for genetic testing. Overall, the results presented in this paper support the need to adopt preanalytical strategies positively related to the successful genetic testing of aged skeletal remains in order to reduce costs and the time of analysis.

Calvarial bone marrow has been found to be central in the brain immune response, being connected to the dura through channels which allow leukocyte trafficking. Temporal bone marrow is thought to play important roles in relation to the inner ear, but is still largely uncharacterized, given this bone complex anatomy. We characterized the geometry and connectivity of rat temporal bone marrow using lightsheet imaging of cleared samples and microCT. Bone marrow was identified in cleared tissue by cellular content (and in particular by the presence of megakaryocytes); since air-filled cavities are absent in rodents, marrow clusters could be recognized in microCT scans by their geometry. In cleared petrosal bone, autofluorescence allowed delineation of the otic capsule layers. Within the endochondral layer, bone marrow was observed in association to the cochlear base and vestibule, and to the cochlear apex. Cochlear apex endochondral marrow (CAEM) was a separated cluster from the remaining endochondral marrow, which was therefore defined as "vestibular endochondral marrow" (VEM). A much larger marrow island (petrosal non-endochondral marrow, PNEM) extended outside the otic capsule surrounding semicircular canal arms. PNEM was mainly connected to the dura, through bone channels similar to those of calvarial bone, and only a few channels were directed toward the canal periosteum. On the contrary, endochondral bone marrow was well connected to the labyrinth through vascular loops (directed to the spiral ligament for CAEM and to the bony labyrinth periosteum for VEM), and to dural sinuses. In addition, CAEM was also connected to the tensor tympani fossa of the middle ear and VEM to the endolymphatic sac. Endochondral marrow was made up of small lobules connected to each other and to other structures by channels lined by elongated macrophages, whereas PNEM displayed larger lobules connected by channels with a sparse macrophage population. Our data suggest that the rat inner ear is surrounded by bone marrow at the junctions with middle ear and brain, most likely with "customs" role, restricting pathogen spread; a second marrow network with different structural features is found within the endochondral bone layer of the otic capsule and may play different functional roles.

DNA analysis plays a crucial role in forensic investigations, helping in criminal cases, missing persons inquiries, and archaeological research. This study focuses on the DNA concentration in different skeletal elements to improve human identification efforts. Ten cases of unidentified skeletal remains brought to the Institute of Forensic Medicine in Timisoara, Romania, underwent DNA analysis between 2019 and 2023. The results showed that teeth are the best source for DNA extraction as they contain the highest concentration of genetic material, at 3.68 ng/µL, compared to the petrous temporal bone (0.936 ng/µL) and femur bone (0.633 ng/µL). These findings highlight the significance of teeth in forensic contexts due to their abundant genetic material. Combining anthropological examination with DNA analysis enhances the understanding and precision of identifying human skeletal remains, thus advancing forensic science. Selecting specific skeletal elements, such as the cochlea or teeth, emerges as crucial for reliable genetic analyses, emphasizing the importance of careful consideration in forensic identification procedures. Our study concludes that automated DNA extraction protocols without liquid nitrogen represent a significant advancement in DNA extraction technology, providing a faster, more efficient, and less labor-intensive method for extracting high-quality DNA from damaged bone and tooth samples.