The pre-styloid compartment of the parapharyngeal space: a three-dimensional digitized model based on the Chinese Visible Human

Surgical anatomy of the lingual nerve for palate surgery: where is located and how to avoid it

PURPOSE

To describe the anatomic relationship of the lingual nerve with the lateral oropharyngeal structures.

METHODS

An anatomic dissection of the lateral oropharyngeal wall was conducted in eight sides from four fresh-frozen cadaveric heads. Small titanium clips were placed along the lingual nerve and the most anterior and medial border of the medial pterygoid muscle. Radiological reconstructions were employed for optimal visualization; the coronal view was preferred to resemble the surgical position. The distance between the lingual nerve and the medial pterygoid muscle at its upper and lower portion was measured radiologically. The trajectory angle of the lingual nerve with respect to the pterygomandibular raphe was obtained from the intersection between the vector generated between the clips connecting the upper and lower portion of the medial pterygoid muscle with the vector generated from the lingual nerve clips.

RESULTS

The mean distance from the upper portion of the medial pterygoid muscle and superior lingual nerve clips was 10.16 ± 2.18 mm (mean ± standard deviation), and the lower area of the medial pterygoid muscle to the lingual nerve was separated 5.05 ± 1.49 mm. The trajectory angle of the lingual nerve concerning to the vector that describes the upper portion of the most anterior and medial border of the medial pterygoid muscle with its lower part was 43.73º ± 11.29.

CONCLUSIONS

The lingual nerve runs lateral to the lateral oropharyngeal wall, from superiorly-inferiorly and laterally-medially, and it is closer to it at its lower third.

Digital three-dimensional model of lumbar region 4-5 and its adjacent structures based on a virtual Chinese human

OBJECTIVE

To study the methods for constructing a digitized three-dimensional (3D) model of a virtual lumbar region and its adjacent structures in order to assist anatomical study and virtual surgery.

METHODS

Images of DSCF5375-p1 to DSCF5745-p1 were taken from the database of the digitized Virtual Chinese human of Southern Medical University in Guangzhou. This region encompasses the superior facet joint of L4 to the inferior edge of the intervertebral body of L5. The regions of interest were interactively segmented from the images utilizing Adobe Photoshop software. The images were further processed using format conversion and segmentation. Finally, a 3D model of the L4-5 region and its neighboring structures was reconstructed with the assistance of Mimics 10.01 software.

RESULTS

A digitized 3D model of this part of the virtual lumbar spine and its adjacent structures was reconstructed. This model allows all constructed structures to be displayed individually or jointly, moved or rotated arbitrarily, setting of different transparencies and convenient measurement of the diameters and angles of the reconstructed structures. The 3D model precisely displays the anatomical relationships between all structures and provides a reliable 3D model for a spinal endoscopic surgery simulation system.

CONCLUSION

Visualization of the digitized 3D reconstruction of the virtual lower lumbar region displays this region and its adjacent structures stereoscopically and in actuality, thus providing morphological data concerning anatomy, image diagnosis and virtual operations in this region.

Distribution of elastic fibers in the head and neck: a histological study using late-stage human fetuses

There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220-320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers. In contrast with the sphenomandibular ligament and the temporomandibular joint disk, in which elastic fibers were partly present, the discomalleolar ligament and the fascial structures around the pterygoid muscles did not have any elastic fibers. In addition, the posterior marginal fascia of the prestyloid space did contain such fibers. Notably, in the middle ear, elastic fibers accumulated along the tendons of the tensor tympani and stapedius muscles and in the joint capsules of the ear ossicle articulations. Elastic fibers were not seen in any other muscle tendons or vertebral facet capsules in the head and neck. Despite being composed of smooth muscle, the orbitalis muscle did not contain any elastic fibers. The elastic fibers in the sphenomandibular ligament seemed to correspond to an intermediate step of development between Meckel's cartilage and the final ligament. Overall, there seemed to be a mini-version of elastic fiber distribution compared to that in adults and a different specific developmental pattern of connective tissues. The latter morphology might be a result of an adaptation to hypoxic conditions during development.

Prestyloid compartment of the parapharyngeal space: a histological study using late-stage human fetuses

PURPOSE

Although the prestyloid space is well known, its definition still remains unclear.

METHODS

Using semiserial sagittal sections of 15 late-stage human fetal heads, we studied details of the topographical anatomy.

RESULTS

A definite posterior marginal fascia of the space was seen along the anterior aspect of the stylopharyngeus and styloglossus muscles. Inferiorly, the prestyloid space faced the bucallis and medial pterygoid muscles and the submandibular gland. The external carotid artery ran along the posterolateral side of the space. The tensor veli palatini fascia did not contribute to the posterior marginal fascia. A major supplying artery of the space was the ascending palatine artery.

CONCLUSIONS

The prestyloid compartment of the parapharyngeal space (hereafter, the prestyloid space) seems to correspond to a border between the first and second pharyngeal arch derivatives. This concept may provide a better understanding of prestyloid space.