Technical aspects and indications for distration osteogenesis

With the introduction of distraction osteogenesis in oral and maxillofacial surgery in the mid 1990s, especially for the treatment of congenital malformations, there was initially a rapid development in the vertical alveolar distraction procedures based on the TRACK (Tissue Regeneration by Alveolar Callus distraction) distractors, which were seen as a preimplantologic grafting procedure. Because the treatment requires high surgical skill and intensive patient care in the postoperative follow-up, the procedure is now used selectively for particular indications. With precise indications, especially in the case of multiple previous surgeries, this method is superior to the other augmentation techniques in terms of complications and the possible vertical defect height reconstruction

3-D based minimally invasive one-stage lateral sinus elevation - A prospective randomized clinical pilot study with blinded assessment of postoperative visible facial soft tissue volume changes

Objective: The purpose of this prospective and randomized clinical study was to assess differences in patient morbidity between minimally invasive lateral sinus elevation (study group, n = 14) and conventional one-stage lateral sinus elevation (control group, n = 12). It was hypothesized that trauma to soft tissue was reduced in the study group. Materials and methods: Optical 3-D imaging was assessed blinded on days 1 and 7 after surgery to determine the visible soft tissue swelling of the upper lip and cheeks. Postoperative pain and discomfort were evaluated by a visual analogue scale (VAS; scale 0-10). Results: Immediately and on day 1 after surgery, the study group patients rated pain and discomfort as 2.4 [SD 1.7] and 3.1 [SD 2.1], respectively, on the VAS; while, the controls rated 4 [SD 1.6] and 5.6 [SD 1.7], respectively. The mean facial soft tissue volume change, assessed on day 1 after surgery, was 5.0 cm(3) [range: 0.2-9.2] for the study group and 15.5 cm(3) (9.3-21.55) for the controls (p = 0.00). Conclusions: Despite the small number of patients in this prospective study, 3-D based minimally invasive one-stage lateral sinus elevation resulted in favourable patient morbidity with less postoperative visible facial soft tissue volume changes. (c) 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

A 5-year prospective radiographic evaluation of marginal bone levels adjacent to parallel-screw cylinder machined-neck implants and rough-surfaced microthreaded implants using digitized panoramic radiographs

Objective: The purpose of this split-mouth study was to compare macro- and microstructure implant surfaces at the marginal bone level over five years of functional loading. Materials and methods: From January to February 2006, 133 implants (70 rough-surfaced microthreaded implants and 63 machined-neck implants) were inserted in the mandible of 34 patients with Kennedy Class I residual dentitions and followed until December 2011. Marginal bone level was radiographically determined at six time points: implant placement (baseline), after the healing period, after six months, and at two years, three years, and five years follow-up. Results: Median follow-up time was 5.2 years (range: 5.1-5.4). The machined-neck group had a mean crestal bone loss of 0.5 mm (0.0-23) after the healing period, 1.1 mm (0.0-3.0) at two years follow-up, and 1.4 mm (0.0-2.9) at five years follow-up. The rough-surfaced microthreaded implant group had a mean bone loss of 0.1 mm (-0.4 to 2.0) after the healing period, 0.5 mm (0.0-2.1) at two years follow-up, and 0.7 mm (0.0-2.3) at five years follow-up. The two implant types showed significant differences in marginal bone levels. Conclusions: Rough-surfaced microthreaded design caused significantly less loss of crestal bone levels under long-term functional loading in the mandible when compared to machined-neck implants. (C) 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

Lingual concavities in the mandible: A morphological study using cross-sectional analysis determined by CBCT

Background: Lingual undercuts are common in the edentulous mandible and pose the risk of perforating the lingual cortical bone during insertion of dental implants, which may lead to hemorrhage or infections of the parapharyngeal space. The aim of our study was to determine the occurrence and extent of lingual undercuts in the molar and premolar/canine region of the mandible. Methods: We analyzed 716 cross-sections of the edentulous molar region and 215 cross-sections of the edentulous first premolar/canine region. Mandibular morphology was classified into a U-configuration (undercut), P-configuration (parallel), and C-configuration (convex), depending on the shape of the alveolar ridge. Depth of the lingual concavity, concavity angle, and further parameters were measured to describe the mandibular morphology. Results: Lingual undercuts had a prevalence of 68% in the molar region. The prevalence was significantly higher in the second molar region (90%) than in the first molar region (56%). A deep position of the inferior alveolar nerve close to the basal cortical bone was significantly associated with the presence of lingual undercuts. Conclusion: Lingual undercuts are a frequent in the edentulous mandible. Cross-sectional analysis of three-dimensional radiographs provides the opportunity to determine a lingual undercut and to prevent complications of perforating the lingual cortical bone. (C) 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

The importance of lymph node ratio for locoregional recurrence of squamous cell carcinoma of the tongue

Introduction: Locoregional recurrence plays a key role in treatment failure of patients with squamous cell carcinoma of the tongue. In a large amount of studies lymph node ratio could be demonstrated as a promising parameter to stratify risk of patients with oral cavity cancer. However data on the influence of lymph node ratio on locoregional recurrence of tongue squamous cell carcinoma is very rare. Material and methods: Retrospective chart review of 130 patients with treatment naive squamous cell carcinoma of the tongue. Exclusion criteria were neoadjuvant chemoradiotherapy, perioperative death, N3 disease, unresectable disease, synchronous malignancy, follow up < 3 months. Contingency tables and chi(2)-test were performed to analyze associations between clinicopathological features and recurrence. All statistic were 2-sided and a p-value < 0.05 was considered as significant. Multivariate analysis was performed using binary logistic regression analysis. A cut off value of 6% for lymph node ratio was applied. Results: Significant correlations were found between locoregional recurrence and pathologic N-Classification (< 0.001), UICC stage (< 0.001), perineural invasion (p = 0.025), grading (p = 0.001), number of resected lymph nodes (p = 0.007) and lymph node ratio (p < 0.001). Multivariate analysis indicated lymph node ratio as solely independent risk factor for locoregional recurrence. Conclusions: Lymph node ratio may be an useful parameter to stratify risk of locoregional recurrence of patients with squamous cell carcinoma of the tongue. Thus lymph node ratio might help to improve diagnosis and therapy of affected patients. (C) 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

Importance of lymph node ratio for locoregional recurrence of squamous cell carcinoma of the buccal mucosa

Background: There is no published study on the influence of lymph node ratio on locoregional recurrence of squamous cell carcinoma (SCC) of the buccal mucosa. Therefore, we focused in our study on this specific anatomic subsite. Methods: We conducted a retrospective chart review of 95 patients from 2003-2013 with treatment-naive SCC of the buccal mucosa. Exclusion criteria were neoadjuvant chemoradiotherapy, perioperative death, N3 disease, unresectable disease, synchronous malignancy, and follow-up <3 months. Statistical analysis was performed using univariate and multivariate analysis. Results: Significant correlations were found between locoregional recurrence and pathologic N classification (P < .001), grading (P = .001), and lymph node ratio (P < .001). Multivariate analysis indicated lymph node ratio as an independent risk factor for locoregional recurrence (P = .002). A cutoff value under 7% led to a 10.383-fold higher risk of incurring a locoregional recurrence. Conclusion: Lymph node ratio is a useful parameter to stratify the risk of locoregional recurrence in patients with SCC of the buccal mucosa

3D-based full-guided ridge expansion osteotomy - A case report about a new method with successive use of different surgical guides, transfer of splitting vector and simultaneous implant insertion

For horizontal bone deficiency alveolar ridge osteotomy is considered an option for augmentation. Major advantages are the option for a one-stage approach and the absence of donor site morbidity. However, the conventional technique is associated with complications such as perforations and fractures of the cortical bone. A case using a 3D based modified, full-guided alveolar ridge expansion is described to explain the technique step by step. Main features of modified technique: successive application of surgical guides for ridge osteotomy and expansion - implementation of virtually determined splitting vector, which allows guided bone splitting along a guide surface of template in an ideal direction - osteotomy as deep as implant length. The example shows that the 3D based modified alveolar ridge osteotomy is a suitable alternative to the conventional technique as it has several advantages such as fewer fractures and perforations of the cortical vestibular bone. The individualized preoperative planning helps to minimize complications. However, long-term outcomes and a study, conducted on a study group, is needed to evaluate the benefits of our presented treatment protocol. (C) 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

Intraoperative Ultrasound Control of Zygomatic Arch Fractures: Does Additional Imaging Improve Reduction Quality?

Purpose: Intraoperative navigation to assess anatomic reduction is the general trend in maxillofacial trauma surgery. The aim of this study was to evaluate the closed reduction outcome of isolated zygomatic arch fractures using ultrasound compared with palpation control. Materials and Methods: In this case-and-control study, the authors identified consecutively treated patients who underwent closed reduction of isolated zygomatic arch fractures using the Volkmann reposition hook with intraoperative ultrasound. Controls were patients with the same diagnosis and surgical procedure without ultrasound imaging. Pre- and postoperative radiographic datasets were geometrically analyzed. The outcome variables postoperative cortical step, persistent postoperative displacement, and overall grade of reduction were compared in the 2 study groups. Subgroups of fracture patterns were classified as M-shaped or variable. Statistical analysis was performed using t test for continuous variables and 2-sided chi(2) test for categorical variables, with a P value less than .05 defined as significant. Results: Sixteen cases with intraoperative ultrasound and 60 controls were identified from the institution's database. The angle of postoperative displacement was significantly decreased in the ultrasound group for all fractures (2.4 degrees vs 5.3 degrees; P = .004) and the variable fracture type (1.6 degrees vs 8.1 degrees; P = .005). Overall grade of reduction was improved in the ultrasound group for all fractures (P = .03) but with no difference solely for M-shaped fractures (P = .37). Conclusions: Although reduction control using palpation and probing using the Volkmann hook showed satisfactory results for M-shaped fractures, additional intraoperative ultrasound imaging showed promise for increasing success rates for the variable type of zygomatic arch fracture. (C) 2018 American Association of Oral and Maxillofacial Surgeon

Analysis of clinicopathological risk factors for locoregional recurrence of oral squamous cell carcinoma - Retrospective analysis of 517 patients

Introduction: Recurrence is one of the main reasons for poor prognosis of OSCC. The mortality rate is approximately 90% and the 5-year overall survival rate decreases from 90% to 30% when recurrence is diagnosed. Identification of clinicopathological risk factors predicting recurrence may be helpful for patient individualized management and improvement of therapy. Therefore we investigated in our study the incidence of locoregional recurrences and their association with clinicopathological factors to identify possible significant risk factors. Material and methods: Our retrospective study consisted of 517 patients, who were diagnosed and treated between 2003-2013 at the Department for Oral and Maxillofacial Plastic Surgery, University of Cologne. Inclusion criteria were patients with treatment naive oral squamous cell carcinoma and primarily curative intended surgery with negative resection margins. Contingency tables and chi(2)-test were performed to analyse associations between clinicopathological features and recurrence. Multivariate analysis was performed using binary logistic regression analysis. Results: We found out a significant correlation in univariate analysis between locoregional recurrence and number of resected cervical lymph nodes (p - 0.013), number of positive cervical lymph nodes (p - 0.041), postoperative radiatio (p - 0.018), extracapsular spread (p - 0.028) as well as grading (p - 0.016). In multivariate analysis only grading was shown as independent risk factor for recurrence. Conclusions: Histological grading has been demonstrated as an independent risk factor for locoregional recurrence in the multivariate analysis. Furthermore, univariate analysis indicated the number of resected and positive lymph nodes, postoperative radiatio and extracapsular spread as significant risk factors. Taking these results into account, the mentioned parameters, especially histological grading, need to be considered for an individualized therapy management of patients with OSCC. (C) 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved

Age-Related Volumetric Changes in Mandibular Condyles

A precise knowledge of the condylar changes with advancing age may improve understanding of pathophysiological alterations of the mandibular condyles. However, the majority of studies focusses on morphological changes, although volumetric analysis based upon cone beam computerized tomography may provide important additional data to characterize mandibular condyles. Therefore, we aimed to provide and compare volumetric data of mandibular condyles of a young and old patient group. This is a retrospective chart review of 195 patients with cone beam computerized tomography between 2007 and 2016. Student t test, analysis of variance, and Pearson correlation test were performed to analyze associations between categorical and continuous variables. P values <0.05 were considered as significant. Volume measurement was performed in a semiautomatic segmentation method with the program ITK-Snap. Side- and sex-specific significant differences between condylar volumes were found both in the young and old patient cohort. Age and posterior occlusal support did not significantly correlate with the condylar volume. Volumetric measurement of the mandibular condyles may serve as an important additional characteristic, derived from 3-dimensional imaging. Significant differences in volumetric measurement of mandibular condyles exist between sex and side, but not in relation to age and occlusal support