Sinus Lift

The Truth About Sinus Lifts

Following loss of the maxillary molars, the alveolar ridge starts to be resorbed, eventually leading to inadequate bone support. This situation complicates implant placement, and until 20 years ago many patients had no choice but to wear removable dentures, which presented a host of problems: adapting to a foreign body in the oral cavity, discomfort in chewing and function and general impairment of quality of life.

In the 1990s, researchers in the expanding field of bone grafting developed a surgical technique to enable implant placement by growing bone at the expense of the maxillary sinus. This technique is called “Lifting the Floor of the Maxillary Sinus”.

 

What is the Maxillary Sinus?

The maxillary sinus is one of several empty cavities in the skull, among which are the frontal, ethmoid and sphenoid sinuses. The maxillary sinuses are located bilaterally above the maxillary alveolus, under the orbital cavity and next to the nasal cavity.

The entire sinus is lined with a delicate tissue layer called a membrane and the space constitutes an integral part of the upper respiratory tract.

 

What is the Function of the Maxillary Sinus?

The functions of the maxillary sinus are multiple: It reduces the weight of the cranial bones and protects the brain from trauma. The sinus also aids in phonetics and regulates the temperature of inhaled air. The membrane lining the internal aspect produces a secretion called mucous which filters the air during breathing.

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What Are the Long-Term Consequences of Tooth Loss?

Extraction of posterior teeth in the maxilla sets in motion a gradual process of resorption of alveolar bone.

Acting in parallel, the cumulative effect of breathing over many years tends to cause expansion of the sinus space (sinus pneumatization). Acting concurrently, the two processes result in a lack of available bone for placement of implants, forcing patients to get removable dentures for their oral rehabilitation.

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Sinus Lift - What’s the Breakthrough?

Sinus lifting in conjunction with bone grafting is a surgical intervention designed to restore the alveolar ridge, and serves as a preparatory phase prior to implant placement.

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What is the Guiding Principle of Sinus Lifting?

The surgical procedure is performed by a specialist trained in microsurgery. Before the surgery treatment, planning is required with the aid of panoramic radiographs and CT scans. Usually the treatment is carried out using local anesthesia and without hospitalization. Patients with phobias of dental treatment can undergo the treatment under deep sedation. Using an intra-oral approach, the surgeon opens a window in the lateral aspect of maxillary bone to access the sinus and then carefully and delicately frees up the tissue lining the sinus floor (which also serves as the roof of the maxillary alveolus). Although this access is performed manually, special care must be taken not to damage or perforate this delicate membrane.

Lastly, the surgeon uses an ultrasonic piezo-electric device, similar to the instrument used by dental hygienists for removing tartar, which allows him to remove bone without damaging the friable soft tissue.

This is made possible by the device’s technology which uses special frequencies capable of distinguishing between hard and soft tissue. The surgeon can thus proceed with peace of mind, confident in the knowledge that the risks of damage to the membrane with potential complications are minimized. Innovative technologies such as the use of lasers increase safety and efficiency for both the surgeon and the patient.

The aim of dissecting and lifting the sinus membrane is to provide a space to accommodate the bone graft. Usually in bone grafts, substitutes from human bone banks or animal sources are used, thus saving the doctor and patient the need to open a second surgical site. After placing the bone graft, the surgeon covers it with a protective collagen membrane to close the window. Conventional suturing marks the termination of the procedure.

הרמת סינוס - אופן הביצוע

 

When Can the Implants be Placed?

In cases where the pre-existing sinus floor is sufficiently thick (i.e. 3-4 mm), the implants may be placed at the same time as the sinus lift so that both the bone graft and the implants will be integrated simultaneously.

If, however, the sinus floor is found to be particularly thin, then the placement of the implants must be postponed for six months until after completion of healing and integration of the bone graft. The combined approach (sinus lift with implant placement) undoubtedly shortens the process of rehabilitation of the area,

but the decision as to the sequencing of the surgery remains at the surgeon’s discretion.

 

How Long Does the Surgery Take?

The procedure lasts from an hour up to an hour and a half on average. What precautions are to be taken by the patient after a sinus lift? As with any other invasive surgical procedure, strenuous physical activity should be avoided in the first few weeks. Nose blowing, which exerts pressure on the nasal passages, should not be engaged in, and flying in airplanes should be deferred for three weeks following the surgery.

 

What Are the Common Side Effects?

Commonly, it is normal for patients to experience sub-orbital swelling and edema accompanied by discomfort for several days, even though they are premedicated with appropriate medication which is supposed to reduce sequelae. Mild hemorrhage from the nose and mouth is not uncommon, and in a few cases ecchymosis can be observed. Severe pain is rare.

 

What Are The Possible Complications?

The most common complication is the development of acute sinusitis several days or weeks following the surgery. Among the symptoms are fever, pressure in the nasal passages under the eye, and general malaise.

 A remedy may be provided by taking a specific and appropriate antibiotic, although at times consultation with an ENT specialist is indicated.

The general dentist may proceed with the restorative phase (abutments and crowns) six months after the placement of the implants.

 

Sinus Lifts - In Summary

In cases of inadequate residual bone in the upper arch, the sinus lift has become a routine surgical procedure in recent years as a preliminary to implant placement. Thanks to this type of surgery, many patients have dispensed with the need for removable dentures. Nevertheless, it is a delicate, invasive procedure which demands a skilled surgeon with much knowledge and experience in this field who must follow a strict treatment protocol.