Osseous Union after Jaw Reconstruction with Fibula-Free Flap: Conventional vs. CAD/CAM Patient-Specific Implants.

This is a monocentric, retrospective study of patients who underwent successful immediate or delayed maxilla or mandible reconstructions with FFF from January 2005 to December 2021. Panoramic radiograph, computed tomography scans, and cone-beam CTs were analyzed concerning the osseous union of the intersegmental junctions between maxillary or mandibular native jaw and fibular bone. The primary parameter was to estimate the status of osseous union according to osteosynthesis type. A total number of 133 patients (PSI: n = 64, non-PSI: n = 69) were included in the present study. The mean age was 56.7 ± 14.0 (Range: 14.7−82.7); the primary diagnosis was in 105 patients a malignant (78.9%) and in 20 patients a benign (15.0%) tumor. Mandible reconstruction was performed on 103 patients (77.4%), and on 30 patients (22.6%), maxilla reconstruction was performed. The radiographic images provided a rate of incomplete osseous union (IOU) of about 90% in both groups in the first 6 months. Imaging between 6 and 12 months reveals an IOU rate in the non-PSI group of 46.3% vs. 52.5% in the PSI group, between 12 and 24 months, an IOU rate of 19.6% vs. 26.1%, between 24 and 36 months 8.9% vs. 21.7%, and after 36 months the IOU rate decreases to 4.2% vs. 18.2%. Multivariate logistic regression shows that only osteosynthesis type (OR = 3.518 [95%-CI = 1.223−10.124], p = 0.02) and adjuvant radiotherapy (OR = 4.804 [95%-CI = 1.602−14.409], p = 0.005) are independent risk factors for incomplete osseous union. Cox regression revealed that the variables plate-system (Hazard ratio, HR = 5.014; 95 %-CI: 1.826−3.769; p = 0.002) and adjuvant radiotherapy (HR = 5.710; 95 %-CI: 2.066−15.787; p < 0.001) are predictors for incomplete osseous union. In our study, the rate of incomplete bony fusion was significantly higher in the PSI group. Jaw-to-fibula apposition zones were significantly more affected than intersegmental zones. In multivariate analysis, a combination of osteosynthesis with PSI and adjuvant radiotherapy could be identified as a risk constellation for incomplete ossification.

Pain perception following computer-controlled versus conventional dental anesthesia: randomized controlled trial.

BACKGROUND: The administration of local anesthesia (LA) in dental practice requires an injection which is the leading cause of patients' fear and anxiety. Computer-controlled local anesthetic injector, designed to reduce the pain of performing local anesthesia by controlling the speed of injection. This single-blind randomised control trial aimed to compare the pain perception after computer-controlled local anesthesia (CCLA) and conventional LA. METHODS: Dental students were both test and operator group versus an experienced dentist as additional operator of the LA. Data were collected regarding gender, age, medical condition, smoking habits. Additionally, operator feedback about the handling, pain at insertion and during infiltration, excitement (Dental Anxiety Scale), and complications were assessed. RESULTS: Out of the 60 included participants, the majority were females (n = 41; 68.3%), medically healthy (n = 54; 90%), and did not receive medications (n = 54; 90%). While the participating students administered 62 (51.7%) injections, the experienced dentist administered 58 (48.3%) injections. The difference in pain perception on puncture between CCLA and conventional injections was not statistically significant (Sig. = 0.285); however, pain perception during injection was significantly different (Sig. = 0.029) between CCLA (1.65 ± 1.93) and conventional injections (2.49 ± 2.31). CONCLUSION: The professional experience influenced the pain perception while applying the LA. CCLA did not reduce pain on puncture significantly; however, pain perception during the injection was significantly reduced in the case of using CCLA devices compared to the conventional syringe.

Osseous Union after Mandible Reconstruction with Fibula Free Flap Using Manually Bent Plates vs. Patient-Specific Implants: A Retrospective Analysis of 89 Patients.

The aim of this monocentric, retrospective clinical study was to evaluate the status of osseous union in uni- and poly-segmental mandible reconstructions regarding conventional angle-stable manually bent osteosynthesis plates (Unilock 2.0 mm) versus titan laser-melted PSI patient-specific implant's (PSI). The clinical impact of PSI's high stiffness fixation methods on bone healing and regeneration is still not well addressed. The special interest was in evaluating the ossification of junctions between mandible and fibula and between osteotomized fibula free flap (FFF) segments. Panoramic radiograph (OPT), computed tomography (CT) scans, or cone-beam CTs (CBCT) of patients who underwent successful FFF for mandible reconstruction from January 2005 to December 2020 were analyzed. A total number of 89 cases (28 females (31.5%), 61 males (68.5%), mean age 58.2 ± 11.3 years, range: 22.8-82.7 years) fulfilled the chosen inclusion criteria for analysis (conventional: n = 44 vs. PSI: n = 45). The present study found an overall incomplete ossification (IOU) rate of 24.7% (conventional: 13.6% vs. PSI: 35.6%; p = 0.017) for mandible to fibula and intersegmental junctions. Between osteotomized FFF segments, an IOU rate of 16% was found in the PSI-group, while no IOU was recorded in the conventional group (p = 0.015). Significant differences were registered for IOU rates in poly-segmental (p = 0.041), and lateral (p = 0.016) mandibular reconstructions when PSI was used. Multivariate logistic regression analysis identified plate exposure and type of plate used as independent risk factors for IOU. Previous or adjuvant radiotherapy did not impact incomplete osseous union in the evaluated study sample. PSI is more rigid than bent mini-plates and shields functional mechanical stimuli, and is the main reason for increasing the rate of incomplete ossification. To enhance the functional stimulus for ossification it has to be discussed if patient-specific implants can be designed to be thinner, and should be divided into segmental plates. This directs chewing forces through the bone and improves physiological bone remodeling.

Computed Tomography Angiography (CTA) before Reconstructive Jaw Surgery Using Fibula Free Flap: Retrospective Analysis of Vascular Architecture.

Computed tomography angiography (CTA) is widely used in preoperative evaluation of the lower limbs' vascular system for virtual surgical planning (VSP) of fibula free flap (FFF) for jaw reconstruction. The present retrospective clinical study analysed n = 72 computed tomography angiographies (CTA) of lower limbs for virtual surgical planning (VSP) for jaw reconstruction. The purpose of the investigation was to evaluate the morphology of the fibular bone and its vascular supply in CTA imaging, and further, the amount and distribution of periosteal branches (PB) and septo-cutaneous perforators (SCPs) of the fibular artery. A total of 144 lower limbs was assessed (mean age: 58.5 ± 15.3 years; 28 females, 38.9%; 44 males, 61.1%). The vascular system was categorized as regular (type I-A to II-C) in 140 cases (97.2%) regarding the classification by Kim. Absent anterior tibial artery (type III-A, n = 2) and posterior tibial artery (type III-B, n = 2) were detected in the left leg. Stenoses were observed mostly in the fibular artery (n = 11), once in the anterior tibial artery, and twice in the posterior tibial artery. In total, n = 361 periosteal branches (PBs) and n = 231 septo-cutaneous perforators (SCPs) were recorded. While a distribution pattern for PBs was separated into two clusters, a more tripartite distribution pattern for SCPs was found. We conclude that conventional CTA for VSP of free fibula flap (FFF) is capable of imaging and distinguishing SCPs and PBs.

Impact of Planning Method (Conventional versus Virtual) on Time to Therapy Initiation and Resection Margins: A Retrospective Analysis of 104 Immediate Jaw Reconstructions.

Virtual surgical planning (VSP) and patient-specific implants are currently increasing for immediate jaw reconstruction after ablative oncologic surgery. This technique contributes to more accurate and efficient preoperative planning and shorter operation time. The present retrospective, single-center study analyzes the influence of time delay caused by VSP vs. conventional (non-VSP) reconstruction planning on the soft and hard tissue resection margins for necessary oncologic safety. A total number of 104 cases of immediate jaw reconstruction with free fibula flap are included in the present study. The selected method of reconstruction (conventionally, non-VSP: n = 63; digitally, VSP: n = 41) are analyzed in detail. The study reveals a statistically significant (p = 0.008) prolonged time to therapy initiation with a median of 42 days when the VSP method compared with non-VSP (31.0 days) is used. VSP did not significantly affect bony or soft tissue resection margin status. Apart from this observation, no significant differences concerning local tumor recurrence, lymph node, and distant metastases rates are found according to the reconstruction method, and affect soft or bone tissue resection margins. Thus, we conclude that VSP for immediate jaw reconstruction is safe for oncological purposes.

Partial and Total Flap Failure after Fibula Free Flap in Head and Neck Reconstructive Surgery: Retrospective Analysis of 180 Flaps over 19 Years.

Fibula free flap (FFF) is widely used in head and neck reconstructive surgery and is considered as a standard and therapy of choice after ablative cancer surgery. The aim of this retrospective monocenter study was to determine the success rates of fibula free flaps for jaw reconstruction after ablative tumor surgery. The disease course of patients who underwent jaw reconstructive surgery with FFF from January 2002 to June 2020 was evaluated regarding the flap success rate. Flap failure was analyzed in detail and categorized into two groups: partial flap failure (PFF) and total flap failure (TFF). A total of 180 free fibular flaps were performed over the last 19 years and a total of 36 flap failures were recorded. TFF occurred in n = 20 (56.6%) and PFF in n = 16 cases (44.4%) cases. No statistically significant differences were found concerning patients' age at flap transfer, sex, BMI, ASA-Score, preoperative non-virtual or virtual surgical planning (non-VSP vs. VSP), and time of reconstruction (immediately vs. delayed). Duration of hospitalization shows statistically significant differences between both groups (p = 0.038), but no differences concerning operating time and duration on Intensive Care Unit (ICU). Partial flap failure appears to be underreported in literature. Sub- and complete failure of the skin paddle leads to clinical complaints like uncovered bone segments and plate exposure. Partial or complete FFF failure lead to infections on the recipient site and prolonged wound healing and therefore may cause a delay of the beginning of adjuvant radiation therapy (RT). PFF of hard tissue can be induced by RT.

Impact of Periosteal Branches and Septo-Cutaneous Perforators on Free Fibula Flap Outcome: A Retrospective Analysis of Computed Tomography Angiography Scans in Virtual Surgical Planning.

BACKGROUND: Virtual surgical planning (VSP) for jaw reconstruction with free fibula flap (FFF) became a routine procedure and requires computed tomography angiography (CTA) for preoperative evaluation of the lower limbs vascular system and the bone. The aim of the study was to assess whether the distribution and density of periosteal branches (PB) and septo-cutaneous perforators (SCP) of the fibular artery have an impact on flap success. METHOD: This retrospective clinical study assessed preoperative CTA of the infra-popliteal vasculature and the small vessel system of 72 patients who underwent FFF surgery. Surgical outcome of flap transfer includes wound healing, subtotal, and total flap loss were matched with the segmental vascular supply. RESULT: A total of 72 patients (28 females, 38.9 %; 44 males, 61.1 %) fulfilled the study inclusion criteria. The mean age was 58.5 (± 15.3 years). Stenoses of the lower limbs' vessel (n = 14) were mostly detected in the fibular artery (n = 11). Flap success was recorded in n = 59 (82.0%), partial flap failure in n = 4 (5.5%) and total flap loss in n = 9 (12.5%). The study found a mean number (± SD) of 2.53 ± 1.60 PBs and 1.39 ± 1.03 SCPs of the FA at the donor-site. The proximal FFF segment of poly-segmental jaw reconstruction showed a higher rate of PB per flap segment than in the distal segments. Based on the total number of prepared segments (n = 121), 46.7% (n = 7) of mono-, 40.4% (n = 21) of bi-, and 31.5 % (n = 17) of tri-segmental fibula flaps were at least supplied by one PB in the success group. Overall, this corresponds to 37.2% (45 out of 121) of all successful FFF. For total flap loss (n = 14), a relative number of 42.9% (n = 6) of distinct supplied segments was recorded. Wound healing disorder of the donor site was not statistically significant influenced by the detected rate of SCP. CONCLUSION: In general, a correlation between higher rates of PB and SCP and the flap success could not be statistically proved by the study sample. We conclude, that preoperative PB and SCP mapping based on routine CTA imaging is not suitable for prediction of flap outcome.

A New Type of Chronic Wound Infection after Wisdom Tooth Extraction: A Diagnostic Approach with 16S-rRNA Gene Analysis, Next-Generation Sequencing, and Bioinformatics.

Delayed-onset infections are rare postoperative complications of lower third molar extractions. This article presents a case of a chronic combined hard and soft tissue infection after the extraction of a third molar, where the causative organisms could only be elucidated by molecular methods. Experimental 16S-rRNA gene analysis with next-generation sequencing and bioinformatics was used to identify the bacterial spectrum of the infection. 16S-rRNA gene analysis delivered the microbiome of the abscessing inflammation while standard culture and laboratory examinations were all sterile. The microbiome showed a mixed bacterial infection with a dominance of Delftia and Alcanivorax (spp.) besides other bacteria of the normal oral flora. Using 16S-rRNA-gene analysis, next-generation sequencing, and bioinformatics, a new type of chronic wound infection after wisdom tooth extraction was found. The property of Delftia and Alcanivorax (spp.) as water-affine environmental bacteria raises suspicion of infection from contaminated water from a dental unit. Thus, osteotomies of teeth should only be done with sterile cooling water. The 16S-rRNA gene analysis should become a part of the routine diagnostics in medical microbiology.

Heterotopic Ossification of the Vascular Pedicle after Maxillofacial Reconstructive Surgery Using Fibular Free Flap: Introducing New Classification and Retrospective Analysis.

Heterotopic ossification (HO) is one of the described phenomena after maxillofacial reconstructive surgery using fibular free flap (FFF) at the reception-site. The aim of this study was to determine the radiological incidence and form of HO along the fibular vascular pedicle as well as the rate of clinical symptoms if present. CT-scans of 102 patients who underwent jaw reconstructive surgery by using FFF from January 2005 to December 2019 were evaluated concerning the presence of HO. Subsequently, the patient files were evaluated to identify the cases with clinical signs and complications related to the presence of HO. A radiological classification of four different HO types was developed. Out of 102 patients, 29 (28.43%) presented radiological findings of HO. Clinical symptoms were recorded in 10 cases (9.8%) (dysphagia (n = 5), trismus (n = 3), bony masses (n = 2)) and from these only five (4.9%) needed surgical removal of calcified structures. HO occurs significantly in younger patients (mean 52.3 year). In maxillary reconstructions, HO was radiologically visible six months earlier than after mandibular reconstruction. Furthermore, HO is observed after every third maxilla and every fourth mandible reconstruction. This study developed for the first time a classification of four distinct HO patterns. HO types 1 and 2 were mostly observed after mandible reconstruction and type 4 predominantly after maxilla reconstruction.

Ex corpore linguae: A cohort analysis after a unique surgical technique in oral cancer resection.

OBJECTIVE: Resection of posteriorly located oral squamous cell carcinomas (OSCCs) remains challenging for head and neck surgeons. However, several surgical techniques, such as lip and mandibular splitting, as well as submental "visor drop-down" of intraoral soft tissues, have been proposed for this purpose. Merrick et al. suggested that a pedicled genial drop-down surgical approach should be used to resect dorsally located OSCCs. Our study investigated patient outcomes following this surgical procedure, as no previous study has analyzed long-term follow-up data. MATERIAL AND METHODS: All patients who underwent surgery using the pedicled genial "visor drop-down" approach at the Maxillofacial Department of the University Hospital Giessen in Germany between 1995 and 2010 were included in this study. In addition, our study required that patients diagnosed with OSCC had no history of other intraoral malignancy or any other form of malignancy. A preliminary questionnaire was completed for each patient based on retrospective analysis of available data from medical reports. RESULTS: A total of 51 patients fulfilled all inclusion and exclusion criteria and were evaluated retrospectively. In total, 32 patients were excluded from the study due to OSCC recurrence or acquisition of a different type of malignancy. The male to female distribution of patients in our study was 30 to 21 (58.8%-41.2%), and the mean ages of female and male patients were 57.7 (SD 14.3) and 55.7 (SD 14.4) years, respectively. Approximately 76.5% of tumors were located along the dorsal aspect of the tongue, 17.6% were along the floor of the mouth, 3.9% were in the dorsal mandibular region, and 1.9% were in the dorsal palatal region. The mean overall operation time was 6.25 h, and 28 patients received microvascular flaps for reconstruction. Results of final histopathological examination suggested primary in-sano resection of the tumor in 84.3% of patients. Overall, the 5-year postoperative survival rate was 52.9%; 31.3% of the patient cohort was not followed up for the full 5-year period. In addition, 15.7% of the patients included in our study died during the study period. Unimpaired functional outcomes in terms of swallowing and speech were observed in 86.3% of patients. CONCLUSION: The pedicled genial "visor drop-down" approach, also known as the ex corpore linguae, is a suitable method for the radical resection of dorsally located OSCCs, with a promising 5-year survival rate and satisfactory postoperative oral function.

Incidence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in patients taking bisphosphonates for osteoporosis treatment - a grossly underestimated risk?

PURPOSE: The aim of this study was to detect the incidence of bisphosphonate-related osteonecrosis of the jaws (BRONJ) in association with osteoporosis in 2009 in the rural district of Marburg-Biedenkopf, Germany. In addition, the therapeutic regimen of dentists in this area was compared to the treatment guidelines of established international associations. METHODOLOGY: A postal survey including 129 dental offices within the named investigation area was conducted. Additionally, the dentists were asked to contribute to this study during a course of retraining. Ultimately, 107 colleagues participated in this study. RESULTS: A total of 37 BRONJ cases were revealed, 37.4 % of those were linked to malignant diseases, 62.6 % to osteoporosis. Noticeably, 30.1 % of the BRONJ cases linked to osteoporosis were connected with intravenous application. In total, 62.6 % of all cases were associated with intravenous and 37.4 % with oral application. Considering the estimated number of 1.014 patients using bisphosphonates for osteoporosis treatment in Marburg-Biedenkopf in 2009, the specific incidence of BRONJ could be narrowed down to about 2.27 %. In proportion to the increasing risk potential of the three patient groups, participants conducted fewer surgical interventions themselves but tended to refer patients to colleagues. CONCLUSION: This study reveals the incidence of BRONJ in association with osteoporosis as being grossly underrated so far, especially in connection with intravenous bisphosphonate treatment. The therapeutic regimen of the dentists who participated correlated with the established guidelines. CLINICAL RELEVANCE: The interface between dentistry and medicine may profit from our study's results which will help to improve interdisciplinary communication. With regard to this, we wish to contribute to an informative discussion since a main focus was to ensure colleagues in their decision making, especially in case of complications after elective dentoalveolar surgery-like implantations. Besides medical there are also economic and political aspects, i.e. the financial responsibility in case of unexpected or inevitable complications, possibly leading to BRONJ, that may become part of future discussions based on this study.