Validity of computed tomography in diagnosing midfacial fractures

The aim of this study was to evaluate the sensitivity, accuracy, and reliability of two-dimensional computed tomography (2D-CT) scans (axial, coronal, sagittal planes) and three-dimensional computed tomography (3D-CT) reconstructions in diagnosing midfacial fractures in relation to actual fractures identified clinically and during surgery (gold standard). The imaging diagnosis was performed by a radiologist and an oral and maxillofacial surgeon. Sixty-two patients with a total of 429 midfacial fractures were included. Frontal sinus and nose fractures were easily diagnosed. For the three CT planes, there was a statistically significant difference between the CT examination and the gold standard for five to seven of the nine bones evaluated, while for 3D-CT, a difference was observed only for fractures of the orbital floor. The inter-observer agreement between the oral and maxillofacial surgeon and the radiologist was 75.5%. In conclusion, in this study 3D-CT reconstructions showed significantly the best sensitivity, accuracy, and reliability for the diagnosis of midfacial fractures. The sagittal reconstructions were the least diagnostic of the 2D-CT images. For areas where the parameters studied showed less agreement and hence a more difficult diagnosis, we recommend a combination of 3D and 2D-CT images to improve diagnostic accuracy.

Migration of tip knife blade through middle-third facial tissues

PURPOSE

The aim of this paper is to report a case of knife aggression with a spontaneous migration of a tip blade lodged in deep tissues 6 months after trauma.

PATIENT

An 18-year-old woman that was a victim of impalement injury with a knife by her boyfriend on the glabella region with a blade fracture and tip lodging into middle-third facial tissues.

RESULTS

After conservative management of a knife tip, a spontaneous migration occurred with its exposition on the zygomatic area, possibly due to a functional treatment to improve mouth opening.

CONCLUSION

Fracture of knife blade with a tip retained deeply into the tissues is considered foreign body, and its removal must be considered. Nevertheless, the basis for this removal takes account the cost-benefit ratio, and if a conservative management was chosen, the clinical and radiological accompanying is mandatory to prevent and to treat its possible complications.

Immediate Implant Placement in the Maxillary Aesthetic Zone: A Cone Beam Computed Tomography Study

This study aimed to investigate the factors that could be associated with the risk of labial cortical bone wall perforation with immediate implant placement (IIP) in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 126 qualified subjects (756 teeth) were included. Implants were virtually positioned in two different positions: in the long axis of the tooth (prosthetically-driven position) and in an ideal position in relation to adjacent anatomical structures (bone-driven position). Two different implant diameters were planned for each tooth position, namely, 3.75 and 4.3 mm for central incisors and canines, and 3.0 and 3.3 mm for lateral incisors. The incidence of perforation was nearly 80% and 5% for prosthetically- and bone-driven position, respectively. Factors associated with a higher risk of cortical bone wall perforation (bone-driven position), according to logistic regression analysis, were women, wider implants, Sagittal Root Position class IV, and decrease of the labial concavity angle. Perforation of the labial cortical bone wall can be greatly minimized when the implant is placed in a bone-driven position compared to a prosthetically-driven position. It is important to preoperatively evaluate the morphological features of the implant site for risk assessment and to individualize the treatment plan.

Retrospective Study Comparing Clinical Outcomes of Fixed Dental Prostheses in Matched Groups of Bruxer and Nonbruxer Patients

BACKGROUND

Tooth-supported fixed dental prosthesis (FDP) is one of the most reliable treatment options to replace missing teeth. The longevity of the treatment could, however, be affected by several general and local factors, especially bruxism.

OBJECTIVE

To investigate the influence of bruxism on the long-term survival of tooth-supported FDPs in bruxers compared to a matched group of nonbruxers, taking several clinical variables into account.

MATERIALS AND METHODS

The present retrospective cohort study was based on records of patients treated with 3-7-unit tooth-supported FDPs with a minimum follow-up time of 6 months after prosthesis delivery. The criteria for the diagnosis of "possible" and "probable" sleep or awake bruxism were used. A matched group of nonbruxers was selected on the basis of similarities in four factors, patients' gender and age, number of prosthetic units of the FDPs, and follow-up time. The paired-samples t-test or Wilcoxon signed rank test were used to compared mean values between the two groups. Contingency tables of categorical data were analyzed by McNemar's test.

RESULTS

The cohort group consisted of 62 noncantilevered FDPs in each group, followed up for a mean of 110.1 and 106.5 months (bruxers and nonbruxers, respectively). Tooth-supported FDPs in bruxers presented significantly higher failure rate than in nonbruxers (32.3% vs. 25.8%, respectively; p = 0.001). Loss of retention and tooth loss were the main reasons for failures in both groups. For nonsmokers, the FDP failure rate was higher in nonbruxers. Technical and biological complications were significantly more prevalent in bruxers compared to nonbruxers.

CONCLUSIONS

Bruxism is suggested to increase technical and biological complications and FDP failure.

Immediate implant placement in the anterior mandible: a cone beam computed tomography study

BACKGROUND

The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth.

PURPOSE

This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study.

MATERIALS AND METHODS

CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed.

RESULTS

Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0).

CONCLUSION

The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning with CBCT is a great tool for minimizing the risk of implant unsafe placement with regards to the anatomical conditions in the mandible.

Pyodermatitis-pyostomatitis vegetans: a case report and systematic review focusing on oral involvement

BACKGROUND

Pyodermatitis-pyostomatitis vegetans (PPV) is a rare mucocutaneous disease characterized by multiple pustules and it is considered a marker for inflammatory bowel disease (IBD). The oral manifestations of this condition are referred to as pyostomatitis vegetans (PSV).

PURPOSE

To investigate which features could help in establishing the diagnosis of PSV, with or without cutaneous lesions, based on information retrieved from all cases of PSV described in the literature. A case of PV from the authors was also included in the analysis.

METHODS

An electronic search was undertaken, last updated in August 2022. Inclusion criteria included publications reporting cases of PSV, with the diagnosis confirmed by the pathological examination of oral or skin lesions, and presence of IBD.

RESULTS/CONCLUSIONS

Sixty-two publications with 77 cases of PSV and an associated IBD were included. Features that are helpful in establishing the diagnosis of PSV are snail track appearance of oral lesions, an associated IBD (which is not always symptomatic), evidence of intraepithelial clefting on microscopic examination of oral lesions, and peripheral blood eosinophilia. A gold standard for the management of PSV does not exist and high-level evidence is limited. There is no established therapeutic protocol for PSV and management primarily consists of topical and/or systemic corticosteroids, antirheumatic drugs (sulfasalazine, mesalazine), monoclonal antibody (infliximab, adalimumab) immunosuppressives (azathioprine, methotrexate), antibiotics (dapsone), or a combination of these. The risk of recurrence of oral lesions is considerable when the medication dose is decreased or fully interrupted.

Clinical Outcomes of Maxillary Sinus Floor Perforation by Dental Implants and Sinus Membrane Perforation during Sinus Augmentation: A Systematic Review and Meta-Analysis

The aim of the present systematic review was to investigate the clinical outcomes after the perforation of the maxillary sinus by dental implants, or after maxillary sinus membrane perforation during sinus lift procedure. Twenty-nine publications were included. Failure rates of implants in cases where perforation of sinus floor had happened (11 studies) was generally low, and only one case of transient sinusitis was reported. The estimated failure rate of these implants was 2.1% (SE 1.0%, p = 0.035). There were 1817 implants (73 failures) placed in augmented sinuses in which the sinus membrane was perforated and 5043 implants (274 failures) placed in sinuses with no perforated membrane, from 18 studies. The odds of implant failure difference between the groups were not significant (OR 1.347, p = 0.197). log OR of implant failure between perforated and non-perforated membrane groups did not significantly change with the follow-up time (-0.004/month; p = 0.500). In conclusion, implant failure rate is generally low either for implants penetrating in the floor of the maxillary sinus or implants placed in augmented sinuses in which the sinus membrane was perforated. The prevalence of postoperative infection/sinusitis is low, and it may depend either on the dimensions of the perforation or on the anatomical predisposition.

Bond strength of zirconia- or polymer-based copings cemented on implant-supported titanium bases - an in vitro study

PURPOSE

To evaluate the bond strength between polymer-based copings and zirconia copings as positive control, cemented on implant-supported titanium bases with different adhesive cement systems. Moreover, to evaluate if airborne-particle abrasion of polymethylmetacrylate (PMMA) would enhance the bond strength.

METHODS

Four groups of different materials were used to fabricate the copings, 30 in each group: airborne-particle abraded milled zirconia (TAZirconia, control group), milled PMMA (TPMMA), airborne-particle abraded milled PMMA (TAPMMA) and 3 D-printed micro filled hybrid resin (TAMFH). Each group of copings was cemented on titanium bases by three different adhesive cement systems, 10 each: Multilink Hybrid Abutment, Panavia V5, RelyX Ultimate. The specimens were stored dry at room temperature for 24 h, subjected to thermocycling for 5000 cycles followed by evaluating the bond strength by tensile strength test.

RESULTS

TPMMA and TAPMMA cemented with Multilink Hybrid Abutment showed statistically significant lower bond strength in comparison to TAZirconia and TAMFH. No difference was observed between the latter two. TPMMA, TAPMMA and TAMFH had a statistically significant lower bond strength compared to the control group when cemented with Panavia V5. TPMMA and TAPMMA cemented with Rely X Ultimate showed statistically significant lower bond strength in comparison to the control group.

CONCLUSION

Almost all experimental groups, except 3 D-printed MFH, performed inferior than the positive control group where the highest bond strength was reported for the cementation of zirconia copings cemented with Panavia V5 or Rely X Ultimate. Airborne-particle abrasion did not improve the bond strength of the PMMA, except when Multilink Hybrid Abutment was used.

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

PURPOSE

The aim of the present systematic review was to investigate the influence of hypertension on the dental implant failure rate.

METHODS

An electronic search was undertaken in four databases, plus a manual search of journals. The I2 statistic was used to check heterogeneity and the inverse-variance method was used for the meta-analysis. The estimate of relative effect for dichotomous outcome was expressed as an odds ratio (OR).

RESULTS

The review included 24 publications. There were 4874 implants (257 failures) placed in hypertensive patients and 16,192 implants (809 failures) placed in normotensive patients. A pairwise meta-analysis showed that implants in hypertensive patients did not have a higher risk of failure than implants placed in normotensive patients (OR 1.100, p = 0.671). The log OR of implant failure between hypertensive and normotensive patients did not significantly change with the follow-up time (p = 0.824).

CONCLUSIONS

This review suggests that implants in hypertensive patients do not present higher odds of failure in comparison to normotensive patients. However, further research on this topic, with the use of more rigorous criteria to diagnose patients as being hypertensive, as well as clearer information about the pharmacological management of the condition in the patients, is recommended.

Smartphone application to report awake bruxism: Development and testing of the Swedish version and a pilot study to evaluate family history in young adults and their parents

BACKGROUND

Together with psychosocial and hereditary factors, bruxism is a possible risk factor for orofacial pain. Bruxism is defined as a masticatory muscle activity characterized by repetitive or sustained tooth contact, or by bracing or thrusting of the mandible. A smartphone application to report awake bruxism (AB) has been developed and translated into more than 25 languages.

OBJECTIVE(S)

To translate the application into Swedish, adapt it to Swedish culture and conduct a study to evaluate the usability of the application for studies on family history and associated risk factors.

METHODS

Translation and cultural adaption of the Swedish version of the application (BruxApp) was carried out in a four-step sequential process. Ten young adults (22-30 years) were recruited together with ten parents (42-67 years) and reported their AB with the application over two seven-day periods. Pain, stress and parafunctional behaviours were assessed by questionnaires.

RESULTS

The back translation check showed minimal discrepancies between the translation and the English version. Participants did not report any problems with the application. Response rates for both groups were 65%. A difference in frequency of AB was shown between young adults and parents (22.0% vs. 12.5%, p < .001). A positive moderate correlation was found between AB and stress (r = 0.54, p = .017).

CONCLUSION

The use of application strategies enables data collection on AB which can be used in both clinical and research settings. The results suggest that the Swedish version is ready for implementation and for studies on the relationships between AB, family history and psychosocial factors.

Clinical Outcomes of Pterygoid and Maxillary Tuberosity Implants: A Systematic Review

Background: This study aimed to assess the survival of implants placed in the maxillary tuberosity or in the pterygomaxillary region of the maxilla, based on a systematic review of the literature. Methods: An electronic search was undertaken in three databases. The cumulative survival rate (CSR) was calculated. The log-rank (Mantel-Cox) test was used to compare the survival distributions between some groups. Results: Thirty-eight studies were included, reporting 3446 implants (3053 pterygoid, 393 tuberosity) in 2245 patients, followed up for a mean ± SD of 61.0 ± 36.3 months (min-max, 1-144). A total of 208 pterygoid and 12 tuber implants failed, with a clear concentration of failures in the first year of follow-up and a 10-year CSR of 92.5% and 96.9%, respectively. The survival of pterygoid implants was lower than that of implants in the maxillary tuberosity (p = 0.006; log-rank test), and the survival of implants submitted to early/delayed loading was lower than that of immediately loaded implants (p < 0.001; log-rank test). Non-splinted implants presented higher failure rates. Few cases of intra- or postoperative complications were reported. Conclusions: Implants placed in the pterygoid process/maxillary tuberosity present a high 10-year CSR, although with lower survival for pterygoid in comparison to tuber implants. Pterygoid/tuber implants that are splinted with other implants may present higher survival rates than those that are not splinted.

Exercise therapy for whiplash-associated disorders: a systematic review and meta-analysis

OBJECTIVES

Acute as well as chronic pain syndromes are common after whiplash trauma and exercise therapy is proposed as one possible intervention strategy. The aim of the present systematic review was to evaluate the effect of exercise therapy in patients with Whiplash-Associated Disorders for the improvement of neck pain and neck disability, compared with other therapeutic interventions, placebo interventions, no treatment, or waiting list.

CONTENT

The review was registered in Prospero (CRD42017060356) and conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A literature search in PubMed, Scopus and Cochrane from inception until January 13, 2020 was combined with a hand search to identify eligible randomized controlled studies. Abstract screening, full text assessment and risk of bias assessment (Cochrane RoB 2.0) were conducted by two independent reviewers.

SUMMARY

The search identified 4,103 articles. After removal of duplicates, screening of 2,921 abstracts and full text assessment of 100 articles, 27 articles that reported data for 2,127 patients were included. The included articles evaluated the effect of exercise therapy on neck pain, neck disability or other outcome measures and indicated some positive effects from exercise, but many studies lacked control groups not receiving active treatment. Studies on exercise that could be included in the random-effect meta-analysis showed significant short-term effects on neck pain and medium-term effects on neck disability.

OUTLOOK

Despite a large number of articles published in the area of exercise therapy and Whiplash-Associated Disorders, the current evidence base is weak. The results from the present review with meta-analysis suggests that exercise therapy may provide additional effect for improvement of neck pain and disability in patients with Whiplash-Associated Disorders.

A Prospective Report of the Clinical Outcome of TiUnite Implants at 20 Years of Follow-up

PURPOSE

To present a survival analysis of 133 consecutively placed moderately rough implants, all with a total follow-up of 20 years.

MATERIALS AND METHODS

A total of 133 implants of the same brand placed in 46 patients at the same county clinic in Sweden were followed up prospectively over 20 years and analyzed for survival and bone height, the latter evaluated in periapical radiographs.

RESULTS

A total of 7 implants failed, 4 of which were in the same patient. Implant failure was associated with a combination of smoking and bruxism in 5 of the 7 failed cases. A 20-year survival rate of 94.7% was observed. Average marginal bone loss (MBL) at 20 years of follow-up was 0.543 ± 1.193 mm, with 9 implants having more than 2 mm of MBL. A total of 20 patients with 25 implants dropped out of the study; however, if death of the patient is excluded as a dropout reason, only 3 implants in 3 patients were unaccounted for.

CONCLUSIONS

Good clinical results in the 95% survival range were observed with moderately rough implants over a 20-year follow-up period.

Clinical outcomes of zirconia implants: a systematic review and meta-analysis

PURPOSE

To assess the clinical outcomes of zirconia dental implants based on an updated systematic literature review.

METHODS

An electronic search was performed in three databases, last updated in June 2023, supplemented by hand searching. The eligibility criteria were clinical studies reporting patients rehabilitated with zirconia implants. The cumulative survival rate (CSR) of implants was calculated. A meta-analysis for marginal bone loss (MBL) under different follow-up times and a meta-regression assessing the relationship between mean MBL and follow-up were done.

RESULTS

Twenty-five studies were included (4017 implants, 2083 patients). Seven studies had follow-up longer than 60 months. 172 implants failed, after a mean of 12.0 ± 16.1 months (min-max 0.3-86.0), of which 47 early failures, and 26 due to implant fracture, the majority in narrow-diameter implants. The 10-year CSR was 95.1%. Implants with coronal part prepared by drills presented statistically significant lower survival than non-prepared implants (p < 0.001). Two-piece implants presented lower survival than one-piece implants (p = 0.017). Implants discontinued from the market presented lower survival than the commercially available ones (p < 0.001). The difference in survival was not significant between implants in maxilla and mandible (p = 0.637). The mean MBL fluctuated between 0.632 and 2.060 mm over long periods of observation (up until 132 months). There was an estimated MBL increase of 0.005 mm per additional month of follow-up.

CONCLUSION

Zirconia implants present high 10-year CSR and short-term low MBL. The review was registered in PROSPERO (CRD42022342055).

CLINICAL RELEVANCE

The clinical outcomes observed for zirconia dental implants are very promising, although these have not yet been extensively studied as titanium alloy implants.

Clinical and radiographic outcomes of mini-implant-retained maxillary and mandibular overdentures: a systematic review and meta-analysis

OBJECTIVE

To assess the clinical and radiographic outcomes of overdentures and their retaining dental mini-implants, based on a single-arm systematic literature review.

METHODS

Electronic search was undertaken in three databases, last updated in October 2023, plus manual search of journals. Cumulative implant survival rate (CSR) and the estimated marginal bone loss (MBL) under different follow-up times were calculated.

RESULTS

Thirty-nine studies were included, with 3,787 mini-implants supporting 1,026 overdentures (109 maxilla, 896 mandible) in 1,005 patients, with a mean follow-up of 28.1 ± 19.8 months (min-max 0.3-84.0). 202 mini-implants failed, after a mean of 9.4 ± 11.8 months (7-year CSR 91.4%). The implant survival was lower in the maxilla in comparison to the mandible (p < 0.001), lower for early/delayed-loaded in comparison to immediately-loaded implants (p = 0.005) and lower for 2-mini-implant in comparison to 4-mini-implant-retained mandibular overdenture (p < 0.001; Log-rank test). A high rate of transversal fracture of the prosthesis and wear of the attachment parts was observed. The estimated mean MBL gradually increased from 0.518 (≤ 6 months) to 1.260 mm (58.8-90 months). There was an estimated MBL increase of 0.011 mm per additional month of follow-up.

CONCLUSION

Although presenting a high 7-year CSR, mini-implant-retained overdentures may require frequent maintenance follow-ups, due to the high rate of technical complications. The estimated MBL of mini-implants over 80 months is low.

CLINICAL RELEVANCE

The ability to anticipate outcomes is an essential part of risk management in clinical practice. The findings reported herein set some recommendations and potential strategies for minimizing failures and complications commonly associated with this mini-implant-retained overdentures.

Risk Factors Associated with Failure and Technical Complications of Implant-Supported Single Crowns: A Retrospective Study

Background and Objectives: Implant-supported single crowns have become a routine approach for the replacement of missing single teeth, being considered as one of the most common ways of rehabilitation when adjacent teeth are healthy. The present retrospective study aimed to investigate the risk factors possibly associated with failure and technical complications of implant-supported single crowns and their supporting implants. Materials and Methods: Patients treated at one faculty (2009-2019) were considered for inclusion. Complications investigated included ceramic fracture/chipping, crown loss of retention/mobility, crown failure/fracture, loosening/loss/fracture of prosthetic screw, and implant failure/fracture. Any condition/situation that led to the removal/replacement of crowns (implant failure not included) was considered prosthesis failure. Univariate/multivariate Cox regression models were used to evaluate the associations between clinical covariates and failure. Results: 278 patients (358 crowns) were included. Mean ± SD follow-up was 56.5 ± 29.7 months. Seven implants (after a mean of 76.5 ± 43.7 months) and twenty crowns (21.3 ± 23.5 months) failed. The cumulative survival rate (CSR) for crowns was 93.5% after 5, remaining at 92.2% between 6 and 11 years. The most common reasons for crown failure were porcelain large fracture (n = 6), crown repeatedly loose (n = 6), and porcelain chipping (n = 5). Men and probable bruxism were identified in the Cox regression model as being associated with crown failure. The most common observed technical complications were mobility of the crown and chipping of the ceramic material, with the latter being observed even in crowns manufactured of monolithic zirconia. Cases with at least one technical complication (not considering loss of screw hole sealing) were more common among probable bruxers than in non-bruxers (p = 0.002). Cases of ceramic chipping were more common among bruxers than in non-bruxers (p = 0.014, log-rank test). Conclusions: Probable bruxism and patient's sex (men) were factors associated with a higher risk of failure of implant-supported single crowns.

Influence of Crown-Implant Ratio and Implant Inclination on Marginal Bone Loss around Dental Implants Supporting Single Crowns in the Posterior Region: A Retrospective Clinical Study

The aim of this present record-based retrospective study was to investigate the influence of the crown-implant ratio (CIR) and implant inclination in relation to the occlusal plane on the marginal bone loss (MBL) around dental implants supporting single crowns in the posterior region of the jaws. All the cases of implant-supported single crowns in the premolar and molar regions were initially considered for inclusion. Only implants not lost, with baseline radiographs taken within 12 months after implant placement and with a minimum of 36 months of radiological follow-up, were considered for the analysis of MBL. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built. After the exclusion of 49 cases, a total of 316 implant-supported single crowns in 234 patients were included. The results from the statistical models suggested that implant inclination and anatomical- and clinical CIR (the main related factors investigated in the study) were not statistically significantly related to MBL over time. Age (older people), tooth region (premolar), and bruxism (bruxers) had a statistically significant influence on MBL over time.

Occlusal acuity and bite force in young adults

Occlusal tactile acuity (OTA) and bite force are essential components of the sensorimotor control of oral behaviors. While these variables have been studied independently, it has not yet been revealed whether compressive force impacts the occlusal perception mediated by the mechanoreceptive afferents in the periodontal ligament. The present study examined the effect of repetition and maximum bite force on OTA by testing nine aluminum foils of different thicknesses together with a sham test with no foil, three times each, in randomized order in 36 healthy individuals. In addition, the 40 μm foil was tested three more times at the start of each session to evaluate possible short-term effects. This test session was repeated with and without an interspersed maximum bite force task in between. The results demonstrated that repeated measurements increased OTA significantly (p = 0.033); a change mainly driven by the 40 μm thickness, whereas maximum bite force tests did not affect OTA (p = 0.097). Collectively, the results suggest that the enhanced OTA may be attributed to repetition-mediated learning and neuroplasticity within the pathways related to OTA. Furthermore, the compressive bite force may have induced a short-term change that lasted seconds and was not detected by the subsequent OTA measurements or may have altogether inhibited the facilitatory effect of repeated OTA. This underscores the potential for future research to explore the implications of compressive force and pain on OTA in patient populations, which could provide valuable insights into the adaptive mechanisms of the sensorimotor system in pathological conditions.

Survival of fixed prosthetic restorations on vital and nonvital teeth: A systematic review

PURPOSE

To evaluate the survival rate of full-coverage tooth-supported fixed prosthetic restorations, single crowns (SCs), and fixed dental prostheses (FDPs), taking into consideration the potential influence of tooth-vitality, presence and type of post, and type of prosthetic restoration material.

MATERIALS AND METHODS

In October 2022, two authors independently conducted a search in PubMed, Web of Science, and Scopus electronic databases as well as a hand search to identify clinical human studies on full-coverage SCs and FDPs supported by vital and/or non-vital abutments and/or a combination of both, with a minimum observation period of 24 months.

RESULTS

Out of 4198 studies identified through the database search and 22 through hand searching, 26 studies fulfilled the inclusion criteria and were included in the analysis of the present systematic review. Included studies scored six points and more according to Newcastle-Ottawa Scale (NOS). The highest estimated 5-year survival rate was observed for (metal-ceramic and all-ceramic) SCs on vital teeth (98.3%; 95% CI [98.1, 98.6%]) and all ceramic SCs on non-vital teeth with fiber post (95.0%; 95% CI [94.5-95.4%]). Metal-ceramic SCs on vital teeth (97.1%; 95% CI [95.6-98.7%]) showed a statistically significant higher estimated 5-year survival rate compared to metal-ceramic SCs with cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001), fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001) and without post (85.7%; 95% CI [80.7, 90.6%], P < 0.032). All-ceramic SCs with fiber post had a statistically significant higher estimated 5-year survival rate (95.0%; 95% CI [94.5-95.4%]) compared to metal-ceramic SCs on non-vital teeth with fiber post (91.3%; 95% CI [90.9-91.6%], P < 0.001). SCs (all-ceramic and metal-ceramic) with fiber post had a statistically significantly higher estimated 5-year survival rate of (92.7%; 95% CI [92.4-92.9%]) than SCs made of metal-ceramic and retained by cast metal post (90.7%; 95% CI [87.4-94.0%], P < 0.001). For FDPs, the 5-year survival rate was significantly higher for FDPs on vital abutments (84.9%; 95% CI [75.9, 93.9%]) compared to FDPs retained by non-vital abutment/s (81.3%; 95% CI [80.3, 82.2%], P = 0.049) irrespective to presence, type of post, and FDPs material. The results are limited by the limited number of studies and the presence of uncontrolled confounding clinical variables.

CONCLUSIONS

Within the limitations of the study, tooth vitality is suggested to contribute positively to the survival of SCs and FDPs.

Immediate implant placement in the premolar maxillary area: a cone-beam computed tomography study

PURPOSE

This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study.

METHODS

CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA).

RESULTS

The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA.

CONCLUSIONS

A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

An expanded odontogenic myxoma in maxilla

Odontogenic myxomas are considered to be a benign odontogenic tumor with locally aggressive behavior, non-metastasizing neoplasm of the jaw bones. It derives from the dental mesenchyme or periodontal ligament. Despite the benign nature of these lesions, there is a high rate of local recurrence after curettage alone and in certain cases requires adequate resection. This paper describes a case of a large odontogenic myxoma in the maxilla, emphasizing a discussion on the differential diagnosis related to radiological findings and the surgical treatment.