Quad Zygoma Protocol

A fully digital planning protocol for dynamic computer-assisted zygomatic implant surgery based on virtual surgery simulation: A dental technique

Dynamic navigation-guided zygomatic implant (ZI) surgery has been a preferred option for achieving optimal prosthetic-driven implant placement. However, during the actual surgical procedure, surgical execution may still be hindered by environmental factors such as mouth opening. A fully digital planning protocol is described that integrated the patient's maxillofacial soft tissue information and virtual surgical handpiece with the drills on the implant planning path to ensure the precise, time-saving, and smooth implementation of dynamic navigation-guided ZI surgery.

Long-term survival and complications of Quad Zygoma Protocol with Anatomy-Guided Approach in severely atrophic maxilla: A retrospective follow-up analysis of up to 17 years

INTRODUCTION

The objective of the study was to provide long-term clinical outcomes and complications in the severely atrophic edentulous maxillae treated by means of the quad zygoma protocol (QZP) using the Anatomy-Guided Approach (AGA).

METHODS

This was a retrospective cohort study of all consecutive patients with severely atrophic edentulous maxilla and insufficient bone height and width in the anterior and posterior regions bilaterally, who underwent rehabilitation with the QZP between May 2006 and December 2021. All patients were followed for at least 1 year. All zygomatic implants (ZIs) were placed by the same surgeon. The primary endpoint of the study was the implant survival rate. Secondary endpoints were implant success rate, prosthesis success rate, complications, and Oral Health-Related Quality of Life using the OHIP-14 questionnaire.

RESULTS

A total of 56 patients (men 16, women 40) with 224 ZIs (Nobel Biocare, n = 204; Straumann, n = 16; Southern Implant, n = 4) placement were included with a mean follow-up period 8.8 ± 3.9 years (range, 1.2-17.0). The survival (success) rate was 97.7%. Five ZIs in four patients failed. The mean time between implant placement and failure was 8.6 years (range, 0.5-13.3). All patients received immediate loading with acrylic prosthesis. The successful rates for the definitive prosthesis were 98.2%. Forty-two patients received posterior cantilever for rehabilitation of fixed definitive prosthesis. Local orofacial inflammation (35.7%) and Sinusitis (12.5%) were the most common complications, occurring at a mean follow-up of 10.0 (range, 4.2-14.9) and 10.3 (range, 4.3-16.2) years, respectively. In 48 patients, the mean score of the OHIP-14 questionnaire was 1.7 ± 2.6 with the follow-up period of 9.0 ± 4.1 years.

CONCLUSIONS

The rehabilitation of severely atrophic edentulous maxilla using the QZP has shown a predictable and high survival rate in the long term. The implementation of an immediate loading protocol offers potential benefits in stabilizing ZIs with cross-arch stabilization. Moreover, the use of a posterior cantilever in reconstruction can effectively establish functional occlusion through well-distributed ZIs, eliminating the need for additional implant placement.

Treatment of Severely Atrophic Maxilla by Using Zygomatic, Pterygoid, and Transnasal Implants

For many decades the success of dental implants has been considered to be dependent predominantly on the quality and quantity of the patient's alveolar bone. Grafting procedures have been commonly used to rehabilitate severely atrophic jaws but these procedures have disadvantages such as long treatment duration, major surgery, the risk of morbidity in the donor area, and high treatment costs. Recently, the use of 4 zygomatic implants has become an important treatment option in the rehabilitation of extremely atrophic maxilla. The quad zygoma technique is a method applied in cases where conventional implants cannot be used in the anterior maxilla. However, the technique has some difficulties and requires surgical experience. An alternative to the use of quad zygomatic implants is the placement of transnasal with zygomatic implants and subperiosteal implants. The aim of this case report was to present the treatment of a patient with severely atrophic maxilla with zygomatic, pterygoid, and transnasal implants.

Influence of Prosthodontic Rehabilitation Using Zygomatic Implants in Covid 19 Related Mucormycosis (Rhino-Orbital-Cerebral) Maxillectomy Patients Upon Post-Operative Stress, Anxiety and Functional Impairment: A Prospective Cohort Study

Purpose

To determine the influence of prosthodontic rehabilitation using zygomatic implants in partial maxillectomy upon post-operative stress, anxiety and functional impairment, due to covid 19 associated rhino-orbital-cerebral mucormycosis (ROCM).

Patients and Methods

Twenty maxillectomy patients fulfilling study criterion, received zygomatic implants (ZI) (quad zygoma) (ZDI Simpladent, Switzerland) retained/supported complete maxillary denture. Assessment of stress, anxiety, masticatory performance and speech were determined using diurnal salivary cortisol level, Appearance Anxiety Inventory, multiple sieve technique and auditory perception analysis, respectively. Data were recorded at 6 different stages of rehabilitation (after maxillectomy, implant placement, and after prosthesis delivery (1 week, 1 month, 6 months and 1 year)). Demographic data were expressed as frequency distribution, while mean values were used to find differences between various rehabilitation stages using Friedman and chi-square test with statistical significance value at p < 0.05.

Results

Average daily salivary cortisol levels declined from post maxillectomy (22.80 ± 0.902) to 1 year after prosthesis wearing (8.65 ± 0.985), indicating stress reduction after ZI rehabilitation. Mean scores for appearance anxiety reduced from pre-prosthetic rehabilitation (27.350 ± 3.030) to 1 year (8.950 ± 0.887) following prosthesis wearing. Functional parameters for mastication and speech also improved significantly during the course of rehabilitation. All differences between pre-prosthetic to 1-year stage after prosthesis wearing were found to be statistically significant at p < 0.05.

Conclusion

Post ROCM maxillectomy cases after prosthetic rehabilitation using zygomatic implants showed significant improvement in the psychological (stress and anxiety) as well as function (mastication and speech) characteristics. Rehabilitation post ROCM maxillectomy with the present approach of fixed prosthesis using zygomatic implants mitigates deficient mastication and speech. It also impacts positively on patient psychology by decreasing stress and anxiety.