Perioperative pain management after scapular tip free flap harvesting for head and neck reconstruction using mini-catheters to inject the local anesthetic

PURPOSE

Although functional and esthetic results after the use of a scapular tip free flap (STFF) in head and neck reconstruction, and the related donor-site morbidity, have been extensively described, data regarding acute postoperative donor-site pain management are lacking. Purpose of this study is to explore the use of mini-catheters to administer local anesthetics for donor-site pain management after reconstruction using STFF.

METHODS

Patients who underwent head and neck reconstruction using a STFF were prospectively enrolled and, through a perineural catheter placed in the donor site during the surgical procedure, a bolus of chirochaine was injected before the patient regained consciousness and at 8, 16, and 24 h postoperatively. Before and 40 min after each dose administration, donor-site pain on a numerical rating scale (NRS; 0-10) was evaluated.

RESULTS

Study population consisted of 20 patients (40-88 years). At 8 h, the pain scores before and after the injection were 0-10 (mean 3.35) and 0-5 (mean 1.25), respectively. At 16 h, the pain scores before and after the injection were 0-8 (mean 2.55) and 0-4 (mean 0.55), respectively. At 24 h, the pain scores before and after the injection were 0-8 (mean 1.30) and 0-4 (mean 0.30), respectively.

CONCLUSION

Statistical analysis confirmed a significant difference between the pain scores before and after administration at 8, 16, and 24 h (p < 0.001, p < 0.001, and p = 0.003, respectively). Mini-catheters for local anesthetic administration represent an effective strategy for pain control after STFF harvesting for head and neck reconstruction.

Hygienic maintenance in patients with maxillae atrophy and in oncological patients with maxillary resection rehabilitated with zygomatic implants: A nested monocentric prospective cohort study

OBJECTIVE

To assess peri-implant soft tissues condition, comparing clinical parameters of implants placed in patients with atrophic upper jaws and patients who underwent maxillary resection for oncological reasons.

BACKGROUND

Zygomatic implants (ZIs) in oncologic patients could be affected by more complications compared to implants placed in atrophic maxillae. The soft tissue condition is an essential requirement for implant success, but few studies have investigated this topic.

METHODS

A nested monocentric prospective parallel cohort (atrophic vs. oncological patients) study was performed. Clinical visits and professional hygiene sessions were performed every three months, and bleeding on probing (BOP), probing pocket depth (PPD), gingival index (GI), plaque index (PI) and implant mobility were recorded by a blind outcome assessor.

RESULTS

In total, 77 ZIs placed in 21 patients were evaluated: 54 (70.1%) ZIs were inserted in patients belonging to the atrophic cohort (PAM) and 23 (29.9%) ZIs in the oncologic cohort (OP). The probability of having BOP at the considered mean follow-up (27 months) was 24.8% (95% CI 19.0-31.9) for PAM and 22.9% (95% CI 15.1-33.9) OP. The mean PPD values were 2.78 ± 1.28 (range 1-8) in PAM and 2.91 ± 1.98 (range 0-10) in OP. None of the implants showed mobility. No associations between group belongingness and the entity of PPD, PI, GI and the risk of BOP were found, adjusting for the considered confounding factors (age, smoking and implant position).

CONCLUSIONS

Under a strict supportive hygiene therapy protocol ZIs in oncologic patients showed similar peri-implant tissue conditions to that of patients with maxillary atrophy.

What is the Incidence of Late Complications Associated With Lower Third Molar Coronectomy? 10-Year Follow-Up Results

PURPOSE

Coronectomy is an operation to manage impacted third molars (M3s) considered at high risk for mandibular nerve injury but long-term outcomes are still lacking. The purpose of this study was to estimate the risk of late complications occurring within 10 years following lower M3 coronectomy.

METHODS

The investigators designed a prospective cohort study and enrolled a sample of 94 patients treated with coronectomy of third mandibular molars at the Unit of Oral and Maxillofacial Surgery of the University of Bologna, from 2009 to 2012. This follow-up study included all of the patients from the original study who completed 10 years of follow-up. The primary outcome variables is postoperative late complication occurring between 5 and 10 years after coronectomy coded as present or absent. Late complications were defined as root exposure, nerve injury, pulpitis, periapical infection, and reoperation. The secondary outcome variable was probing pocket depth. Covariates examined were age, smoking and type of M3 impaction. Descriptive statistical analyses were performed.

RESULTS

The inception cohort was composed of 94 subjects who had 116 coronectomies (k) completed. The study cohort was composed of subjects with 10 years of follow-up and included 48 subjects (k = 60) with a mean age of 28.99 ± 8.9 years. Between years 5 and 10 of follow-up, 2 subjects (4%) have complications; all root exposures diagnosed at years 8 or 9 after surgery. In another case root removal was required for orthodontics reason. No case of nerve injury to the inferior alveolar nerve occurred, and no periapical infection was observed around the residual roots. The mean 10-year probing pocket depth was 3.31 ± 0.92 mm (1,66-5,66 mm). There were too few complications to identify risk factors for late complications.

CONCLUSIONS

Within all the limitations of this study, the results of this prospective study imply that coronectomy is a useful surgical technique for the treatment of M3s at high neurological risk, to avoid nerve injury to the inferior alveolar nerve. In addition, after coronectomy, retained roots did not develop late infection or periapical infection in the long term. However, in a few cases, removal of retained roots was required at 10 years, due to root migration in the oral cavity. The risk for late complications is uncommon, but persistent.

The Curved Presplitting Technique in a Totally Edentulous Atrophic Mandible: A Surgical Case Report

The management of horizontally fully edentulous atrophic ridges is a common problem in dental implantology. This case report describes an alternative modified two-stage presplitting technique. The patient was referred for an implant-supported rehabilitation of their edentulous mandible. CBCT scans showed a mean available bone width of about 3 mm. At the first stage, four linear corticotomies were performed using a piezoelectric surgical device. At the second surgical stage 4 weeks later, bone expansion was performed, and four implants were placed in the interforaminal area. The healing process was uneventful. No fractures of the buccal wall and no neurologic lesions were observed. Postoperative CBCT scans showed a mean bone width gain of about 3.7 mm. Implants were uncovered 6 months after the second surgery, and 1 month later, a fixed provisional screw-retained prosthesis was delivered. This approach could be used as a reconstructive technique that avoids using grafts and reduces treatment times, possible complications, postsurgical morbidity, and costs by exploiting the patient's native bone as much as possible. Considering the limitations of a case report, randomized controlled clinical trials are needed to confirm the results and validate this technique.

Influence of Keratinized Tissue on Short Dental Implants: A Parallel Cohort Retrospective Study on 217 Implants with a Mean Follow-up of 4.1 Years

PURPOSE

To assess whether the presence or absence of keratinized tissue height (KTh) may have an influence on marginal bone levels, complications, and implant survival for short implants.

MATERIALS AND METHODS

The study was designed as parallel cohort retrospective research. Short implants with an implant length < 7 mm were considered. One cohort was composed of patients with short implants surrounded by ≥ 2 mm of KTh (adequate KTh); the other cohort included implants with < 2 mm of KTh (not-adequate KTh). Outcome measures were marginal bone level (MBL) changes, failures, and complications.

RESULTS

One hundred ten patients treated with 217 short and extrashort implants (4 to 6.6 mm long) were retrospectively included. The mean follow-up was 4.1 years after prosthetic loading (range: 1 to 8 years). The differences between KTh groups in MBL were not statistically significant at every follow-up considered: 0.05 mm at 1 year (P = .48), 0.06 mm at 3 years (P = .34), 0.04 mm at 5 years (P = .64), and 0.03 at 8 years (P = .82). A total of nine complications were reported: three in the not-adequate KTh group and six in the adequate group; the difference was not statistically significant (OR: 3.03, 95% CI: 0.68 to 13.46, P = .14). Five implants failed due to peri-implantitis, two in the not-adequate KTh group and three in the adequate group, without a statistically significant difference (OR: 2.76, 95% CI: 0.42-17.99, P = .29).

CONCLUSION

This study showed no statistically significant differences in MBL, complications, and implant failure rates between short implants with adequate or not-adequate KThs. However, given the importance of patient comfort while brushing and plaque accumulation, keratinized tissue grafts could be important in selected patients, especially for those who are severely atrophic, also taking into consideration all the limitations of this study and the mediumterm follow-up. Nevertheless, longer follow-ups, larger numbers of patients, and randomized controlled clinical trials are needed before making more reliable clinical recommendations. Int J Oral Maxillofac Implants 2023;38:462-467. doi: 10.11607/jomi.9918.

A comparison of accuracy between three different facial detection systems for prosthodontic esthetic preview: a single-blinded in vitro study

BACKGROUND

The aim of this study was to compare the accuracy of 3 different devices for facial images acquisition, useful for prosthodontic esthetic preview.

METHODS

Bidimensional extraoral photographs (Nikon D300), facial scans (Bellus3D) and 3D digital stereophotogrammetry photos (3dMD Face System) were acquired from 15 patients. The intraoral impressions of all subjects were digitally taken through a scanner (i500; Medit). Files obtained from each acquisition method were transferred on Exocad Software, and the measurements of the frontal teeth were performed and compared with those of the intraoral scans, assumed as reference. The data were statistically analyzed (Friedman and Dunn tests) with P<0.05.

RESULTS

As for central and lateral incisors, no significant difference emerged between 2D digital photography and intraoral scans, both in height and width. Measures obtained with Bellus3D significantly differed from the reference data in width of all teeth, except for central incisors. Values referred to canines were those more subjected to significant distortions in width for all devices.

CONCLUSIONS

Within the limits of this study, measures of frontal teeth acquired by 2D digital photography were similar to those of intraoral scans both in height and width, while those obtained with 3D facial scanners were more subjected to distortions in mesial-distal dimension.

A Plaster Cast Contact Scan Method to Assess the Accuracy of Full-Arch Computer-Aided Implant Surgery

PURPOSE

The aim of this study was accuracy assessment of placed implants in full-arch cases using specific software and hardware to perform static computer-assisted implantology and immediately loaded prostheses. The degree of deviation existing between planned and achieved implants was carried out by a new noninvasive measurement procedure of the implant position performed on stone casts.

MATERIALS AND METHODS

Fourteen stone casts retrieved from 14 full-arch fully guided implant treatments were selected to perform the study. Each cast, manufactured for the surgical treatment by using a specific laboratory kit, was obtained from the respective surgical guide. A sleeve for each implant was embedded into the guide, which helped the examiners to manufacture a stone cast per guide containing the implant analogs, which was used to recover the final position of the planned implants. A total sample of 60 implants were assessed. The postoperative casts, poured to produce the immediate prostheses, were then processed by a contact (or tactile) scanner, and the generated standard tessellation language (STL) files were overlapped (best-fit alignment) using engineering software that revealed all the measured discrepancies. In terms of accuracy, differences relating to arch, assessed bone quality, implant length, and drill length (prolongation short or long) were reported.

RESULTS

The use of a noninvasive tactile scanner revealed mean entry point horizontal deviations of 0.30 mm (SD: 0.39 mm), mean entry point vertical deviations of 0.20 mm (SD: 0.25 mm), mean apical horizontal deviations of 0.50 mm (SD: 0.73 mm), and mean apical vertical deviations of 0.24 mm (SD: 0.28 mm). The frontal and lateral angular deviations were investigated, and corresponding mean values of 1.99 degrees (SD: 2.30 degrees) and 1.80 degrees (SD: 2.44 degrees) were detected.

CONCLUSION

The reported results demonstrate that the contact tactile scan is a viable and biologic way to assess implant deviations.

Simultaneous GBR and Implant Placement with Resorbable Membranes in the Rehabilitation of Partially Edentulous and Horizontally Atrophic Dental Arches: A Retrospective Study on 97 Implants with a 3- to 7-Year Follow-up

This retrospective study evaluates the clinical and radiographic outcomes of simultaneous guided bone regeneration (GBR) and implant placement procedures in the rehabilitation of partially edentulous and horizontally atrophic dental arches using resorbable membranes. A total of 49 patients were included, and 97 implants were placed. Patients were followed up for 3 to 7 years after loading. The data indicate that GBR with simultaneous implant placement and resorbable membranes can be a good clinical choice, and the data suggest that it could be better to horizontally reconstruct no more than 3 mm of bone in order to reduce the number of complications and to obtain stable results. However, this technique remains difficult and requires expert surgeons.

Digital planning of composite customized veneers using Digital Smile Design: Evaluation of its accuracy and manufacturing

OBJECTIVES

This study aimed to evaluate the production of customized composite veneers starting from a two-dimensional (2D) digital preview using the Digital Smile System (DSS). MATERIAL AND METHODS: A photographic examination of 30 patients was performed by taking two digital pictures of the face and a digital preview through the DSS. Moreover, optical scans of the dental arches were obtained and the data were entered into a three-dimensional (3D) software to prepare a virtual preview. The standard tessellation language files were sent for production using CAD-CAM technology. The Friedman test, Bonferroni, and Dunn post hoc tests were used, comparing the linear measurements of the 2D and 3D plans and the final veneers (α = .05).

RESULTS

Significant differences emerged between the pictures and digital scans on the mesial-distal widths of the lateral incisors and canine. Linear measurements in the 2D plan were significantly different from those of the 3D plan, except for the height measures of incisors. No significant changes were found on comparing the parameters of the 2D and 3D plans with those of the final pieces.

CONCLUSIONS

The customized veneers were clinically adequate and similar to 2D and 3D plans, although significant differences emerged between the picture and digital scans as well as between the 2D and 3D plans.

Guided Bone Regeneration using Titanium Mesh to Augment 3-dimensional alveolar defects prior to implant placement. A Pilot Study

Objectives

To evaluate the outcomes of bone regeneration using a customized titanium mesh scaffold to cover a bone graft for reconstruction of complex defects of the jaws.

Materials and Methods

19 large defects were digitally reconstructed using CT scans according to the prosthetic requirements. A titanium mesh scaffold was designed to cover the bone (autologous/bovine bone particulate) graft. At least 6 months after surgery, a new cone‐beam CT was taken. The pre‐ and postoperative CT datasets were then converted into three‐dimensional models and digitally aligned. The actual mesh position was compared to the virtual position to assess the reliability of the digital project. The reconstructed bone volumes (RBVs) were calculated according to the planned bone volumes (PBVs), outlining the areas under the mesh. These values were then correlated with the number of exposures, locations of atrophy, and virtually planned bone volume.

Results

The mean matching value between the planned position of the mesh and the actual one was 82 ± 13.4%. 52.3% (40% early and 60% late) exposures were observed, with 15.8% exhibiting infection. 26.3% resulted as failures. The amount of reconstructed bone volume (RBV) in respect to PBV was 65 ± 40.5%, including failures, and 88.2 ± 8.32% without considering the failures. The results of the exposure event were statistically significant (p = .006) in conditioning the bone volume regenerated.

Conclusions

This study obtained up to 88% of bone regeneration in 74% of the cases. The failures encountered (26%) should underline the operator's expertise relevance in conditioning the final result.

A 5-year randomized controlled clinical trial comparing 4-mm ultrashort to longer implants placed in regenerated bone in the posterior atrophic jaw

BACKGROUND

Short implants (up to 5-mm long) have shown good results when compared to longer implants placed in augmented bone.

PURPOSE

To evaluate if 4-mm ultrashort implants could also be an alternative to bone augmentation in the severely atrophic posterior jaws. The primary aim of the study was to compare implant survival rates between study groups.

MATERIALS AND METHODS

Eighty partially edentulous patients with posterior atrophic jaws (5-6 mm of bone above the mandibular canal and 4-5 mm below the maxillary sinus) were included: 40 patients in the maxilla and 40 in mandible. The patients were randomized to receive one to three 4-mm ultrashort implants or one to three implants at least 10-mm long in augmented bone. Results are reported 5 years after loading with the following outcome measures: implant and prosthetic failures, complications and peri-implant marginal bone level changes.

RESULTS

Thirty-two complications were reported for the control group in 18 patients versus 13 complications in 10 patients in the test group, the difference being not statistically significant (p = 0.103). In the augmented group, 12 implants failed in 6 patients versus 7 short implants in 6 cases, and 9 prostheses failed in the control group while 4 in the test one, without statistically significant differences (p = 1.000 and 0.363, respectively). At 5 years after loading, short implants lost on average 0.58 ± 0.40 mm of peri-implant marginal bone and long implants 0.99 ± 0.58 mm, the difference was statistically significant (p = 0.006).

CONCLUSION

Four-millimeter ultrashort implants showed similar if not better results when compared to longer implants placed in augmented jaws 5 years after loading. For this reason, their use could be in specific cases preferable to bone augmentation since the treatment is less invasive, faster, cheaper and associated with less morbidity. However, longer follow-ups and larger trials are needed.

Dynamic Navigation in Implant Dentistry: A Systematic Review and Meta-analysis

PURPOSE

Dynamic navigation is a technique that allows for the placement of dental implants using a computer-guided approach according to preoperative planning. Its accuracy has been assessed in several previous studies. The purpose of this study was to summarize data on implant placement accuracy using dynamic navigation, to synthesize the frequency of intraoperative complications and implant failures, and to compare this technique with static computer-guided surgery and a freehand approach.

MATERIALS AND METHODS

Electronic and manual literature searches until December 2019 were performed. The outcome variables were implant placement accuracy using dynamic navigation, accuracy differences between dynamic and static techniques and between dynamic and freehand techniques, intraoperative complications, and implant failures. Random-effects meta-analyses were performed.

RESULTS

A total of 32 studies were included; 29 reported accuracy values (2,756 implants), and 10 focused on complications and implant failures (1,039 implants). The pooled mean implant placement errors were 0.81 (95% CI: 0.677 to 0.943) mm at the entry point and 0.910 (95% CI: 0.770 to 1.049) mm at the apical point. The pooled mean vertical and angular deviations were 0.899 (95% CI: 0.721 to 1.078) mm and 3.807 (95% CI: 3.083 to 4.530) degrees. The navigation group showed significantly lower implant placement errors with respect to the freehand technique (P < .01) and similar accuracy values (P ≥ .05) compared with the static technique. The pooled prevalence of failures was 1% (95% CI: 0.00% to 2%).

CONCLUSION

Dynamic navigation provided small implant placement errors, comparable with those obtained using static computer-guided surgery, and can be considered a more accurate technique than conventional freehand surgery.

Flapless and bone-preserving extraction of partially impacted mandibular third molars with dynamic navigation technology. A report of three cases

AIM

Most of the intra- and postoperative patient discomfort related to complex mandibular third molar (M3M) extraction is proportional to the invasiveness of the surgery. This can be minimized through the support of dynamic navigation (DN) technology, which can be successfully applied in dental implantology.

MATERIALS AND METHODS

Three patients, one female (aged 25 years) and two males (aged 18 and 51 years, respectively) underwent the DN-supported extraction of partially impacted M3Ms with a flapless approach that required minimal bone removal. The patients' discomfort and the speed of recovery were considered to be proof of the quality of the adopted procedure.

RESULTS

No postoperative discomfort such as pain or swelling was recorded in the immediate postoperative period, and no complications were reported within a month of the surgery. No medications were prescribed. The procedure lasted no longer than 20 min in all cases.

CONCLUSION

Using DN technology, the real-time 3D monitoring of the clinical situation in each surgical phase enabled the surgeon to avoid soft tissue detachment as well as limit bone loss and intraoperative bleeding, thanks to a precise multi--section of the tooth and important nearby anatomical structures, respectively.

Computer-Aided Rehabilitation Supported by Zygomatic Implants: A Cohort Study Comparing Atrophic with Oncologic Patients after Five Years of Follow-Up

The aim of this study was to evaluate the survival and clinical success rate, complications, and patients’ quality of life after computer-aided rehabilitation supported by zygomatic implants in cases of severe maxillary atrophy (ten patients) and in bone defects in oncologic patients (ten patients). All patients underwent computer-aided planning and surgery. Seventy-three zygomatic implants were placed. The mean follow-up period was 39.9 months. Implant survival and clinical success rate, the effectiveness of planning the implant length, biological and prosthetic complications, and the quality of life were evaluated. The five-year implant survival rate for patients with maxillary atrophy and oncologic patients was 97.4% and 96.7%, respectively. The prosthetic survival rate was 100%. Two implant failures occurred in the first year. One implant failure was observed in each group. Minor biological and prosthetic complications occurred in both groups without significant differences. All complications were managed without affecting the treatment. The quality of life increased by 71.3% in the atrophic group and by 82.9% in the oncologic group. Zygomatic implant rehabilitation seems to be a reliable technique for patients with maxillary atrophy and for oncologic patients. The three-dimensional computer-aided approach allows the surgeon to plan the surgery and increase its predictability. Early prosthesis loading certainly allows for better functional outcomes.

3D planning of ear prosthesis and navigated flapless surgery for craniofacial implants: A pilot study

New 3D digital technologies can be applied to implant-supported ear prostheses to restore anatomical structures damaged by cancer, dysplasia, or trauma. However, several factors influence the accuracy of implant positioning using a cranial template. This pilot study describes an innovative navigated flapless surgery for craniofacial implants, prosthetically guided by 3D planning of the ear prosthesis. Laser surface scanning of the face allowed for mapping of the healthy ear onto the defect site, and projection of the volume and position of the final prosthesis. The projected ear volume was superimposed on the skull bone image obtained by cone-beam computed tomography (CBCT), performed with the navigation system marker plate positioned in the patient's mouth. The craniofacial implants were fitted optimally to the ear prosthesis. After system calibration, real-time navigated implant placement based on the virtual planning was performed with minimally invasive flapless surgery under local anesthesia. After 3 months of healing, digital impressions of the implants were made, and the digital manufacturing workflow was completed to manufacture the ear prosthesis anchored to the craniofacial implants. The proposed digital method facilitated implant positioning during flapless surgery, improving the ear prosthesis manufacturing process and reducing operation time, patient morbidity, and related costs. This protocol avoids the need for a reference tool fixed in the cranial bone, as is usually required for maxillofacial surgery, and confirmed that surgical navigation is useful for guiding the insertion of craniofacial implants during flapless surgery.

Three-Dimensional Radiographic Evaluation of the Malar Bone Engagement Available for Ideal Zygomatic Implant Placement

Zygomatic implant rehabilitation is a challenging procedure that requires an accurate prosthetic and implant plan. The aim of this study was to evaluate the malar bone available for three-dimensional zygomatic implant placement on the possible trajectories exhibiting optimal occlusal emergence. After a preliminary analysis on 30 computed tomography (CT) scans of dentate patients to identify the ideal implant emergencies, we used 80 CT scans of edentulous patients to create two sagittal planes representing the possible trajectories of the anterior and posterior zygomatic implants. These planes were rotated clockwise on the ideal emergence points and three different hypothetical implant trajectories per zygoma were drawn for each slice. Then, the engageable malar bone and intra- and extra-sinus paths were measured. It was possible to identify the ideal implant emergences via anatomical landmarks with a high predictability. Significant differences were evident between males and females, between implants featuring anterior and those featuring posterior emergences, and between the different trajectories. The use of internal trajectories provided better bone engagement but required a higher intra-sinus path. A significant association was found between higher intra-sinus paths and lower crestal bone heights.

Analysis of Marsupialization of Mandibular Cysts in Improving the Healing of Related Bone Defects

PURPOSE

Marsupialization, designed to reduce the mandibular cyst volume, has continued to debated regarding its influence on the healing of the related bone cavity. The aim of the present study was to evaluate the 3-dimensional radiographic variation over time in mandibular odontogenic cystic lesions after marsupialization and assess the correlations between these variations and variables that can affect the procedure.

MATERIALS AND METHODS

We planned a retrospective cohort study. The predictor variables were the treatment duration, preoperative volume, patient age, histologic type, and number of preoperative residual bony walls. The outcomes variables were the postoperative volume reduction and the daily reduction rate calculated using computed tomography (CT) from before to after marsupialization using software designed for volumetric reconstruction and measurement of cyst-related bone defects. The descriptive and bivariate statistics were computerized, and the significance level was set at P = .05.

RESULTS

The sample included 15 patients (12 men and 3 women; mean age, 51.6; range, 27 to 85 years) affected by keratocysts (n = 6), dentigerous cysts (n = 6), and radicular cysts (n = 3) who had undergone marsupialization. The median duration of marsupialization was 406 days (25th to 75th percentile, 276 to 519). The mean ± standard deviation (SD) pre- and postdecompression volumes were 6,908.27 ± 2,669.058 and 2,468.13 ± 1,343.517 mm³, respectively (P < 0.001), and the mean ± SD percentage of reduction was 63.90 ± 13.12%. The volume decrease in the bone defects correlated positively with the treatment duration (P = .009) and preoperative volume (P < .001). However, no correlation was found with the other variables (P > .05) nor between the daily reduction rate and other variables (P > .05).

CONCLUSIONS

Marsupialization appears useful in improving the healing of cyst-related bone defects in mandibles, especially larger defects. Further studies with a wider sample size would add more knowledge to this topic.

Dynamic Navigation in Dental Implantology: The Influence of Surgical Experience on Implant Placement Accuracy and Operating Time. An in Vitro Study

AIM

the aim of this in vitro study was to test whether the implant placement accuracy and the operating time can be influenced by the operator's experience.

MATERIALS AND METHODS

sixteen models underwent a (Cone Beam Computer Tomography) CBCT and implant positioning was digitally planned on this. The models were randomly assigned to four operators with different levels of surgical experience. One hundred and twelve implant sites were drilled using a dynamic navigation system and operating times were measured. Based on postoperative CBCTs, dental implants were virtually inserted and superimposed over the planned ones. Two-dimensional and 3D deviations between planned and virtually inserted implants were measured at the entry point and at the apical point. Angular and vertical errors were also calculated.

RESULTS

considering coronal and apical 3D deviations, no statistically significant differences were found between the four operators (p = 0.27; p = 0.06). Some vectorial components of the deviation at the apical point and the angular errors of some operators differed from each other.

CONCLUSIONS

within the limitations of this study, dynamic navigation can be considered a reliable technique both for experienced and novice clinicians.

P752 Mitral regurgitation in patients with severe aortic stenosis: role of valvular calcification in the persistence of mitral regurgitation after aortic valve replacement

Introduction

mitral regurgitation is often associated with severe aortic stenosis but the indications for its correction at the time of aortic valve surgery are still unclear. Despite the indication for mitral valve repair or replacement in the case of severe secondary mitral regurgitation, many patients are left untreated. This is due to the common belief that secondary mitral regurgitation mostly improves after the aortic valve is treated.

Purpose

the aim of the study is to investigate the prevalence and distribution of mitral calcifications, their role in the development of mitral regurgitation and in its reduction after aortic valve replacement.

Methods

we reviewed all patient’s records who underwent aortic valve replacement for aortic stenosis at our institution from 12/2014 to 12/2016. Pre and post-operative echocardiograms were reviewed by experienced echocardiographer. Patients were then divided into 4 categories (functional, mild, moderate and severe calcification) on the basis of the presence, distribuition and severity of calcification on the mitral apparatus.

Results

at the end 651 patients were collected and analyzed. Mean age was 74yo. 334 (51,4%) of them were males. Most patients (63,1%) had only mild mitral regurgitation but 147 (22,6%) of them had moderate or severe mitral regurgitation. The presences of moderate or severe calcification of the mitral apparatus resulted to be a risk factor for the presence of mitral regurgitation associated with aortic stenosis as shown in Table 1. After surgical aortic valve replacement less than 21% of the patients showed a reduction of the degree of mitral regurgitation. We found no statistical difference between groups about mitral regurgitation changes after aortic valve replacement.

Conclusions

Mitral regurgitation is a common finding in patients with severe aortic stenosis and it’s prevalence is higher in patients with mitral calcifications. Few patients, however showed a reduction in the degree of mitral regurgitation after surgical aortic valve replacement with no difference related to the severity of annular or leaflets calcifications.

TABLE 1 Logistic regression for the presence of mitral regurgitation Mitral Regurgitation Change after Aortic Valve Replacement CALCIFICATION DEGREE OR C.I. 95% p Reduced p Unchanged p Increased p Functional 53(21%) 176(71%) 18(7%) Mild 1.244571 0.81 - 1.93 0.32 28(20%) 0.86 105(76%) 0.43 6(4%) 0.34 Moderate 1.637297 1.05 - 2.56 0.03* 25(17%) 0.41 109(76%) 0.34 9(6%) 0.86 Severe 2.369245 1.46 - 3.85 &lt;0.01* 29(25%) 0.48 78(68%) 0.67 7(6%) 0.86 OR= Odds Ratio; C.I.=Confidence Interval; Functional= no calcification; Mild, Moderate and Severe= degree of mitral annular and leaflets calcifications.

Augmented reality for dental implantology: a pilot clinical report of two cases

BACKGROUND

Despite the limited number of articles dedicated to its use, augmented reality (AR) is an emerging technology that has shown to have increasing applications in multiple different medical sectors. These include, but are not limited to, the Maxillo-facial and Dentistry disciplines of medicine. In these medical specialties, the focus of AR technology is to achieve a more visible surgical field during an operation. Currently, this goal is brought about by an accurate display of either static or dynamic diagnostic images via the use of a visor or specific glasses. The objective of this study is to evaluate the feasibility of using a virtual display for dynamic navigation via AR. The secondary outcome is to evaluate if the use of this technology could affect the accuracy of dynamic navigation.

CASE PRESENTATION

Two patients, both needing implant rehabilitation in the upper premolar area, were treated with flapless surgery. Prior to the procedure itself, the position of the implant was virtually planned and placed for each of the patients using their previous scans. This placement preparation contributed to a dynamic navigation system that was displayed on AR glasses. This, in turn, allowed for the use of a computer-aided/image-guided procedure to occur. Dedicated software for surface superimposition was then used to match the planned position of the implant and the real one obtained from the postoperative scan. Accuracies, using this procedure were evaluated by way of measuring the deviation between real and planned positions of the implants. For both surgeries it was possible to proceed using the AR technology as planned. The deviations for the first implant were 0.53 mm at the entry point and 0.50 mm at the apical point and for the second implant were 0.46 mm at the entry point and 0.48 mm at the apical point. The angular deviations were respectively 3.05° and 2.19°.

CONCLUSIONS

From the results of this pilot study, it seems that AR can be useful in dental implantology for displaying dynamic navigation systems. While this technology did not seem to noticeably affect the accuracy of the procedure, specific software applications should further optimize the results.

Free flap head and neck reconstruction in the elderly: what is the impact on quality of life?

Morphofunctional reconstruction is a pivotal aspect in the surgery of head and neck neoplasms: nowadays, microvascular free flap surgery represents the gold standard. In choosing the surgical technique, the effects on residual quality of life, especially in elderly people, usually considered more fragile and so often excluded from microsurgical procedures, must be taken into account. This multicentre study evaluated the quality of life index in patients more than 75 years of age and who underwent to head and neck microsurgical reconstruction. Data from patients aged > 75 years at the time of major head and neck reconstruction conducted with free flaps between 1 January 2005 and 30 June 2015 were analysed retrospectively. We administered the Italian version of Quality of Life questionnaire SF-36, at least 24 months after surgery. Results were compared to those for the general Italian population of the same age. We enrolled 39 patients with an average age of 80.6 years. The results did not differ significantly from the reference population. The international literature has already shown that chronologic age is not a valid parameter to determine the surgical treatment modality. Even considering the quality of residual life, our study supports the indication for free-flap reconstruction of head and neck defects in the elderly, confirming its effectiveness in this population.

Dynamic navigation: a prospective clinical trial to evaluate the accuracy of implant placement

AIM

The objective of this prospective pilot clinical study was to evaluate the accuracy of a new dynamic navigation system and postoperative clinical outcomes.

MATERIALS AND METHODS

Ten patients were recruited and 18 implants were placed. The surgery was performed with the navigation system and according to the virtual planning. Ten implants were placed using a flapless technique and eight implant sites were prepared with a combined piezo-drill method. The deviation between the real implant position obtained from the postoperative cone beam computed tomography (CBCT) scan and the planned implant position was measured.

RESULT

The average deviation was 1.19 ± 0.54 mm. The mean deviation measured at the insertion point was 1.04 ± 0.47 mm and at the apical point it was 1.35 ± 0.56 mm. The depth error was 0.43 ± 0.34 mm. The axis deviation was 6.46 ± 3.95 degrees. No significant differences were found between the flapless and the open-flap approaches and between the conventional and piezoelectric techniques. No complications occurred.

CONCLUSION

The accuracy values reported in this study are comparable, although not superior, to the literature data regarding dynamic and static computer-guided surgery. Dynamic navigation could increase the quality and safety of interventions and may reduce morbidity when compared with freehand insertion techniques. Deviation at the entry point (mm) Deviation at the apex (mm) Depth deviation (mm) Angular deviation (degrees) Mean 1.04 1.35 0.43 6.46 SD 0.47 0.56 0.34 3.95 Maximum 2.21 2.28 1.41 6.46 Minimum 0.45 0.59 0.03 3.95 Deviation at the entry point (mm)Deviation at the apex (mm)Depth deviation (mm)Angular deviation (degrees)OF0.96 ± 0.331.45 ± 0.600.35 ± 0.227.93 ± 5.15FL1.10 ± 0.581.27 ± 0.570.49 ± 0.425.28 ± 2.60Data are shown as mean ± SDOF = open-flap surgery; FL = flapless surgery Deviation at the entry point (mm)Deviation at the apex (mm)Depth deviation (mm)Angular deviation (degrees)P1.01 ± 0.251.37 ± 0.480.44 ± 0.267.63 ± 4.30C1.06 ± 0.621.34 ± 0.660.42 ± 0.415.52 ± 3.81Data are shown as mean ± SDP = piezoelectric tips; C = conventional burs.

Masseteric cooptation and crossfacial nerve grafting: Is it still applicable 22 months after the onset of facial palsy?

BACKGROUND

Eighteen months is usually considered the cutoff time within which recovery of the mimic muscle remains possible using facial nerve cooptation. Few reports on the use of cooptation after this interval have appeared. Purpose of this study is to investigate the feasibility of this procedure also after 22 months.

METHODS

Six patients treated via crossfacial nerve grafting between healthy and paralyzed middle and middle-upper facial nerve branches and masseteric cooptation of the main trunk of the paralyzed facial nerve between 20 and 24 months after the onset of palsy were analyzed. Population consisted of two males and four females ages 8-42 years (mean 24 years). Facial palsy developed after acoustic neuroma resection in three patients, after the removal of a cerebellopontine angle astrocytoma in one, and as a consequence of Bell's palsy or cerebral hemorrhage in the other two (one each). House-Brackman and Sunnybrook clinical evaluation systems and FDI questionnaire were used to assess results.

RESULTS

House-Brackman scores changed from VI before the operation for all patients to II for two patients and III for four patients. Sunnybrook scores were 0-10 before the operation, but 62-84 at the last visit. Mean FDI scores moved from 24 to 38.5 meaning a statistical high significant improvement (P < .01).

CONCLUSIONS

Masseteric/crossfacial nerve grafting is feasible for patients with palsies 20-24 months in duration, affording satisfactory functional and esthetic results and a dramatic improvement in quality of life.

Inefficient skeletal muscle oxidative function flanks impaired motor neuron recruitment in Amyotrophic Lateral Sclerosis during exercise

This study aimed to evaluate muscle oxidative function during exercise in amyotrophic lateral sclerosis patients (pALS) with non-invasive methods in order to assess if determinants of reduced exercise tolerance might match ALS clinical heterogeneity. 17 pALS, who were followed for 4 months, were compared with 13 healthy controls (CTRL). Exercise tolerance was assessed by an incremental exercise test on cycle ergometer measuring peak O₂ uptake (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙O_2peak), vastus lateralis oxidative function by near infrared spectroscopy (NIRS) and breathing pattern (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙E _peak). pALS displayed: (1) 44% lower \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙O_2peakvs. CTRL (p < 0.0001), paralleled by a 43% decreased peak skeletal muscle oxidative function (p < 0.01), with a linear regression between these two variables (r² = 0.64, p < 0.0001); (2) 46% reduced \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\dot{{\rm{V}}}$$\end{document}V˙E_peakvs. CTRL (p < 0.0001), achieved by using an inefficient breathing pattern (increasing respiratory frequency) from the onset until the end of exercise. Inefficient skeletal muscle O₂ function, when flanking the impaired motor units recruitment, is a major determinant of pALS clinical heterogeneity and working capacity exercise tolerance. CPET and NIRS are useful tools for detecting early stages of oxidative deficiency in skeletal muscles, disclosing individual impairments in the O₂ transport and utilization chain.

Polymeric Supports for Controlled Release of Ethylene for Food Industry

In modern fruit supply chain a common method to trigger ripening is to keep fruits inside special chambers and initiate the ripening process through administration of ethylene. Ethylene is usually administered through cylinders with inadequate control of its final concentration in the chamber. The aim of this study is the development of intelligent polymeric supports able to accurately regulate ethylene concentration in the atmosphere where fruits are preserved. Two different technologies were proposed: a polymeric (PEGDA) film and a polymeric (PLA) bag filled with inclusion complex of ethylene/α-cyclodextrin. The complex was prepared by molecular encapsulation which allows the entrapment of ethylene into the cavity of α-cyclodextrin. After encapsulation, ethylene can be gradually released from the inclusion complex and its release rate can be regulated by temperature and humidity. Intelligent polymeric film was prepared by dispersing inclusion complex into a thin polymeric film produced by UV-curing. Intelligent polymeric bag was made by inserting inclusion complex into heat sealed bag. The kinetics of ethylene release was studied for both systems, showing that it can effectively possible to control the release of ethylene within confined volume. Furthermore, modelling and simulations of ethylene release in a food container were made, demonstrating that it is possible to modulate release rate and, thus, control ripening.

Acute focal brain damage alters mitochondrial dynamics and autophagy in axotomized neurons

Mitochondria are key organelles for the maintenance of life and death of the cell, and their morphology is controlled by continual and balanced fission and fusion dynamics. A balance between these events is mandatory for normal mitochondrial and neuronal function, and emerging evidence indicates that mitochondria undergo extensive fission at an early stage during programmed cell death in several neurodegenerative diseases. A pathway for selective degradation of damaged mitochondria by autophagy, known as mitophagy, has been described, and is of particular importance to sustain neuronal viability. In the present work, we analyzed the effect of autophagy stimulation on mitochondrial function and dynamics in a model of remote degeneration after focal cerebellar lesion. We provided evidence that lesion of a cerebellar hemisphere causes mitochondria depolarization in axotomized precerebellar neurons associated with PTEN-induced putative kinase 1 accumulation and Parkin translocation to mitochondria, block of mitochondrial fusion by Mfn1 degradation, increase of calcineurin activity and dynamin-related protein 1 translocation to mitochondria, and consequent mitochondrial fission. Here we suggest that the observed neuroprotective effect of rapamycin is the result of a dual role: (1) stimulation of autophagy leading to damaged mitochondria removal and (2) enhancement of mitochondria fission to allow their elimination by mitophagy. The involvement of mitochondrial dynamics and mitophagy in brain injury, especially in the context of remote degeneration after acute focal brain damage, has not yet been investigated, and these findings may offer new target for therapeutic intervention to improve functional outcomes following acute brain damage.

The masseteric nerve: a versatile power source in facial animation techniques

The masseteric nerve has many advantages including low morbidity, its proximity to the facial nerve, the strong motor impulse, its reliability, and the fast reinnervation that is achievable in most patients. Reinnervation of a neuromuscular transplant is the main indication for its use, but it has been used for the treatment of recent facial palsies with satisfactory results. We have retrospectively evaluated 60 patients who had facial animation procedures using the masseteric nerve during the last 10 years. The patients included those with recent, and established or congenital, unilateral and bilateral palsies. The masseteric nerve was used for coaptation of the facial nerve either alone or in association with crossfacial nerve grafting, or for the reinnervation of gracilis neuromuscular transplants. Reinnervation was successful in all cases, the mean (range) time being 4 (2-5) months for facial nerve coaptation and 4 (3-7) months for neuromuscular transplants. Cosmesis was evaluated (moderate, n=10, good, n=30, and excellent, n=20) as was functional outcome (no case of impairment of masticatory function, all patients able to smile, and achievement of a smile independent from biting). The masseteric nerve has many uses, including in both recent, and established or congenital, cases. In some conditions it is the first line of treatment. The combination of combined techniques gives excellent results in unilateral palsies and should therefore be considered a valid option.

Selective deep lobe parotidectomy for pleomorphic adenomas

The authors' experience of the selective deep lobe parotidectomy for the treatment of pleomorphic adenomas of the deep parotid lobe is presented. A retrospective analysis of 11 patients treated between 1997 and 2010 was performed; seven were males and four were females, ranging in age from 35 to 51 years. Parameters evaluated included facial nerve weakness, the occurrence of Frey's syndrome, cosmetic outcome, and recurrence. Follow-up ranged from 18 months to 11 years. No major complications, permanent facial nerve weakness, or Frey's syndrome occurred. Four patients developed temporary facial nerve impairments that lasted between 2 and 6 weeks, and two developed a sialocele that healed in 9 days in one case and 12 days in the other. The overall cosmetic assessment was excellent in eight patients, good in two, and satisfactory in the remaining one. No recurrences occurred. The selective deep lobe parotidectomy can be considered an effective technique for the management of deep parotid lobe pleomorphic adenomas. The major advantages of this procedure include a reduction in complications such as facial nerve impairments and Frey's syndrome, and an improved cosmetic outcome.

Orthognathic surgery for the complete rehabilitation of Moebius patients: principles, timing and our experience

Moebius syndrome is a rare disorder found in approximately 1/100,000 neonates and the treatment of facial palsy is now well established worldwide and consists of free-muscle transplants reinnervated with motor nerves. Dentofacial deformities are often detected in Moebius patients, and different degrees of micrognathia are often present, particularly in patients with complete expressions of Moebius syndrome. However only two published reports have described the surgical treatment of such anomalies in these patients; in both cases, the suggested approach consisted of orthognathic surgery followed by soft-tissue management. In this paper we discuss the indications and correct timing of orthognathic surgery and suggest to perform facial animation at an early age and then to wait for the completion of maxillofacial skeletal growth before performing orthognathic surgery. Finally, facial animation should precede orthognathic surgery in adult patients to prevent lower lip deformities and to ensure more predictable and satisfactory results.