External Occipital Research Articles

Guidelines to minimize risk when dry needling the rectus capitus posterior major muscle.

Headache disorders are prevalent often leading to disability. The rectus capitus posterior major muscle (RCPMaj) may contribute to headache symptoms via nociceptive convergence and myodural bridging. To establish guidelines for needle length and needle angle to mitigate risks during dry needling RCPMaj. Cadaveric investigation. Twenty-five cadavers (mean age: 80.1±13.2 years) were placed in prone. Depth measurements from the skin to the C2 spinous process were taken following midline incision. Dissection continued exposing the RCPMaj for three measures including: 1) posterior angle from the frontal plane, 2) lateral angle from midline, and 3) distance from the external occipital protuberance to the lateral most RCPMaj. Mean values for tissue thickness overlying C2 spinous process (37±7.3mm), RCPMaj posterior angle from the frontal plane (65.2° ±10°), RCPMaj lateral angle from midline (34.7° ±12.9°), and distance from the external occipital protuberance to the lateral most RCPMaj (30.6mm±9.3mm) were used to calculate a needle inclination of ≤45° and a needle length <40mm to reach the occipital portion of RCPMaj with an a priori insertion point of midway between the C2 spinous process and the C1 transverse process. Inserting a dry needle <40mm in length midway between the C2 spinous process and the C1 transverse process with a cranial angle of ≤45° relative to the frontal plane would increase the likelihood of reaching the RCPMaj and mitigate penetrating deeper structures.

The influence of age, biological sex, anthropometrics, and neck characteristics on external occipital protuberance size

Background40–45 % of the population presents with enlarged external occipital protuberances (EEOPs), which can lead to pain. EEOP occurrence is higher in younger males; however, the reason is debated. We used plane lateral radiographs to investigate how anthropometrics, age, biological sex, head and neck kinematics, and neck strength differ between those with and without an EEOP. MethodsData was compiled across four study samples, which included lateral radiographs taken in a neutral neck posture (n = 102, 50% females). An enlarged EOP was defined as being longer than 10 mm, and this threshold was used to classify participants as having a presence or absence of an EEOP. Statistical analyses were used to compare outcome measures between those with and without an EEOP presence for age, biological sex, skull angle, intervertebral joint angle (C1-C2 through C6-C7), and neck strength (flexion and extension). ResultsTwenty-four percent of participants (19 males and five females, p = 00.002 for biological sex differences) presented with an EEOP; only one was over 30 years old. There were no significant main effects on the skull and intervertebral joint angles, participant anthropometrics, or neck strength. ConclusionsThis study confirmed that enlarged EOPs are more prevalent in males; however, neck posture and other anthropometrics do not differ with the presence or absence of an EEOP.

Exostosis of the external occipital protuberance as a sign of technological progress? – a review of recent reports

Exostosis of the external occipital protuberance as a sign of technological progress? – a review of recent reports

An anatomical analysis of the occipital nerve complex: an essential tool for the application of occipital nerve blocks

BackgroundOccipital nerve blocks are essential in diagnosing and treating headache disorders such as migraine, cervicogenic headache, occipital neuralgia, and cluster headache. In this study, we aimed to investigate the potential compression points of the greater occipital nerve (GON), third occipital nerve (TON), and lesser occipital nerve (LON) which are targeted to block in occipital nerve blocks and to develop a method to detect these points easily.MethodsTo identify potential compression points of the GON, TON, and LON, we dissected 43, 41, and 26 cadavers, respectively. A rigid, transparent tool divided into 1 × 1 cm sections was placed on the external occipital protuberance to measure the determined points. The cadaveric head was viewed from above, vertically, and the coordinates corresponding to each point were noted separately.ResultsSix, four, and one potential entrapment points were detected for the GON, TON, and LON, respectively. The distances of the point where the GON arose from the lower border of the obliquus capitis inferior muscle and the emerging point of the TON from the C2-C3 vertebrae to the posterior midline were statistically significant in terms of the sides (p = 0.040). Similarly, there was a statistical significance between genders for the distance of the point where the LON arose from the posterior edge of the sternocleidomastoid muscle to the posterior midline (p = 0.002).ConclusionsWe believe that with the method developed, the GON, TON, and LON compression points can be easily localized and blocked in diagnosing and treating patients experiencing headaches such as migraines, cervicogenic headaches, occipital neuralgia, and cluster headache.

Localization of the greater occipital nerve through palpation of bony landmarks: A cadaveric study

Objectiveto provide anatomic confirmation that standard methods which practitioners skilled in palpation use, can reliably identify the most likely site of emergence of the greater occipital nerve in most patients. The location and frequency of subcutaneous emergence of the greater occipital nerve and occipital artery with respect to the external occipital protuberance-mastoid line are reported. MethodsThe external occipital protuberance and the mastoid processes were identified by palpation bilaterally on 57 body donors and the medial trisection point of a line connecting these bony landmarks was identified. A 4 cm circular dissection guide divided into 4 quadrants was centered on the trisection point and used to guide the removal of a circle of skin. The in-situ location of the nerve and artery were exposed by deep dissection within the circle. The frequency of the emergence and occurrence of the nerve and artery by quadrant were analyzed. ResultsIn 114 total dissections the greater occipital nerve was found to emerge within the circle 96 times (84%) and the occipital artery 100 times (88%). The nerve (90%) and artery (81%) emerged from the two inferior quadrants most of the time with no difference noted between male and female donors. The greater occipital nerve and occipital artery were found to emerge together most commonly in inferior lateral quadrant. Branches of the nerve and artery traveled together most frequently through the two lateral quadrants. ConclusionThis study confirmed that the medial trisection point of the external occipital protuberance-mastoid line can be located via palpation and reliably used to pinpoint the subcutaneous emergence of the greater occipital nerve and occipital artery in most individuals. When relying on palpation alone to identify the trisection point in the clinic, infusion of nerve block inferior and lateral to this point is most likely to bathe the greater occipital nerve in anesthetic.

Prevalence and Morphometry of Occipital Foramen in Dry Skulls and its Clinical Implications.

The occipital emissary foramen (OEF) located on the occipital bone transmits the occipital emissary vein, which connects the occipital vein to the confluence of cranial venous sinuses. The OEF varies in incidence, number, size, and location. Knowledge of this foramen is essential for carrying out suboccipital and transcondylar surgeries without clinical implications. Hence, the study was planned. The aim of the present study is to elaborate on incidence, location, and morphometry consisting of the number and size of this foramen in light of clinical bearing in the context of the Indian population. The study was carried out in the Department of Anatomy using 80 skulls of unknown age and sex. The occipital bone of the skull was observed for the incidence, number, size, and location of the occipital emissary vein and associated clinical implications were elaborated. The incidence of occipital foramen was 36.25% and detected in 29 skulls. All these occipital foramina were patent. The mean diameter of this foramen was 0.6mm. The most common location of these foramina was the left side of the foramen magnum, followed by the left side of the external occipital crest. The information about the incidence, number, size, and location of OEF is important to prevent catastrophic bleeding during surgery in the region of the occipital bone. The awareness of differential morphometry and morphology of occipital foramina is of great importance for neurosurgeons during suboccipital craniotomy and skull base surgeries, including far lateral and transcondylar approaches to access posterior cranial fossa for management of pathologies in the cranial cavity.

The Frequency of Occipital Spurs in Relation to the Cephalic Index: An Anatomorphometric Cone Beam CT Study.

The occipital spur (OS) can be described as an abnormal elongation of the external occipital protuberance (EOP). The cephalic index (CI) refers to the ratio of width to length in any skull. The aim of the present study was to evaluate the frequency and types of OS. It also aimed to determine the mean CI and the distribution of skull types using cone beam computed tomography (CBCT). And to determine if there was a relationship between the cephalic index and the presence and types of OS. CBCT scans from 523 patients were included in the study. OSs were classified as type 1 (flat), type 2 (crest), and type 3 (spine). Skull length and width were measured on axial sections and the CI was calculated. Based on the cephalic index (CI), skull types were classified as dolichocephalic (CI < 75), mesocephalic (75 < CI < 80), brachycephalic (80 < CI < 85), and hyperbrachycephalic (CI > 85). The most common cranial types in the study group were brachycephalic (44.7%), mesocephalic (28.3%), hyperbrachycephalic (21.2%), and dolichocephalic (5.7%). Regarding the presence of OS, 54.3% of the participants had no OS, 23.1% had flat type, 15.3% had crest type, and 7.2% had spin type OS. There was a statistically significant difference (P < 0.05) in the frequency of OS according to skull type. This study, the first to evaluate CI and OS using CBCT, concludes that brachycephaly is the most common cranial type. OS is more common in mesocephalic and dolichocephalic skulls, at older ages, and in males.

An update on migraine: Current and new treatment options.

Migraine headache is a common and potentially debilitating disorder often treated by physician associates/assistants (PAs) and other providers. With the recent advances in new drugs and device technology for the treatment of migraine, the American Headache Society has released a consensus statement on both preventive and acute strategies for clinical practice. The US FDA has recently approved various types of medications and devices for the treatment and prevention of migraine attacks including several calcitonin gene-related peptide (CGRP) receptor inhibitors, a selective serotonin receptor agonist (SSRA), noninvasive vagus nerve stimulation (nVNS), external trigeminal nerve stimulation (e-TNS), and external concurrent occipital and trigeminal neurostimulation (eCOT-NS), among other pharmacologic and nonpharmacologic options. This article provides a review of migraine prevention and acute treatment protocol, highlighting new approaches to both.

Use of bone landmarks for assessing the safety of acupuncture on the posterior midline of the neck region

ObjectiveMany acupuncture acupoints are located on the posterior midline of the neck region. The needling depth for acupuncture is important for practitioners, and an unsafe needling depth increases the possibility of damage to the spinal cord and brainstem. Can the safety of acupuncture be assessed by examining bone structures? We focused on this aim to carry out this study.MethodsThe shortest distance from the posterior border of the foramen magnum to the line joining both upper ends of the posterior border of the mastoid process was measured on 29 skulls. Distances from the posterior border of the vertebral foramen to the tip of the spinous process and posterior tubercle of the atlas were measured and evaluated from 197 dry cervical vertebrae and 31 lateral cervical radiographs of patient subjects. The anatomic relationships of the vertebral canal with the external occipital protuberance, tip of the spinous process of the axis, tip of the posterior tubercle of the atlas, and upper end of the posterior border of the mastoid process were observed and evaluated via lateral cervical radiography.ResultsThe shortest distance from the foramen magnum to the line between the mastoid processes was 4.65±1.75 mm, and the distance from the superior border of the vertebral foramen of the atlas to the posterior tubercle was less than the distance from the inferior border. The distance from the superior border of the vertebral canal to the tip of the spinous process in C2-C7 was greater than the distance from the inferior border. The mean lengths of the superior border of the C2 spinous process and the inferior border of the C7 spinous process were greater than 21 mm and 31 mm, respectively. The line from the upper end of the posterior border of the mastoid process to the tip of the C2 spinous process or 10 mm deep to the tip of the C2 spinous process was posterior to the vertebral canal.ConclusionsOn the posterior midline of the neck region between the tip of spinous process of axis and external occipital protuberance, if the needle reaches the depth of the line between the upper end of posterior border of mastoid process and the tip of the spinous process of the axis, approximately 10 mm along the spinous process of the axis, the needle is in the safe region. The mean length of the C2-C7 spinous process is suitable to accommodate the needling depth of the adjacent acupoint. Bone structures can be used to effectively assess the safety of acupuncture on the posterior midline of the neck region.

A Comprehensive Study of the Potential Compression Points of the Third Occipital Nerve and Its Possible Clinical Interests.

The anatomic features of the third occipital nerve (TON) are the least studied among the occipital nerves. This study aimed to analyze the anatomic features and potential compression points of the TON. The posterior neck and scalp of 39 cadavers were dissected. The TON was carefully followed from the emerging point from C2-C3 vertebrae distally. Its muscular investments were detected. The determined points were marked superficially and measured according to external occipital protuberance with Image J software. The TON revealed 4 different potential entrapment points along its course. The most proximal point was between the C2 and C3 vertebrae. The second and third points were at their piercing points of semispinalis capitis and splenius capitis muscles, respectively. The final point was at its penetrating point of the trapezius muscle. The TON did not pierce the semispinalis capitis muscle on 6 sides, and pierced this muscle from 3 different points by splitting into 3 branches on 1 side. On 5 sides, the TON split into 2 branches and perforated the splenius capitis muscle from 2 different points. There were 4 potential compression points regarding the TON. These entrapment points and variations of the TON may play a significant role in understanding the reason for TON-related headaches and the treatment of headaches caused by the TON.

Morphological and morphometric anatomy of the lesser occipital nerve and its possible clinical relevance

The lesser occipital nerve (LON) has one of the most variations among occipital nerves. We aimed to investigate morphological and morphometric features of LON. A total of 24 cadavers, 14 males (58%) and 10 females (42%), were dissected bilaterally. LON was classified into 3 types. The number of branches and the perpendicular distances of the point where LON emerged from the posterior border of sternocleidomastoid muscle to vertical and transverse lines passing through external occipital protuberance were determined. The shortest distance between LON and great auricular nerve (GAN), and linear distance of LON to its branching point were measured. The most common variant was Type 1 (30 sides, 62.5%), followed by Type 2 (12 sides, 25%) and Type 3 (6 sides, 12.5%), respectively. In males, Type 1 (22 sides, 78.6%) was the most common, while Type 1 (8 sides, 40%) and Type 2 (8 sides, 40%) were equally common and the most common in females. On 48 sides, 2–9 branches of LON were observed. The perpendicular distance of said point to vertical and transverse lines was meanly 63.69 ± 11.28 mm and 78.83 ± 17.21 mm, respectively. The shortest distance between LON and GAN was meanly 16.62 ± 10.59 mm. The linear distance of LON to its branching point was meanly 31.24 ± 15.95 mm. The findings reported in this paper may help clinicians in estimating the location of the nerve and/or its branches for block or decompression surgery as well as preservation of LON during related procedures.

The triangular area between the greater, lesser, and third occipital nerves and its possible clinical significance.

Occipital Neuralgia (ON) is defined as a unilateral or bilateral pain in the posterior area of the scalp occurring in the distribution area or areas of the greater occipital nerve (GON), lesser occipital nerve (LON), and/or third occipital nerve (TON). In the present study, the purpose was to show the possible importance of the triangular area (TA) in nerve block applied in ON by measuring the TA between GON, TON, and LON. A total of 24 cadavers (14 males, 10 females) were used in the present study. The suboccipital region was dissected, revealing the points where the GON and TON pierced the trapezius muscle and superficial area, and the point where the LON left the sternocleidomastoid muscle from its posterior edge and was photographed. The area of the triangle between the superficial points of these three nerves and the center of gravity of the triangle (CGT) were determined by using the Image J Software and the results were analyzed statistically. The mean TA values were 952.82 ± 313.36 mm2 and 667.55 ± 273.82 mm2, respectively in male and female cadavers. Although no statistically significant differences were detected between the sides (p > 0.05), a statistically significant difference was detected between the genders (p < 0.05). The mean CGT value was located approximately 5cm below and 3-3.5cm laterally from the external occipital protuberance in both genders and sides. In ON that has more than one occipital nerve involvement, all occipital nerves can be blocked by targeting TA with a single occipital nerve block, and thus, the side effects that may arise from additional blocks can be reduced. The fact that there was a statistically significant difference according to the genders in the TA suggests that different block amounts can be applied according to gender.

Determination of skull variation in Akkaraman and Kangal Akkaraman sheep by geometric morphometric method

Sheep breeding has an important place in the world and in Turkey, as sheep are farm animals that provide most of their nutritional needs from pasture, have good adaptability and are low in cost. Akkaraman sheep and the Kangal Akkaraman sheep, which was considered its sub-variety until 2012, constitute half of the sheep population in Turkey. In this study, morphometric diversity between the skulls of Akkaraman and Kangal Akkaraman breed sheep was examined by geometric morphometric method. 2D images obtained from 3D models of 24 male sheep skulls from two different provinces were analyzed using 10 landmarks from dorsal and lateral views. The results from the dorsal view, the first three principal components (PC1, PC2 and PC3) accounted for a total of 64.13% of the morphological variation and the largest changes in are associated with external occipital protuberance, midline nasofrontal suture and rostral edge of the incisive fissure. From the lateral view, three first principal components explained the morphological variation 27.56%, 22.32% and 10.65% respectively. In the comparison of the skull morphology of Akkaraman and Kangal Akkaraman sheep from dorsal and lateral views, no allometric components were identified, as most of the described shape variations were not size-dependent. As a result of these analyses, more detailed information was obtained about the shape differences of the skull. Geometric morphometric analysis is successful in detecting differences in skull shape of different sheep breeds and can be successfully used for classification.

Noisy galvanic vestibular stimulation influences head stability in young healthy adults while standing on a moving platform

BackgroundThe ability to stand with eyes closed on a sinusoidal translational moving platform may be affected by spatial orientation owing to vestibular input information. Moreover, changes in the frequency of the moving platform may affect the sensory reweighting through somatosensory and vestibular sensations. However, it is unclear whether noisy galvanic vestibular stimulation (nGVS), which activates vestibular-related brain regions, affects the stability of individuals standing on a platform moving at different frequencies. Research questionDo vestibular stimulation by nGVS and changes in the frequency of translationally moving platforms affect the standing stability of individuals? MethodsThirty-one healthy young adult participants were provided both sham and nGVS interventions while they maintained a static standing position, with their eyes closed, on an anterior-posterior sinusoidal translation platform. The nGVS was adapted to an optimal intensity below the perceptual threshold (frequency band: 100–640 Hz), and the sham stimulus was adapted to 0 µA. The participants were randomly assessed for postural stability at 0.2, 0.6, and 1.2 Hz moving platform frequencies for 80 s each under both stimulus conditions. Postural stability was calculated as the root mean square (RMS) sway from head accelerations in the anteroposterior (AP) and mediolateral (ML) directions for 50 s between 20 and 70 s during the 80 s period, measured using an inertial sensor placed on the external occipital ridge. ResultsnGVS significantly reduced the RMS sway of head acceleration in the AP direction compared with sham stimulation. Furthermore, nGVS significantly reduced RMS sway in the ML direction compared with sham stimulation at a 1.2 Hz moving platform oscillation. SignificanceThese findings suggest that postural adjustment by the vestibular system influences head stability on a moving platform at specific sinusoidal translation frequencies, suggesting that nGVS may reduce head sway.

Cervical Range of Motion Assessment through Inertial Technology: A Validity and Reliability Study

Inertial technology has spread widely for its comfortable use and adaptability to various motor tasks. The main objective of this study was to assess the validity of inertial measurements of the cervical spine range of motion (CROM) when compared to that of the optoelectronic system in a group of healthy individuals. A further aim of this study was to determine the optimal placement of the inertial sensor in terms of reliability of the measure, comparing measurements obtained from the same device placed at the second cervical vertebra (C2), the forehead (F) and the external occipital protuberance (EOP). Twenty healthy subjects were recruited and asked to perform flexion–extension, lateral bending, and axial rotation movements of the head. Outcome measurements of interest were CROM and mean angular velocities for each cervical movement. Results showed that inertial measurements have good reliability (0.75 &lt; ICC &lt; 0.9). Excellent reliability (ICC &gt; 0.9) was found in both flexion and right lateral bending angles. All parameters extracted with EOP placement showed ICC &gt; 0.62, while ICC &lt; 0.5 was found in lateral bending mean angular velocities both for F and C2 placements. Therefore, the optimal sensor’s positioning emerged to be EOP. These results suggest that inertial technology could be useful and reliable for the evaluation of the CROM.

Modified interfacet technique using shaped autologous occipital bone mass for basilar invagination

PurposeIn economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet technique for the treatment of BI using shaped autologous occipital bone mass to reduce BI and to save economical expenditure. MethodsThe data of 6 patients with BI who underwent modified interfacet technique using shaped autologous occipital bone mass in our hospital from April 2020 to February 2021 were retrospectively analyzed. During the operation, osteotomy at the external occipital protuberance was performed using ultrasonic osteotome, followed by interfacet release and implantation of shaped autologous occipital bone mass to complete vertical reduction. The atlantodental interval (ADI), Chamberlain's line violation (CLV), clivo-axial angle (CXA) and cervico-medullary angle (CMA) were compared before and after surgery. Additionally, we observed implant stability during the follow-up period to assess the long-term success of the modified interfacet technique. ResultsThe surgical procedure was successful in all six patients, with no reported incidents of vascular injury, spinal cord injury, or dural tear. Following the operation, improvements were observed in the ADI, CLV, CXA, and CMA. Throughout the follow-up period, the implants remained stable, demonstrating no complications such as bone resorption of the autologous occipital bone mass, implant fracture, or displacement. ConclusionThe utilization of shaped autologous occipital bone mass in atlantoaxial interfacet bone grafting has demonstrated effectiveness and feasibility. This technique offers simplicity, ease of preparation, and cost-effectiveness, making it a viable option for treating BI.

Can exostoses of the external occipital protuberance and superior nuchal lines cause headache? A report of two cases

Compression of the occipital nerves can cause occipital headache. Several potential compression points have been identified along their course. One of these points is the hitherto undescribed instance of exostoses of anatomic structures of the occipital bone. A 34-year-old man with a prominent external occipital tuberance and superior nuchal lines complained of headache in the area of distribution of the greater occipital nerve with tenderness near the bony protrusion on palpation. A 44-year old woman experienced stabbing pain in the lateral orbital region with pressure on the ossified insertion of the ipsilateral trapezius muscle near the external occipital protuberance. Local nerve block achieved temporary relief of pain. Exostosis of the external occipital protuberance and superior nuchal lines may impinge on the greater and third occipital nerves. The characteristics of the pain in our cases differ in some aspects from those of occipital neuralgia.

External occipital protuberance classification with special reference to spine type and its clinical implications

This investigation aimed to study the types of external occipital protuberance (EOP) with special reference to Type 3 (spine type). Detailed information will be useful for clinicians to manage occipital headaches or issues related to the biomechanics of the neck and for accurate radiological interpretations. Thirty-one dry intact cadaveric skulls were studied for EOP classification. In Type III EOP cases, the size of EOP was noticed using different modalities and compared. The superior nuchal lines and external occipital crest were observed for their prominence and any variation. 42% of the skulls belong to Type 1, 51.5% to Type 2, and 6.5% to Type 3 EOP. Superior nuchal lines and external occipital crest were more prominent in Types 2 and 3 EOP. In Type 3 EOP cases, the mean length, width, and thickness of the spine as measured directly on the skull were 16.63mm; 20.1mm, and 7.82mm respectively, the same as radiograph findings. CT examination revealed the average volume as 0.95 cm3. Out of two Type 3 EOP cases, the spine with larger values for its size was having a lesser volume value in CT. Plain lateral radiography is a reliable method to measure the length and thickness of spinous EOP. However, more values of these parameters for morphometry of the EOP spine do not mean more volume of EOP and vice versa. Detailed information regarding the occurrence of occipital spur and its morphology will be of great importance to neurosurgeons, sports, physicians, emergency departments, and radiologists.

Morphometric Evaluation of Occipital Artery

Objective: Occipital artery anatomy should be well known in order to minimize complications that may occur in the occipital artery, which is closely adjacent to this nerve, during greater occipital nerve blockade. In this study, it is aimed to evaluate the morphometric relationship of the occipital artery with neighboring anatomical structures in order to prevent damage during clinical applications. Materials and Methods: This study was carried out using CTA images of the head and neck region of patients who applied to Balikesir University Medical Faculty Training and Research Hospital for various reasons between 2015 and 2021. In the study, CTA images of 85 individuals aged 35-63 years were evaluated morphometrically using Radiant DICOM viewer 64-bit computer software. The obtained data were transferred to SPSS Version 25 software and analyzed quantitatively. Results: According to the results obtained from the study, no significant difference was found between the variables and genders. As the age of the individual increased, it was observed that the left occipital artery was located more inferolateral to the external occipital protuberance. As a result of the data obtained, a negative correlation was observed between the closest distance between the right OA-ML and the right EOP-ML and the spinous process of the seventh cervical vertebra. Conclusion: In line with the average values obtained as a result, it is thought that an injection to the central point of the triangular area, which is formed as a result of combining the reference points in the posterior occiput, may be safer in order to protect the occipital artery.

Topographic and anatomical relationships of the lower jaw and auricle in human prenatal ontogenesis

Aim to describe the topographic and anatomical relationships of the fetal lower jaw and auricle in the mid-gestation period.&#x0D; Material and methods. The 110 mandibles of human fetuses of the second trimester were selected for the study and divided into groups by sex and age. The morphological techniques and the method of ultrasound scanning were used to determine the topographic relationships of the lower jaw and the fetal ear, the location of the central part of the auricle relative to the lower jaw (the line connecting the gnathion point and the external occipital protuberance) at different age periods.&#x0D; Results. During the mid-gestation period, with the growth of the fetus, the auricle normally shifts upward relative to the mandible. At the beginning of the study period, the auricle is located just below the angle of the lower jaw. Its central part (C) is below the line (AB) connecting the gnathion point and the external occipital protuberance. The perpendicular from the conditional center of the auricle to the line AB is half the diameter of the auricle 3.7 1.1 mm. In the second age group, the auricle is located at the level of the branch and angle of the lower jaw Its conditional center (C) is below the line AB and is of the diameter of the auricle 3.1 0.8 mm. By the end of the mid-gestation period, the auricle is displaced to the level of the processes of the lower jaw above the notch. Its central part is above line AB, the perpendicular from point C to line AB is 6.1 1.4 mm.&#x0D; Conclusion. The deviations in the formation of the topographic and anatomical relationships of the lower jaw and auricle of the fetus from 14 to 27 weeks of gestation can be additional criteria for the development of congenital fetal pathology and require the fetoabnormal alertness.