Sinus Lift With Upper Jaw İmplants

Sinus lift with upper jaw implants

For many patients, deciding to have dental implants is an exciting step towards regaining their smile and chewing comfort. However, for those missing upper back teeth (molars and premolars), this journey often encounters an obstacle. Your dentist may examine your X-ray and say, “You don’t have enough bone due to your sinus.”

This may sound alarming, but it is actually the most common issue encountered in the upper jaw. The solution is a procedure called a sinus graft (or sinus lift). Despite its intimidating name, this is a predictable and well-established surgical procedure that creates new bone where there was previously only air.

What is the Maxillary Sinus?

Maxillary sinuses are air-filled cavities located inside your cheekbones, just above your upper back teeth.

Think of the sinus as an empty room in a house:

• The floor of this room is the bone that holds your tooth roots.
• The ceiling is the base of your eye socket (orbit).
• The lining of the room is a delicate tissue called the Schneiderian membrane.

When you are young and have all your teeth, this room is relatively small. As you age, especially after losing teeth, the sinus gradually expands.

The Problem: ‘Lost’ Bone

Why is there insufficient bone for an implant? Generally due to a double effect:

1. Shrinkage from Below: When a tooth is extracted, the jawbone that supported it begins to shrink because it no longer receives stimulation from chewing movements.
2. Expansion from Above: Once the roots are gone, the air pressure in the sinus gradually pushes the floor downwards. The sinus enlarges and the bone thins.

Over time, the bone between the mouth and the sinus can become as thin as paper, sometimes only a few millimetres thick. However, a standard dental implant typically requires approximately 10-12 mm of bone height for reliable stability. Attempting to place an implant here without a graft is like hanging a heavy picture frame on a plasterboard wall with no nails behind it – it can simply fall straight through.

Pre-operative Check: Is Your Sinus Healthy?

Before sinus lift surgery, your dentist must ensure that the “sinus chamber” is clean and healthy.

You wouldn't renovate a room with a leaky roof; similarly, you shouldn't place a bone graft in a diseased sinus.

Your doctor will check for:

• Odontogenic sinusitis: Many sinus infections actually originate from infected teeth. Bacteria from a bad tooth root can spread to the sinus.
• Cysts and polyps: Fluid-filled sacs or soft tissue growths that can block the sinus's natural drainage.
• Septa (internal walls): In some sinuses, bony partitions, like walls dividing a room, are present. These ‘speed bumps’ complicate surgery and require careful planning to prevent tearing the membrane.

A CBCT scan (3D tomography) is necessary to identify these issues and measure the amount of bone remaining before surgery.

Solution: Sinus Lift Surgery

Surgeons classify the difficulty of the case based on the amount of natural bone remaining under the sinus. A commonly used system is the Subantral (SA) Classification.

Ideal Scenario

• Bone height: 12 mm below the sinus.
• Treatment: No graft is required. The implant can be placed in a normal area.

‘Internal’ Lift (Minimal Bone Loss)

• Bone height: Approximately 10–12 mm. Only slightly shorter than ideal.

What is done?

The surgeon prepares the implant site but stops 1–2 mm before reaching the sinus floor. Using a small instrument called an osteotome, the remaining bone is gently tapped upwards, lifting the sinus floor by a few millimetres. The implant is placed immediately into this area, and a small amount of grafting material may be added.

“Lateral Window” (Moderate Bone Loss)

• Bone height: Between 5 mm and 10 mm.

What is done?

The surgeon opens a small window on the side of the upper jaw (in the gum area). Through this window, the sinus membrane (‘wallpaper’) is carefully pushed upwards and inwards. The newly created space is filled with bone graft material. Since at least 5 mm of natural bone remains to hold the implant, implants are usually placed at the same time as the graft.

Two-Stage Surgery (Severe Bone Loss)

• Bone height: Less than 5 mm.

What is done?

In this case, there is too little bone to stabilise the implant during grafting. Therefore, the treatment is two-stage:

1. First, a lateral window sinus lift is performed and the sinus is filled with graft material.
2. The graft is typically allowed to heal and harden for 6-9 months.
3. Once this graft has transformed into solid bone, you return to the clinic for implant placement.

Types of Graft Material Placed in the Sinus Cavity

The purpose of a sinus graft is to transform the air-filled lower part of the sinus into strong, living bone. Surgeons may use different types of grafts:

• Autograft: Your own bone, usually taken from the jaw or behind the jaw. This is considered the gold standard for stimulating new bone formation.
• Allograft: Processed bone taken from a human donor.
• Xenograft: Processed bone of animal origin (usually bovine/cow). This is slowly resorbed and is excellent for volume maintenance over time.

Typically, a mixture of materials is used to combine rapid healing with long-term volume stability.

Sinus Lift Complications and Recovery

The most common intraoperative complication is membrane perforation, i.e. a small tear in the sinus membrane.

• If the tear is small, the surgeon can usually patch it with a collagen membrane and continue.
• If the tear is large, the procedure may need to be stopped and repeated after healing.

Your recovery depends largely on the graft remaining stable and sinus pressure being maintained.

Post-operative rules generally include:

• Do not blow your nose:Blowing your nose creates sudden pressure that could displace the graft or reopen the membrane.
• Sneeze with your mouth open: This helps reduce pressure on the sinus.
• Use prescribed decongestants or sprays if recommended: These keep the sinus clear and reduce pressure during healing.

Summary

The maxillary sinus is a complex anatomical structure, but it does not prevent you from having dental implants.

Whether you need a small ‘touch’ with osteotomies or a large lateral window sinus lift procedure, these techniques have high success rates when properly planned.

By analysing your personal anatomy and selecting the correct protocol, your surgeon can create a solid bone foundation in the upper jaw and provide your implants with the stable support they need for a healthy, long-lasting smile.