Quality of life in oncologic patients after maxillectomy operations: clinical case series on different rehabilitation protocols.

OBJECTIVE: The study's purpose was to compare the quality of life (QoL) in oncologic patients treated with different rehabilitation protocols following maxillary tumor resections. PATIENTS AND METHODS: The patients were divided into three groups. Group A: 18 Patients with maxillary obturator prosthesis. Group B: 17 Patients with simultaneous autologous tissue reconstruction. Group C: 12 Patients with prosthesis on zygomatic implants. The post-operative QoL was compared using standard questionnaires, investigating items like pain, mood, social relations, and specific functions that could potentially compromise the post-operative QoL. A secondary analysis compared reconstructed vs. non-reconstructed patients. RESULTS: Most questionnaire items did not show significant differences among groups. Statistically significant outcomes were found in two parameters (social contact and sexuality), in which patients treated with zygomatic implants had the best satisfaction, and patients with obturator prostheses showed the lowest satisfaction. Patients belonging to the non-reconstructed group showed better moods than those in the reconstructed group, while taste problem complaints and pain were lower in the reconstructed group. CONCLUSIONS: Although the type of reconstruction procedure depends on the type of maxillectomy to be performed and on the general health situation of each patient, the impact of the rehabilitation protocol on the patients' QoL should be accounted for when planning the treatment.

A novel guided zygomatic implant surgery system compared to free hand: A human cadaver study on accuracy.

OBJECTIVES: The aim of this human cadaver study was to compare the accuracy of guided versus free-hand zygomatic implant placement. For the guided implant placement laser sintered titanium templates were used. METHODS: Forty zygomatic implants were placed in ten cadavers heads. For each case two implants were inserted using the guided protocol (Ezgoma guide, Noris Medical, Israel) and the related surgical kit and the other two by using a free hand approach. Post-operative computed tomography (CT) scans were carried out to assess the deviations between planned and inserted implants. The accuracy was measured by overlaying the post-operative CT scan (with the final position of the achieved implants) with the pre-operative CT scan (with the planned implants). RESULTS: The difference of the mean between planned and placed zygomatic implants by using surgical guides or free hand were statistically significant for all the variables evaluated: angular deviation (1.19°±0.40° and 4.92°±1.71°, p<0.001), linear distance deviation at coronal point (0.88 mm±0.33 mm and 2.04 mm±0.56 mm, p<0.001), at apical point (0.79 mm±0.23 mm and 3.23 mm±1.43 mm, p<0.001) and at apical depth (0.35 mm±0.25 mm and 1.02 mm±0.61 mm, p<0.001). CONCLUSIONS: The proposed guided surgery system exhibited a higher accuracy for all the investigated variables, when compared to the free hand technique.

Diagnosis and treatment of a rare case of adenomatoid odontogenic tumor in a young patient affected by attenuated familial adenomatosis polyposis (aFAP): case report and 5 year follow-up.

BACKGROUND: The adenomatoid odontogenic tumor (AOT) is a quite rare odontogenic tumor, with an incidence rate of approximately 12 cases/year worldwide. Attenuated familial adenomatous polyposis (aFAP) is a syndrome characterized by a significant risk to develop colon cancer. The aim of the paper is to describe a case never reported before in the literature: an AOT developed in a patient with aFAP; moreover, we want to show how it appears 5 years after surgery and after the regeneration of the eroded bone tissue, using the Platelet-Rich Fibrin (PRF) as filling material. CASE PRESENTATION: We report the case of a female 18 years old patient, affected by aFAP; she comes to us with a swelling on the right hemi-face. We performed several radiological exams, and they showed a neoformation approximately 2 cm in diameter: this neoformation packed the upper right canine, therefore, we hypothesized a dentigerous cyst. We decided to proceed to open biopsy and enucleation of the lesion. An intra-operative endodontic treatment on the adjacent partially resorbed teeth was also performed. Finally, we performed a reconstruction of eroded bone tissue, by use of Platelet-Rich Fibrin as filling material. The samples fixed and embedded in paraffin have led to the diagnosis of AOT. After 5 years from the surgery, we did not find any clear sign of relapse, in addition, the use of PRF has favored an optimal osteogenesis at the surgical site. CONCLUSIONS: Undoubtedly, a correct diagnosis of AOT allows to have a more performing clinical and surgical approach. Furthermore, this case could document a new manifestation of aFAP in extra-intestinal site. The onset of an AOT is quite rare in the general population, and this rarity could represent a critical point for its diagnosis; AOT onset in a patient with aFAP is a finding that could represent a new element of diagnosis and, therefore, the starting point to perform a more effective therapy.

How does an error in positioning the template affect the accuracy of implants inserted using a single fixed mucosa-supported stereolithographic surgical guide?

Computer-aided implantology using a single fixed stereolithographic surgical guide involves a sequence of diagnostic and therapeutic events, and errors can creep in at different stages. Taken together, these can be termed the 'total error'. A positioning of the surgical guide on the support surface different to that of the diagnostic template may generate an error that reoccurs with all the implants inserted, and this error can be termed the 'guide positioning error'. The aim of the present study was to measure the deviation between the planned and inserted implants due to this guide positioning error, to evaluate if this error was statistically significant, and concurrently, to assess the influence of the type of arch (upper vs lower jaw) and mucosal thickness on the guide positioning error. Twenty-four subjects were treated and 172 implants inserted. Preoperative and postoperative computed tomography images were compared using Mimics software to determine the total error and guide positioning error. Quantitative data were described; the t-test and Pearson correlation coefficient were used. The guide positioning error was found to affect the accuracy, but was statistically significant only for global coronal deviation (P = 0.038). Arch of support and mucosa thickness did not affect the guide positioning error.

Is it possible to improve the accuracy of implants inserted with a stereolithographic surgical guide by reducing the tolerance between mechanical components?

When using a stereolithographic surgical guide, a potentially clinically relevant error may be the mechanical error caused by the bur guide cylinder gap due to the presence of a rotational allowance of drills in the tubes. The aim of the present study was to determine if it is possible to reduce the total error by limiting the tolerance among the mechanical components and to evaluate its clinical incidence. Sixty implants were inserted in eight totally edentate subjects using the External Hex Safe(®) system with mechanical components modified to minimize the tolerance. Pre- and postoperative computed tomography images were compared, and the angular deviation was calculated between the planned and the placed implants. The mean angular deviation was 2.02° (range 0.81-3.48°; standard deviation 0.87). The results of the present study show that by limiting the error that originates from mechanical components, the total error could be significantly reduced.

The intrinsic error of a stereolithographic surgical template in implant guided surgery.

The aim of the present study was to assess the clinical relevance of the potential mechanical error (intrinsic error) caused by the cylinder-burr gap in a 'single type' stereolithographic surgical template in implant guided surgery. 129 implants were inserted in 12 patients using 18 templates. The pre- and postoperative computed tomography (CT) scans were matched allowing comparison of the planned implants with the placed ones. Considering only the angular deviation values, the t test was used to determine the influence of the guide fixation and the arch of support on accuracy values. The Pearson correlation coefficient was used to correlate angular deviation and bone density. The intrinsic error was mathematically evaluated. t test results indicated that the use of fixing screws (P=009) and the upper arch support (P=027) resulted in better accuracy. The Pearson correlation coefficient (0.229) indicated a significant linear correlation between angular deviations and bone density (P=009). A mean intrinsic error of 2.57 was mathematically determined considering only the angular deviation, as it was not influenced by other variables. The intrinsic error is a significant factor compared to all the variables that could potentially affect the accuracy of computer-aided implant placement.

The accuracy of CBCT in measuring jaws bone density.

BACKGROUND: The cone-beam computerized tomography (CBCT) has become widely used for oral and maxillofacial imaging, providing a good spatial resolution, gray density range, and contrast, as well as a good pixel/noise ratio. In the CBCT the dimensional accuracy is also comparable with Computer Tomography (CT), but in contrast to the CT, the gray density values of the CBCT images (voxel value [VV]) are not absolute. AIM: The aim of the study was to evaluate if there is a statistically significant difference in bone density values, defined as gray density values (VV), using two different CBCT exposure radiation (8 mAs or 15 mAs). MATERIALS AND METHODS: 10 dry mandibles were CBCT scanned using two different exposure radiation (8 mAs or 15 mAs). Using software and a radiographic template, the CBCT-scan images were overlapped and two datasets were created, each one giving the respective gray values (VV), of the same area with the same spatial coordinates. The quantified gray density values of the planned volume were measured and expressed as VV in two different exposure radiation scans Groups (Group A: 8 mAs; Group B: 15 mAs). For the statistical analysis, t-test was used. RESULTS: The differences between the CBCT gray density values (VV) of the Groups (Group A: 8 mAs; Group B: 15 mAs) were statistically significant (p <= .05). CONCLUSIONS: This study demonstrated that the use of a CBCT to evaluate the bone density of jaws is not useful when the values are taken as absolute values. In spite of the lower radiation dose and costs of CBCT, this new technique does not allow an accurate assessment of bone density.

Depth deviation and occurrence of early surgical complications or unexpected events using a single stereolithographic surgi-guide.

The purpose of this study was to determine the accuracy of depth implant insertion and to describe the frequency of early surgical complications or unexpected events, recorded using a single, totally guided, stereolithographic surgi-guide (bone-, mucosa- and teeth-supported) for both osteotomy site preparation and implant delivery. Ten adults were included in this study. Six patients were treated in both arches, and the number of computer aided implantology (CAI) interventions was 16, which equalled the number of guides used, for a total of 111 implants inserted. Complications and unexpected events occurred during the positioning of the surgical guide and whilst preparing the implant site and installing implants. In order to minimize the risk of complications and unexpected events, attention must be paid to every stage of treatment, including checking computed tomography (CT) images, guide manufacturing, proper guide positioning in the mouth, guide fixation, rotational allowance of drill in tubes, shape and sharpness of the drills, first entry point, mouth opening and guided implant insertion.