Tympanometry was analysed according to cleft type with respect to age in 239 cleft palate patients (57 with bilateral cleft lip and palate (BCLP)), 122 with unilateral cleft lip and palate (UCLP) and 60 with isolated cleft palate (ICP). The frequency of type B tympanograms was 46.5 per cent in the BCLP group, 50.6 per cent in the UCLP group and 58.3 per cent in the ICP group. Type A tympanograms were more frequently observed in older patients (median age 11 years) in comparison to type B (median age five years; p < 0.001) and type C (median age six years; p < 0.001). The total sample showed an age-related decrease in the frequency of type B tympanograms (rs = -0.3942; p < 0.001). The frequency of type A tympanograms increased significantly with age (rs = 0.4263; p < 0.001), whereas type C was not correlated with age. In the UCLP group, the frequency of type B tympanograms decreased with age (rs = -0.4430; p < 0.001), the decrease being faster than in the BCLP group (rs = -0.3186; p = 0.001) and the ICP group (rs = -0.3378; p < 0.0001)). Type B tympanograms had the highest correlation with a hearing loss of 21-40 dB at mean hearing level at speech frequencies (MHLSF) (rs = 0.4574; p < 0.001), a lower correlation with a hearing loss of 11-20 dB (rs = 0.2184; p = 0.02) and the lowest correlation with hearing loss above 40 dB. At the ages of one to three, the frequency of type B is higher in UCLP patients than in the BCLP and ICP groups, decreasing at seven to 12, increasing again at 13 to 15, and thereafter showing a continuous decrease. In the BCLP group, the frequency of type B increased significantly at the ages of four to six and then decreased continuously from seven to 18. In ICP patients, the changes in the frequency of type B with age are not significant until the age of 15; at the age of seven, it is higher than in the BCLP and ICP groups. The type C tympanogram is not typically found in cleft palate patients and its frequency is not correlated with age. It can be presumed that each type of cleft lip and palate, due to its characteristic conditions in the epipharynx, will favour a different mode of pathophysiological development of middle-ear disease.

No abstract

The main goal of our dynamic 3D computer-assisted reconstruction of a metallic retrobulbar foreign body following orbital injury with ethmoid bone involvement was to use 3D-information obtained from standard computed tomography (CT) data to explore and evaluate the nasal cavity, ethmoidal sinuses, retrobulbar region, and the foreign body itself by simulated dynamic computed visualization of the human head. A foreign body, 10 x 30 mm in size, partially protruded into the posterior ethmoidal cells and partially into the orbit, causing dislocation and compression of the medial rectus muscle and inferior rectus muscle. The other muscles and the optic nerve were intact. Various steps were taken to further the ultimate diagnosis and surgery. Thin CT sections of the nasal cavity, orbit and paranasal sinuses were made on a conventional CT device at a regional medical center, CT scans were transmitted via a computer network to different locations, and special views very similar to those seen on standard endoscopy were created. Special software for 3D modeling, specially designed and modified for 3D C-FESS purposes, was used, as well as a 3D-digitizer connected to the computer and multimedia navigation through the computer during 3D C-FESS. Our approach achieves the visualization of very delicate anatomical structures within the orbit in unconventional (non-standard) sections and angles of viewing, which cannot be obtained by standard endoscopy or 2D CT scanning. Finally, virtual endoscopy (VE) or a 'computed journey' through the anatomical spaces of the paranasal sinuses and orbit substantially improves the 3D C-FESS procedure by simulating the surgical procedure prior to real surgery.

One of the main objectives of our 3-dimensional (3D) computer-assisted functional endoscopic sinus surgery was to design a computer-assisted 3D approach to the presurgical planning, intraoperative guidance, and postoperative analysis of the anatomic regions of the nose and paranasal sinuses. Such an extremely powerful approach should allow better insight into the operating field, thereby significantly increasing the safety of the procedure. The last step to implementing the technology in the operating room was to connect the computer workstations and video equipment to remote locations by using a high-speed, wide-bandwidth computer network. During patient preparation, the surgeon in the operating room consulted remote experienced and skillful surgeons by viewing CT images and 3D models on computer workstations. The surgeon and consultants used software for CT image previews and 3D model manipulations on top of collaboration tools to define the pathosis, produce an optimal path to the pathosis, and decide how to perform the real surgical procedure. With tele-flythrough or tele-virtual endoscopy rendered through the use of 3D models, both surgeons can preview all the characteristics of the region (ie, anatomy, pathosis) and so predict and determine the next steps of the operation. This ensures greater safety thanks to the operation guidance and reduces the possibility of intraoperative error. The duration of the teleconsultation is thus shortened, which may prove the greatest benefit of tele-3D computer-assisted surgery. If this method were used, clinical institutions would spend less money for telesurgical consultation.

We have carried out three-dimensional, computer-assisted, functional endoscopic sinus telesurgery. Surgeons at different locations up to 300 km apart could not only see and transfer video images but also transfer three-dimensional computer models and manipulate them in realtime during surgery. Two different approaches were used. In the first telesurgery procedure we used M-JPEG compression and transmitted the data using fibre optic connections (ATM OC-3) at a bandwidth of 155 Mbit/s. In the second telesurgery procedure video images were transmitted over four E1 digital lines, amounting to about 8 Mbit/s of bandwidth, with better compression standards, such as MPEG1 and 2. We found that MPEG2 video compression produced the best picture quality for the operating field and endoscopic cameras. For conferencing and consultation between two or more connected sites during the surgery, we used JPEG and MPEG1 video compression with audio. The main feature of our three-dimensional telesurgery was the use of three-dimensional modelling of the operative field. This is important for emergency surgical interventions. We do not advocate that inexperienced surgeons operate on patients, not even with the guidance of a remote surgeon. However, three-dimensional telesurgery may become very valuable for experienced surgeons in the future.