Frequency and Characterization of the Infratemporal Spine in a Sample of Chilean Human Skulls

Abstract

CÁCERES, F.; PEDEMONTE, M. E.; CERDA, V. & SOTO, R.Frequency and characterization of the infratemporal spine in a sample of Chilean human skulls. Int. J. Morphol., 34(4):1414Morphol., 34(4): -1418Morphol., 34(4): , 2016. SUMMARY:The infratemporal spine, or sphenoidal tubercle, is a bony structure described in both classical anatomical literature and contemporary literature. However, the available literature does not mention the specific anatomical characteristics or the distribution of this bony element in the population. The aim of this study was to define this structure, identify its presence, and identify its morphology in a sample of Chilean human skulls. Fifty-seven dry skulls, obtained from the morphology unit at Universidad de los Andes, were used. The great wings of the sphenoid bone on both sides of the skull were evaluated in search of the infratemporal spine. These spines were classified according to their morphological characteristics of either laminar, pyramidal, or truncated pyramidal, as they related to the infratemporal crest and as they related to the pterygoid process. The presence of the infratemporal spine was found in 100 % of the studied skulls, unilaterally or bilaterally. The most common morphology was found to be laminar (40 %), followed by pyramidal (35 %), and, finally, truncated pyramidal (24 %). The majority (73 %) of these infratemporal spines was closely associated with the pterigoyd process with a complete or partial relation, with fewer (34 %) being associated with the infratemporal crest.

Bilateral giant and unilateral duplicated sphenoidal tubercle

“…The SphT could appear isolated from the infratemporal crest, which is different of the classical textbooks definition [3].…”

“…The sphenoidal tubercle (SphT) or infratemporal spine is a bony prominence located at the anterior end of the infratemporal crest of the greater sphenoidal wing [3], which is different of the sphenoidal spine located posteriorly [20]. The SphT was also described as a retroorbital "pyramidal process" and was observed to have three surfaces, anterior, posterior and lateral [7].…”

“…The SphT was also described as a retroorbital "pyramidal process" and was observed to have three surfaces, anterior, posterior and lateral [7]. However, several morphologies of the SphT were described in a dry bones study: pyramidal, truncated pyramidal, smooth laminar, spiniform laminar and irregular laminar [3]. The spiniform type was the most frequent in a lot of 304 skulls [1].…”

“…The infratemporal crest separates the temporal and infratemporal surfaces of the greater wing and attaches either fibres of temporal muscle or the lateral pterygoid muscle [18]. The respective deep portion of the temporal muscle was either indicated as sphenomandibular fascicle [3], or it was described as an individual structure, the sphenomandibular muscle, distinct from the overlying temporalis muscle [8]. This muscle fascicle could compress the maxillary nerve to trigger orofacial pain [3].…”

“…The respective deep portion of the temporal muscle was either indicated as sphenomandibular fascicle [3], or it was described as an individual structure, the sphenomandibular muscle, distinct from the overlying temporalis muscle [8]. This muscle fascicle could compress the maxillary nerve to trigger orofacial pain [3]. The inconstant pterygoideus proprius muscle of Henle could also originate from the infratemporal crest to insert either on the tuber palati, or on the lateral pterygoid plate [24].…”