The Incidence of Atlanto-Occipitalization and Additional Foramina Present in The Dry Skulls of Nepalese Population

Introduction: Atlanto-occipitalization(AOZ) is one of the congenital anomalies related to craniovertebral synostosis. The clear understanding of its anatomical features and cranial foraminal variants plays a critical role in finding the possible coping mechanism with its pathogenesis such as segmental instability or neurologic deficits. Objective: This study aimed to investigate the incidence of occipitalization of Atlas and related variant foramina, as the baseline awareness of these conditions among the Nepalese population is yet to be documented. Methodology: A retrospective study was performed for the total 86 dry skulls available in the department of Anatomy in Katmandu University of Medical Sciences, Institute of Medical Science, and B.P. Koirala Institute of Health Sciences. The skulls were examined thoroughly to evidence the occurrence of cranio-vertebral variations. Result: Out of 86 human adult skulls, 2 cases (2.32 %) were found with partial AOZ presenting posterior spina bifida close to the midline. Sphenoidal emissary foramen (SEF) was also observed in 17 skulls (19.76 %), an additional foramen lying anteromedial to the foramen ovale. Moreover, one of the skulls (1.16 %) was found with the presence of pterygospinous bar creating an additional foramen ‘foramen of Civinini’ in the lateral pterygoid plate of the sphenoid bone. Conclusion: The incidence of AOZ and pterygospinous bar seems to be quite low as compared to the cases of SEF. However, the knowledge of such variations and the presence of additional foramina carry great significance for orthopedists and neurosurgeons to have prognostic implications and an accurate surgical approach.

An Endoscopic Endonasal Nasopharyngectomy with Posterolateral Extension

Background Invasion depth influences the choice for extirpation of nasopharyngeal malignancies. This study aims to validate the feasibility of endoscopic endonasal resection of lesions with a posterolateral invasion. As a secondary goal, the study intends to propose a classification system of endoscopic endonasal nasopharyngectomy determined by the depth of posterolateral invasion. Methods Eight cadaveric specimens (16 sides) underwent progressive nasopharyngectomy using an endoscopic endonasal approach. Resection of the torus tubarius, Eustachian tube (ET), medial pterygoid plate and muscle, lateral nasal wall, and lateral pterygoid plate and muscle were sequentially performed to expose the fossa of Rosenmüller, petroclival region, parapharyngeal space (PPS), and jugular foramen, respectively. Results Technical feasibility of endonasal nasopharyngectomy toward a posterolateral direction was validated in all 16 sides. Nasopharyngectomy was classified into four types as follows: (1) type 1: resection restricted to the posterior or superior nasopharynx; (2) type 2: resection includes the torus tubarius which is suitable for lesions extended into the petroclival region; (3) type 3: resection includes the distal cartilaginous ET, medial pterygoid plate, and muscle, often required for lesions extending laterally into the PPS; And (4) type 4: resection includes the lateral nasal wall, pterygoid plates and muscles, and all the cartilaginous ET. This extensive resection is required for lesions involving the carotid artery or extending to the jugular foramen region. Conclusion Selected lesions with posterolateral invasion into the PPS or jugular foramen is amenable to a resection via expanded endonasal approach. Classification of nasopharyngectomy based on tumor depth of posterolateral invasion helps to plan a surgical approach.

Skeletal width changes after mini-implant–assisted rapid maxillary expansion (MARME) in young adults

ABSTRACT Objectives To observe skeletal width changes after mini-implant–assisted rapid maxillary expansion (MARME) and determine the possible factors that may affect the postexpansion changes using cone-beam computed tomography (CBCT) in young adults. Materials and Methods Thirty-one patients (mean age 22.14 ± 4.76 years) who were treated with MARME over 1 year were enrolled. Four mini-implants were inserted in the midpalatal region, and the number of activations ranged from 40 to 60 turns (0.13 per turn). CBCT was performed before MARME (T0), after activation (T1), and after 1 year of retention (T2). The mean period between T1 and T0 was 6 ± 1.9 months and between T2 and T1 was 13 ± 2.18 months. A paired t-test was performed to compare T0, T1, and T2. The correlations between the postexpansion changes and possible contributing factors were analyzed by Pearson correlation analysis. Results The widths increased significantly after T1. After T2, the palatal suture width decreased from 2.50 mm to 0.75 mm. From T1 to T2, decreases recorded among skeletal variables varied from 0.13 mm to 0.41 mm. This decrease accounted for 5.75% of the total expansion (2.26 mm) in nasal width (N-N) and 19.75% at the lateral pterygoid plate. A significant correlation was found between postexpansion change and palatal cortical bone thickness and inclination of the palatal plane (ANS-PNS/SN; P < .05). Conclusions Expanded skeletal width was generally stable after MARME. However, some amount of relapse occurred over time. Patients with thicker cortical bone of the palate and/or flatter palatal planes seemed to demonstrate better stability.

Three-Dimensional Determination of the Fusion Zone between the Distal Maxilla and the Pterygoid Plate of the Sphenoid Bone and Considerations for Implant Treatment Procedure

During pre-operation planning, an implantologist has to decide about the location of a dental implant based on the available bone, anatomical structures and future prosthetics. The aim of this study was to provide an overview of the configurations of the junction zone of the pterygoid process, maxillary tuberosity and pyramidal process among the population and to determine the usefulness of 3D model visualization in regard to precision of anatomical structure projections for clinical planning. A total of 72 cases were analyzed for seven measurements (lateral, medial, rostral, caudal, area, line-1 longitudinal, line-2 transverse) on both body sides—right (R) and left (L). In 57 cases, age and sex of the patient were given. In 15 cases this information was missing. Among the group of 57 cases with complete data, there were 30 females (F) and 27 males (M). A total of 57 models of upper jaws including the adjacent pterygoid process of the sphenoid bone were taken for investigation. The results of the comparison between the right and left side showed no differences (p > 0.05) in values of the measured parameters. The results of the comparison between males and females showed a statistically significant difference when assessing the line-2 transverse (p < 0.05)—in the male group the average was 8.22 mm, in the female group the average was lower (7.83 mm). No statistically significant differences in values of the measured parameters for females and males were found for the left side nor for the right side. In all examined specimens there was enough bone surface in the fusion zone to allow for the stable placement of one tuberopterygoid implant.

Malignant melanoma of the nasal mucosa

Nose's Paranasal sinus & malignant melanoma are rarely seen, bold tumor with a prevalence rates of 0.68 percent across every malignant tumor. The neuroectodermal cells which are termed as Melanomas are found in skin's base layer, iris’s vascular intraocular coat, skin adnexa, & infrequently into outer covering of mucous. Blockage feeling of nose & bleeding from the nose are the symptoms which are most commonly reported, however patient may have symptoms that are nonspecific, leading to a delay in diagnosis which results in appropriate prediction of treatment's outcome. This study defines a 70 years female with the history of nose blockage feeling. Physicians suggest performing Nose’s CT scan, in which they came to know that large polypoidal portion in right nostril, extending to the nasopharynx, and eroded part of the sinus wall, septum and right medial pterygoid plate. Immunochemical study done revealed positive results for S100, vimentin, & HMB-45, which made the outcome suitable for tumor. An individual suffering from this will have no recurrence.

Anatomical Variations and Relationships of the Infratemporal Fossa: Foundation of a Novel Endonasal Approach to the Foramen Ovale

Objective Access to the infratemporal fossa (ITF) is complicated by its complex neurovascular relationships. In addition, copious bleeding from the pterygoid plexus adds to surgical challenge. This study aims to detail the anatomical relationships among the internal maxillary artery (IMA), pterygoid plexus, V3, and pterygoid muscles in ITF. Furthermore, it introduces a novel approach that displaces the lateral pterygoid plate (LPP) to access the foramen ovale. Design and Main Outcome Measures Six cadaveric specimens (12 sides) were dissected using an endonasal approach to the ITF modified by releasing and displacing the LPP and lateral pterygoid muscle (LPTM) as a unit. Subperiosteal elevation of the superior head of LPTM revealed the foramen ovale. The anatomic relationships among the V3, pterygoid muscles, pterygoid plexus, and IMA were surveyed. Results In 9/12 sides (75%), the proximal IMA ran between the temporalis and the LPTM, whereas in 3/12 sides (25%), the IMA pierced the LPTM. The deep temporal nerve was a consistent landmark to separate the superior and inferior heads of LPTM. An endonasal approach displacing the LPP in combination with a subperiosteal elevation of the superior head of LPTM provided access to the posterior trunk of V3 and foramen ovale while sparing injury of the LPTM and exposing the pterygoid plexus. The anterior trunk of V3 traveled anterolaterally along the greater wing of sphenoid in all specimens. Conclusion Displacement of the LPP and LPTM provided direct exposure of foramen ovale and V3 avoiding dissection of the muscle and pterygoid plexus; thus, this maneuver may prevent intraoperative bleeding and postoperative trismus.

Fluoroscopically guided mandibular nerve block: a modified lateral approach

Background and objectivesMandibular nerve blocks are indicated for atypical face pain and trigeminal neuralgia. We hypothesized that a modified lateral approach, which entailed a combination of lateral and anterior approach techniques to the mandibular nerve block would lead to similar efficacy and improved safety profile rather than the typical lateral or anterior techniques.MethodsThis alternative approach was derived from anatomical investigation using the Radiology Anatomy Atlas Viewer and reconstructed axial cadaveric slices. We used axial slices at the level of the lateral pterygoid plate, and at the level of the temporomandibular joint to devise a needle path appropriate for this block.ResultsThe modified lateral approach to the mandibular nerve block was verified theoretically through cadaveric reconstructed slices and has been successfully performed in our practice. Precise needle trajectory could avoid both periosteal contact and gross redirection, as well as other procedural complications.ConclusionThe modified lateral approach to a mandibular nerve block avoids the respective risks associated with either the lateral and anterior approach. Facial intervention techniques typically pose increased safety challenges, however through cadaveric anatomic reconstruction, we have developed a safer approach for mandibular nerve blockade.