Visualisation of the vomerovaginal canal during endonasal transpterygoid approaches and CT imaging diagnosis.

The vomerovaginal canal (VVC) and palatovaginal canal (PVC) are two canals that open forward to the posterior wall of the pterygopalatine fossa (PPF). Although the anatomy and computed tomography (CT) appearances of the PVC have been well studied, the VVC has been rarely reported, especially in endoscopic examinations. Some studies have even failed to distinguish the PVC from the VVC on CT images. The purpose of this study was to demonstrate the anatomy of the VVC on endoscopy and reveal its differences from the PVC, and to analyse the relative positions of the VVC, PVC, and pterygoid canal on CT images. Ten dry skull bases were studied to observe the structures involved in the formation of the VVC. Dissection of four cadaveric heads was performed to demonstrate the anatomy of the VVC on endoscopy. Coronal CT image analysis in 70 patients was conducted to evaluate the distances and relative positions between the VVC, PVC, and pterygoid canal. The PVC and VVC were also compared on axial CT images. The osteological study showed the top wall of the VVC was the antero-inferior wall of the sphenoid sinus. The VVC may be a helpful landmark in endoscopic endonasal transpterygoid approaches. Steps and discrimination in the dissections of the VVC and PVC were described. The interval between the PVC and VVC could be observed on both coronal and axial CT images. The coronal CT images of patients showed differences in the positions and distances among the three canals at both the anterior and posterior apertures of the PVC. The VVC can be easily mistaken for the PVC if its existence is not suspected. The anatomical morphologies and trajectories of the VVC and PVC differed on both nasal endoscopy and CT. The existence of the VVC should be considered during surgery and CT diagnosis within this area.

Line of Sight in Hominoids.

OBJECTIVES: It remains unclear how the realignments of the face and basicranium that characterize humans were acquired, both phylogenetically and ontogenetically. The developmentally constrained nature of the skull has been previously demonstrated in other primates using Donald H. Enlow's mammalian craniofacial architectural relationships. Here, we compare crania of our closest relatives to gain greater understanding of how and why the relationship of the face and cranial base is developmentally constrained in order to inform instances of abnormal growth and clinical intervention. STUDY DESIGN: A method for evaluating these fundamental architectural relationships using 3D landmark data was developed, thereby taking overall size and the geometric relationships among points into account. A sample of cone-beam computed tomography scans derived from humans and extant apes were analyzed (n=10 and n=6, respectively), as well as fossil hominid crania (n=7). Landmarks for 23 craniofacial architectural points were identified and recorded. RESULTS AND CONCLUSIONS: Principal components analyses reveal that despite the similarities in craniofacial architecture between humans, extant apes and fossil hominids, appreciable trends in variation between the extant species suggest that the repositioning of the foramen magnum was only one of a constellation of traits that realigned the basicranium and face during the transition to bipedalism.

Sphenovomerine suture: a useful landmark for locating sphenoid sinus ostium.

AIM: The aim of this study was to determine whether the sphenovomerine suture (SVS) can be used as a landmark to localize the sphenoidal sinus ostium. METHODS: Endoscopic imaging was done on 152 skulls to identify ostium of the sphenoidal sinus, the SVS, and the articulation of sphenoidal process of palatine bone between the body of the sphenoid and the sphenopalatine foramen. The variables were as follows: (1) the distance between the medial border of the ostium and SVS (DSO-SVS); (2) the angle between them (ASO-SVS); (3) the distance between the inferior border of the ostium and the horizontal line (DSO-HL); (4) the distance between intersection point of the SVS-sphenoidal process of the palatine bone and the medial border of sphenopalatine foramen (DSPF-SVS); and (5) the number of sphenopalatine foramen. RESULTS: Of the 152 skulls, 289 sides were included in the study. The mean value for DSO-SVS was 3.15 (1.35) mm, DSO-HL was 5.99 (2.38) mm, DSPF-SVS was 7.07 (1.96) mm, and ASO-SVS was 5.99 (9.73) mm. As DSPF-SVS decreases, DSO-SVS and DSO-HL decrease with statistical significance (Ps = 0.02 and 0.001, respectively). The distribution of the numbers of sphenopalatine foramen was as follows: one 90%, two 9.7%, and four 0.3%. CONCLUSIONS: The horizontal distance between the SVS and the sphenopalatine foramen plays a significant role in identifying the location of sphenoid sinus ostium. As with the other landmarks, the SVS provides an additional benefit in locating the sphenoid sinus ostium for endoscopic sinus surgeons. The incidence of 4 sphenopalatine foramen is 0.3%.

Developmental oronasal fistula of the incisive papilla.

Various terms (including patent nasopalatine fistula and patent nasopalatine duct) have been used to describe the presence of a developmental fistulous tract that connects the oral and nasal cavities through an oral opening located at the incisive papilla. Reportedly, this condition is a rare developmental variant; approximately 40 cases have been reported in the literature. Because awareness of this entity is important to avoid misdiagnosis, this article presents the clinical and conebeam computed tomography findings of two cases. Based on a review of the development of the nasopalatine structures in man, the authors propose that this entity be classified as a developmental oronasal fistula of the incisive papilla.

The nasal septum: an osteometric study of 16 cadaver specimens.

Studies of the shape, dimensions, and other morphologic characteristics of the nasal septum are scant in the literature. We conducted a study of 16 male cadavers to measure six osseous components of the nasal septum and to calculate the proportional contribution that each made to the total septal bone surface area. We found a wide range of inter-specimen variations in both categories. It is our hope that a better understanding of nasoseptal anatomy will improve surgical technique.

Macro- and micro-anatomical, histological and computed tomography scan characterization of the nasopalatine canal.

AIM: To determine the human anatomic variability of the nasopalatine canal and determine its characteristics using an anatomical, histological and computed tomography (CT) scan evaluation. MATERIALS AND METHODS: Measurements for the canal characteristics were carried out on 163 dry human skulls and 120 upper jaw spiral CT scans, taken from patients for pre-operative planning purposes of implant placement in the incisor region. Furthermore, four human cadaver specimens were imaged using a high-resolution magnetic resonance imaging (HR-MRI) unit. Afterwards, these specimens were serially sectioned for histological examination to evaluate the nasopalatine canal region and its content. RESULTS: The nasopalatine canal anatomy showed a large variability in morphology and dimensions, with the canal branching in up to four canals at the level of the nose. The canal diameter was on average 3.3 mm (+/-0.9 mm SD), and typically enlarged by age and male gender (p<0.05). HR-MRI and histological sections enabled to identify the neurovascular structures within the canals. CONCLUSIONS: The large anatomic variations, the increased canal dimensions with age and the neurovascular canal content are all factors favouring a thorough three-dimensional planning before surgery, such as implant placement, of the anterior maxillary region.

Skull anatomy of the miniaturized gecko Sphaerodactylus roosevelti (Squamata: Gekkota).

A detailed description of the skull and jaw of the gecko Sphaerodactylus roosevelti is presented. The bones are described articulated and isolated with special consideration given to the type of suture among joining elements. S. roosevelti was compared with 109 gekkotan species to evaluate the osteological variation and to find characters for cladistic analysis. Changes in the skull associated with the miniaturization process are discussed within the sphaerodactylid geckos. A noticeable increase of overlapping sutures was observed in the snout of the smallest sphaerodactylids compared to other gekkotans. This pattern is convergent with that in miniaturized pygopodids and may be attributed to adaptations for decreasing mechanical resistance of the cranium during feeding or burrowing. New cranial characters support Sphaerodactylinae as a monophyletic group and should be useful for resolving questions such as their relationship with other gekkotans.