▋ Introduction

Cleft lip and palate is a common congenital craniofacial anomaly, often associated with congenital tooth agenesis, malocclusion, and extensive maxillary bone defects.

For these patients, full-arch maxillary implant rehabilitation frequently requires extensive bone grafting procedures. Compared to conventional bone grafting with implant placement, zygomatic implants provide a faster and less invasive treatment alternative.

▋ Case Presentation

This case involves a 41-year-old female patient who presented to our clinic seeking maxillary full-arch reconstruction due to severe periodontal disease.

Her medical history revealed prior cleft lip and palate repair and a Le Fort I osteotomy. She has hypothyroidism, currently well controlled with medication. She denied any history of bisphosphonate or steroid use, as well as smoking or bruxism.

▋ Patient Condition

Intraoral examination revealed not only severe maxillary bone defects but also compromised bone healing following the previous Le Fort I osteotomy. This resulted in insufficient bilateral alveolar bone support for occlusal loading.

After discussion, the patient opted for rehabilitation using four zygomatic implants to reduce treatment time and avoid extensive bone grafting.

Clinical photographs showed ill-fitting anterior prostheses, generalized periodontal disease, and scar tissue from previous cleft repair.

▋ Diagnosis and Treatment Planning

Panoramic radiography demonstrated generalized severe periodontal disease with extensive maxillary bone resorption, along with previously placed L-shaped plates and screws from orthognathic surgery.

Cone-beam computed tomography (CBCT) revealed congenital defects of the maxillary alveolar bone and hard palate due to cleft deformity, resulting in poor structural continuity among the alveolar bone, zygomatic bone, and nasal bone.

Additionally, poor bone healing after the Le Fort I osteotomy compromised the three primary maxillary load-bearing buttresses: the canine buttress, zygomatic buttress, and pterygoid buttress. As a result, the bilateral maxillary alveolar bone was nearly unsupported.

▋ Zygomatic Implant Treatment Design

Conventional implant placement combined with bone grafting would likely result in insufficient stability in this case.

For large-scale and stable reconstruction, options such as free fibula flap reconstruction may be considered to provide adequate hard and soft tissue support.

Therefore, a treatment plan utilizing four zygomatic implants for maxillary reconstruction was established.

▋ Surgical Procedure and Technique

Due to incomplete healing in the anterior cleft region, the soft tissue in this area was preserved during surgery. Only the alveolar ridge flaps along the zygomatic implant trajectory were elevated to minimize the risk of creating an oro-nasal communication.

To avoid interference with implant placement, part of the previously placed titanium screws and L-shaped plates from the Le Fort I osteotomy were removed.

Four zygomatic implants were then successfully placed in the maxilla.

▋ Postoperative Follow-up

A provisional full-arch fixed prosthesis was delivered within two weeks postoperatively. The definitive prosthesis was completed within one year, during which occlusal discrepancies were corrected.

At 4.5 years of follow-up, the implants remained stable with successful osseointegration. The patient demonstrated good occlusal function and oral hygiene.

▋ Conclusion

Patients with extensive maxillary defects due to congenital conditions or tumor resection have historically posed significant challenges for full-arch implant rehabilitation. Traditional approaches often require bone harvesting from other anatomical sites, such as the iliac crest or even free fibula flaps. These procedures are extensive and demanding for both patients and clinicians.

The All-on-4 concept provides an alternative solution for full-arch reconstruction, offering improved function for such patients. However, due to the variability and extent of maxillary defects, treatment planning remains complex.

Each case requires individualized implant design and strategic planning to achieve optimal functional outcomes. In future reports, additional cases of full-arch reconstruction in special patient populations will be presented.