Anatomical and clinical considerations regarding the greater palatine foramen.

OBJECTIVE: In this study, we mapped the topography of the greater palatine foramen (GPF), within the South-Eastern European population, according to clinically identifiable anatomical landmarks. MATERIALS AND METHODS: We used 100 dry adult human skulls, of which 75 were bilaterally dentate, whereas 25 were partially edentulous. RESULTS: The shape of the GPF was oval in 84% of the cases. The foramen was located internally from the third molar in 73% of the skulls. The greater palatine canal showed an antero-infero-medial direction in 82% of the cases. The average values of the distances between the GPF and the oral surfaces of the maxillary third molar, the medio-palatine suture, the posterior margin of the hard palate, the pterygoid hamulus and the pterygo-maxillary suture were 11.0 (SD 1.5), 14.5 (SD 0.8), 4.4 (SD 1.1), 12.0 (SD 1.8) and 10.5 mm (SD 1.3), respectively. CONCLUSIONS: A thorough knowledge of GPF's various positions may assist the clinicians in providing improved surgical techniques in the area.

Evaluation of dental and maxillary development in patients with cleft lip alveolus.

Our purpose was to determine in 20 unilateral cleft lip and alveolus subjects characteristics of the maxillary permanent teeth and maxillary arch development. Clinical and radiographic examinations have been carried out to identify congenitally missing teeth and sagittal skeletal patterns. Study cast assessment was undertaken to evaluate mesiodistal widths of individual teeth, intercanine and intermolar distances for the maxillary arch, as well as dental relationships. We observed that the congenital absence of the upper incisors was higher on the cleft side than on the non-cleft side. There was a statistically significant difference between the mesiodistal widths of cleft-side permanent upper lateral incisors, and their antimeres (p<0.05). Most of the patients presented a class II dental relationship on the affected side comparing to class I/class III Angle on the unaffected side. We concluded that patients with isolated cleft lip and alveolus present perturbations in dental and maxillary arch development, a more severe disruption being recorded on the cleft side.

Typical and atypical neurovascular relations of the trigeminal nerve in the cerebellopontine angle: an anatomical study.

The aim of the present study was to anatomically evaluate in adults the neurovascular trigeminal relations in the cerebellopontine angle (CPA), from a morphological and topographical perspective and thus to improve, detail and debate the pre-existing information, with educational and surgical implications. For the present anatomical study we performed bilateral dissections on 20 human adult skull bases, in formalin-fixed cadavers, at the level of the cerebellopontine angle, using the anatomical superior approach; we also studied 20 additional drawn specimens-cerebellum and brainstems, from autopsied cadavers, in order to better document the vasculature at the trigeminal root entry zone (REZ). The most constant but not exclusive neurovascular relations of the trigeminal nerves were those with the superior cerebellar artery (SCA) and the superior petrosal vein (the petrosal vein of Dandy). The regular possibility for the SCA to appear divided into a medial and a lateral branch and these to represent individual trigeminal relations at the level of the pontine cistern or REZ must not be neglected. The petrosal vein tributaries can also represent superior, inferior, or interradicular trigeminal relations. Arterioles emerging from the SCA or the anterior inferior cerebellar artery (AICA) represented trigeminal relations either at the REZ or were coursing between the trigeminal roots. A dissected specimen presented a radicular trigeminal artery emerging from the basilar artery and entering the trigeminal cavum inferior to the nerve. Another specimen presented two bony lamellae superior to the trigeminal nerve at the entrance in the trigeminal cavum-these lamellae were embedded within the lateral border of tentorium cerebelli and the posterior petroclinoid ligament. So we bring here an evidence-based support extremely useful not only for specialists dealing with this area but also for educational purposes. It appears important not only to consider the typical anatomy at this level but also to take into account the atypical and hardly predictable morphologies that may alter the diagnoses and the specific surgical procedures.

The pterygopalatine ganglion in humans: a morphological study.

As a rule the pterygopalatine ganglion (PPG) is considered to be a single structure of the parasympathetic nervous system, associated with the maxillary nerve in the pterygopalatine fossa (PPF). A few structural studies in humans are available in the indexed references. We designed the present study of the PPG in order to provide evidence of possible variations in morphological patterns of the PPG. We performed dissections of the PPF on 20 human adult heads, using different approaches. The dissected specimens were stained with hematoxylin-eosin and silver (Bielschowsky) or prepared for immunohistochemistry for synaptophisin and neurofilament. Four morphological types of the PPG were defined macroscopically: A (10%): partitioned PPG, the upper partition receiving the vidian nerve; B (55%): single, the upper part (base) receiving the vidian nerve; C (15%): single, but the vidian nerve reaches the lower part (tip) of the ganglion; D (20%): partitioned, the lower partition receiving the vidian nerve. We propose that it may be inappropriate to invariably regard the PPG as a single morphological structure. From individual to individual the PPG may present either as a single ganglion or as a partitioned one, with distinct superior and inferior components. Nevertheless, the presence of the dispersed pterygopalatine microganglia (DPPG) evidenced by histochemistry and immunohistochemistry serves to complete an individually variable morphological pattern of a structure usually described as single. The individual variation may be the reason for failures in ablation procedures of the PPG; partitions of the PPG and/or the DPPG may functionally correlate with specific territories and targets and further tracing studies may be helpful in validating or invalidating this theory.

Details of the intralingual topography and morphology of the lingual nerve.

The lingual nerve supplies the tongue with trigeminal sensory fibers and sensory fibers that originate from the chorda tympani. The aim of this study was to investigate, by dissection, the anatomical features of the lingual nerve at the level of the tongue and to correlate the findings with existing data. Six human adult cadavers dissected bilaterally and 6 specimens of tongue-pharynx-larynx from autopsied adult cadavers were studied. The lingual nerve gives off its terminal branches at the anterior border of the hyoglossus muscle where the anastomotic loops between the lingual and hypoglossal nerves are found. Two morphological types of terminal division of the lingual nerve were seen: a single primary trunk or two primary trunks, a medial one distributed in the middle third of the tongue and a lateral one for the anterior third of the tongue. The primary terminal branches of the lingual nerve were located on the outer surface of the genioglossus muscle, forming a nervous layer over the deep artery of the tongue. The following emerged from the primary trunk(s): thin branches for the ipsilateral mucosa of the ventral surface of the tongue and 4-9 thick secondary trunks, with palisade disposition and translingual courses that followed the outer surface of the genioglossus muscle towards the dorsal mucosa of the ipsilateral part of the tongue, anterior to the circumvallate papillae.