RESUMEN
The sinuous canal is an anatomically well-defined intramural canal of the maxillary sinus (MS) folded within the antral walls. Commonly, its first, infraorbital part, courses within the antral roof, while its second, transverse facial part courses below the infraorbital foramen within the anterior antral wall. While retrospective files of patients that were scanned in cone-beam computed tomography (CBCT) for different dental medical purposes were observed randomly, a peculiar variant of the sinuous canal was noticed and further documented. The respective canal origin was far posterior in the infraorbital groove and the canal coursed through the MS embedded within an incomplete oblique septum dividing the antrum into anterosuperior and posteroinferior chambers. Then the sinuous canal continued with the transverse facial segment. As the sinuous canal contains the superior anterior alveolar nerve and artery, major suppliers of the frontal teeth, it is recommended to document in CBCT a possible transantral, and not intramural, course of it, especially when surgical or endoscopic corridors through the MS are planned.
Asunto(s)
Tomografía Computarizada de Haz Cónico , Seno Maxilar , Endoscopía , Humanos , Nervio Maxilar , Seno Maxilar/diagnóstico por imagen , Estudios RetrospectivosRESUMEN
The pneumatisation of the articular tubercle (PAT) of the temporal squama isa rare condition that modifies the barrier between the temporomandibular joint(TMJ) space and the middle cranial fossa. During a routine examination of thecone-beam computed tomography (CBCT) files of patients who were scannedfor dental medical purposes, we identified a case with multiple rare anatomicvariations. First, the petrous apex was bilaterally pneumatised. Moreover, bilateraland multilocular PAT were observed, while on one side it was further found thatthe pneumatic cells were equally dehiscent towards the extradural space and thesuperior joint space. To the best of our knowledge, such dehiscence has not previouslybeen reported. The two temporomastoid pneumatisations were extendedwith occipital pneumatisations of the lateral masses and occipital condyles, thelatter being an extremely rare evidence. The internal dehiscence of the mandibularcanal in the right ramus of the mandible was also noted. Additionally, doublemental foramen and impacted third molars were found on the left side. Suchmultilocular PAT represents a low-resistance pathway for the bidirectional spreadof fluids through the roof of the TMJ. Further, it could add to a morphologicalpicture of hyperpneumatisation of the posterior cranial fossa floor, which couldsignify the involvement of the last four cranial nerves in the clinical picture of TMJpain.
Asunto(s)
Hueso Temporal/patología , Articulación Temporomandibular/patología , Adulto , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Imagenología Tridimensional , Hueso Temporal/diagnóstico por imagen , Articulación Temporomandibular/diagnóstico por imagenRESUMEN
The study of anatomical variations is important not only for collecting anthropometric data, but also for improving clinical protocols and understanding why a particular clinical procedure sometimes does not yield the expected results. We report the case of a 74 year-old patient, in which we observed combined anatomical variants of the mandible and maxillary bone. One of these was the unilateral mylohyoid bridge (MB) of the uncommon, lingular type. This MB extended posteriorly to the spine of Spix, over the sulcus colli behind the spine. It thus formed a common mandibular canal (MC) which further divided into a retromolar canal and the MC proper. This combination of variants in the mandible has not, to our knowledge, previously been reported, at least in studies using cone beam computed tomography (CBCT). Additionally we found multiple accessory canals (ACs) deriving from the canalis sinuosus, which opened opposite to each frontal tooth, presumably carrying either dental fibers of the palatine nerves, or palatine fibers of the anterior superior alveolar nerve. Although the ACs in the anterior palate are well established anatomical variants, the MB appears in publications rather as an anthropological identifier. However, when present, it can impede anaesthesia of the lower teeth and thus deserves to be included in anatomical descriptions. The evaluation of patients in CBCT should observe the anatomical features on a case-by-case basis and it also provide data for studies of MB prevalence in large numbers of patients.