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The Angle Orthodontist May 2019To investigate the time and pattern of fusion of the spheno-occipital synchondrosis in patients with skeletal Class I and Class III malocclusion using cone-beam computed...
OBJECTIVES
To investigate the time and pattern of fusion of the spheno-occipital synchondrosis in patients with skeletal Class I and Class III malocclusion using cone-beam computed tomography (CBCT).
MATERIALS AND METHODS
A total of 262 CBCT images were collected: 140 skeletal Class I (0° < ANB < 4°; 71 males, 69 females) and 122 skeletal Class III (ANB ≤ 0°; 61 males and 61 females). The fusion stages were identified using CBCT images of a six-stage system defined by the appearance of osseous cores and ossifying vestige in the synchondrosis. The age distributions of each stage and the pattern of fusion were evaluated.
RESULTS
The stages of fusion progressed with increasing age ( < .05, = .824), and the age distributions in the female groups were generally 1 to 3 years younger than those in the male groups. However, no significant differences were observed between the skeletal Class I and Class III groups regarding the time of ossification of the synchondrosis. The osseous cores appeared most frequently in the supero-center part, followed by the mid-center part of the synchondrosis.
CONCLUSIONS
The time and pattern of fusion of the spheno-occipital synchondrosis are not apparently different between patients with Class I malocclusion and those with Class III malocclusion. The osseous cores appear frequently in the supero-center and mid-center of the synchondrosis with various patterns before the end of the pubertal growth spurt period.
Topics: Cone-Beam Computed Tomography; Female; Humans; Male; Malocclusion, Angle Class I; Malocclusion, Angle Class III; Occipital Bone; Sphenoid Bone
PubMed: 30516418
DOI: 10.2319/052218-386.1 -
Scientific Reports Sep 2021Morphological changes in the child skull due to mechanical and metabolic stimulation and synostosis of the suture are well known. On the other hand, few studies have...
Morphological changes in the child skull due to mechanical and metabolic stimulation and synostosis of the suture are well known. On the other hand, few studies have focused on clinical conditions relevant for adult skull deformity. We retrospectively reviewed computed tomography (CT) findings obtained from 365 cases that were treated for head injuries, moyamoya disease, cervical internal carotid artery stenosis, and mental diseases, and investigated the morphological changes in the skull associated with these diseases. The findings from head injuries were used not only for control subjects, but also for the analysis of generational changes in skull shape based on birth year. Head shape had a brachiocephalic tendency with occipital flattening in people born from the 1950s onwards. Cases of moyamoya disease, cervical internal carotid artery stenosis, and mental diseases showed significantly thicker frontal and occipital bone than those of control subjects. The skull thickening was especially noticeable in the frontal bone in moyamoya disease. Plagiocephaly was significantly frequent in moyamoya disease. These uncommon skull shapes are useful CT findings in screening subjects for early evidence of mental diseases and intracranial ischemic diseases with arterial stenosis.
Topics: Aged; Carotid Stenosis; Craniocerebral Trauma; Female; Frontal Bone; Humans; Male; Mental Disorders; Middle Aged; Moyamoya Disease; Occipital Bone; Retrospective Studies; Skull; Tomography, X-Ray Computed
PubMed: 34475458
DOI: 10.1038/s41598-021-97054-4 -
Journal of Radiology Case Reports Dec 2021Encephalocele is protrusion of brain parenchyma through a defect in the cranium. It is classified into various types based on the defect location: sincipital... (Review)
Review
Encephalocele is protrusion of brain parenchyma through a defect in the cranium. It is classified into various types based on the defect location: sincipital (fronto-ethmoidal), basal (trans-sphenoidal, spheno-ethmoidal, trans-ethmoidal, and spheno-orbital), occipital and parietal. Double encephaloceles are very rare with only a handful of cases reported in the literature and most of these cases involved either occipital or sub-occipital region. All, except one, cases of double encephaloceles were diagnosed postnatally. We present a case of double encephalocele with parietal and occipital components diagnosed in utero. To the best of our knowledge, this is the first case of double encephalocele involving the parietal and occipital skull bones diagnosed in-utero.
Topics: Encephalocele; Humans; Occipital Bone
PubMed: 35519000
DOI: 10.3941/jrcr.v15i12.4230 -
Anatomical Record. Part B, New Anatomist Mar 2005Human and chimpanzee occipital bones are thought to grow and develop in distinctly opposite bone remodeling patterns. Preliminary research examining growth-remodeling...
Human and chimpanzee occipital bones are thought to grow and develop in distinctly opposite bone remodeling patterns. Preliminary research examining growth-remodeling fields (GRFs) from the surfaces of the occipital bone in modern humans and chimpanzee indicates this may not be entirely correct. By using vinyl/resin-casting techniques, coupled with scanning electron and reflected-light microscopy, GRF profiles from a cross-sectional sample of humans and chimpanzees have documented the ongoing histological activities that reflect developmental processes through which taxon-specific ontogenetic trajectories alter bone morphology. Surface bone profiles aid in explaining how the posterior skull takes shape, thereby aiding in our understanding of the developmental processes that may contribute to the morphological variation in the posterior skull in humans and chimpanzees.
Topics: Animals; Bone Remodeling; Corrosion Casting; Humans; Microscopy, Electron, Scanning; Occipital Bone; Pan troglodytes; Resins, Synthetic; Species Specificity
PubMed: 15761834
DOI: 10.1002/ar.b.20055 -
Journal of Anatomy Sep 2021This article presents the results of a dissection series investigating a previously neglected ligamentous structure attached to the human occipital bone, the Ligamentum...
This article presents the results of a dissection series investigating a previously neglected ligamentous structure attached to the human occipital bone, the Ligamentum condylicum posterius or posterior condylar ligament, and relates these results to the manifestation of a likewise poorly recognized occipital bony variation, the Processus condylicus posterior. The dissection of 50 human cranio-cervical junctions revealed the existence of the posterior condylar ligament in 98% of all cases, sometimes containing free elongated ossicles and osseous spurs at the insertion points at the occipital bone. In two cases the osseous formation of a Processus condylicus posterior became apparent (4%), which further provided the opportunity to study the behaviour of the ligament in these cases. In this article, we show and discuss that the posterior condylar ligament and osseous structures possibly derive from tissue that originates from the material of the dorsal arch of the Proatlas, a rudimentary vertebra between occipital bone and atlas. For this purpose, the Ponticulus atlantis posterior as another Proatlas-manifestation, whose origin from the dorsal Proatlas-arch is widely accepted in literature, is considered. This bony variant was found in 11 specimens (22%) in the present study and further served to classify and interpret the findings of the much rarer Processus condylicus posterior. As a result of this dissection series and a review of literature on this understudied topic, a typology of manifestations of the posterior condylar ligament, Processus condylicus posterior and related structures like free ossicles has been introduced.
Topics: Aged; Aged, 80 and over; Atlanto-Occipital Joint; Female; Humans; Male; Middle Aged; Neck; Occipital Bone
PubMed: 33846976
DOI: 10.1111/joa.13444 -
European Journal of Medical Research Nov 2023The hypoglossal canal is a dual bone canal at the cranial base near the occipital condyles. The filaments of the hypoglossal nerve pass through the canal. It also...
BACKGROUND
The hypoglossal canal is a dual bone canal at the cranial base near the occipital condyles. The filaments of the hypoglossal nerve pass through the canal. It also transmits the meningeal branch of the ascending pharyngeal artery, the venous plexus and meningeal branches of the hypoglossal nerve. The hypoglossal nerve innervates all the intrinsic and extrinsic muscles of the tongue except the palatoglossal and is fundamental in physiological functions as phonation and deglutition. A surgical approach to the canal requires knowledge of the main morphometric data by neurosurgeons.
METHODS
The present study was carried out on 50 adult dried skulls: 31 males: age range 18-85 years; 19 females: age range 26-79 years. The skulls came from the ''Leonetto Comparini'' Anatomical Museum. The skulls belonged to people from Siena (Italy) and its surroundings (1882-1932) and, therefore, of European ethnicity. The present study reports (a) the osteological variations in hypoglossal canal (b) the morphometry of hypoglossal canal and its relationship with occipital condyles. One skull had both the right and left hypoglossal canals occluded and, therefore, could not be evaluated. None of the skulls had undergone surgery.
RESULTS
We found a double canal in 16% of cases, unilaterally and bilaterally in 2% of cases. The mean length of the right and left hypoglossal canals was 8.46 mm. The mean diameter of the intracranial orifice and extracranial orifice of the right and left hypoglossal canals was 6.12 ± 1426 mm, and 6.39 ± 1495 mm. The mean distance from the intracranial end of the hypoglossal canal to the anterior and posterior ends of occipital condyles was 10,76 mm and 10,81 mm. The mean distance from the intracranial end of the hypoglossal canal to the inferior end of the occipital condyles was 7,65 mm.
CONCLUSIONS
The study on the hypoglossal canal adds new osteological and morphometric data to the previous literature, mostly based on studies conducted on different ethnic groups.The data presented is compatible with neuroradiological studies and it can be useful for radiologists and neurosurgeons in planning procedures such as transcondilar surgery. The last purpose of the study is to build an Italian anatomical data base of the dimensions of the hypoglossal canal in dried skulls..
Topics: Male; Adult; Female; Humans; Adolescent; Young Adult; Middle Aged; Aged; Aged, 80 and over; Cadaver; Occipital Bone; Hypoglossal Nerve; Heart; Italy
PubMed: 37941031
DOI: 10.1186/s40001-023-01489-6 -
Medical Hypotheses Jan 2022Chiari malformation Type I (CMI) is characterized by herniation of the cerebellar tonsils through the foramen magnum. The pathophysiology of CMI is not well elucidated;...
Chiari malformation Type I (CMI) is characterized by herniation of the cerebellar tonsils through the foramen magnum. The pathophysiology of CMI is not well elucidated; however, the prevailing theory focuses on the underdevelopment of the posterior cranial fossa which results in tonsillar herniation. Symptoms are believed to be due to the herniation causing resistance to the natural flow of cerebrospinal fluid (CSF) and exerting a mass effect on nearby neural tissue. However, asymptomatic cases vastly outnumber symptomatic ones and it is not known why some people become symptomatic. Recently, it has been proposed that CMI symptoms are primarily due to instability of either the atlanto-axial (AA) or the atlanto-occipital (AO) joint and the cerebellar tonsils herniate to prevent mechanical pinching. However, only a small percentage of patients exhibit clinical instability and these theories do not account for asymptomatic herniations. We propose that the pathophysiology of adult CMI involves a combination of craniocervical abnormalities which leads to tonsillar herniation and reduced compliance of the cervical spinal canal. Specifically, abnormal AO and/or AA joint morphology leads to chronic cervical instability, often subclinical, in a large portion of CMI patients. This in turn causes overwork of the suboccipital muscles as they try to compensate for the instability. Over time, the repeated, involuntary activation of these muscles leads to mechanical overload of the myodural bridge complex, altering the mechanical properties of the dura it merges with. As a result, the dura becomes stiffer, reducing the overall compliance of the cervical region. This lower compliance, combined with CSF resistance at the same level, leads to intracranial pressure peaks during the cardiac cycle (pulse pressure) that are amplified during activities such as coughing, sneezing, and physical exertion. This increase in pulse pressure reduces the compliance of the cervical subarachnoid space which increases the CSF wave speed in the spinal canal, and further increases pulse pressure in a feedback loop. Finally, the abnormal pressure environment induces greater neural tissue motion and strain, causing microstructural damage to the cerebellum, brainstem, and cervical spinal cord, and leading to symptoms. This hypothesis explains how the combination of craniocervical bony abnormalities, anatomic CSF restriction, and reduced compliance leads to symptoms in adult CMI.
Topics: Adult; Arnold-Chiari Malformation; Cranial Fossa, Posterior; Foramen Magnum; Humans; Magnetic Resonance Imaging; Subarachnoid Space
PubMed: 34992329
DOI: 10.1016/j.mehy.2021.110740 -
Journal of Anatomy Oct 1994Serial sections of 108 human embryos from stage 11 to stage 23 were investigated, and 33 reconstructions were prepared. The existence of 4 occipital somites was...
Serial sections of 108 human embryos from stage 11 to stage 23 were investigated, and 33 reconstructions were prepared. The existence of 4 occipital somites was confirmed. The important developmental distinction between axial (central) and lateral components obtains in the occipital as well as in the vertebral region. The lateral occipital components begin to show dense areas as the cervical region is approached. The lateral occipital and vertebral components arise in registration with the initial sclerotomes. In both the occipital and the vertebral region the related nerves and intersegmental arteries traverse the loose areas of the sclerotomes. The axial occipital region is not segmented, whereas the cervical components develop from perinotochordal loose areas. Three complete centra (known as XYZ) develop in the atlanto-axial region, although they are related to only 2 1/2 sclerotomes and only 2 neural arches. The height of the XYZ complex equals that of 3 centra elsewhere, and not 2 1/2, as previously maintained. The experimental findings in the occipitocervical region of the chick embryo show both similarities to, as well as differences from, the data for the human embryo. A scheme showing the early development of the entire vertebral column is included.
Topics: Atlanto-Occipital Joint; Cervical Vertebrae; Humans; Occipital Bone; Spinal Nerves
PubMed: 7961131
DOI: No ID Found -
Journal of Neurology, Neurosurgery, and... Feb 1949
Topics: Humans; Occipital Bone; Platybasia
PubMed: 18111230
DOI: 10.1136/jnnp.12.1.61 -
Romanian Journal of Morphology and... 2009The incidence of variations of falx cerebelli was studied in 52 adult cadavers of south Indian origin, at Kasturba Medical College Mangalore, after removal of calvaria....
The incidence of variations of falx cerebelli was studied in 52 adult cadavers of south Indian origin, at Kasturba Medical College Mangalore, after removal of calvaria. In eight (15.4%) cases, we observed duplicated falx cerebelli along with duplicated occipital sinus and internal occipital crest. The length and the distance between each of the falces were measured. The mean length of the right falces cerebelli was 38 mm and the left was 41 mm. The mean distance between these two falces was 20 mm. No marginal sinus was detected. Each of the falces cerebelli had distinct base and apex and possessed a distinct occipital venous sinus on each attached border. These sinuses were noted to drain into the left and right transverse sinus respectively. After detaching the dura mater from inner bony surface of the occipital bone, it was noted that there were two distinct internal occipital crests arising and diverging inferiorly near the posterolateral borders of foramen magnum. The brain from these cadavers appeared grossly normal with no defect of the vermis. Neurosurgeons and neuroradiologists should be aware of such variations, as these could be potential sources of hemorrhage during suboccipital approaches or may lead to erroneous interpretations of imaging of the posterior cranial fossa.
Topics: Adult; Cadaver; Cerebellum; Cranial Sinuses; Dura Mater; Humans; Occipital Bone
PubMed: 19221654
DOI: No ID Found