Sinus lift, or how not to stay with a removable prosthesis on the upper jaw.
The anatomical structures that can restrict the conduct of implantation are the maxillary sinus – the cavity inside the upper jaw, which is lined with mucous membrane. There are so many variants of its structure that we can say that you wouldn’t find two exactly alike.
Maxillary sinus is connected with the nasal cavity through special nasal passages, so it participates in breathing. Maxillary sinus in its structure may be a multi-chamber or have one cavity. Multi-chamber is created by bony plates that grow from the inner wall of the sinus cavity in it. Each plate is also lined with mucous. Depending on the size of sinus of lateral teeth of the upper jaw can be placed in the bone and does not have any relation to it, or – right under it, or sometimes the sinus mucosa covers the very roots of the teeth.
After the extract of any tooth in the maxillary sinus we can see an atrophy of the jaw bone from both sides of the mouth, and from the maxillary sinus. This two-way process leads to a drastic reduction of the size of bones of the upper jaw to the posterior areas, sometimes to the point where between the sinus mucosa and mucosa of the mouth there is 1 mm of bone.
For the possible placement of implants in this area we offer methodology of sinus lift, increasing size of bone by raising the bottom of the maxillary sinus. Technique of the operation is as follows. An incision is made in the oral cavity up to the place of the expected bone increase. The gums are exfoliated; in the external wall of the sinus we do a little hole, without affecting the lining of the sinuses. Using a special tool Mucosa is peeled from the inner walls of the sinus and raised to the desired height. The resulting space is filled with bone substitute, own bone or a mixture thereof (based on the methodology used by the surgeon).
The method described above is called an open sinus lift. There is a so-called closed variant. It is used in cases when the implantation lacks 1-2 mm of the bone. This technique is carried out as follows: a hole is formed by the implant to its full length, not reaching the maxillary sinus for 1-2 mm. Then, with the help of special tools – osteotome – the remaining bone fragment is gently lifted into the sinus, if necessary, through a formed hole, bone material is added to provide an additional amount of bone and the implant is installed.
If there is a 4-5 mm alveolar bone, an implantation can be combined with holding an open sinus lift. This amount of bone is usually sufficient for primary fixation of the implant. The combination of implantation and sinus lift in one procedure significantly shortens the duration of implant treatment.
Sinus lift requires a very accurate performance. But even the most experienced surgeons complain that in their practice the mismatch of maxillary sinus mucosa occurs frequently. Sometimes it depends on the thickness of the mucous: thinner it is, the probability is higher (usually a smoker has very thin mucus). Depending on the size of the gap, implantologists use various methods of closing them, from suturing to cover the mucous membrane of special biological usually based on collagen.