RADIOLOGIC ANATOMY R. Jacobs N. Mraiwa D. van Steenberghe G. Sanderink M. Quirynen Appearance of the mandibular incisive canal on panoramic radiographs Received: 3 September 2003 / Accepted: 7 February 2004 / Published online: 10 June 2004 Ó Springer-Verlag 2004 Abstract Panoramic radiographs are routinely used in the dental office for various diagnostic purposes. This study aimed to evaluate the visibility of neurovascular structures in the mandibular interforaminal region on such radiographs. Panoramic radiographs were obtained with a Cranex Tome (Soredex) from 545 consecutive patients using a standard exposure and positioning protocol. For visibility scoring of neurovascular struc- tures, a four-point rating scale was used. The mandib- ular canal and the mental foramen could be observed in the majority of the cases with good visibility. The lingual foramen was visualized in 71% of the cases, with good visibility in 12%. An incisive canal was identified in 15% of the images, with good visibility in only 1%. An anatomical variation to be considered is the anterior looping of the mental nerve (in 11% of images). Pano- ramic radiographs can be used for visualization of the mental foramen and a potential anterior looping but not for locating the mandibular incisive canal. To verify its existence for preoperative planning purposes, cross- sectional imaging modalities (HR-CT or spiral tomog- raphy) should be preferred. Keywords Incisive nerve Panoramic radiography Mandible Osseointegration Preoperative planning Introduction Nowadays, panoramic radiography is often used in dental practice, because it provides visibility of ana- tomical structures in pathological changes of the teeth, jaws and temporomandibular joints. However, a pano- ramic radiograph is a two-dimensional (2D) image, lacking information in the bucco-lingual direction and magnifying in both vertical and horizontal directions. It has been shown that cross-sectional imaging (e.g. con- ventional spiral tomography or spiral CT) offers a better alternative for the precise visualization of anatomical structures in the oral region [3, 4, 7, 8, 16, 17]. Never- theless, the fact that panoramic imaging is widely used for evaluation of the jaws, justifies the interest in determining the visibility of anatomical structures on these films. Several reports have studied the delineation of the mandibular canal and/or the mental foramen as visual- ized on panoramic images [11, 12, 22]. The visibility of the mandibular incisive canal on panoramic images, however, is poorly documented [13, 16]. The presence of a neurovascular bundle in the interforaminal region may present some risks during surgery and therefore a pre- operative radiographic identification is considered of utmost importance [7]. In addition, anatomical varia- tions may occur, including the occurrence of multiple mental foramina [19, 20], mandibular incisive foramen [21], anterior looping of the mental nerve [1, 13], absence of the mandibular canal with agenesis of teeth on that side [9, 10] and absence of mental foramina [5]. The overall aim of the present study was to evaluate the visibility of the incisive canal and other anatomical R. Jacobs (&) N. Mraiwa Oral Imaging Center, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium E-mail: reinhilde.Jacobs@uz.kuleuven.ac.be Tel.: +32-16-332410 Fax: +32-16-332484 R. Jacobs N. Mraiwa D. van Steenberghe M. Quirynen Department of Periodontology, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium D. van Steenberghe M. Quirynen Department of Anatomy, Faculty of Medicine, Katholieke Universiteit Leuven, Minderbroedersstraat 12, 3000 Leuven, Belgium G. Sanderink Department of Oral Radiology, Academic Center for Dentistry, Amsterdam, The Netherlands Surg Radiol Anat (2004) 26: 329–333 DOI 10.1007/s00276-004-0242-2