Position Statement

Zygomatic Implants

Position Statement of the American College of Prosthodontists
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Edentulism is a chronic disease associated with significant rates of morbidity and health issues.¹ It is estimated that 12 million Americans are completely edentulous and 36 million are edentulous in one jaw. Restoring the edentulous maxilla when adequate bone is present is well managed with conventional endosseous root form implants. The Oral Health Quality of Life index (OHQOL) is vastly improved when immediate prostheses are used, and patients prefer this approach when given the option.¹⁸ In a clinical scenario of severe maxillary osteomalacia, atrophy, surgical resection, or trauma, conventional implant placement may not be possible. The resorption of the maxilla in a posterior/superior direction results in a smaller osseous base that necessitates a larger volumetric replacement of the denoalveolar complex, presenting greater challenges to the team. The complications of sinus disease and enlarged pneumatized sinuses may create the need for multiple grafting procedures to develop suitable osseous tissue and may not present the most desirable pathway for patients.

Thus, the dental team is presented with two options: grafting versus graftless solutions. The “grafting approach” has advantages in that it is predictable,² the surgery is less complex, the patients have easier postoperative recuperations to endure, and implants tend to be where the final tooth alveolar envelope needs to be. The disadvantages are increased treatment time, multiple surgical procedures, morbidity of the donor site, and instability of the removable denture during the prolonged bone graft maturation period. When sinus elevations are used, the graft may be more palatal than the tooth position, immediate loading is generally not possible, and costs are usually higher.

The “graftless” option uses the zygomatic implant first introduced by Per-Ingvar Brånemark in 1988 and made available to the profession in 1998 after a decade of clinical use proved its viability.^3,4 The procedure is well documented in the literature with recent modifications to the surgical approach. The initial protocol involved the placement of two zygomatic implants and additional root form implants in the anterior maxilla splinted together supporting a screw-retained fixed dental prosthesis (FDP). This often resulted in implants placed medial to the alveolar ridge. Thus, the restoration was less than ideal for speech, hygiene, and comfort.

Recent protocols have evolved that use multiple zygoma implants in each zygoma.^5,6 A protocol has been established for the total rehabilitation of atrophic maxillae employing four zygomatic fixtures in an immediate loading system. The literature presents a 30-month clinical and radiographic follow-up. ^7,8 A new approach to rehabilitate the severely atrophic maxilla using extra-maxillary anchored implants in immediate function^9,10 enables the placement of an immediately loaded prosthesis without the requirement for anterior root form implants in some patients. The zygomatic implants will emerge within the tooth/alveolar envelope, thus yielding a more anatomically accurate prosthesis. The advantages are shortened treatment times, immediate placement of a fixed screw-retained interim prosthesis, potentially lower cost, and no need for adjunct grafting. Success rates for this approach are well documented.^11,12 There is an evidence-based prospective clinical study on titanium implants in the zygomatic arch for prosthetic rehabilitation of the atrophic edentulous maxilla with a follow-up of 6 months to 5 years.^13-16 A drawback to this approach is the potential loss of a zygomatic implant may result in partial or total prosthesis loss. The surgical procedure is also significantly more complex, and for patient comfort should be performed under general anesthesia. This often involves the need for an anesthesiologist.

It is the position of the American College of Prosthodontists that the use of the zygomatic implant in various clinical scenarios with multiple configurations enables the dental team to restore quality of life and gives patients an expedited and predictable option. 

References

1. Felton D: Complete edentulism and comorbid diseases: An update. J Prosthodont 2016;25:5-20

2. Keller EE, Tolman DE, Eckert SE: Maxillary antral-nasal inlay autogenous bone graft reconstruction of compromised maxillaw: A 12-year retrospective study. Int J Oral Maxillofac Implants 1999;14:707-721

3. Brånemark PI, Gröndahl K, Ohrnell LO, et al: Zygoma fixture in the management of advanced atrophy of the maxilla: technique and long-term results. Scand J Plast Reconstr Surg Hand Surg 2004;38:70-85

4. Branemark P-I: The Zygomatic Fixture: Clinical Procedures (ed 1). Gothenburg, Sweden, Nobel Biocare AB, 1998, p. 1

5. Balshi TJ, Wolfinger GJ, Petropoulos VC: Quadruple zygomatic implant support for retreatment of resorbed iliac crest bone graft transplant. Implant Dent 2003;12:47-53Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:817-826

6. Davo R, Pons O, Rojas J, et al: Immediate function of four zygomatic implants: a 1-year report of a prospective study. Eur J Oral Imp 2010;3:323-334

7. Duarte LR, Filho HN, Francischone CE, et al: The establishment of a protocol for the total rehabilitation of atrophic maxillae employing four zygomatic fixtures in an immediate loading system--a 30-month clinical and radiographic follow-up. Clin Implant Dent Relat Res 2007;9:186-196

8. Davo, Malevez C, Rojas J, Rodríguez J, et al: Clinical outcome of 42 patients treated with 81 immediately loaded zygomatic implants: a 12- to 42-month retrospective study. Eur J Oral Implantol 2008;1:141-150

9. Malo P, Nobre Mde A, Lopes I: A new approach to rehabilitate the severely atrophic maxilla using extramaxillary anchored implants in immediate function: A pilot study. J Prosthet Dent 2008;100:335-366

10. Aparicio C, Ouazzani W, Aparicio A, et al: Immediate/early loading of zygomatic implants: clinical experiences after 2 to 5 years of follow-up. Clin Implant Dent Relat Res 2010;12:e77-e82

11. Balshi SF, Wolfinger GJ, Balshi TJ: Retrospective analysis of 110 zygomatic implants in a single-stage immediate loading protocol. Int J Oral Maxillofac Implants 2009;24:335-341

12. Chrcanovic BR, Abreu MH: Survival and complications of zygomatic implants: a systematic review Oral Maxillofac Surg 2013;17:81-93

13. Aparicio C, Ouazzani W, Garcia R, et al: A prospective clinical study on titanium implants in the zygomatic arch for prosthetic rehabilitation of the atrophic edentulous maxilla with a follow-up of 6 months to 5 years. Clin Implant Dent Relat Res 2006;8:114-122

14. Kahnberg KE, Henry PJ, Hirsch JM, et al: Clinical evaluation of the zygoma implant: 3-year follow-up at 16 clinics.J Oral Maillofac Surg 2007;65:2033-2038

15. Parel SM, Brånemark PI, Ohrnell LO, et al: Remote implant anchorage for the rehabilitation of maxillary defects. J Prosthet Dent 2001;86:377-381

16. Bedrossian E, Rangert B, Stumpel L, et al: Immediate function with the zygomatic implant: a graftless solution for the patient with mild to advanced atrophy of the maxilla. Int J Oral Maxillofac Implants 2006;21:937-942

17. Davo R, Malevez C, Rojas J: Immediate function in the atrophic maxilla using zygomatic implants: a preliminary study. J Prosthet Dent 2007;97:S44-S51

18. Balshi TJ, Wolfinger GJ: Treatment of congenital ectodermal dysplasia with zygomatic implants: a case report. Int J Oral Maillofac Implants 2003;17:277-281

19. Dolz J, Silvestre FJ, Montero J: Changes in general and oral health-related quality of life in immediate or conventionally loaded dental implants: A nonrandomized clinical trial. Int J Oral Maxillofac Implants 2014;29:391-401