The American Academy of Prosthodontists reports that more than 35 million Americans do not have any teeth, and 178 million people in the U.S. are missing at least one tooth. These numbers are expected to grow in the next two decades.
Most of the time, the teeth that are missing are the molars, either in the upper or lower jaw. After missing a molar in upper jaw, the patient experiences both bone resorption and expansion of the maxillary sinus. With the increase in popularity of dental implants and the increase quality of life of patients, rehabilitation of the edentulous posterior jaw often represents a clinical challenge.
Before the utilization of dental implants, patients with missing teeth and deficient bone in the posterior maxilla could only be rehabilitated with removable prostheses or short implants that prevent invasion of the sinus. Sometimes bone resorption and sinus expansion is so advanced that even short implants cannot be placed.
In those cases, advanced procedures like maxillary sinus elevation are needed to increase the amount of vertical bone height in the posterior maxilla for the placement of implants. Generally speaking, two procedures are available depending on the quantity of bone left.
In case of small augmentations needed, the use of a tapping motion on blunted posts can create sufficient space for implant placement (Internal or Direct Sinus Lift).
In case of more bone required, a more invasive procedure is required. A small perforation on the lateral wall of the sinus is performed and the creation of a window in that area can favor deposition of more grafting material for larger augmentation (External or Indirect Sinus Lift). Also, the quantity of bone available before the augmentation can allow the simultaneous placement of the implant, which tip will be surrounded by the graft material used for sinus augmentation.
In case of minimal bone levels before the augmentation, the sinus lift is performed and implants are usually placed 6 to 9 months after healing. It is very important that patients are healthy individuals with no uncontrolled systemic pathologies and conditions (uncontrolled diabetes, uncontrolled hypertensions for example). Also, the sinuses need to be clear from any diseases like cysts, sinusitis and infections.
In conclusion, sinus augmentation can be a valuable option to restore the posterior upper jaw in case of long absence of teeth, bone loss and sinus expansion.
– By Lorenzo Mordini DDS, MS