Factors influencing the fracture of dental implants

BACKGROUND

Implant fractures are rare but offer a challenging clinical situation.

PURPOSE

To determine the prevalence of implant fracture and the possible risk factors predisposing an implant to a higher fracture risk.

MATERIALS AND METHODS

This retrospective study is based on 2670 patients consecutively treated with implant-supported prostheses. Anatomical-, patient-, and implant-related factors were collected. Descriptive statistics and survival analyses were performed. Generalized estimating equations (GEE) evaluated the effect of explanatory variables on implant fracture.

RESULTS

Forty-four implants (out of 10 099; 0.44%) fractured. The mean ± standard deviation time for fracture to occur was 95.1 ± 58.5 months (min-max, 3.8-294.7). Half of the occurrences of fracture happened between 2 and 8 years after implantation. Five factors had a statistically significant influence on the fracture of implants (increase/decrease in fracture probability): use of higher grades of titanium (decrease 72.9%), bruxism (increase 1819.5%), direct adjacency to cantilever (increase 247.6%), every 1 mm increase in implant length (increase 22.3%), every 1 mm increase in implant diameter (decrease 96.9%).

CONCLUSIONS

It is suggested that 5 factors could influence the incidence of implant fractures: grade of titanium, implant diameter and length, cantilever, bruxism.

Osteoradionecrosis of the jaws--a current overview--Part 2: dental management and therapeutic options for treatment

PURPOSE

The aim of this paper is to explore the current theories about pretreatment assessment and dental management of patients receiving head and neck radiotherapy, and the therapeutic options to treat osteoradionecrosis of the jaws, based on the literature review.

DISCUSSION

Osteoradionecrosis is one of the most serious oral complications of head and neck cancer treatment. Osteoradionecrosis is a severe delayed radiation-induced injury, characterized by bone tissue necrosis and failure to heal. Osteoradionecrosis either stabilizes or gradually worsens and is notoriously difficult to manage. Because most cases occur in patients who were dentulous in the mandible at tumor onset, proper dental management is the single most important factor in prevention.

CONCLUSIONS

Complete dental clearance before treatment is no longer necessary. Controversy exists regarding the management of osteoradionecrosis of the maxillofacial skeleton because of the variability of this condition. The treatment of osteoradionecrosis has included local wound care, antibiotic therapy, surgical procedures, and the administration of hyperbaric oxygenation. Recently, new methods of treatment were introduced, according to the new theory about its pathophysiology.

Central giant cell lesion of the jaws: An updated analysis of 2270 cases reported in the literature

PURPOSE

To review all available data published on central giant cell lesion (CGCL) of the jaws into a comprehensive analysis of its clinical/radiological features, with emphasis on the predictive factors associated with its recurrence.

METHODS

An electronic search was undertaken in 5 databases (February/2018), looking for reporting cases of CGCLs.

RESULTS

A total of 365 publications were included, comprising 2270 lesions. CGCLs were more prevalent in women and the mandible. Cortical bone perforation occurred in 50% of the cases. Marginal/segmental resection was more often performed in larger lesions, and drug therapy was more frequent in small lesions. Recurrence was reported in 232 of 1316 cases (17.6%). The recurrence rate of the aggressive lesions (22.8%) after surgical treatment was higher than non-aggressive lesions (7.8%). Four of 5 CGCLs showed partial/total regression with pharmacological treatment. Aggressive lesions showed a worse response to corticosteroids than non-aggressive lesions. For the lesions submitted to surgery as the first treatment, curettage, enucleation, or marginal resection in relation to segmental resection, aggressive lesions, cortical bone perforation, and tooth root resorption were associated with increased recurrence rate. Recurrence related to a combination of surgical/pharmacological treatment could not be evaluated due to the variety of protocols.

CONCLUSIONS

Aggressive CGCLs recur more often than the non-aggressive ones. Despite sometimes showing poor response to corticosteroid injection or surgical curettage, a combination of both treatment strategies should be considered in aggressive cases to reduce morbidities associated with radical surgery. The best protocol to manage aggressive and non-aggressive lesions remains to be determined.

Facial fractures in children and adolescents: a retrospective study of 3 years in a hospital in Belo Horizonte, Brazil

AIM

The purpose of this study was to review the etiology, incidence and treatment of selected oral and maxillofacial fractures in children in Belo Horizonte, Brazil, during a period of 3 years.

MATERIALS AND METHODS

The data collected for this study included age, gender, etiology, date of trauma, associated maxillofacial trauma, anatomic site of fracture and treatment. The analysis involved descriptive statistics and chi-squared test, Bonferroni test, Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whiney tests and analysis of variance.

RESULTS AND CONCLUSIONS

This study examined 566 facial fractures in 464 children of 18 years of age or less. The majority of fractures were observed in children within the age group of 13-18 years of age. Bicycle accidents were the major cause of trauma, followed by falls. The mandible was found to be the most common fractured bone in the facial skeleton, followed by the nose. A conservative approach was applied in most cases.

Open versus closed reduction: mandibular condylar fractures in children

PURPOSE

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of mandibular condylar fractures (MCFs) in children.

METHODS

An electronic search in PubMed was undertaken in May 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies published in English or German from the last 20 years (from 1992 onwards) reporting clinical series of MCFs in children and adolescents until the age of 18.

RESULTS

The search strategy initially identified 542 studies. The references from 1992 onwards totaled 339 articles. Twenty-seven studies were identified without repetition within the selection criteria. Additional hand-searching yielded two additional papers.

CONCLUSIONS

Pediatric MCFs require thoughtful consideration in management to avoid significant growth disturbance. Early treatment is indicated in order to improve the chances for favorable development. Long-term follow-up is required, in order to properly treat late complications that may appear. Coronal computed tomography is helpful in substantiating the correct final diagnosis. Many studies show that conservative treatment (CTR) has satisfactory long-term outcome of jaw function, occlusion, and facial esthetics, despite a high frequency of radiological aberrations. Surgery before puberty should be reserved for exceptional cases such as missile injuries, in cases with extensive dislocation and lack of contact between the fragments, in cases with multiple midfacial fractures, in which the mandible has to serve as a guide to reposition the midfacial bones, and in cases which the dislocation of the fractured stump creates a functional impediment that cannot be resolved by CTR. As the craniofacial skeleton becomes more adult-like in its form at about 12 years of age, the decreased remodeling capacity in the adolescents may occasionally result in abnormally shaped condylar heads or shortened ramus heights that may lead to persistent malocclusion. Thus, the indication of open reduction and internal fixation increases with age.

Facial fractures in the elderly: a retrospective study in a hospital in Belo Horizonte, Brazil

BACKGROUND

An increasing incidence of maxillofacial trauma in the elderly has been noted, as a consequence of increased longevity, resulting in a higher percentage of elderly people in the population.

METHODS

A retrospective study was undertaken to assess facial fractures in elderly presenting during the period 2000 to 2002 in Belo Horizonte, Brazil. The data collected included age, gender, etiology, date of trauma, maxillofacial trauma, anatomic site of fracture, and treatment. The statistical analysis involved evaluation of measures of central tendency and variability and calculation of proportions.

RESULTS

It encountered 165 facial fractures in 122 elderly aged 60 years or older. The majority of fractures were sustained by elderly in the age group 60 years to 69 years. Falls was the major cause of trauma followed by car accidents. The mandible was found to be the most common fractured bone in the facial skeleton, followed by the zygomatic complex. A conservative approach was accomplished in the most of cases.

CONCLUSION

Gender was associated with the presence or absence of fractures and with the etiology. There was no association between age and fractures. No association was found between etiology and age for women and men. The proportion of fractures of the zygomatic arch, mandible body, and parasymphysis treated surgically were statistically higher than the same proportion among the cases of other fractures. The fractures of the nose were more often treated conservatively than other fractures.

Flapless versus conventional flapped dental implant surgery: a meta-analysis

The aim of this study was to test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants being inserted by a flapless surgical procedure versus the open flap technique, against the alternative hypothesis of a difference. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not. The search strategy resulted in 23 publications. The I2 statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used for random-effects model or fixed-effects model, when indicated. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimeters. Sixteen studies were judged to be at high risk of bias, whereas two studies were considered of moderate risk of bias, and five studies of low risk of bias. The funnel plots indicated absence of publication bias for the three outcomes analyzed. The test for overall effect showed that the difference between the procedures (flapless vs. open flap surgery) significantly affect the implant failure rates (P = 0.03), with a RR of 1.75 (95% CI 1.07-2.86). However, a sensitivity analysis revealed differences when studies of high and low risk of bias were pooled separately. Thus, the results must be interpreted carefully. No apparent significant effects of flapless technique on the occurrence of postoperative infection (P = 0.96; RR 0.96, 95% CI 0.23-4.03) or on the marginal bone loss (P = 0.16; MD -0.07 mm, 95% CI -0.16-0.03) were observed.

Smoking and Dental Implants: A Systematic Review and Meta-Analysis

Background and Objectives: Tobacco is today the single most preventable cause of death, being associated with countless diseases, including cancer and neurological, cardiovascular, and respiratory diseases. Smoking also brings negative consequences to oral health, potentially impairing treatment with dental implants. The present review aimed to evaluate the influence of smoking on dental implant failure rates and marginal bone loss (MBL). Materials and Methods: Electronic search was undertaken in three databases, plus a manual search of journals. Meta-analyses were performed, in addition to meta-regressions, in order to verify how the odds ratio (OR) and MBL were associated with follow-up time. Results: The review included 292 publications. Altogether, there were 35,511 and 114,597 implants placed in smokers and in non-smokers, respectively. Pairwise meta-analysis showed that implants in smokers had a higher failure risk in comparison with non-smokers (OR 2.402, p < 0.001). The difference in implant failure between the groups was statistically significant in the maxilla (OR 2.910, p < 0.001), as well as in the mandible (OR 2.866, p < 0.001). The MBL mean difference (MD) between the groups was 0.580 mm (p < 0.001). There was an estimated decrease of 0.001 in OR (p = 0.566) and increase of 0.004 mm (p = 0.279) in the MBL MD between groups for every additional month of follow-up, although without statistical significance. Therefore, there was no clear influence of the follow-up on the effect size (OR) and on MBL MD between groups. Conclusions: Implants placed in smokers present a 140.2% higher risk of failure than implants placed in non-smokers.

Accuracy evaluation of computed tomography-derived stereolithographic surgical guides in zygomatic implant placement in human cadavers

Presurgical planning is essential to achieve esthetic and functional implants. For implant planning and placement, the association of computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques furnishes some advantages regarding tridimensional determination of the patient's anatomy and fabrication of both anatomic models and surgical guides. The goal of this clinical study was to determine the angular deviations between planned and placed zygomatic implants using stereolithographic surgical guides in human cadavers. A total of 16 zygomatic implants were placed, 4 in each cadaver, with the use of stereolithographic (SLA) surgical guides generated by computed tomography (CT). A new CT scan was made after implant insertion. The angle between the long axis of the planned and actual implants was calculated. The mean angular deviation of the long axis between the planned and placed implants was 8.06 ± 6.40 (mean ± SD) for the anterior-posterior view, and 11.20 ± 9.75 (mean ± SD) for the caudal-cranial view. Use of the zygomatic implant, in the context of this protocol, should probably be reevaluated because some large deviations were noted. An implant insertion guiding system is needed because this last step is carried out manually. It is recommended that the sinus slot technique should be used together with the CT-based drilling guide to enhance final results. Further research to enhance the precision of zygomatic implant placement should be undertaken.

Juvenile ossifying fibroma of the jaws and paranasal sinuses: a systematic review of the cases reported in the literature

The aim was to compare clinical and radiological features of the two juvenile ossifying fibroma (JOF) variants, trabecular (JTOF) and juvenile psammomatoid ossifying fibroma (JPOF). An electronic search was undertaken in March 2019. Eligibility criteria included publications having sufficient clinical, radiological, and histological information to confirm the diagnosis. A total of 185 publications and 491 cases were included. Most JOFs, including both variants, showed bone expansion, were painless, presented no cortical perforation and no secondary aneurysmal bone cyst, did not cause tooth root resorption, and had a mixed unilocular radiodensity appearance and well-defined limits on radiological examination. Patients with JPOF were on average older than those with JTOF. Enucleation and curettage was associated with a considerably high recurrence rate, regardless of the anatomical location or variant type of the lesion. Enucleation followed by either curettage or peripheral osteotomy showed lower recurrence rates than enucleation only. When resection was performed, only one case of JTOF presented recurrence. In conclusion, JOF lesions presented high rates of recurrence after treatment by curettage and enucleation only. Although surgical resection of JOFs resulted in the virtual absence of recurrence, enucleation followed by peripheral osteotomy/curettage should be the treatment of choice for both JOF variants to avoid the disfigurement usually associated with surgical resection.

Bruxism and Dental Implants: A Meta-Analysis

PURPOSE

To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss after the insertion of dental implants in bruxers compared with the insertion in non-bruxers against the alternative hypothesis of a difference.

METHODS

An electronic search was undertaken in June 2014. Eligibility criteria included clinical studies, either randomized or not.

RESULTS

Ten publications were included with a total of 760 implants inserted in bruxers (49 failures; 6.45%) and 2989 in non-bruxers (109 failures; 3.65%). Due to lack of information, meta-analyses for the outcomes "postoperative infection" and "marginal bone loss" were not possible. A risk ratio of 2.93 was found (95% confidence interval, 1.48-5.81; P = 0.002).

CONCLUSIONS

These results cannot suggest that the insertion of dental implants in bruxers affects the implant failure rates due to a limited number of published studies, all characterized by a low level of specificity, and most of them deal with a limited number of cases without a control group. Therefore, the real effect of bruxing habits on the osseointegration and survival of endosteal dental implants is still not well established.

Assessment of accessory canals of the canalis sinuosus: a study of 1000 cone beam computed tomography examinations

The aim of this study was to verify the presence, spatial location, and calibre of the accessory canals (AC) of the canalis sinuosus by cone beam computed tomography, and their relationship to the anterior maxilla. This retrospective analysis included the scans of 1000 subjects. Parameters registered were sex, age, number of AC, presence or absence of AC with a diameter <1.0mm, AC diameter (only for AC with a diameter >1.0mm), and AC location in relation to the adjacent teeth. Males showed a statistically higher frequency of AC than females. The difference in age distribution was not statistically significant. Twenty percent of all AC presented a diameter of a least 1.0mm. The end of the AC trajectory was most frequently located palatal to the anterior maxillary teeth. All relationships analyzed here were very weak (age vs. number of AC, age vs. AC diameter, number of AC vs. sex). Overall, the results of this study showed that AC of the canalis sinuosus are a common anatomical structure in the anterior maxilla, regardless of age and sex.

Prophylactic antibiotic regimen and dental implant failure: a meta-analysis

The aim of this meta-analysis was to investigate whether there are any positive effects of prophylactic antibiotic regimen on implant failure rates and post-operative infection when performing dental implant treatment in healthy individuals. An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomised or not. The search strategy resulted in 14 publications. The I(2) statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used with a fixed- or random-effects model, depending on the heterogeneity. The estimates of relative effect were expressed in risk ratio (RR) with 95% confidence interval. Six studies were judged to be at high risk of bias, whereas one study was considered at moderate risk, and six studies were considered at low risk of bias. The test for overall effect showed that the difference between the procedures (use versus non-use of antibiotics) significantly affected the implant failure rates (P = 0.0002), with a RR of 0.55 (95% CI 0.41-0.75). The number needed to treat (NNT) to prevent one patient having an implant failure was 50 (95% CI 33-100). There were no apparent significant effects of prophylactic antibiotics on the occurrence of post-operative infections in healthy patients receiving implants (P = 0.520). A sensitivity analysis did not reveal difference when studies judged as having high risk of bias were not considered. The results have to be interpreted with caution due to the presence of several confounding factors in the included studies.

Peripheral giant cell granuloma: An updated analysis of 2824 cases reported in the literature

OBJECTIVE

To integrate the available data published on peripheral giant cell granuloma (PGCG) into a comprehensive analysis of its clinical/radiological features.

MATERIALS AND METHODS

An electronic search was undertaken in January 2018 in 5 databases, looking for publications reporting cases of PGCGs. Probability of recurrence was calculated for some variables.

RESULTS

A total of 165 publications were included, 2824 lesions identified. PGCGs were slightly more prevalent in women and more prevalent in mandibles, usually asymptomatic, and presenting erosion of the subjacent bone in almost one-third of cases. Additional curettage (2.8%) or peripheral osteotomy (0%) after excision presented lower recurrence rates in comparison with excision alone (16%). Excision followed by curettage decreases the probability of recurrence by 85% in comparison with excision alone. Other factors (age, lesion size, follow-up, gender, location, clinical symptoms, bone erosion) seem to do not influence the probability of recurrence.

CONCLUSIONS

As surgical excision alone shows a considerable recurrence rate, excision followed by an additional therapy-curettage or peripheral osteotomy-should be the first choice of treatment of PGCG.

Osseoperception in Dental Implants: A Systematic Review

PURPOSE

Replacement of lost teeth has significant functional and psychosocial effects. The capability of osseointegrated dental implants to transmit a certain amount of sensibility is still unclear. The phenomenon of developing a certain amount of tactile sensibility through osseointegrated dental implants is called osseoperception. The aim of this article is to evaluate the available literature to find osseoperception associated with dental implants.

MATERIALS AND METHODS

To identify suitable literature, an electronic search was performed using Medline and PubMed database. Articles published in English and articles whose abstract is available in English were included. The articles included in the review were based on osseoperception, tactile sensation, and neurophysiological mechanoreceptors in relation to dental implants. Articles on peri-implantitis and infection-related sensitivity were not included. Review articles without the original data were excluded, although references to potentially pertinent articles were noted for further follow-up. The phenomenon of osseoperception remains a matter of debate, so the search strategy mainly focused on articles on osseoperception and tactile sensibility of dental implants. This review presents the histological, neurophysiological, and psychophysical evidence of osseoperception and also the role of mechanoreceptors in osseoperception.

RESULTS

The literature on osseoperception in dental implants is very scarce. The initial literature search resulted in 90 articles, of which 81 articles that fulfilled the inclusion criteria were included in this systematic review.

CONCLUSION

Patients restored with implant-supported prostheses reported improved tactile and motor function when compared with patients wearing complete dentures.

Three-dimensional versus standard miniplate fixation in the management of mandibular angle fractures: a systematic review and meta-analysis

The aim of the present study was to test whether there is a significant difference in the clinical outcomes between standard and three-dimensional (3D) miniplate fixation in the management of mandibular angle fractures (MAFs). An electronic search without date and language restrictions was performed in October 2013. Inclusion criteria were studies in humans including randomized controlled trials, controlled clinical trials, and retrospective studies, with the aim of comparing the two techniques. Six studies were included. The meta-analyses revealed statistically significant differences for the incidence of hardware failure and postoperative trismus. There were no significant differences in the incidence of postoperative infection, malocclusion, wound dehiscence, non-union/malunion, or paresthesia. The cumulative odds ratio was 0.42, meaning that the use of 3D miniplates in the fixation of MAFs decreases the risk of the event (postoperative complication) by 58%. The results of this meta-analysis showed lower postoperative complication rates with the use of 3D miniplate fixation in comparison with the use of standard miniplate fixation in the management of MAFs.

Is the intake of selective serotonin reuptake inhibitors associated with an increased risk of dental implant failure?

The aim of this retrospective study was to investigate the association between the intake of selective serotonin reuptake inhibitors (SSRIs) and the risk of dental implant failure. Patients were included if they were taking SSRIs only and no other medication, did not present any other systemic condition or compromising habits (bruxism, smoking, snuff), and complied with the use of prophylactic antibiotics for implant surgery. The multivariate generalized estimating equation (GEE) method and multilevel mixed-effects parametric survival analysis were used to test the association between SSRI exposure (predictor variable) and the risk of implant failure (outcome variable), adjusting for several potential confounders (other variables). The total number of implants with information available and meeting the necessary eligibility criteria was 931 (35 failures). These were placed in 300 patients. The implant failure rate was 12.5% for SSRI users and 3.3% for non-users (P=0.007). Kaplan-Meier analysis showed a statistically significant difference in the cumulative survival rate (P<0.001). The multivariate GEE model did not show a statistically significant association between SSRI intake and implant failure (P=0.530), nor did the multilevel model (P=0.125). It is suggested that the intake of SSRIs may not be associated with an increased risk of dental implant failure.

Considerations of mandibular angle fractures during and after surgery for removal of third molars: a review of the literature

BACKGROUND

Angle fractures are quite common considering that the angle of the mandible forms an area of lower resistance which contains a thicker upper border, a thin basilar bone, and the presence of an impacted mandibular third molar. Common complications of mandibular third molar surgery include alveolar osteitis (dry socket), secondary infection, nerve dysfunction, and hemorrhage. Reports of mandibular fracture during and after third molar removal are uncommon.

PURPOSE

The purpose of this paper is to discuss the risk and predisposing factors that should be analyzed regarding the possibility of immediate and late mandibular angle fractures and their need for surgical treatment as a means through which to remove impacted molars. This study is based on a thorough review of the literature as well as on one immediate and one late mandibular angle fracture as described by the authors' own personal experience.

CONCLUSIONS

The danger of an immediate jaw fracture can be avoided by means of proper instrumentation and by refraining from excessive force on the bone. The tooth should be sectioned in such a way as to minimize the extent of bone removal and force caused by instrumentation. The danger of a late jaw fracture can be avoided by precise diagnosis in cases of patients over 25 years of age, particularly men, whose tooth roots are superimposed on or adjacent to the inferior alveolar canal on a panoramic image, any local pathology and systemic disease or medications which may impair bone strength, and patients who present bruxism and are active athletes.

Odontogenic myxoma: An updated analysis of 1,692 cases reported in the literature

The aim of the present study was to integrate the available data published on odontogenic myxoma (OM) into a comprehensive analysis of its clinical/radiological features. Electronic search undertaken in January/2018, looking for publications reporting cases of OM. A total of 377 publications were included. We identified 1,692 lesions, and 695 were used for the analysis of recurrence. There is a predominance of OMs in females and in mandibles. OMs usually present with bone expansion, asymptomatic cortical perforation, and a multilocular appearance. Lesion location (maxilla/mandible), bone expansion, cortical bone perforation, locular radiological appearance, tooth resorption, odontogenic epithelial rests, or angular septa are not associated with recurrence. While curettage (31.3%) showed the highest recurrence rate, marginal resection (1.3%) and segmental resection (3.1%) showed the lowest values. Enucleation + peripheral osteotomy (6.7%) showed better results than enucleation (13.1%) or enucleation + curettage (12.7%). In comparison with unilocular lesions, multilocular ones were significantly more prevalent in mandibles, more often presented expansion and cortical bone perforation, had larger mean size, and were more often treated by segmental resection. Conservative surgical procedures are associated with higher probability of recurrence of OM. Taking into consideration the recurrence rate and morbidity associated with different surgical treatments, tumor enucleation followed by peripheral osteotomy should be considered as the first therapeutic choice.

An intraoral surgical approach to the styloid process in Eagle's syndrome

PURPOSE

The purpose of this study is to present an alternative method to the extraoral surgical approach to remove the elongated styloid process, the intraoral surgical approach, and discuss their advantages and disadvantages. A literature review is also presented.

PATIENTS AND METHODS

A casuistic of intraoral surgical approach to remove the elongated styloid process is presented in five patients.

RESULTS

Four patients experienced postoperative moderate pain and trismus for 1 week. Bilateral surgery in one patient caused severe trismus, great discomfort, and moderate difficulty in breathing. All were followed up for 6 months and showed complete relief of the oral pharyngeal symptoms and complete improvement in functional ability.

DISCUSSION

The advantages of the external approach are good visualization and reduced possibility of deep neck space infection. The disadvantages are an external scar, longer duration of surgery, and risk of injury to the facial nerve. The advantages of the intraoral approach are that the method is safe, simple, and less time consuming and an external scar is avoided. The disadvantages are possible infection of deep neck spaces, risk of injury to major vessels, and poor visualization.

CONCLUSIONS

Intraoral resection of the styloid process is a safe treatment technique of Eagle's syndrome. It is not recommended the bilateral intervention at the same surgery, because of possible great discomfort at postoperative time.

Open versus closed reduction: diacapitular fractures of the mandibular condyle

PURPOSE

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle.

METHODS

An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions.

RESULTS

The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers.

CONCLUSIONS

The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical therapy. If conducted properly, surgical treatment of DFs is a safe and predictable procedure and yields good results.

Calcifying epithelial odontogenic tumor: An updated analysis of 339 cases reported in the literature

PURPOSE

The aim of this study was to integrate the available data published on calcifying epithelial odontogenic tumors (CEOT) into a comprehensive analysis of its clinical and radiologic features.

MATERIALS AND METHODS

An electronic search was undertaken in May 2016. Eligibility criteria were publications having enough clinical, radiological and/or histological information to confirm definite diagnosis.

RESULTS

A total of 362 lesions were found, 339 with enough information were analyzed. Variants clear cells (n = 33) and Langerhans cells (n = 10) were rarely described in the literature, as well as lesions with malignant transformation (n = 8). Central lesions (n = 264) were more prevalent than their peripheral counterparts (n = 24). A higher prevalence characterized the mandible, posterior region, and third and fourth decades. About 40% of the peripheral lesions showed signs of underlying bone erosion, and about half of the central ones showed signs of cortical bone perforation. Recurrence was found in all lesions (12.6%), peripheral lesions (18.8%), central lesions (11.6%), clear cell (10.7%), Langerhans cell (0%), and those with malignant transformation (42.9%). Excision or curettage was associated with the highest recurrence rate. None of the variables showed a statistically significant influence on the recurrence rate.

CONCLUSIONS

The possible locally aggressive behavior of the lesions recommends a less conservative management than simple curettage. The clear cell variant shows similar demographic data and biological behavior compared to the non-variant lesions, suggesting that the presence of clear cells does not have an important clinical significance.

Ameloblastic Fibrodentinoma and Ameloblastic Fibro-Odontoma: An Updated Systematic Review of Cases Reported in the Literature

PURPOSE

To integrate the available data published on ameloblastic fibrodentinoma (AFD) and ameloblastic fibro-odontoma (AFO) into a comprehensive analysis of its clinical and radiologic features.

MATERIALS AND METHODS

An electronic search was undertaken in August 2016. Eligibility criteria included publications reporting cases of AFD or AFO with enough clinical, radiologic, and histologic information to confirm the diagnosis. Demographic data, lesion site and size, treatment approach, and recurrence were analyzed and compared between AFD and AFO.

RESULTS

Fifty-four publications reporting on 64 AFDs (60 central, 4 peripheral) and 137 publications reporting on 215 AFOs (211 central, 3 peripheral, 1 unknown) were included. The difference in recurrence rate (when the information about recurrence was provided) was not statistically relevant. The mean age of patients affected by AFD was not statistically different from that of patients affected by AFO.

CONCLUSIONS

AFD and AFO presented several similarities: higher prevalence in men and in the mandibles, similar mean age of patients, rate of cortical bone perforation and of the lesions' association with displaced or unerupted teeth and tooth root resorption, mean lesion size, and recurrence rate. The lesions differed in the presence of radiopacities and locularity. Taken together, these data do not support the concept of progressive maturation of these tumoral conditions.

Retrospective evaluation of implant-supported full-arch fixed dental prostheses after a mean follow-up of 10 years

OBJECTIVE

To assess the outcomes of implant-supported full-arch fixed dental prostheses (ISFAFDPs) and the supporting implants.

MATERIAL AND METHODS

This retrospective study included patients treated with ISFAFDPs at one specialist clinic. Implant/prosthesis failure and complications were the outcomes analyzed. Survival analysis methods were used.

RESULTS

A total of 709 patients with 869 ISFAFDPs (4,797 implants) were included, with a mean ± SD follow-up of 10.7 ± 7.2 years. A total of 353 implants and 62 prostheses failed. Estimated cumulative survival rates were as follows: 93.3% (95% CI 91.3, 95.3) after 10 years and 87.1% (95% CI 83.4, 90.8) after 20 years. Implants installed in bruxers, smokers, and maxilla had a lower survival than implants installed in non-bruxers, non-smokers, and mandible, respectively. A total of 415 ISFAFDPs (47.8%) presented technical complications, of which 67 (7.7%) presented only occurrences of loss/fracture of implant access hole sealing. Bruxism was a factor to exert a higher risk of screw loosening (HR 3.302; also in younger patients), screw fracture (HR 4.956), ceramic chipping/fracture (HR 5.685), and loss/fracture of acrylic teeth (HR 2.125; this last complication with higher risk also in men, in maxillae, and when the opposing jaw presented natural dentition or fixed prostheses). Patients with bruxism had a statistically significant higher risk of prosthesis failure than non-bruxers (HR 3.276).

CONCLUSIONS

ISFAFDPs presented good long-term prognosis. Failure of several supporting implants was the main reason for failure. The results of the present study strongly suggest that bruxism is an important contributor to implant and prosthesis failure, as well as to an increased prevalence of technical complications in ISFAFDPs.

Biomechanical evaluation and surface characterization of a nano-modified surface on PEEK implants: a study in the rabbit tibia

Polyether ether ketone (PEEK) is today frequently used as a biomaterial in different medical operations due to its excellent mechanical and chemical properties. However, the untreated surface of PEEK is bioinert and hydrophobic, and it does not osseointegrate in its pure form. The aim of this study was to evaluate a unique nano-modified surface of PEEK with respect to osseointegration. Forty-eight threaded, non-cutting PEEK implants were inserted bilaterally in the tibia of 24 rabbits. Half of the implants (n=24) were coated with nanocrystalline hydroxyapatite (test) and the remaining implants (n=24) were left uncoated (control). Half of the animals (n=12) were euthanized after 3 weeks of healing and the remaining (n=12) after 12 weeks. The implant retention was measured with a removal torque apparatus. Surface analysis was performed with interferometry, scanning electron microscopy, and X-ray photon spectroscopy to relate the removal torque to the applied surface. The test implants revealed a significantly higher retention after 3 weeks (P=0.05) and 12 weeks (P=0.028) compared to controls. The result of the present study proves that the addition of nanocrystalline hydroxyapatite coating to PEEK surfaces significantly increases its removal torque and biocompatibility.