Anatomical Patterns of the Nasopalatine Canal and Incisive Foramen in an African Setting: A Cross-Sectional Study.

Study Design: Descriptive cross-sectional. Objective: To determine the morphology and morphometry of the nasopalatine canal (NPC) and incisive foramen (IF) in an African population. Methods: Measurements of the NPC and the IF were carried out on 150 Cone-Beam computed tomography (CBCT) scans. The maxillary bone thickness anterior to the NPC was measured at 3 levels. Independent t-test and Chi-square test were performed to determine the presence of sexual dimorphism. Results: The presence of one Stenson's foramen was most prevalent. The mean length of NPC was 13.21 ± 3.25 mm with significantly longer canals in males. The most prevalent shape of NPC was cylindrical in sagittal view and a single canal in coronal view. The mean angulation of NPC was 118.42° to the horizontal plane. The average dimensions of the IF were 3.53 mm and 3.07 mm in the anteroposterior and mediolateral diameter, respectively, while the most common shape was round. The anterior maxillary bone was thicker in males and generally reduced in thickness from the anterior nasal spine superiorly towards the alveolar crest inferiorly. Conclusion: This study highlights the anatomical characteristics of the NPC and IF, with significant sexual dimorphism observed regarding the number of Stenson's foramina, length of NPC, shapes of the NPC and IF, as well as alveolar bone thickness anterior to NPC.

Anatomical Variations in the Origin of the Lingual Artery in the Kenyan Population.

Study design: Descriptive cross-sectional study. Objective: To determine the variations in origin of the LA and its relationship to surgical landmarks. Background: The Lingual artery (LA) is a branch of the External Carotid Artery (ECA) that constitutes the principal supply to structures within the oral cavity and floor of the mouth. Knowledge of its variant anatomy is therefore vital during radiological and surgical procedures performed in the head and neck region since they may predispose it and other branches of the ECA to iatrogenic injury. There is, however, a dearth of regional data on the same. Materials and Methods: A total of 70 LA dissections were performed bilaterally on 35 human cadavers. The borders of the carotid triangle were identified after which the external carotid artery and its branches were exposed. The pattern of origin and the diameter of the LA was noted and distances from its origin to the CB, GCHB and the HN were measured. Similar measurements were carried out for any variant trunks. Data was collected and analyzed using SPSS (IBM version 27). A paired t-test was used to compare side differences. Representative photos of the vessel and its variations were taken. Results: The LA was found to be present in all cadavers dissected and was bilaterally symmetrical in 43% of cases. Four (4) types of branching patterns were encountered in the present study, the most commonly observed being the solitary LA followed by the LFT, TLT and finally the TLFT. The average diameter was least in the solitary pattern and greatest in the TLT. In relation to the CB, the solitary LA originated at a distance of 1.51 ± 0.89 cm while the LFT, TLT and TLFT originated at a distance of 1.80 ± 0.73 cm, 1.02 ± 0.64 cm and 1.25 ± 0.01 cm respectively from the CB. The mean distance from the origin of the LA to the GCHB was least in the TLT and greatest in the TLFT. With reference to the hypoglossal nerve, the LA was at an average, 0.82 ± 0.15 cm from the HN for the solitary pattern, 1.34 ± 0.86 cm for the LFT, 1.34 ± 0.90 cm for the TLT and 1.38 ± 0.93 cm for the TLFT. Conclusion: The LA in the Kenyan population exhibited a high frequency of variation in comparison to other populations regarding its pattern of origin and relationship to landmarks such as the CB, GCHB and HN. These findings may provide further insight into the understanding of the vascular anatomy to the radiologist and the surgeon to avert complications and improve overall treatment outcome.

The Journey of the Lingual Artery from the Neck to the Oral Cavity: A Cadaveric Study.

Study Design: Descriptive cross-sectional. Objective: The origin of the lingual artery (LA) has been well studied due to its implication in neck dissection, but the course thereafter to the oral cavity is less described. This cadaveric study traced the journey of the LA from the external carotid artery to its terminal branches in the tongue. Methods: Following bilateral neck dissections in 35 black Kenyan cadavers, the incidence of Beclard's, Lesser's and Pirogoff's triangles, the types of LA origin with its length, relationship to the hyoglossus muscle and anastomosis with other vessels were documented. Results: Beclard's triangle was found in 64 dissections (91.42%), Lesser's in 46 dissections (65.71%) and Pirogoff's in 39 dissections (55.71%). The LA presented either as a solitary branch (67.15%) or as a branch of either the linguofacial (LFT-24.29%), thyrolingual (TLT-2.72%) or thyrolinguofacial (TLFT-2.86%) trunk. The solitary LA was the longest at 6.93 mm, followed by the TLT branch (6.58 mm), LFT branch (6.12 mm) and TLFT branch (5.65 mm). The majority of solitary LA and LA branches of LFT and TLFT passed through the hyoglossus, while all LA branches of the TLT coursed medial to the muscle. All variants of LA have been found to anastomose with the submental artery (SMA) at frequencies that ranged from 11.10% to 100%. Conclusions: The LA was found in all cadavers and all Beclards' triangles. There is a significant incidence of LFT and TLFT variants in the Kenyan population. The LA passed either through or medial to the hyoglossus with no lateral relationship being observed.

Anatomical Variations in the Origin of the Lumbar Artery: A Cadaveric Study Augmented by CT Findings.

BACKGROUND: Anatomical variations of lumbar arteries predispose them to iatrogenic injury during endovascular intervention or surgery. Due to limited morphological data on lumbar arteries in our setting, we aimed to determine their variant anatomy among Kenyans. METHODS: We performed the study on 90 cadaveric specimens and 120 computed tomography (CT) scans. Cadavers were dissected to expose the aorta and the lumbar arteries emerging from them. The number, origins, location relative to the vertebral bodies, and relations to aortic bifurcation were determined in cadavers and CT scans. Data were analyzed using SPSS (version 21.0). RESULTS: On average, 3 (3/90 [3.3%]), 4 (63/90 [70%]) or 5 (24/90 [26.7%]) pairs of lumbar arteries were observed among the cadaveric specimens, whereas 4 (100/120 [83.3%]) or 5 (20/120 [16.7%]) pairs were observed in CTs. Differences in the number of pairs observed in the cadaveric versus CT study were not statistically significant (P = .542). There were no sex differences in the number of lumbar artery pairs observed in CT scans (P = .178). The first 3 lumbar artery pairs had a single-origin, whereas the fourth lumbar artery had a common-stem origin. The first, second, and third lumbar arteries mostly originated at the upper third of their respective vertebral bodies. The fourth lumbar artery predominantly originated at the lower third. CONCLUSION: Our study's findings show unique variation in the lumbar arteries' relation to the vertebral bodies and the distances between artery pairs. LEVEL OF EVIDENCE: IV (cross-sectional study). CLINICAL RELEVANCE: Variations in the anatomy of the lumbar arteries should be taken into consideration, especially in surgical or interventional procedures to avoid inadvertent injury of the vessels.

Microscopic features of the rat adrenal gland associated with chronic codeine phosphate administration.

Codeine is an opioid analgesic and antitussive that has been widely abused. Some adverse effects noted with its abuse include adrenocortical insufficiency and activation of the hypothalamic-pituitary-adrenal axis. The structural basis for these dysfunctions is not clearly understood. Twenty-five adult male rats were used for the study. They were divided into intervention and control groups that were administered 40 mg/kg of codeine phosphate and normal saline respectively by gavage daily for 50 days. Subsequently, both groups were given normal saline for a further fourteen days to note recovery changes. At day 0, 50 and 64, rats were randomly selected from both groups, euthanized and adrenal glands harvested for histological processing and analysis. At day 50 of codeine administration, the adrenal glands demonstrated an increase in zona fasciculata thickness but a decrease in zona reticularis thickness. Lower values were noted in the volume density of zona reticularis and cells count of the medulla in the experimental compared to the control groups (P-value<0.05). The experimental group also showed an increase in vascularization and connective tissue in the glands. After 14 days of recovery, most of the changes observed in experimental animals were reversed and the adrenal glands in both groups had similar features. A decrease in cell count of the adrenal medulla was however observed (P-value<0.05). In conclusion administration of codeine phosphate causes discernible changes in the microscopic structure of the adrenal gland, most of which appear to be reversed after two weeks recovery period.

Morphometric Dimensions of the Calcaneus.

Calcaneal morphometric dimensions influence surgical treatment plans after injury. These dimensions display population heterogeneity, and there is a paucity of data in the setting of our hospital in Kenya. Further, estimation of calcaneal dimensions during reconstruction in comminuted fractures can be difficult. This cross-sectional study therefore aims to determine equations for estimation of these dimensions as well as provide local data. Sixty-four bilateral calcanei of adult indigenous Kenyans were obtained from the National Museum of Kenya and measured for maximum anteroposterior length, maximum height, cuboidal facet height, body height, and load arm length. The data were coded into SPSS software, and means were calculated. Paired t tests, independent t tests, and Pearson correlation tests were done, and linear regression model equations were developed. Data are presented using tables. In millimeters, the mean right and left values, respectively, were as follows: maximum anteroposterior length, 36.1063 and 35.3047; maximum height, 68.958 and 68.266; cuboidal facet height, 27.815 and 27.841; body height, 47.94 and 48.98; and load arm length, 18.83 and 17.93. Paired and independent t tests did not reveal statistically significant difference between the variables based on side or sex. Pearson correlational tests between the maximum length on each side and other variables revealed strong positive correlations, apart from the maximum width and load arm length on both sides. All correlational R2 values were statistically significant, apart from that of the maximum width bilaterally. The calcaneus in our setting also showed markedly reduced values compared with other populations. These findings, and the proposed equations we developed, may be considered in local calcaneal reconstruction.

Variations of the Anatomy and Bony Landmarks of Deep Circumflex Iliac Artery in a Select Kenyan Population.

BACKGROUND: The deep circumflex iliac artery (DCIA) is a large caliber artery which branches laterally from the external iliac artery (EIA), directly opposite the origin of the inferior epigastric artery (IEA). Population variations have been reported in its origin, length, and branching patterns. These may alter its relationship to palpable surgical landmarks such as the anterior superior iliac spine (ASIS) and the pubic tubercle (PT) which are used to locate the artery preoperatively, thus predisposing it iatrogenic injury. Despite this, there is paucity of data from the Kenyan setting. STUDY DESIGN: Cross-sectional study design. OBJECTIVE: To determine the variations of the anatomy and bony landmarks of the Deep circumflex iliac artery in a select Kenyan population. METHODS: A total of 104 DCIA from 52 formalin fixed adult cadavers were dissected to expose the DCIA, following which its vessel of origin and distance from the ASIS and PT, relation to the inguinal ligament (IL), length and branching patterns were noted. The average of the measurements were calculated. All data were collected and analyzed using Microsoft Excel 2007 (Microsoft Corporation, Redmond, WA). Representative photos of the vessel and its variations were taken. RESULTS: The DCIA was found to be present and bilaterally symmetrical in all cadavers. In all cases observed, it originated as a lateral branch from the EIA (100%), opposite the IEA and directly behind the IL in 98% of the cases. Its average distance from the ASIS along the IL was 7.28 ± 0.99, while it was 5.91 ± 1.03 from the pubic tubercle to its origin. Its length ranged from 3.7 cm to 9.5 cm, with an average length of 3.86 cm in the right limb and 3.67 cm in the left limb. As regards its branching patterns, in 78% of the cases, it bifurcated into the horizontal and ascending branches, in 6%, it trifurcated and in 4%, it divided into more than 3, exhibiting a fine tree-like branching (arborization). CONCLUSION: The DCIA in our setting exhibited variations from other settings and an increase in awareness of these variations will probably reduce future iatrogenic lesions of the DCIA and its major branches in Kenya.

Cerebral Artery Hypoplasia in a Select Adult Kenyan Population.

Background Hypoplasia of cerebral arteries predisposes to stroke and cerebral aneurysms which have an increased incidence in sub-Saharan Africa. The frequency and pattern of cerebral artery hypoplasia, however, shows population variations, and data from the African population remain scanty. Objectives This study aimed to determine the percentage of hypoplasia in the anterior, middle, and posterior cerebral, anterior and posterior communicating, basilar, and vertebral arteries. Materials and Methods Sections of the basilar, vertebral, posterior, and anterior communicating arteries and anterior, middle, and posterior cerebral arteries were taken, processed for histology, and examined with a light microscope at ×40. The images of the vessels were taken by a photomicroscope and circumference analyzed with the aid of Scion image analyzer. The average diameter of 10 sections was taken to be the diameter of the artery in analysis. Hypoplasia was then defined as internal diameter ≤1 mm. Photographs of representative samples of asymmetry were taken, data were analyzed using SPSS, and gender differences were analyzed using the Student's test. Results were presented in tables. Results Two hundred and eighteen formalin-fixed brains of adult Kenyans at the Department of Human Anatomy, University of Nairobi, were studied. Of the 218, 48 brains (22%) did not have vessels with any form of hypoplasia while 170 (78%) did have vessels. Of these, anterior circulation hypoplasia (anterior cerebral artery and posterior communicating artery) was seen in 100 brains (46%) and posterior circulation hypoplasia (middle and posterior cerebral, basilar, and vertebral arteries) in 69 brains (32%). Conclusion Cerebral arterial hypoplasia is frequent in the select adult Kenyan population.

The Relation of the Extracranial Spinal Accessory Nerve to the Sternocleidomastoid Muscle and the Internal Jugular Vein.

The spinal accessory nerve (SAN) exhibits variant anatomy in its relation to the internal jugular vein (IJV) as well as the sternocleidomastoid muscle (SCM). These variations are important in locating the nerve during surgical neck procedures to avoid its inadvertent injury. These variations, however, are not conserved among different populations and data from the Kenyan setting are partly elucidated. This study, therefore, aims to determine the variant anatomical relationship of the SAN to the SCM and IJV in a select Kenyan population. Forty cadaveric necks were studied bilaterally during routine dissection and the data collected were analyzed using SPSS version 21. Means and modes were calculated for the point of entry of the SAN into the posterior triangle of the neck as well as for its relation to the SCM. Side variations for both of these were analyzed using Student's t -test. Data relating the SAN to the IJV were represented in percentages and side variations were analyzed using the chi-square test. The SAN point of entry into the posterior triangle of the neck was 5.38 cm (3.501-8.008 cm) on the left side and 5.637 cm (3.504-9.173 cm) on the right side ( p = 0.785) from the mastoid process. The nerve perforated the SCM in four cases (10%) on the left side and in eight cases (20%) on the right ( p = 0.253). The SAN lay predominantly medial to the IJV on both sides of the neck, 87.5% on the left side of the neck versus 82.5% on the right ( p = 0.831). In conclusion, the variant relation of the SAN to the IJV and SCM as observed in this setting is an important consideration during radical neck procedures and node biopsies.