What Is the Ideal Criteria for Getting Dental Implants?
Dental implants are the best treatment rehabilitation modalities for missing teeth in today's dentistry field as well as in the modern and advancing field of implant dentistry and maxillofacial surgery. Dental implants can offer more reliability and efficiency, especially in terms of chewing, grinding, and speech compared to the traditional prosthetic rehabilitation strategies that were considered for most patients over the earlier decade like crown, bridge, or removable or cast partial dentures. However, not all patients can be suitable cases for getting dental implants because the inclusion criterion depends upon various local and patient systemic factors or health status that should be assessed by the implant dentist or surgeon preoperatively. Further, it is rather the anatomic planning, the exact implant position at the dental implantation site of the jaw, and restorative demands that pose greater challenges to the oral surgeon or implant dentist for the planning, execution, and surgical positioning of the dental implants.
What Are the Mandibular High-Risk Zones for Dental Implants?
Submandibular Fossa:
Of all the high-risk zones in implant dentistry, the most risky zone is the posterior region of the mandible or the lower jaw. This is because of the presence of the inferior alveolar nerve, an important innervating structure to the lower jaw that is bilaterally present. This zone close to the submandibular fossa is considered to be the particularly injurious operative zone that may cause possible operative as well as post-operative complications.
If one needs to get a dental implant in the lower jaw second or first molars region, a skilled implantologist (dental implant specialist), or a maxillofacial surgeon would definitely and even easily prepare the site for dental implantation and carry out the procedure successfully. However, even for the skilled operator, this zone of the submandibular fossa of the lower jaw poses some challenges during surgery. The care that should be firstly exercised by the dental implant specialist or operator in this region is to prevent any possible injury to the underlying neurovascular bundle close to the inferior alveolar nerve region.
The second precaution to be taken while preparing the implant site or during the osteotomy preparation is to prevent injury to an important structure making the great vascularity in the lower jaw, the lingual cortex. Any improper or uncautious manipulation of the dental surgical instrument at this site may result in the possible perforation of the lingual cortex. This is the major reason why the submandibular fossa that houses and is quite close to these multiple vital and vascular bone, and blood vessel structures is deemed the risky zone.
Current dental implant research also cautions the dental operator or the surgeon to be careful during surgical instrumentation at this region closer to the lingual cortex. This is because inadvertent risks that can be induced by surgical trauma can result in trauma to the local arteries in this region (arterial jaw trauma), and subsequently would lead to a hematoma (an abnormal collection of blood outside the blood vessels) formation. These hematomas would be operator or surgery induced at the lingual cortex region that would pose a major vascular and post-operative complication to the dental implant patient. The presence of a hematoma post-implant surgery is usually not common. However, when it occurs in the submandibular or sublingual spaces, it would bring many surgical cases likely to be a result of injury either to the aforementioned neurovascular bundle of the lower inferior alveolar jaw nerve or as a result of the perforation of the cortex in the lingual bone.
Posterior Lingual Concavity:
After the submandibular fossa region, the next high-risk zone is again in the lower jaw or mandible in the posterior lingual concavity (LC). This is a region where the mandibular fossa would tend to be at the deepest and is hence, called a concavity. The risk specifically to the anatomic structures of the lower jaw region can be particularly high in this region, not only through dental implantation that would cause a possible injury but even through other invasive surgical procedures, such as pericoronitis (infection of the gum around the wisdom teeth) or wisdom tooth or other molar tooth extractions, biopsies from the floor of the mouth, bone augmentation procedures, osseodistraction surgery (a surgical procedure to lengthen the mandible by gradually separating a bone segment, allowing new bone to fill the gap) of the mandible or lower jaw, osteoplasties, surgical and non-surgical treatments to reshape bone and treat severe gum disease, improving periodontal health. and deep periodontal therapies, lateral or onlay grafts for the lower jaw as in the case of reconstruction surgeries would all pose a possible risk of injury in this lingual concavity region, commonly referred to in dental literature and medicine as the posterior lingual depression or concavity.
Preventing Surgical Injuries:
Oral surgery experts warn not only of the possible dangers of sublingual (region under the tongue) or submandibular hematoma post-surgery which would be a difficult condition for the patient to deal with and for the operator to treat as well. However, current dental implant research also further warns operators to be cautious during instrumentation lest a surgical injury results in excessive bleeding from the afflicted site or even possible facial space infection from the jaw post-operatively.
Though preoperative evaluation with clinical palpation, the use of CBCT or computed cone beam tomography imaging in the maxillofacial regions, caliper used, and even dental cast analysis of the patient are certainly some of the strategies that can help prevent these surgical risks, all these techniques still have fair limitations along with their pros or benefits. Therefore, with the advent of computer-guided surgical templates that are preoperatively planned by the implant dentist and with the efficient visualization of the lower jaw anatomy through CBCT, many of these surgical risks in high-risk implant zones can be prevented by the dental operator.
Conclusion
Hence, high-risk zones for dental implants in the lower jaw region need perspective by the oral surgeon. These are complications that need to be understood in detail by the implant surgeon and they must prevent it by adopting a thorough preoperative evaluation of the dental site of implantation.
