Pterygoid Implants: Anatomy, Indications, Placement and Protocols

Pterygoid implants are long dental implants placed through the maxillary tuberosity and anchored in the dense bone of the pterygomaxillary region, where the maxilla meets the pterygoid process of the sphenoid bone. They give posterior support to fixed full-arch and partial restorations in an atrophic posterior maxilla, without sinus augmentation or bone grafting.

For patients with severe posterior bone loss and sinus pneumatization, pterygoid implants extend the implant-supported arch back to the second-molar region. They reduce or eliminate distal cantilevers, and they often avoid the morbidity and treatment time of grafting. This guide covers the anatomy, case selection, placement principles, prosthetic integration and risk management that clinicians should understand before adding pterygoid implants to their full-arch protocols.

Why Pterygoid Implants Exist

The posterior maxilla is often the most difficult site in the mouth for implants. After tooth loss, alveolar resorption and sinus pneumatization leave little vertical bone below the sinus floor, and the remaining bone is usually low-density. Clinicians traditionally have four options: sinus floor augmentation, short implants, tilted implants that end mesial to the sinus, or accepting a distal cantilever on the prosthesis.

Pterygoid implants offer a fifth option. They bypass the deficient alveolar bone entirely and engage the cortical bone behind the maxillary sinus. This places an implant at the far distal end of the arch, which matters biomechanically: a terminal implant at the second-molar position shortens or removes the cantilever and spreads occlusal load across a wider anteroposterior spread.

Pterygomaxillary Anatomy

The Pterygomaxillary Region

The pterygomaxillary region is where three bones meet. The maxillary tuberosity forms the posterior end of the maxilla. Behind it sits the pyramidal process of the palatine bone. The pterygoid process of the sphenoid bone rises superiorly and posteriorly. A pterygoid implant passes from the tuberosity, through the pyramidal process, into the pterygoid process.

The Pterygoid Plates

The pterygoid process divides into the medial and lateral pterygoid plates, separated by the pterygoid fossa. These plates are dense cortical bone. Engaging them is what gives a pterygoid implant its primary stability, even when the tuberosity bone around the implant's coronal portion is soft.

Tuberosity, Pterygomaxillary and Pterygoid Implants

The literature uses these terms loosely. It helps to separate them by where the apex ends:

• Tuberosity implants are confined to the maxillary tuberosity.
• Pterygomaxillary implants engage the tuberosity and the pyramidal process of the palatine bone.
• Pterygoid implants continue into the pterygoid process of the sphenoid and engage the pterygoid plates.

Structures at Risk

Superior and posterior to the pterygoid plates lies the pterygopalatine fossa, which contains the internal maxillary artery and its branches. The descending (greater) palatine artery runs through the greater palatine canal medial to the implant path, and the pterygoid venous plexus lies laterally. Trajectory control is primarily about staying within bone and away from these structures. That is why CBCT-based planning is essential.

Indications and Case Selection

Typical Indications

• Atrophic posterior maxilla where conventional implants cannot be placed without sinus augmentation
• Full-arch rehabilitation where a distal implant is needed to reduce or eliminate a posterior cantilever
• Patients who are not candidates for grafting, or who prefer to avoid it
• Adjunct posterior anchorage in hybrid protocols with conventional, tilted or zygomatic implants

Contraindications and Cautions

• Limited mouth opening that prevents straight-line access to the tuberosity
• Pathology, unfavorable anatomy or insufficient bone along the planned path on CBCT
• General medical contraindications to implant surgery, including uncontrolled systemic disease
• Operator inexperience. Pterygoid placement is largely tactile and blind to direct vision, so it should be learned under supervision.

Pterygoid Implant Placement: Principles

Planning

Plan every pterygoid implant on CBCT. Assess bone density and height at the tuberosity, the path through the pyramidal process, the position and thickness of the pterygoid plates, and the distance to the pterygopalatine fossa. Planning software lets you simulate implant length and angulation. Guided or navigated surgery can add control in difficult anatomy.

Trajectory and Angulation

The implant enters at the tuberosity and runs in an oblique, posterior and superior direction toward the pyramidal process and pterygoid plates. Published descriptions place pterygoid implants at roughly 45°–60° to the maxillary plane (Balaji et al., 2017), with a mild mesial or palatal inclination depending on anatomy. Because the implant is steeply angled, the prosthetic connection almost always needs an angled multi-unit abutment to restore a usable path of insertion.

Osteotomy and Insertion

Follow the manufacturer's drilling sequence in the IFU. In practice, clinicians use the change in resistance as the drill or implant moves from the softer tuberosity into the cortical pterygoid plate as tactile confirmation of engagement. Primary stability comes from that apical cortical engagement. Long implants are therefore typical, commonly in the 15–20+ mm range, depending on anatomy.

Loading

When primary stability and cross-arch splinting meet IFU criteria, pterygoid implants are often included in immediate-loading full-arch protocols. When stability is uncertain, delayed loading remains the conservative choice.

Prosthetic Integration

• Angled multi-unit abutments bring the access channel of a steeply angled pterygoid implant to an acceptable position and align it with the rest of the arch. See Surcam multi-unit abutments in 17°/18°, 30° and 45°.
• Rigid cross-arch splinting distributes load across all implants and protects each one during healing.
• Framework design should allow hygiene access around the most distal abutment. This area is hard for patients to clean.
• Occlusion on the terminal implant should be managed with care, especially in provisional prostheses.

Pterygoid Implants vs Zygomatic Implants vs Grafting

Approach	Anchorage	Typical role	Key considerations
Pterygoid implant	Pterygoid plates of the sphenoid, via the tuberosity	Posterior (second-molar) support; reduces distal cantilever	Tactile placement, posterior access, vascular structures superior and posterior
Zygomatic implant	Zygomatic bone	Severe maxillary atrophy, including cases with no usable posterior or anterior alveolar bone	Advanced training; sinus and orbital proximity
Sinus augmentation + conventional implants	Grafted sinus floor	Posterior support when grafting is acceptable	Additional surgery and healing time; graft-related complications
Tilted implants (All-on-4 style)	Anterior/premolar maxilla, mesial to the sinus	Full-arch support without grafting	A distal cantilever is usually still present

Pterygoid and zygomatic implants are often combined. For example, zygomatic implants can provide mid-arch support while pterygoid implants anchor the distal ends in the same graftless full-arch plan. See Prof. Samer Sarouji's zygomatic and pterygoid case.

Complications and Risk Mitigation

• Bleeding: from the pterygoid venous plexus or branches of the internal maxillary artery if the trajectory overshoots. Mitigate with CBCT planning, length selection and controlled depth.
• Trajectory errors: perforation outside the intended bony path, or failure to engage the pterygoid plate, which reduces primary stability.
• Access and visibility: limited mouth opening and posterior position complicate instrumentation and impression-taking.
• Post-operative discomfort or trismus: usually transient.
• Prosthetic and hygiene challenges: at the distal abutment, managed through abutment selection and framework design.

Long-term clinical series, including Balshi et al.'s analysis of 356 pterygomaxillary implants (1999), and later systematic reviews (Bidra & Huynh-Ba, 2011) form the evidence base for pterygoid implants. Outcomes depend heavily on case selection, surgical experience and prosthetic design.

Choosing a Pterygoid Implant

A pterygoid implant needs to advance along a long, angled path and then grip cortical bone at the apex. Surcam's pterygoid implants are designed for this:

• Diameter: Ø4.2 mm
• Lengths: 16–28 mm (16, 18, 20, 22, 25 and 28 mm)
• Neck options: a 2 mm smooth neck for soft-tissue management and hygiene, or a 4 mm TiN-coated tissue-level neck for margin visibility and a smooth, durable collar
• Design: conical core with coarse macro-threads for firm purchase, and an anchoring apex for directional control
• Material and surface: Ti-6Al-4V ELI with an SLA surface (sandblasted and double acid-etched)
• Connection: internal hex 2.43 mm, restored with Surcam multi-unit abutments

Pterygoid Implant FAQs

What is a pterygoid implant?

A long implant placed through the maxillary tuberosity and anchored in the pterygoid plates of the sphenoid bone. It provides posterior support for fixed restorations in an atrophic posterior maxilla, without sinus grafting.

At what angle are pterygoid implants placed?

They follow an oblique posterior and superior path, described in the literature at roughly 45°–60° to the maxillary plane. The exact angulation is planned on CBCT for each patient.

How long are pterygoid implants?

They are longer than conventional implants because they must reach the pterygoid plates. Lengths of 15–20+ mm are common, and Surcam pterygoid implants come in 16–28 mm.

Can pterygoid implants be loaded immediately?

Often, yes, as part of a cross-arch splinted full-arch protocol when primary stability meets IFU criteria. When stability is uncertain, delayed loading is recommended.

Pterygoid or zygomatic implants: which should I use?

They solve different problems. Pterygoid implants add distal support at the back of the arch. Zygomatic implants provide anchorage when the maxilla itself cannot support implants. Many graftless full-arch plans use both. See our zygomatic implants clinical guide.

References and Further Reading

1. Balaji VR, Lambodharan R, Manikandan D, Deenadayalan S. Pterygoid implant for atrophic posterior maxilla. Journal of Pharmacy & Bioallied Sciences. 2017. PMC5731027
2. Balshi TJ, Wolfinger GJ, Balshi SF. Analysis of 356 pterygomaxillary implants in edentulous arches for fixed prosthesis anchorage. International Journal of Oral & Maxillofacial Implants. 1999.
3. Bidra AS, Huynh-Ba G. Implants in the pterygoid region: a systematic review of the literature. International Journal of Oral and Maxillofacial Surgery. 2011.
4. American College of Prosthodontists. Position statement: Use of implants in the pterygoid region for prosthodontic treatment.

This article is intended for licensed dental professionals. Indications, drilling protocols, torque values and loading decisions must follow the product IFU and the clinician's judgment.