Facial skeleton displacement in non-syndromic brachycephaly.

BackgroundSupralabyrinthine petrous bone cholesteatoma is a rare subtype in which hearing preservation may be achievable depending on the anatomical extent and surgical approach. Appropriate selection of surgical strategy is essential.Case PresentationA 31‐year‐old man presented with a 2‐year history of persistent left otorrhea. Otoscopic examination revealed pars flaccida cholesteatoma. Pure‐tone audiometry demonstrated hearing loss with an air–bone gap of 35 dB. Computed tomography showed soft‐tissue density extending from the tympanic cavity and mastoid air cells to the supralabyrinthine petrous apex. Inner ear function was almost preserved.InterventionA staged surgical approach was adopted due to active inflammation. First, canal wall–down tympanomastoidectomy via a transmastoid approach was performed to control infection. Six months later, second‐stage surgery was performed using the middle cranial fossa approach for complete removal of the supralabyrinthine cholesteatoma, along with ossicular chain reconstruction.OutcomeNo intraoperative or postoperative complications occurred. Postoperative non–echo‐planar diffusion‐weighted MRI at 4 months showed no residual disease. At 22 months, hearing improved with an air‐conduction threshold of 21.7 dB, and no tympanic membrane findings suggestive of recurrence were observed.ConclusionIn supralabyrinthine petrous bone cholesteatoma, selecting the surgical approach based on lesion extent, inflammatory status, and the need for hearing preservation is important for optimizing outcomes. In cases with extensive disease and significant inflammation, a staged strategy incorporating the middle cranial fossa approach may represent a safe and effective option for achieving disease eradication while minimizing the risk of inner ear dysfunction and postoperative complications.

The petrous bone is considered the most efficient source of endogenous DNA across skeletal tissues in ancient DNA (aDNA) research as well as in forensic work. Recently, ancient DNA in auditory ossicle bones was shown to be comparably well-preserved as in the petrous, although no attempt was made to distinguish among the three ossicle bones. In this study, we compare aDNA profiles across matched ossicle- and petrous-derived sequencing libraries prepared from 29 human skeletons from Neolithic Anatolia and Medieval Iberia. We find that the stapes and incus provide higher human endogenous aDNA than the petrous bone, with >2×; higher median rates of endogenous aDNA recovery, while the malleus performs similarly to the petrous. Human aDNA fragments retrieved from the stapes were 8% longer than those from the petrous, whereas postmortem damage, clonality and contamination rates were comparable among the studied bone types. These observations are corroborated by data from non-matched ossicle or petrous libraries from 81 individuals from the same contexts, with the highest endogenous aDNA content observed in the stapes. Despite being the smallest bone in the human skeleton, the stapes, along with the incus, may be among the most optimal aDNA sources yet identified.

Endoscopic transnasal surgery offers a minimally invasive alternative to transcranial approaches for accessing midline skull base lesions involving the petrous apex and petroclival region. However, lateral access, particularly behind the petrous internal carotid artery (ICA), remains limited. The contralateral transmaxillary (CTM) approach provides a more direct surgical trajectory, more parallel to the petrous ICA. Yet, lateral access through this approach can be restricted by anatomic barriers, including the pterygoid process and lateral buttress of the maxillary sinus. We aimed to evaluate the contralateral transmaxillary-transpterygoid (CTMP) approach, with and without the lateral buttress removal (CTMP-LBR), to determine whether these modifications could enhance surgical access to the petroclival region. Ten sides from 5 formalin-fixed, latex-injected cadaveric specimens were dissected to compare CTM, CTMP, and CTMP-LBR approaches. Petrous bone drilling was directed posterolaterally behind the petrous ICA toward the region medial to the cochlea. In addition, 30 sides from computed tomography angiography scans were analyzed to obtain radiographic measurements for each approach. Compared with CTM, both CTMP and CTMP-LBR significantly increased access for retrocarotid petrous bone drilling (P < .001) and yielded a wider surgical angle relative to midline (P < .001), in both cadaveric and radiographic analyses. In dissections, 20% of sides required CTM only, 50% benefited from CTMP, and 30% required CTMP-LBR to achieve adequate lateral access. Radiographic analysis revealed that CTMP required a median of 4 mm of pterygoid drilling, whereas CTMP-LBR required 9 mm and enabled a trajectory parallel to the petrous ICA with only 11 mm of soft tissue displacement. Patients with smaller angles between the petrous ICA and the horizontal plane were significantly more likely to benefit from CTMP over CTM (P = .005). Modification of the CTM approach with pterygoid drilling and optional LBR improves retrocarotid access. Preoperative evaluation of the petrous ICA angle may help optimize patient-specific planning in endoscopic petroclival surgery.

In many low- and middle-income countries (LMCIs), particularly in Sub-Saharan Africa (SSA), skull base surgery is limited by inadequate infrastructure, scarce surgical tools, and few structured training opportunities. Given its technical complexity, requiring mastery of intricate neurovascular and craniofacial anatomy, as well as a coordinated multidisciplinary approach, these gaps pose major barriers to safe and effective care. To sustain the training of LMICs neurosurgeons, the authors propose a practical framework for establishing skull base skills laboratories in resource-limited settings. We describe the microsurgical laboratory at IRCAD Africa, Kigali, inaugurated in October 2023, providing training for African surgeons in minimally invasive surgery (MIS) across multiple surgical disciplines; this includes skull base surgery through both open microsurgical and endoscopic techniques. Training included theoretical and practical modules, live demonstrations, and supervised cadaveric dissections. Trainees reflected daily on their learning via structured questionnaires. The IRCAD Africa 360° Skull Base Course, launched in May 2024 and repeated in May 2025, trained 75 surgeons from 12 African countries. The course featured 11 wet lab stations with preserved human specimens, covering six modules: antero-lateral corridor, temporal fossa floor, petrous bone and posterior petrosal approach, cranio-cervical junction, endoscopic endonasal, and extended endonasal approaches. Essential tools and practical guidelines were provided. Participants reported high satisfaction with both theory and hands-on training. SSA neurosurgeons show growing interest in developing skull base surgery skills. Cadaveric dissection remains the most effective training method and the IRCAD Africa 360° Skull Base Course demonstrates that high-level skull base education can be successfully delivered in resource-limited settings.

ABSTRACTObjectivesThe cranial base is located at the interface between the face, the brain, and the vertebral column. Understanding its growth is essential for elucidating key aspects of craniofacial development, neurodevelopment, and locomotor function. This study aims to examine the developmental trajectories of the three cranial fossae, anterior, middle, and posterior, in terms of both size and shape.Materials and Methods203 CT scans of individuals aged from birth to 15 years were segmented and analyzed. Traditional morphometric analyses based on linear measurements were first conducted to assess changes in length and width during growth. Geometric morphometric methods were applied to investigate shape variation, using a template of 32 anatomical landmarks and two curves of semi‐landmarks.ResultsGrowth of the cranial base followed a rapid phase from 0 to 2 years and a slower growth until adolescence. Transverse dimensions generally reach adult proportions earlier than anteroposterior lengths. The posterior fossae exhibit pronounced anteroposterior and transverse expansion. Shape analyses reveal coordinated changes of fossae boundaries, including reorientation of the petrous temporal bones and increased curvature of the sphenoid wings. Strong allometric relationships and morphological integration are observed during the initial rapid growth phase. Sexual dimorphism has a statistically significant but moderate effect on cranial base fossae shape during ontogeny.DiscussionThe cranial base exhibits biphasic growth, early‐integrated shape changes, and later modularization, reflecting coordinated cranial and brain development. These patterns provide a reference for comparative studies in primates and highlight the importance of cranial base development for neurocranial and facial morphogenesis.

Endolymphatic sac tumours (ELSTs) are rare, locally aggressive neoplasms of the temporal bone that often present at an advanced stage due to their indolent clinical course. Complete surgical excision may be technically challenging when tumours involve the jugular foramen, cerebellopontine angle (CPA) or adjacent cranial nerves and may therefore be associated with significant neurological morbidity. To evaluate facial nerve and radiological outcomes following planned subtotal resection with selective use of adjuvant radiotherapy in patients presenting with advanced sporadic ELST. A retrospective review was performed of patients diagnosed with ELST and managed at the National Skull Base Centre, Beaumont Hospital. Clinical presentation, radiological findings, surgical approach, extent of resection, histopathological features, adjuvant therapy and postoperative outcomes were analysed. All patients underwent screening for von Hippel-Lindau (VHL) disease. Facial nerve function was assessed using the House-Brackmann (HB) grading system. Radiological stability was evaluated using serial postoperative magnetic resonance imaging (MRI). Two patients presented with locally advanced ELST involving the petrous temporal bone and skull base with cranial nerve involvement at diagnosis. Both patients underwent screening for von Hippel-Lindau disease. Both underwent transmastoid subtotal resection to preserve neurological function. One patient subsequently received adjuvant radiotherapy, while the second was managed with radiological surveillance alone. Patient 2 improved from House-Brackmann grade V to grade II, while Patient 1 maintained grade II function. Serial postoperative MRI demonstrated stable residual disease. In selected cases of advanced sporadic ELST, planned subtotal resection with selective adjuvant radiotherapy may preserve cranial nerve function while maintaining short-term radiological stability.

The petrous portion of the temporal bone (often informally referred to as the "petrous bone") is a key element in human evolutionary studies due to its exceptional preservation of biomolecules and morphological information. Intensive and often redundant sampling raises concerns about sustainability and long-term conservation, however. Digital recording of morphology (micro-computed and medical tomography) can preserve what destructive sampling destroys, enabling future analyses, yet there have been concerns regarding its effect on biomolecular preservation. Here, we present a systematic observational assessment of whether micro-computed tomography (µCT)-a widely used tool for digital preservation-affects ancient DNA (aDNA) integrity in archaeological human petrous portions. We analyzed 93 archaeological samples from Argentina, of which 50 were µCT-scanned prior to molecular analysis and 43 were not. We compared six commonly used molecular parameters, including endogenous DNA content, read length, cytosine deamination patterns, and mitochondrial and nuclear contamination estimates. No statistically significant differences were observed between scanned and unscanned samples across these parameters (Mann-Whitney/Wilcoxon tests, p > 0.05). Although mitochondrial contamination estimates were marginally higher in scanned samples (p = 0.051), they largely remain below the widely accepted 5% threshold for genomic analysis. Moreover, this pattern was not observed when considering nuclear contamination. Within the limits of this non-paired design, these results suggest that µCT imaging, under the scanning parameters applied here, does not introduce large or systematic bias derived from disruptions in standard aDNA preservation metrics. Building on these observations and on our collaborative experience with the shared use of archaeological samples across complementary research lines, and given that our results show that µCT imaging under appropriate scanning conditions does not significantly compromise DNA preservation, we propose a sustainable, multi-step workflow that integrates biological profiling, osteobiography, imaging, and compositional pre-screening prior to molecular sampling. This approach aims to maximize the scientific information obtained from skeletal collections while minimizing destructive practices, thereby promoting ethical and sustainable research on irreplaceable anthropological remains, and fostering interdisciplinary collaboration.

Purpose: Scientists have discovered more information on ancient genes, migration patterns, and human population evolution by studying DNA extracted from old samples. This research aimed to synthesize current understanding of the relationship between MTHFR mutation and ancient DNA, exploring possible implications for our understanding of the evolutionary and genetic underpinnings of disorders.Materials and methods: Genomic DNA isolation from petrous bone and teeth samples was performed using the Ancient DNA extraction from bones and teeth kit. In the obtained genomic DNAs, the gene-specific region was amplified by PCR, and the polymorphic locus located in this region was observed on high-resolution agarose gel. The MTHFR mutation was examined by genotyping based on DNA sequence analysis.Results: MTHFR A1298C mutation was detected in three samples and MTHFR C1298C mutation was detected in one sample.Conclusion: Looking at MTHFR changes in ancient DNA helps scientists understand how these gene differences affected human survival.

BACKGROUND Temporal bone necrosis is a rare condition, most commonly caused by radiation therapy, bisphosphonate treatment, and osteomyelitis. Cholesteatoma can contribute to temporal bone necrosis, particularly in the presence of secondary ear infections. We report a case of extensive temporal bone necrosis with intracranial involvement in a patient with mastoid and petrous apex cholesteatoma, further complicated by actinomycosis. CASE REPORT A 47-year-old woman presented with persistent otorrhea and right-sided conductive hearing loss. Imaging demonstrated diffuse necrotic tissue extending from the retroauricular soft tissues to the middle ear and the petrous apex of the temporal bone, with erosion of the tegmen tympani. An extended petrosectomy was performed with particular attention to preserving the facial nerve. Histopathologic examination revealed the coexistence of cholesteatoma, necrotic bone sequestra, and colonies of Actinomyces. Postoperatively, the patient completed a course of intravenous antibiotics and adjuvant hyperbaric oxygen therapy. At 1-year follow-up, no evidence of recurrence was observed on radiological and clinical evaluation. CONCLUSIONS This case underscores an unusual presentation of temporal bone necrosis, occurring in the absence of conventional predisposing factors. The concomitant presence of cholesteatoma and Actinomyces infection highlights the importance of considering atypical etiologies in progressive otologic disease. Early diagnosis, comprehensive surgical debridement, and multidisciplinary management were essential to achieving favorable clinical and radiological outcomes.

Mobilization or resection of the Eustachian tube through an endoscopic transpterygoid approach (ETPA) improves access to the anterior petrous region. This maneuver is particularly beneficial for resecting extradural skull base malignancies where complete removal of involved or affected bone is necessary. Preservation of the Eustachian tube may potentially decrease hearing morbidity; however, this modification may also result in less than complete resection of these lesions. Many patients receive adjuvant radiotherapy, which can itself cause secondary hearing impairment. We sought to determine whether a significant difference in hearing outcomes exists between open and ETPA (Carrau Prevedello Kasemsiri classification type E) approaches, which would justify further investigation into Eustachian tube preservation. A single-center retrospective review was performed comparing patients who underwent either open or endoscopic resection of a petroclival malignancy. Demographic variables, baseline hearing function, preoperative and postoperative audiometric data, and rates of mitigating strategies were collected. Twenty-nine open and 31 endocopic endoansal transptreygoid class E approach resections were included. New subjective hearing loss (71% open vs 77 % ETPA; P = .56), persistent loss (68% vs 77%; P = .39), and use of mitigating strategies (45% vs 68%; P = .13) did not differ significantly. Median time to hearing loss was 18 months for open vs 6 months for ETPA (P = .21). Pure-tone audiometry remained lower after ETPA at all timepoints. Postoperative radiotherapy increased the risk of permanent hearing loss (adjusted hazard ratio 3.92; P = .043), and prior mitigation was protective (adjusted hazard ratio 0.18; P = .023). Surgical approach was not independently associated with hearing loss (adjusted hazard ratio 1.86; P = .102). The ETPA approach was not associated with a higher rate of new post-treatment hearing loss compared with open, while yielding higher rates of gross total resection. Future studies may help to further characterize hearing morbidity after Eustachian tube manipulation.

Sinonasal and petrous bone fungal infections are rare and life-threatening conditions that essentialy arise in immunocompromised patients. They are mainly due to Aspergillus in patients with hematological diseases and to Mucorales in diabetic. Invasive fungal sinusitis can be acute (invasive aspergillosis, rhino-orbito-cerebral mucormycosis) but chronic invasive sinusitis can also exist (invasive chronic fungal sinusitis and granulomatous invasive fungal sinusitis). Petrous bone fungal infections are similar to bacterial necrotizing otitis externa and are most often due to Aspergillus. The diagnosis must be made as early as possible with surgical biopsies, to allow early therapeutic management. Histopathological analysis is essential to confirm the diagnosis. The treatment is multidisciplinary and combines antifungal treatments with etiological care, sometimes associated with debridement surgery especially for mucormycosis.

A45-year-old male patient presented with pronounced swelling of the external auditory canal and symptoms of otitis externa which did not respond to conservative treatment. Due to concomitant mastoiditis, mastoidectomy was performed in the later course, which did not provide conclusive histological results. In the absence of improvement, biopsy of the external auditory canal and mastoid revision with repeated pathological analysis were carried out. Ultimately, amyeloid sarcoma representing arelapse of previously remitted acute myeloid leukemia (AML) was identified.

ImportanceOpening the cochlear‒carotid recesses through the endoscope-assisted modified translabyrinthine approach to treat lesions in the petrous apex has been demonstrated to preserve the cochlea and hearing. The objective parameters of recesses and their relationships with vital structures were fundamental to the effective application of this technique.ObjectiveHerein, we present a quantitative analysis of cochlear‒carotid recesses on high-resolution computed tomography (HRCT) images and discuss their implications for hearing preservation in the surgical management of massive petrous bone cholesteatomas (PBCs).DesignObservational study.ParticipantsTwenty samples (40 sides) obtained between April and June 2021 radiographically via HRCT.MethodsHRCT images of 40 ears were acquired at 0.60 mm thickness and processed via Mimics. The intrinsic structures of the temporal bone were reconstructed in a 3D view. The morphological data were precisely measured on multiplanar reconstructed images. In addition, clinical implications were demonstrated in one patient with massive temporal bone cholesteatoma.ResultsA 3D model of the cochlear‒carotid recesses was reconstructed. The recesses were essentially divided into 2 parts, namely, the triangle anterior and superior to the cochlea (TASC) and the triangle anterior and inferior to the cochlea (TAIC). The size of the cochlear‒carotid recesses varied widely among the samples. The TASC was accessible in 80% of the samples via a conventional ear endoscope with a diameter of 3 mm, while the applicability of the TAIC was 62.5%. We further discovered that the low position of the trigeminal nerve impression and the small distance between the cochlea and the jugular bulb suggested narrow recesses. The thickness of the compact bone shell of the cochlear lumen acted as a safe drilling divider.ConclusionsHRCT and 3D reconstruction clearly displayed cochlear‒carotid recesses. For patients with massive PBC, the use of an endoscope to open recesses is feasible in the majority of cases and increases the possibility of preserving the structure and function of the cochlea. Individualized preoperative measurements of cochlear‒carotid recesses via HRCT could help surgeons perform safe and accurate dissection.

Thermal fractures of the skull or even the complete loss of skull structures can make it extremely difficult or even impossible to assess additional mechanical head trauma in severely burnt bodies. However, as the petrous part of the temporal bone is very dense, it often remains more intact, even when other structures of the head are destroyed. It has been suggested in the past that certain lesions of the petrous bone, particularly transverse fractures, may indicate the presence of mechanical trauma. In this retrospective study, a total of 54 cases comprising 108 petrous bones with thermal damage to the head were examined based on CT data and reports, focusing on the occurrence of longitudinal and transverse petrous bone fractures and auditory ossicle luxation in relation to the degree of burning and mechanical trauma. None of the 44 cases without assumedly present mechanical head trauma displayed a fracture of the petrous bone or dislocation of the ossicular chain. In contrast, four transverse and five longitudinal fractures as well as two ossicle dislocations were seen in the ten cases with mechanical trauma to the head. These results indicate that the presence of petrous bone fractures and auditory ossicle lesions are highly indicative of an additional mechanical trauma - possibly before being burnt - thus demanding further investigations.

Methylation-based forensic donor age estimation is an emerging field in forensic genomics. It can be used not only to estimate the age of a living person, but also to determine age-at-death of an unknown corpse or skeleton. Therefore, age estimation tools suitable for bone samples have been developed in recent years. As commonly known, methylation profiles differ considerably between different sample types. However, it is unclear whether different types of bones display different methylation patterns and whether exposure to forensically relevant environmental conditions affects bone methylation. In this study, we used the VISAGE enhanced age estimation tool for bones to estimate the age of freshly collected bone samples from 30 individuals. Five bone types (rib, femur, clavicle, iliac crest and petrous bone) were analysed for each individual. While we found high overall age estimation errors with this tool (MAE = 9.79 years, mean error = -7.25 years), only the petrous bones displayed statistically significantly different age estimation errors compared to at least one of the other four bone types. As is commonly necessary when adapting a methylation-based assay in different laboratories, a linear transformation between predicted and chronological age was applied to calibrate the estimates to our cohort, which led to an improved overall MAE of 7.03 years. In addition, this study mimicked casework samples by exposing the femur samples of the cohort to burying, submersion in water or burning. From the mock casework samples, only 12 produced a result with an MAE of approximately 10-15 years using the transformation model. Finally, two actual casework samples were analysed. Although it was technically possible to generate an age estimate, the results obtained with the transformation model deviated considerably from the chronological ages (estimation error of 10 and 29 years, respectively). We concluded that it is generally possible to estimate age-at-death from bone material through DNA methylation analysis when the bone material is fresh. However, under forensically relevant conditions, it might be difficult to obtain reliable age estimation results.

Inframeatal intradural retrosigmoid petrosectomy (IIRP): Multicenter experience and anatomical review of an effective approach to the petroclival region.

Foreign bodies (FB) in the external auditory canal (EAC) of the ear are a common occurrence. Depending on the nature or extent of damage to the affected Ear Nose Throat organ, FB can constitute a life-threatening emergency requiring appropriate treatment. This treatment must be expertly performed to prevent a risk of complications. We present a 17-year-old female patient who consulted for ear pain and right peripheral facial paralysis following attempts to remove a FB from her right ear. The FB was an earring stud embedded in the tympanic cavity after several unsuccessful attempts to remove it at various healthcare facilities in Kinshasa. Although the FB was initially located in the right EAC, it was identified in the right tympanic cavity using a petrous bone scan. Treatment consisted of extracting the FB from the tympanic cavity via a retroauricular approach, followed by physical therapy sessions and ophthalmological treatment for peripheral facial paralysis. Received: April 17th, 2025 Accepted: July 19th, 2025 https://dx.doi.org/10.4314/aamed.v19i1.20

Meningiomas are histologically and genetically heterogeneous tumors with varying anatomical distributions. While distinct genetic mutations have been associated with specific tumor locations, the spatial distribution of histological subtypes and their relationship to radiogenomic profiles remains poorly defined. Moreover, the predictive value of spatial information for histopathological classification and tumor grading has not yet been systematically explored. This study aimed to systematically analyze the anatomical predilection of histological meningioma subtypes and their concordance with known mutation-specific spatial patterns, and the predictive potential of voxel-based spatial features. We retrospectively analyzed 737 patients undergoing surgical resection of intracranial meningiomas. Preoperative magnetic resonance images were normalized to a common stereotactic space, and tumors were semi-automatically segmented. Voxel-based lesion-symptom mapping (VLSM) was performed to identify subtype-specific spatial clustering. Spatial distributions were compared with mutation maps from current literature using receiver operating characteristic analysis (AUC-ROC). Additionally, multinomial logistic regression models were applied to evaluate whether tumor localization could predict histological subtype and World Health Organization (WHO) grading. Histological subtypes showed distinct spatial preferences. Meningothelial meningiomas clustered in the anterior and middle skull base; fibrous and transitional types predominated in the convexity, falx, and tentorium; secretory tumors localized to the sphenoid wing and petroclival region; and atypical meningiomas were common in the anterior falx and frontal convexity. Psammomatous meningiomas displayed a broader distribution with involvement of the petrous bone and foramen magnum. AUC analysis revealed strong concordance between histological subtypes and mutation maps, confirming known histogenomic associations (e.g. KLF4/TRAF7 with secretory; NF2 with fibrous and transitional; SMO with meningothelial). No associations to any mutation map were observed for angiomatous, microcystic and metaplastic meningiomas. Predictive modeling based solely on spatial features achieved moderate accuracy for subtype classification and higher accuracy for WHO grade prediction. Meningioma subtypes show distinct, statistically robust anatomical predilections that align with known genetic mutation maps. Predictive modeling highlights that spatial features themselves hold diagnostic and prognostic value, linking anatomical localization to tumor biology and aggressiveness. The study introduces anatomically precise voxel-based templates that may improve radiogenomic classification and non-invasive genotype prediction.

Evaluating fluctuating and directional asymmetry in postnatal petrous bone growth: a 3D morphometric study.