Infraorbital canal bilaterally replaced by a lateroantral canal

Abstract

The infraorbital canal (IOC) normally courses above the maxillary sinus in the orbit floor. During a retrospective study of cone beam computed tomography (CBCT) scans, we found a previously unknown variant of the IOC. The IOCs were absent, being replaced by lateroantral canals coursing around and not above the maxillary sinus to open at infraorbital foramina which were located above the second upper premolar teeth. On coronal multiplanar reconstructions, the lateroantral canals were located anatomically at the outer limit of the zygomatic recess of each maxillary sinus, while the upper wall of the sinus was devoid of any canal. Such rare variant should be kept in mind by dental practitioners and surgeons, as it can determine modifications of common procedures. In this regard, the anatomy of maxilla, as well as mandible, should be evaluated in CBCT on a case-by-case basis.

Variability in the number of infraorbital foramina in rhesus macaques (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis)

“…In textbooks, the direction of the canal, for needle insertion to ION blocking is simply described as being “cephalad” (Barash, Cullen, & Stoelting, 2001) or “laterally and cephalad” (Miller, 2000). Rusu, Săndulescu, and Ilie (2015) indicate an anterolateral trajectory of IOC. The direction of the course of AC2 in the present study is superomedially, IOC is very slightly superomedially while AC1 is anterolaterally.…”

Morphometric evaluation and surgical implications of the infraorbital groove, canal and foramen on cone-beam computed tomography and a review of literature

“…Von Arx et al [76] defined canalis sinuosus, as a tortuous bone channel originating from the IOC slightly posterior to the IOF and coursing in an anteromedial direction to the anterior wall of the nasal antrum below the orbital margin. Rusu et al [64] identified a case in which the IOC was absent and the lateroantral duct was present. In this study a very rare case was detected; IOC was divided into two canals in the maxillary sinus and the smaller one was directed to the lateral wall of the nasal cavity and opened to the inferior nasal meatus in front of the opening of the nasolacrimal duct (Fig.…”

Computed tomography evaluation of the morphometry and variations of the infraorbital canal relating to endoscopic surgery

“… 1 , 3 The lateroantral type that can determine modifications of common procedures should be kept in mind by dental surgeons preoperatively. 4 …”

“…We categorized the IOC corpus types according to the relationship with the maxillary sinus into four types as follows, which are based on the Ference et al 2 classification of the ION and Rusu et al 4 definition of the lateroantral type. IOC Type 1, within the maxillary bony roof ( Fig.…”