Retrospective assessment of dental implant-related perforations of relevant anatomical structures and inadequate spacing between implants/teeth using cone-beam computed tomography
Dental implants are quickly becoming the preferred method of replacing missing teeth. With a remarkably high success rate, why wouldn’t it be? However, what about the implants that fail or cause other complications associated with placement? A reported cause of implant failure is implant-related perforations. In a recent retrospective study published in January 2020 in Clinical Oral Investigations, the authors assessed the prevalence of dental implant-related perforations of relevant anatomical structures.1
The most common cause of esthetic and biomechanical damage involves malposition or abnormal angulation. A poorly placed implant may lead to injuries to anatomical structures, such as perforation of the mandibular canal, maxillary sinus membrane, nasal cavity floor, roots of adjacent teeth, and buccal or lingual cortical bone.
To avoid these issues, well planned pre-surgical placement should be determined via cone-beam computed tomography (CBCT). Additionally, it is the position of the American Academy of Oral and Maxillofacial Radiology that postoperative assessment with CBCT for patients presenting with implant mobility or altered sensation. This is especially important for posterior mandibular implants that present in this manner.
The study assessed 1109 implants, 330 were in the anterior maxilla, 426 in the posterior maxilla, 91 in the anterior mandible, and 262 in the posterior mandible. Of the implants assessed nearly one-third perforated anatomical structures, and one-fifth had inadequate spacing between adjacent tooth/implant. The prevalence of perforated anatomical structures was substantially higher in the maxilla (43.5%) compared with the mandible (11.3%). Previous studies have found the same issue with higher prevalence in the maxilla as compared to the mandible.
The relationship between maxillary sinus perforation and implant failure rate is controversial, however, sinus perforation can lead to chronic sinusitis and other complications. The most common perforation found in the mandible was the mandibular canal. This perforation is associated with inadequate pre-surgical planning. Complications of mandibular canal perforation range from a painless loss of sensation to severe and permanent pain.
Other perforations that were less common in this study– but can have significant consequences– are nasal cavity perforations which can reduce airflow, adjacent tooth root which can lead to endodontic lesions, and buccal cortical plate which can lead to peri-implantitis and implant loss. The most concerning of these fewer common perforations is that of the lingual cortical plate of the mandible. This perforation has the potential to develop life-threatening conditions, such as floor of the mouth hematoma with airway obstruction.
The results indicated that implants perforating an adjacent structure presented with a higher prevalence of thread exposure. Thread exposure in the posterior has been linked to higher implant failure rates due to greater masticatory load and insufficient bone height. Additionally, implants placed too close to adjacent teeth/implants lea
d to individual bone loss and horizontal bone collapse leading to thread exposure.
Adequate pre-surgical planning and utilization of imaging devices, like CBCT has the potential to greatly reduce malposition or abnormal angulation avoiding future complications. Image-guided surgery methods are associated with higher accuracy for correct positioning.
The authors note, despite the large sample size, the results should be interpreted with caution due to the absence of clinical information, including preoperative planning, intra- and postoperatively complications, and patients’ symptomatology.
The authors conclude by saying “both implant-related perforations of relevant anatomical structures and inadequate spacing between implants and adjacent teeth/implants are relatively more common in the maxilla and are associated with implant thread exposure.”
Have you seen implant failures as a direct result of implant-related perforations? Have you seen complications that did not necessarily end in implant failure due to implant-related perforations? Does your practice have a CBCT device on the premises? Does your practice utilize image-guided implant surgery?
1. Gaêta-Araujo H, Oliveira-Santos N, Mancini AXM, Oliveira ML, Oliveira-Santos C. Retrospective assessment of dental implant-related perforations of relevant anatomical structures and inadequate spacing between implants/teeth using cone-beam computed tomography [published online ahead of print, 2020 Jan 20]. Clin Oral Investig. 2020;10.1007/s00784-020-03205-8. doi:10.1007/s00784-020-03205-8