CASE PRESENTATION
A 27 year old African male presented to the Department of Oral and Maxillofacial Surgery, University of Nairobi, Kenya, with spontaneous, severe pain of left mandible for 7 days. Intraoral examination revealed bilateral Angle’s class 2 molar relationship. The maxillary canines were missing (disimpactions performed 10 years ago) and carious lesions were present on 17 and 36 with both teeth being tender to percussion.
A panoramic radiograph revealed radiolucencies with probable pulpal involvement on the mesial aspect of 17 and 36. The maxillary third molars were impacted. Mandibular second and third molars (37, 38, 47, 48) were impacted bilaterally with their occlusal surfaces in contact and roots pointed in opposite directions (Figure 1). In order to evaluate the nature of the molar impaction, proximity to mandibular canal and bucco-lingual positioning within the mandible, a Cone-Beam Computed Tomography (CBCT) scan was performed (Figure 2-7). The imaging parameters were as follows: CS 8200 3D (12X10), Voltage, 90kV; exposure time, 10 s; current 5.0 mA; voxel size 150 microns.
A reconstructed panoramic was generated using CS Version 8 software. Tracking of the mandibular canal was done by applying the color tracer to the smallest slice thickness of 15 microns to illustrate the entire path of the canal in one view (Figure 2). Coronal sections confirmed contact between the mandibular canal and roots of 37 and 47. For reproducibility of measurements, only reference (main) orthogonal planes were examined in split views of 5x5, while oblique sections were only employed for visual illustration. Additionally, the distal roots of the 37 and 47 were 4.6 mm and 3.3 mm respectively from the inferior border of the mandible. (Figure 3 and 4). Thinning of the lingual cortex and paucity of cancellous bone lingual to the 37 and 47 was observed. Cortical perforation was however ruled out. Curved roots of second mandibular molars were noted which were in contact with the mandibular canal. (figure 3-6)
Axial sections of the maxilla imaging revealed three-rooted second maxillary premolars (15 and 25). Both had divergent mesiobuccal, distobuccal and palatal roots with corresponding root canals. (Figure 7) The patient was managed conservatively by endodontic treatment of the carious teeth (17 and 36). Due to the asymptomatic nature of presentation, he was advised on disimpaction of impacted maxillary molars while long term follow up was recommended for the KMs.