Background and Rationale The rehabilitation of the severely atrophied maxilla utilizing zygomatic implants is a highly predictable and effective treatment modality. However, managing the peri-implant soft tissue in these complex cases remains a significant clinical challenge. Because zygomatic implants frequently emerge through thin, non-keratinized, and mobile alveolar mucosa rather than thick, attached gingiva, the peri-implant environment is highly susceptible to complications. Inadequate soft tissue thickness can lead to mucosal recession, exposure of the implant collar, plaque accumulation, and ultimately peri-implantitis, which threatens the long-term success of the prosthesis.

To mitigate these risks and achieve an optimal permucosal seal, soft tissue augmentation is often required. Vascularized soft tissue grafts are preferred in these compromised anatomical sites due to their robust blood supply and enhanced healing capacity. The Buccal Fat Pad (BFP) flap is a well-documented and frequently utilized technique for this purpose; however, its volume can be unpredictable, and it may be unavailable due to prior surgeries or anatomical deficiencies. Therefore, evaluating robust alternatives, such as the Palatal Pedicle Flap (PPF)-which utilizes the thick, keratinized palatal mucosa-is critical for optimizing surgical outcomes.

Study Design and Methodology This study is structured as a prospective, randomized controlled clinical trial utilizing a split-mouth design. The split-mouth approach is strategically chosen to eliminate inter-subject biological and immunological variability, allowing each patient to effectively serve as their own control. Patients presenting with a severely resorbed maxilla requiring bilateral zygomatic implant placement will be enrolled.

Following successful implant placement, the right and left maxillary quadrants will be randomized. One side will be assigned to receive soft tissue augmentation using the standard Buccal Fat Pad (BFP) flap, while the contralateral side will be assigned to receive the Palatal Pedicle Flap (PPF).

Surgical Intervention Overview All surgical procedures will be performed under appropriate anesthesia following standard sterile protocols.

For the BFP side: The buccal fat pad will be accessed via a vestibular mucosal incision, carefully bluntly dissected, mobilized, and advanced over the zygomatic implant collar without tension.

For the PPF side: A palatal pedicle flap will be meticulously outlined, elevated with its vascular supply intact, rotated, and adapted around the contralateral implant collar.

Both flaps will be secured using appropriate resorbable sutures to ensure tension-free primary closure and optimal tissue adaptation around the implant abutment interface. Post-operative care will adhere to standard institutional guidelines, including the prescription of appropriate analgesics, antibiotics, and antimicrobial mouth rinses.

Clinical Significance By systematically comparing the healing trajectories, tissue stability, and functional outcomes of the BFP and PPF techniques over a 6-month period, this trial aims to provide definitive, evidence-based guidance for soft tissue management in zygomatic implantology. Furthermore, it seeks to validate the PPF as a reliable and predictable reconstructive alternative in clinical scenarios where the buccal fat pad is deemed insufficient or inaccessible.

Inclusion Criteria:

Patients ≥18 years with severely atrophic maxilla.

• Acquired maxillary defects resulting from trauma, pathology, or previous surgical resection.
• Indicated for zygomatic implant-supported fixed prosthesis.
• Sufficient mouth opening for zygomatic implants placement.
• Patients willing to sign informed consent and attend follow-ups.

Exclusion Criteria:

• Uncontrolled systemic disease affecting healing (e.g., uncontrolled diabetes, etc).
• Heavy smokers
• Previous radiotherapy or bisphosphonate therapy.
• Active sinus or nasal infection.
• Severe parafunctional habits (e.g., bruxism).
• Pregnant or lactating women.
• Patients with psychiatric disorders affecting compliance.