Controversies in ameloblastoma management: evaluation of decision making, based on a retrospective analysis.

BACKGROUND: The ameloblastoma management is still challenging to the high recurrence rates and significant morbidity associated with radical treatment. The purpose of this 10-year retrospective study was to analyze the influence of ameloblastoma type and treatment strategy on the long-term outcomes and recurrence rates. MATERIAL AND METHODS: The retrospective analyses of 64 histologically-confirmed ameloblastoma cases was performed. The possible risk factors for recurrence and the development of complications were estimated statistically. RESULTS: The treatment strategy applied for this group of patients was the following: thirty-four patients (53.1%) were treated conservatively with enucleation or extended bone curettage. Radical treatment (bone resection) was applied in 30 (46.9%) cases. The follow-up period ranged from 2 to 10 years (mean value 4.28 ± 3,26). General recurrence rate consisted 32.8%. This study did not find significant correlations between clinical or histopathological features of the ameloblastoma and the recurrence rate. The only factor that significantly influence recurrence rate was the treatment strategy (41% in conservative treatment vs 15% in radical treatment, p<0.05). Postoperative complications were observed in 42 patients (65.6%) and included face asymmetry and disfigurement (17.2%), temporary paresthesia of the inferior alveolar nerve (IAN) - 23.4%, permanent paresthesia of IAN - 20.3%, paresis of a marginal branch of the facial nerve - 6.3%, infection 12.5%, and swelling - 20.3%. The complication rates, esthetic and functional deficiency were significantly higher in radically treated patients (p<0.05) Conclusions: Our study confirms that higher recurrence rate is associated with conservative treatment for ameloblastoma, while radical treatment leads to an increased number of postoperative complications that affect the patient's quality of life.

Epidemiology of maxillofacial trauma in the elderly: A European multicenter study.

INTRODUCTION: The progressive aging of European population seems to determine a change in the epidemiology, incidence and etiology of maxillofacial fractures with an increase in the frequency of old patients sustaining craniofacial trauma. The objective of the present study was to assess the demographic variables, causes, and patterns of facial fractures in elderly population (with 70 years or more). MATERIALS AND METHODS: The data from all geriatric patients (70 years or more) with facial fractures between January 1, 2013, and December 31, 2017, were collected. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, etiology, site of facial fractures, synchronous body injuries, Facial Injury Severity Score (FISS). RESULTS: A total of 1334 patients (599 male and 735 female patients) were included in the study. Mean age was 79.3 years, and 66% of patients reported one or more comorbidities. The most frequent cause of injury was fall and zygomatic fractures were the most frequently observed injuries. Falls were associated with a low FISS value (P<.005). Concomitant injuries were observed in 27.3% of patients. Falls were associated with the absence of concomitant injuries. The ninth decade (P<.05) and a high FISS score (P<.005) were associated with concomitant body injuries too. CONCLUSIONS: This study confirms the role of falls in the epidemiology of facial trauma in the elderly, but also highlights the frequency of involvement of females, and the high frequency of zygomatic fractures.

Management of mandibular condylar fractures in patients with atrophic edentulous mandibles.

INTRODUCTION: Treatment of condylar fractures in patients with atrophic edentulous mandibles is a peculiar field that has been little considered in the literature. The aim of the study was to assess the demographic and clinical variables as well as management and outcome of mandibular condylar fractures in edentulous patients with atrophic mandibles that were treated at several European departments of oral and maxillofacial surgery. METHODS: The data of all patients with fractures of the atrophic edentulous mandible from the involved maxillofacial surgical units across Europe between January 1, 2008, and December 31, 2017. Only patients that were diagnosed with condylar fractures of the edentulous atrophic mandible were included. RESULTS: A total of 52 patients met the inclusion criteria and were included in the study: 79% of patients reported one or more comorbidities. Thirty-four unilateral neck or subcondylar fractures, 9 bilateral neck or subcondylar condylar fractures, 7 unilateral head condylar fractures, and 2 bilateral head condylar fractures were diagnosed. No treatment was performed in 37 cases, whereas in 4 patients a closed treatment was decided, and 11 patients underwent open reduction and internal fixation. Outcome was considered to be satisfying in 48 patients, with no complications. CONCLUSIONS: The golden rule still remains that the diagnosis of a subcondylar or neck fracture in an edentulous patient should constitute an indication for open reduction and internal fixation. However, an appropriate choice of management options has to be individualized on a case by case basis, also depending on the patient consent.

A comparative biomechanical evaluation of different osteosynthesis techniques used for intracapsular condylar head fractures.

PURPOSE: The aim of the present experimental study was to evaluate the biomechanical behavior in different types of osteosynthesis (titanium screws, bioresorbable pins and miniplates) used in management of intracapsular condylar head fractures. METHOD: Experimental models of the condylar head fractures were simulated on 15 dry human cadaveric mandibles. Osteotomized mandibles were randomly divided into three groups with different fixation systems used: 1) 15 mm long titanium screws, 2) 15 mm long bioresorbable pins Sonic Pins Rx, 3) T-shaped titanium miniplate and 7 mm long titanium screws. Mandibles were loaded in TIRAtest testing machine (Germany). The main types of deformations, including torsion, bending and shearing, were simulated to study the biomechanical characteristics of the fixation systems. RESULTS: Titanium bicortical screws demonstrated the highest stiffness in standard loading conditions. The fixation with bioresorbable pins showed lower stiffness in both frontal and sagittal loads. This is indicative of the fact that resorbable pins, which have numerous advantages for clinical usage, cannot provide adequately stable fixation in maximal masticatory loads. The mandibles fixed with T-shaped plate had the lowest stiffness. CONCLUSION: Screw or pin fixation, regardless of the material used, was not resistant to rotational loads. On the contrary, the stiffness of T-shaped plates was quite significant. In real clinical conditions, if rotational displacements are not effectively compensated by irregularities in the fracture surface and precise repositioning of the bone fragments, combined use of miniplates and bicortical titanium screws or two screws can be beneficial.

Quantification of the mandibular defect healing by micro-CT morphometric analysis in rats.

PURPOSE: The goal of this study was the evaluation of the bone tissue structural characteristics over the time course of mandibular defect healing using micro-CT technique, as well as determination of the inter-relationships between different micro-CT parameters used for assessment of the bone regeneration process and the patterns of their dynamic changes. MATERIALS AND METHODS: The body and ramus of the mandible was exposed in 24 Wistar rats. A 2-mm full thickness bony defect was created. Animals were randomized into four groups, which were ended 3, 6, 12 and 24 weeks after operation. The mandible was excised and underwent micro-CT analysis. For statistical evaluation, the Mann-Whitney U test, polynomial or exponential regression and Spearman analysis were applied. RESULTS: The absolute volume of the bone regenerate increased from 1.69 ± 0.53 mm3 (3 weeks) to 3.36 mm3 ± 0.56 (6 months), as well as percentage of bone volume, increased significantly from 12.5 ± 2.3% at the 3-week term to 26.4 ± 8.7% at the 3-month term or 23.1 ± 8.7% at the 6-month term. Structural (trabecular) thickness gradually increased from 0.13 ± 0.007 mm at the 3-week term to 0.3 ± 0.11 mm at the 6-month term. The structural model index was 0.79 ± 0.46 in the early phase after trauma and then decreased to negative values. CONCLUSION: The bone regeneration process was characterized by a significant increase (p < 0.05) in bone volume, percentage of bone volume, structural thickness and bone mineral density, and a decrease in bone surface-to-volume ratio and volume of pore space from the 3-week term to the 6-month term. These changes can be mathematically described by nonlinear exponential regression models.

[Postradial sialozoadenitis in patients with papillary carcinoma of the thyroid gland].

The authors present the results of investigation of 42 patients with salivary gland dysfunction after radioactive iodine-131 ablation therapy concerning papillary thyroid carcinoma. Clinical manifestations of postradial sialodenitis with secretory insufficiency of different degree were revealed. These side effects required an application of the special therapy.

[Immediate and long-term results of surgical treatment of patients for traumatic mandibular fracture].

The analysis of immediate and long-term results of the surgical treatment of 286 patients, operated for traumatic mandibular fractures in the Department of Oral and Maxillofacial Surgery, National O. O. Bogomolets Medical University. In 67% of patients the anatomical shape of the bone was adequately restored. The presence of residual displacements in other cases was determined by the fracture type and localization, the technical complexity of the surgical intervention, lack of fixation rigidity under certain functional load conditions. In long terms of observation the infection and inflammatory complications were observed in 13.4% of patients, delayed unition and non-unition of bone fragments occurred--in 4.7%, arthosis with persistent dysfunction of the temporomandibular joint--in 6.7%, fibrous ankylosis--in 1.3%. Secondary displacement of fragments was observed in 23.5% of patients due to insufficient stiffness and reliaability of the bone-fixatorsystem. The non-precise reposition of fragments and secondary displacements in the early and late postoperative period were the main cause of occlusal disturbances of various severities, noted in 28% of operated patients, limitation of mouth opening (10%), TMJ disorders and changes in masticatory stereotype (33%), the sensation of pain and discomfort in tough food chewing (35%). A statistical analysis of the effectiveness of different osteosynthesis methods depending on the type and localization of the fracture was carried out and recommendations for usage of fixation devices in clinical practice were given.

[Determination of regimes of functional loading in the patients with traumatic mandibular fractures after osteosynthesis performance using modern methods of computer modeling].

There are presented the modern possibilities of application of the computeric modeling methods, including CAD/CAM/CAE technologies, in the planning of osteosynthesis and determination of the functional loading regimes in the patients, suffering traumatic mandibular fracture. Virtual models of the systems "bone-fixator", created on the ground of analysis of the spiral CT and functional investigations data, have had demonstrated highly precisely the anatomic peculiarities of the patients chewing system, ununiform physicomechanical properties of the fractures bone tissues and conditions of functional loading while the teeth closure. Mathematical calculations, conducted on the models, have permitted to estimate the value and character of the local pressure and deformity, occurring in the system elements, and to estimate its rigidity and safety in conditions of the chewing load. The model calculations were taken in account while choosing the patients rehabilitation regimes in posttraumatic period. Clinical investigations, conducted in immediate and late follow-up periods after the operation, have confirmed the trustworthiness of the model calculations and possibility of the method application while decision making in complex, atypical clinical settings.

[Medical errors and complications in surgical treatment of traumatic fractures of the mandibula].

There were the data adduced concerning the rate and character of the physician mistakes and complications while surgical treatment of the mandibula fractures. The main causes of the physician mistakes occurrence and the ways of their prophylaxis were determined. There was established, that the physician mistakes rate while performing mandibular ostheosynthesis constitutes 32.8%, in 6.8% of the observations the negative outcomes elimination demands the essential prolongation of the treatment period, reoperations performance of the dental malocclusion correction, using orthopedic or orthodontic methods. The majority of mistakes, afforded intraoperatively, constitute the outcome of nonadequate preoperative diagnosis and planning of the treatment measures. There are discussed the possibilities of application of modern methods of computeric diagnosis and virtual modeling of surgical interventions for minimization of intraoperative risk and reduction of the mistakes and complications rate of the mandibular fractures surgical treatment.

[Surgical treatment of mandibular fractures in its portions of the body and angle].

The data about surgical treatment efficacy for mandibular fractures in portions of the body and the angle, depending on the trauma character and the method of osteosynthesis applied, were adduced. The main criteria, according to which the surgical interventions efficacy was estimated, were: the reposition accuracy, stability of the fragments fixation invasiveness, and the operation duration, The results of treatment of biomechanically-favorable linear fractures, occurring perpendilular to the mandibular axis, are trustworthy better (P < 0.05) than such of biomechanically-unfavorable oblique, fragmental fractures with the bone defects. Effective treatment of a biomechanically-favorable fractures is possible to guarantee using installation of one miniplate on the site of external oblique line. In biomechanically-unfavorable fractures the necessity have appeared to increase the fixing plates quantity, their rigidity raising or the functional restrictions introduction postoperatively.

[Expert systems as the instrument for postop diseases]. / Ekspertna systema iak zasib diahnostyky khirhichnykh zakhvoriuvan'.

There was proposed an expert system for conduction of differential diagnosis of surgical diseases, stimulating the mathematic models creation, the filling up of tables of the features values of all diagnostic hypothesis possible with subsequent staged exception of the least adequate of them. The expert diagnostic system proposed may be applied in clinical practice and pedagogic process while teaching of students.

[Antimicrobial action of ozone in the treatment of mandibular fracture]. / Antimikrobnoe deistvie ozona pri lechenii pereloma nizhnei chelusti.

During experiment in vitro and in the clinical environment in patients with the mandibula fracture there were studied up antimicrobic action of the ozonized distilled water, the ozone concentration in which had constituted 0.3 mg/l. Ozonecontaining solution was used in the form of small baths and gargles instead of conventional antiseptic solutions. While local application the pronounced antimicrobic action of ozone was noted. Additionally there was established immunomodulating action of ozone on the local immunity factors in oral cavity, demonstrated by the rise of the secretory immunoglobulin A (SIgA) level and by lowering of the serum immunoglobulins in saliva. This had witnessed the rise of resistance and lowering of expression of the mucosal inflammatory changes. In patients, to whom the conventional treatment was done, the immunologic indexes dynamics was opposite, witnessing presence in them posttraumatic immunodepression. The comparison of data, obtained in the clinic and in experiment, permits to suggest, that antimicrobic action of ozone is mostly mediated via the local immunity activization.

[Pathomorphological aspects of the inflammatory process in soft tissues during the ozone application in the experiment]. / Patomorfologicheskie osobennosti techeniia vospalitel'nogo protsessa v miagkikh tkaniakh pri vozdeistvii ozonom v éksperimente.

In 35 white rats of Wistar line abscess of soft tissues was modelled. In animals of principle group influence of ozone-oxygenous gaseous mixture with concentration of ozone 0.1 mg/m3 times daily during 10 min were applied. While applicating ozone were noted reduction of exudative reaction and more rapid change of inflammatory phase, more early formation and maturation capsule around necrotic zone, than in control group, that promoted effective delineation of damage focus and enhancement of the inflammatory and dystrophic changes severity in tissues surrounding abscess.