Robert Kirmeier

Evaluation of three‐dimensional changes after sinus floor augmentation with different grafting materials

OBJECTIVE The aim of this retrospective investigation was to assess the dimensional stability of different grafting materials after maxillary sinus floor augmentation with computed tomography (CT) scans. MATERIALS AND METHODS Two postoperative CT scans were available from 16 patients who had undergone maxillary sinus lift procedures. The first scan was made within a few days after the surgical intervention and the second one >6 months later. A total of 25 maxillary sinuses were augmented with different materials before implant insertion by lateral antrostomy in a staged approach. The volume of bone formation was calculated using the Somaris Sienet Magic View software. RESULTS Based on volumetric measurements of the augmented domes derived from the image sections, shrinkage was about 26%. The mean of the augmented bone volume was 3.02 cm(3) (1.4-5.56 cm(3); SD+/-1.18 cm(3)) as determined in the first CT scan. The respective mean volume in the second CT scan amounted to 2.28 cm(3) (0.92-4.46 cm(3); SD+/-1.07 cm(3)). CONCLUSION Within the limits of our descriptive and analytic study, the results indicate a significant reduction of the graft volume after maxillary sinus augmentation. Further prospective studies will have to evaluate the quantitative changes of different bone graft materials for maxillary sinus augmentation procedures in order to improve long-term implant stability.

The supernumerary nasal tooth

Teeth exceeding the normal dental complement that have erupted into the nasal cavity are a rare pathological entity. This case report describes a female patient with recurrent complaints and fetid discharge from the left nasal cavity. The suspected clinical diagnosis of a supernumerary nasal tooth was confirmed by computed tomography. After endoscopic removal, the tooth was examined using X-ray microtomography and thin-section preparations; these findings are presented for the first time. A literature search identified 25 supernumerary nasal teeth in 23 patients.

Reproducibility of volumetric measurements on maxillary sinuses.

Although computer assisted volumetric quantification of human maxillary sinuses is commonly used to measure volumetric changes during life, reliability data for this procedure are lacking. The objective of this retrospective study is to test a semi-automatic virtual volumetric analysis technique on 36 CT scans of human maxillary sinuses. Three examiners with different clinical experience performed all measurements in three replicates. As principle of proof, the technique was examined on 12 phantoms with known volumes. The validation of the method revealed that the mean relative error was 0.364%. For the retrospective volumetric measurements from maxillary sinuses the intra- and inter-examiner agreement was quantified using appropriate intraclass correlation coefficients (ICC 1,k and ICC 2,k) and the Bland-Altman analysis. ICC values ranging from 0.997 to 0.999 indicate almost perfect agreement for intra- and inter-examiner data. The Bland-Altman analysis demonstrated good intra- as well as inter-examiner agreement for the two proficient examiners and a lack of agreement for the untrained examiner. It can be concluded that this measurement procedure using CT scans could be strongly recommended for clinical application to determine the volume of human maxillary sinuses reliably.

Oral Rehabilitation of Adult Twins With Severe Lack of Bone Due to Hypohidrotic Ectodermal Dysplasia : A 12-Month Follow-Up

PURPOSE Patients with x-linked hypohidrotic ectodermal dysplasia (XLHED, OMIM 305100) often present with exceptional oral conditions, because alveolar ridges can remain severely hypotrophic due to oligo- or anodontia in the primary and/or permanent dentition. This can seriously disable a young person physically and psychologically, and lead to sociopsychological isolation. PATIENTS AND METHODS The oral rehabilitation of fraternal male twins with XLHED, one with severe hypodontia and the other with anodontia is described. The treatment of both patients comprised augmentation of the jaws using bicortical corticocancellous bone blocks from the medial aspect of the anterior hip, delayed implantation, and restoration of the occlusion with bar-retained overdentures. The multidisciplinary team approach included an oral and maxillofacial surgeon, a prosthodontist, and a speech therapist. RESULTS After uneventful healing, the 12-month follow-up showed that sufficient osseointegration of the implants for optimized function was obtained by creating adequate de novo bone volume in the underdeveloped jaw regions. Full regular masticatory function was achieved, and esthetics were improved considerably in both patients. CONCLUSION Augmentation and implant placement prior to prosthetic rehabilitation appears to be a suitable treatment option for adult patients with XLHED.