Sinus Complications with the Use of Temporary Anchorage Devices

I read with interest the article on temporary anchorage devices.¹ Unfortunately, the discussion of the potential complications of treatment made no mention of thickening of the sinus membrane or possible sinus infection. Given the type of anchor used, the depth at which it is screwed and the amount of bone on the buccal aspect of the maxillary molars, one could argue that the anchor will pierce the membrane and cause sinus complications.

We can see from the published radiographs that the sinuses appear clear at the start of treatment. After treatment, however, the sinus space seems to be almost completely closed. This may be the result of a reaction of the sinus membrane to perforation, infection or intrusion of the molar.

The authors should have added that pre- and postoperative CT scans should be taken (along with any other imaging deemed necessary) to avoid problems, and they should have mentioned the sinus complications related to this type of procedure. Finally, readers would be able to gather more information from this case if the radiographs had been included in their original format.

Dr Jean Routhier
Quebec City, Quebec

One of the Authors Responds

I thank Dr. Routhier for his observations. With regards to sinus perforation with the use of temporary anchorage devices, no such incident has been reported in the literature. I do not say this to lessen the importance or the possibility that it may occur. I totally agree that using CT or cone-beam images would further improve placement of these devices and prevent any complications.

When using mini-screws, our protocol usually includes taking bitewing and periapical radiographs at different angles and time points to rule out placing the screws close to vital structures (still keeping in mind that these are only 2-dimensional images).

Whether or not the sinus was perforated in our case,¹ I feel that panoramic radiographs can give a general view of the sinuses (although, admittedly, not a definitive one). Because there was no history of sinusitis during the course of treatment and because the patient did not experience any sinus trouble, we did not consider the cloudiness in the panoramic view a significant one. Furthermore, there was no difference in the sinus presentation between the pre- and postoperative cephalometric images. Again, I emphasize that all these images are 2-dimensional and there is always the potential for false-positive findings.

With respect to the format of the radiographs, they were pictures taken in a dark room using a digital Nikon 7-megapixel camera with the radiographs placed on a light box (viewer).

I do agree with Dr. Routhier with respect to using current advanced imaging to avoid any complications during this procedure and to facilitate pre- and postoperative evaluation. It would be a good suggestion for orthodontists to adopt cone-beam images as part of their protocol when using temporary anchorage devices.

Dr. Khalid H. Zawawi