The Maxillomandibularis Muscle.

Fibers of the lateral pterygoid muscle (LPM) occasionally originate on the posterior surface of the maxilla. Anatomic exploration of an adult patient's cone beam computed tomography files revealed a previously unreported unilateral anatomic variant of the LPM. The variant consisted of a distinctive muscular slip that originated on the tuberosity of the maxilla and coursed postero-laterally through the notch of the mandible to insert on an accessory pterygoid fovea on the outer condylar pole. This maxillomandibular muscle was lateral to the inferior head of the LPM. Therefore, it could contribute to the antero-inferior displacement and medial rotation of the mandibular condyle during the movements of the temporomandibular joint. The maxillomandibular muscle should be added to the extensive spectrum of anatomical variations of the LPM; however, prevalence studies should assess whether its maxillary attachment is the rule or the exception.

Extruded Nucleoli of Human Dental Pulp Cells.

Background and Objectives: The dental pulp stem cells are highly proliferative and can differentiate into various cell types, including endothelial cells. We aimed to evaluate the ultrastructural characteristics of the human dental pulp cells of the permanent frontal teeth. Materials and Methods: Human adult bioptic dental pulp was collected from n = 10 healthy frontal teeth of five adult patients, prior to prosthetic treatments for aesthetic purposes. Tissues were examined under transmission electron microscopy. Results: We identified cells with a peculiar trait: giant nucleoli resembling intranuclear endoplasmic reticulum, which mimicked extrusion towards the cytoplasm. These were either partly embedded within the nuclei, the case in which their adnuclear side was coated by marginal heterochromatin and the abnuclear side was coated by a thin rim of ribosomes, or were apparently isolated from the nuclei, while still being covered by ribosomes. Conclusions: Similar electron microscopy features were previously reported in the human endometrium, as nucleolar channel system; or R-Rings induced by Nopp140. To our knowledge, this is the first report of extruded nucleolar structure in the dental pulp. Moreover, the aspect of giant extruded nucleoli was not previously reported in any human cell type, although similar evidence was gathered in other species as well as in plants.

Rare Anatomic Variation: Pneumatized Secondary Middle Turbinate.

The nasal turbinates adhere to the lateral nasal wall and are subjected to various morphological variations. A common variation is concha bullosa, the pneumatization of a nasal turbinate. Another possible variation is the secondary middle turbinate (SMT) which originates from the lateral wall of the middle nasal meatus. Pneumatized SMTs were previously found only twice in Computed Tomography (CT) studies. It is hereby reported the third such evidence, gathered in a 44 y.o. male patient which was scanned in Cone Beam CT (CBCT) for routine dental medical procedures. In the present case the superior turbinates were pneumatized and were found bilateral SMTs. The left SMT was unpneumatized and projected medially and the right SMT was pneumatized and projected infero-medially. The right pneumatized SMT was communicating through a narrow isthmus with the ethmoidal bulla; beneath these two, a large ethmoidal infundibulum opened medially through a narrow semilunar hiatus. Such extremely rare anatomic variations could impede on the normal drainage of the ostiomeatal unit and could lead to inadvertent surgical corridors if they are not documented in CT or CBCT.

The Sutton's Foramen of the Oblique Line of Mandible.

Although the foramina of the adult mandible are well known and extensively studied, still additional foramina and canals could persist from the fetal stage and be detected occasionally in adult. At a routine anatomical evaluation of the Cone Beam Computed Tomography (CBCT) scan of a female patient of 47 years old, a rare anatomical variant of the mandible was found, and is presented here. It was termed foramen lineae obliquae and it was found in the right hemimandible at the level of the second molar, on the oblique line. From that foramen a canal continued within the mandible to join the mandibular canal. On orthogonal slices was accurately detected that the content of that foramen and canal was connected to an intramasseteric network, which was strongly suggestive for that content being vascular. Although a contribution from the buccal nerve could not be withdrawn, the most reasonable content to speculate is the aberrant anastomotic artery of the facial and inferior alveolar arteries. Vascular foramina of the mandible are relevant during various surgical procedures. Surgeons should be aware that if an artery is commonly regarded as a supplier of a muscle inserted on the mandible, it should not be rejected a priori the possibility for that artery being also an extrinsic supplier of the mandible, through an unexpected foramen in the vicinity of that muscle.

The oral mucosa: Epithelial professional phagocytes, lymphatics, telocytes, and false telocytes.

BACKGROUND: The oral mucosa protects the underlying tissue from mechanical damage as well as from the entry of exogenous particles and microorganisms. Telocytes (TCs) are disputed stromal cells featuring peculiarly long and thin processes with uneven calibre known as telopodes, which play a number of roles within the interstitia. The present study aimed to test the key markers recommended for discriminating between TCs and false TCs in samples of normal oral mucosa. METHODS: Archived paraffin-embedded oral mucosa samples were tested by means of immunohistochemistry with the following markers: CD34, D2-40, CD31 and CD68. RESULTS: The epithelial expression of CD68, D2-40 and CD34 was detected. Two subsets of CD34-expressing stromal cells were identified, large cells with telopodial processes, presumably of the hematopoietic lineage, and spindle-shaped TC-like cells. Macrophages and TC-like cells within the lamina propria expressed CD68. The lymphatic endothelia were found to express CD31 and D2-40, but not CD34. Sprouting lymphangiogenesis was demonstrated by the lymphatic endothelial tip cells, which were projecting thin processes within the connective stroma. CONCLUSIONS: The epithelial expression of CD68 suggests the professional phagocytic potential of the oral epithelium. Regarding the TCs and TC-like cells in the oral mucosa they could not be accurately distinguished from other possible cell types, neither on morphological basis (evidence of telopodes) nor by use of panels of markers which include CD34.