Introduction
Zygomatic implants are a type of dental implant used to support a dental prosthesis in patients with severe bone loss in the upper jaw. Unlike traditional dental implants, which are anchored into the jawbone, zygomatic implants are anchored into the zygomatic bone, which is denser and provides a more stable foundation. Zygomatic implants were first introduced in the late 1990s by Dr. Per Ingvar Brånemark, widely acknowledged as the “Father of Dental Implantology”. For cases of severe maxillary atrophy, zygomatic implants provide an effective and predictable implant supported dental rehabilitation without the need for bone augmentation, such as sinus augmentation or guided bone regeneration.
Patient selection
Selecting an appropriate case for this procedure is very important. The patient should be evaluated with a full history and physical examination to ensure they are an appropriate candidate for the procedure. The indications for this procedure include severe maxillary atrophy. Patients unwilling or unable to tolerate multiple procedures are good candidates for this procedure. Along with this, patients seeking an immediately loaded fixed prosthesis are treated with zygomatic implants. Interdisciplinary consultation and planning between an oral and maxillofacial surgeon and prosthodontist or general dentist is crucial. Cone-beam computed tomography (CBCT) is recommended for preoperative evaluation to evaluate the distance from the alveolar ridge to zygoma body to obtain an estimate for implant sizes to evaluate the quality and quantity of the zygomatic bone available. A minimum of 7 mm of anchorage into the zygoma is required for stability of zygomatic implants, with a greater amount required if 2 implants are to be placed.
Advantages
Immediate Function: Often, the prosthesis can be attached on the same day as the implant placement, allowing for immediate function.
Avoidance of Bone Grafts: They eliminate the need for bone grafting procedures, which can be more invasive and require longer healing times.
High Success Rates: Studies have shown high success rates for zygomatic implants, making them a reliable option for patients with severe bone loss.
Techniques for placing zygomatic implants
1. Intra-sinus Approach (Caldwell-Luc Approach)
This technique involves creating an access window in the lateral wall of the maxillary sinus. The implant is then placed through the sinus cavity into the zygomatic bone. The primary advantage of this procedure is that it provides good visualization and access to the zygomatic bone. On the other hand, its primary disadvantage is increased risk of sinus complications and requiring precise handling to avoid damage to the sinus membrane.
2. Extra-sinus Approach
In this technique, the implant is placed outside the maxillary sinus, avoiding the sinus cavity entirely. This approach often involves drilling a hole through the alveolar crest and positioning the implant along the lateral wall of the maxilla and into the zygomatic bone. Ideally, the implant should be placed as distally as possible, preferably in the second premolar or first molar region. The advantage of this procedure is reduced risk of sinus complications, potentially less invasive. However, the procedure requires careful planning and precise execution to ensure proper implant alignment and stability. This technique is particularly useful for patients with advanced buccal concavities in the posterior maxilla, where bulky ridges can cause discomfort.
3. Palatal Approach
In this procedure, the implant is placed from the palatal side of the maxilla, angling towards the zygomatic bone. This approach is often used when there is severe bone loss in the maxilla. The procedure avoids the sinus cavity, suitable for patients with severe maxillary atrophy. However, it is more technically challenging due to the anatomical considerations of the palatal area.
4. Slot Technique
This technique involves creating a slot in the lateral wall of the maxilla where the implant will be placed. The implant is then angled and inserted into the zygomatic bone. It provides a stable path for implant placement, minimizes sinus involvement. The procedure requires precise planning and surgical skill to ensure proper slot creation and implant placement.
5. Hybrid Technique
This procedure combines elements of intra-sinus and extra-sinus techniques. Implants may be placed with varying angulations to optimize bone engagement and prosthetic support. The advantage of this technique is flexibility in approach, can be tailored to individual patient’s anatomical needs. However, it is a complex procedure and requires advanced surgical expertise.
Complications associated with zygomatic implant placement
While zygomatic implants offer a solution for patients with severe bone loss in the upper jaw, there are potential complications associated with the procedure. These complications can be categorized into immediate, early, and late complications:
Immediate Complications
Hemorrhage: Excessive bleeding during surgery, which can occur due to the rich blood supply in the facial region.
Injury to Adjacent Structures: Potential damage to the infraorbital nerve, resulting in temporary or permanent numbness or altered sensation in the cheek and upper lip.
Early Complications
Sinusitis: Inflammation or infection of the maxillary sinus can occur, particularly if the implant perforates the sinus membrane or is placed through the sinus.
Infection: Post-operative infection at the surgical site can lead to pain, swelling, and implant failure.
Swelling and Bruising: Post-operative swelling and bruising are common and typically subside within a few days to weeks.
Pain and Discomfort: Pain and discomfort are expected after the surgery, which can be managed with prescribed pain medications.
Late Complications
Implant Failure: Although rare, implant failure can occur if the implant does not integrate properly with the bone or if there is persistent infection or mechanical overload.
Chronic Sinusitis: Persistent or recurrent sinus infections may occur if the implant continuously irritates or perforates the sinus membrane.
Prosthetic Complications: Issues related to the dental prosthesis, such as loosening, breakage, or misalignment, can occur and may require adjustments or replacements.
Soft Tissue Complications: Ulceration, inflammation, or recession of the soft tissues around the implant can occur, leading to discomfort and aesthetic concerns.
How to avoid complication associated with zygomatic implant placement
Pre-surgical Planning: Thorough pre-surgical evaluation and planning using CBCT scans and digital planning software to assess anatomy and plan implant placement accurately.
Surgical Expertise: Ensuring the procedure is performed by an experienced oral and maxillofacial surgeon or a periodontist specialized in implantology.
Aseptic Technique: Adhering to strict aseptic techniques to minimize the risk of infection.
Post-operative Care: Following post-operative care instructions meticulously, including maintaining oral hygiene, taking prescribed medications, and attending follow-up appointments.
Patient Selection: Careful selection of suitable candidates for zygomatic implants, considering factors such as overall health, bone quality, and absence of contraindications like active sinus infections.
Conclusion
Zygomatic implants are a reliable and predictable long-term solution for patients with severe maxillary bone loss. The choice of technique for placing zygomatic implants depends on the patient’s specific anatomy, the extent of bone loss, and the surgeon’s expertise. It’s crucial to work with a skilled and experienced surgeon who can determine the most appropriate approach for your individual case. While complications can occur, with proper planning, surgical expertise, and post-operative care, the risks can be minimized, and successful outcomes can be achieved. The long-term predictability of zygomatic implants is generally favorable, with many studies and clinical reports indicating high success rates and stable outcomes over extended periods. However, like any medical procedure, outcomes can vary based on multiple factors, including the patient’s health, the skill of the surgeon, and adherence to post-operative care.
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