Bilateral giant and unilateral duplicated sphenoidal tubercle.

The sphenoidal tubercle (SphT), also known as pyramidal tubercle or infratemporal spine projects from the anterior end of the infratemporal crest of the greater sphenoidal wing. As it masquerades the lateral entrance in the pterygopalatine fossa it could obstruct surgical corridors or the access for anaesthetic punctures. The SphT is, however, an overlooked structure in the anatomical literature. During a routine cone beam computed tomography study in an adult male patient we found bilateral giant SphTs transforming the infratemporal surfaces of the greater wing into veritable pterygoid foveae. Moreover, on one side the SphT appeared bifid, with a main giant partition, of 9.17 mm vertical length, and a secondary laminar one. The opposite SphT had 14.80 mm. In our knowledge, such giant and bifid SphTs were not reported previously and are major obstacles if surgical access towards the pterygopalatine fossa and the skull base is intended.

Endothelial progenitor cells populate the stromal stem niche of tympanum.

The tympanic membrane (TM) integrity is of utmost importance for the sense of hearing. Therefore, the intrinsic potential of the TM to regenerate and repair deserves complete characterisation. Existing studies brought evidence on the epithelial stem niche of the TM. However, the stromal compartment was not evaluated for harbouring a distinctive stem, or progenitor, niche. We aimed doing this in transmission electron microscopy. We used TMs dissected out from 3 male Oryctolagus cuniculus rabbits. Evidence of stromal quiescent stem cells was gathered. Moreover, endothelial progenitor cells were found in the TM, being accurately identified by two specific ultrastructural markers of the endothelial lineage: the Weibel-Palade bodies and the stomatal diaphragms of the subplasmalemmal caveolae. The stromal stem niche of the TM appears to be a distinctive contributor during physiological and pathological processes of the TM, such as cholesteatoma formation, at least as a biological support for processes of vasculogenesis. However, further characterisation of the molecular pattern of the stromal stem niche of the TM is mandatory.

Anatomic variation of alveolar antral artery.

The alveolar antral artery (AAA) was unanimously encountered in a few available studies with an intraosseous course to anastomose with the infraorbital artery. We report here two cases in which dissection revealed an extraosseous placement of this artery, between the lateral wall of the maxillary sinus and the Schneiderian membrane. The frequency of occurrence of the intraosseous anastomosis should be so modified from 100% to < 100%. This arterial course over the Schneiderian membrane is important during surgical procedures: if it is identified preoperatively it can be avoided, or ligaturated, if not, it may be accidentally severed and uncomfortable haemorrhage may disturb the surgical procedure. In the first case reported here hybrid morphology of the AAA was also found, demonstrating that arterial anatomy should be considered with caution, on a case-by-case basis.

The extramandibular inferior alveolar nerve in cases with severely atrophic lower jaws.

There are very few evidences on the extramandibular course (EMC) of the inferior alveolar nerve (IAN). We report here two such cases. The first one was encountered at dissection, in a human adult female cadaver where the right IAN terminal division was identified in the premolar region, above a severely atrophied mandibular body. The second case was a patient evaluated by cone-beam CT, who presented with an extremely atrophic mandible with bilateral extramandibular courses of the IANs. Such severe atrophy of the mandible may be considered as residual ridge class 7 along with the existing Atwood classes. EMCs of the IAN may not only occur in extreme mandibular atrophy, but also in dentate mandibles. In edentulous mandibles, an extramandibular IAN may complicate local surgical procedures or hamper denture wearing.

Altered anatomy in a case with a buccally impacted maxillary canine tooth.

Bilateral dissections of maxilla were performed in a human adult cadaver head, male, aged 53 years. After the en block removal of the soft tissues in the oral and infraorbital regions, the antero-lateral surface of maxilla was exposed and also the vestibular aspect of the upper alveolar process. An oblique labially impacted right upper canine was evidenced, completely submucosal: its apex was tangent to the maxillary sinus floor, while the superior side of the apical part of the root was in close relation with the floor of the laterally expanded inferior nasal meatus. Superior and adjacent to the neck of that impacted canine a follicular cyst was evidenced and the antral wall presented distally to the apex of the impacted canine a dehiscent area, where the antral mucosa was only covered by an incomplete thin bony lamella. The incisors on that side were present but no resorption was identified at their level. Within the anterior border of the wall separating the maxillary sinus, small, and the inferior nasal meatus, the nerve for that impacted canine was coursing; the nerves for the upper incisors were initially located within the antero-lateral wall of the inferior nasal meatus. Although small, the maxillary sinus presented a supero-medial recess above the enlarged inferior nasal meatus and lateral to the normally-sized middle nasal meatus.

The anatomy of a horizontally impacted maxillary wisdom tooth.

A completely horizontally impacted upper third molar was revealed after routine dissection of a 62-year-old human cadaver of a Caucasian male. The molar was penetrating into the maxillary sinus and there was antral dehiscence of its bony alveolus. The bony alveolus was immediately in front of the greater palatine canal contents, and the bottom of the alveolus was dehiscent towards the greater palatine foramen. Within the greater palatine canal and foramen the greater palatine artery was duplicated and the nerve was found. Such antral relations of an impacted upper third molar predispose to oroantral communications if extraction is performed, while the close neurovascular relations represent a risk factor for postextractional haemorrhage and neurosensory disturbances and must be borne in mind when deciding on or performing the extraction.