Can cystic lesions of the jaws be considered as the cause of mandibular asymmetry?

Background The aim of this study is to investigate the presence of condylar and ramal asymmetry in patients with a cyst larger than 10 mm in the maxilla or mandible.Material and Methods Condylar and ramal asymmetry index measurements of 47 patients (mean age: 28.85 ± 15.348) in the study group and 40 patients in the control group (mean age: 33.73 ± 13.095) were performed using panoramic radiographs. The study group consists of patients with cysts larger than 10 mm in diameter in the maxilla or mandible. The control group consisted of patients with no radiolucent lesions and no history of trauma. The possible statistical difference between the groups was evaluated by the Mann-Whitney U test.Results No statistically significant difference was observed in asymmetry indices according to gender and the jaw (maxilla or mandible) in which the cyst was located. However, it was determined that CAI and RAI values were statistically significantly different between the study and control groups (p = 0.047 and p = 0.016, respectively).Conclusions The presence of intraosseous cysts larger than 10 mm in the jaws was found to be associated with condylar and ramal asymmetry. Key words:Condylar asymmetry, ramal asymmetry, odontogenic cysts     

Can the durability of one-step self-etch adhesives be improved by double application or by an extra layer of hydrophobic resin?

OBJECTIVES: This study evaluated the immediate and 6-month resin-dentin micro-bond strength (microTBS) of one-step self-etch systems (Adper Prompt L-Pop [AD] 3M ESPE; Xeno III [XE] Dentsply De Trey; iBond [iB] Heraeus Kulzer) under different application modes. MATERIALS AND METHODS: Dentin oclusal surfaces were exposed by grinding with 600-grit SiC paper. The adhesives were applied according to the manufacturer's directions [MD], or with double application of the adhesive layer [DA] or following the manufacturer's directions plus a hydrophobic resin layer coating [HL]. After applying the adhesive resins, composite crowns were built up incrementally. After 24-h water storage, the specimens were serially sectioned in "x" and "y" directions to obtain bonded sticks of about 0.8mm2 to be tested immediately [IM] or after 6 months of water storage [6M] at a crosshead speed of 0.5mm/min. The data from each adhesive was analyzed by a two-way repeated measures ANOVA (mode of application vs. storage time) and Tukey's test (alpha=0.05). RESULTS: The adhesives performed differently according to the application mode. The DA and HL either improved the immediate performance of the adhesive or did not differ from the MD. The resin-dentin bond strength values observed after 6 months were higher when a hydrophobic resin coat was used than compared to those values observed under the manufacturer's directions. CONCLUSIONS: The double application of one-step self-etch system can be safety performed however the application of an additional hydrophobic resin layer can improve the immediate resin-dentin bonds and reduce the degradation of resin bonds over time.     

Risk factors associated with inferior alveolar nerve injury after extraction of the mandibular third molar—a comparative study of preoperative images by panoramic radiography and computed tomography

In this study we investigated the relationships among the risk factors for inferior alveolar nerve injury (IANI), and the difference between preoperative imaging findings on panoramic radiographs and computed tomography (CT), by univariate and multivariate analyses. We determined the following to be significant variables by multivariate analysis: panoramic radiographic signs, such as the loss of the white line of the inferior alveolar canal or the diversion of the canal; excessive haemorrhage during extraction; and a close relationship of the roots to the IAN (type 1 cases) on CT examination. CT findings of type 1 were associated with a significantly higher risk (odds ratio 43.77) of IANI. In addition, many panoramic findings were not consistent with CT findings (275 of 440 teeth; 62.5%). These results suggest that CT findings may be able to predict the development of IANI more accurately than panoramic findings. Panoramic radiography alone did not provide sufficiently reliable images required for predicting IANI. Therefore, when the panoramic image is suggestive of a close relationship between the impacted tooth and the IAN, CT should be recommended as a means of conducting further investigations.     

Can electrocautery of the mandibular condyle effectively treat condylar hyperplasia?

This study aims to introduce and evaluate a novel technique to treat unilateral condylar hyperplasia (UCH) by electrocauterization of the mandibular condyle via an intraoral approach.Patients suffering from unilateral condylar hyperplasia (UCH) were included in this study. All patients underwent electrocauterization of the affected condyle. An intraoral incision on the anterior border of the mandibular ramus was made to expose the external surface of the ramus and access the anterior border of the condylar head. A hole was then drilled into the condyle and cauterization was performed; six patients also received orthognathic surgery during the procedure. Patients underwent careful clinical assessment and radiological evaluation including panoramic view, lateral and posteroanterior cephalometry, cone-beam computed tomography (CBCT) and scintigraphy to assess condylar growth for a period of 12–24 months. Ten patients (5 male and 5 female) with active UCH type 1B or 2A were included in this study with a mean age of 20.7 years (range, 18–21.7 years). At the 12-month postoperative assessment, clinical evaluation showed stable dental occlusion with no midline shift; scintigraphy showed persistently reduced cellular activity, and computed tomography scans revealed no degeneration in either of the condyles with complete healing of the drilled holes.Within the limitations of this study it seems that the proposed treatment approach might be an alternative to previously established protocols.     

Can children be affected by bisphosphonate-related osteonecrosis of the jaw? A systematic review

Knowledge of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is mostly based on adult cases, however bisphosphonates are also currently recommended for different paediatric diseases resulting in osteoporosis. The aim of this study was to review the literature on the risk of developing BRONJ in children and adolescents. The PubMed, LILACS, Web of Science, Scopus, and Cochrane databases were searched using the key words “bisphosphonates”, “osteonecrosis”, “jaw”, and “children”. Literature reviews, case reports, abstracts, theses, textbooks, and book chapters were excluded. Studies involving children and young adults (younger than 24 years of age) were included. A total of 56 publications were identified. After applying the eligibility criteria, only seven articles remained. Although no cases of osteonecrosis were identified, all studies had weaknesses such as a limited sample size or the absence of risk factors for the development of osteonecrosis. There is general consensus that this subject should be of concern and that further studies should be conducted before any definitive opinion is reached. It is believed that patients with secondary osteoporosis who use bisphosphonates continuously should be followed up during adulthood, since bone turnover decreases over the years.     

Can the intra-examiner variability of Little's Irregularity Index be improved using 3D digital models of study casts?

Objectives

To compare contact point displacement measurements, used to determine the Little's Irregularity Index (LII) score on study casts and digital models of study casts by an independent examiner.

Methods

The contact point displacement measurements of the six maxillary anterior labial teeth were measured on ten study casts using digital callipers and their associated digital models using Creo Parametric software on five occasions following scanning using a LAVA Chairside Oral Scanner (LCOS) three-dimensional (3D) intra oral scanner. Means, standard deviations and coefficients of variation (CoV) were determined, data analyses (Pearson's correlation coefficients (PCCs) and Intraclass correlation coefficients (ICCs)) and statistical analyses (three and two-way analyses of variance (ANOVAs) and Independent Sample Student's t-tests) were carried out (p < 0.05).

Results

Significant positive correlations for the contact point displacement measurements were evident between all measurement time points for the study casts (r > 0.978; p < 0.0001 and ICC > 0.910; p < 0.0001) and the digital models (r > 0.963; p < 0.0001 and ICC > 0.986; p < 0.0001). The CoV results showed that the contact point displacement measurement data from the digital models was more reproducible than the study casts. Of the 50 Independent Sample Student's t-tests, 21 significant increases (p < 0.042) were reported in contact point displacement measurements <2.9 mm for the digital models compared with the study casts.

Conclusion

The use of 3D digital models can improve the reliability of LII measurements by reducing the subjectivity associated with choosing the anatomic tooth contact points and the awkwardness of measuring the contact point displacements on study casts using a cumbersome calliper technique.

Clinical significance

Intra-examiner variability in the measurement of LII is still evident with digital models suggesting that either improved software specifically aimed at the orthodontic community be identified or a new method for measuring anterior incisor crowding be sought.     

Garrè's osteomyelitis managed by root canal treatment of a mandibular second molar: incorporation of computed tomography with 3D reconstruction in the diagnosis and monitoring of the disease

AIM: To report the healing of Garrè's osteomyelitis involving a mandibular second molar following root canal treatment. SUMMARY: To describe the endodontic management of Garrè's osteomyelitis involving a mandibular second molar. In this case, computed tomography (CT) was used to evaluate the status of the periapical lesion. Five years after root canal treatment, the tooth and supporting tissues appeared healthy both clinically and radiographically and were functioning well. KEY LEARNING POINTS: Garrè's osteomyelitis of an adult can be managed by root canal treatment. Computed tomography could be used for diagnosis and treatment planning in endodontics.     

Can bite force be predicted from the shape of the face?

The relationships between maximum bite force (MBF) and facial architecture have been tested in a sample of 118 dental students. The strongest correlations were seen with the variables representative of posterior face height and facial divergence. No correlation could be seen between MBF and incisor's position. MBF allowed only partial discrimination of the individuals in different subgroups constituted by cluster analysis. MBF is to consider as a representation of the individual aptitude to develop more or less powerful forces. It summarises only part of the functional information influencing facial form.     

Can magnetic resonance imaging replace single photon computed tomography and computed tomography in detecting bony invasion in patients with oral squamous cell carcinoma?

AIM: To determine whether MRI can replace SPECT and CT in detecting bone invasion in patients with oral SCC. MATERIALS AND METHODS: A retrospective and independent review of the MRI, SPECT, and when available CT, images of 23 patients with oral malignancy who had formal bone resection was undertaken. Our gold standard was histopathology. RESULTS: Bone involvement was seen in 19/23 resections. Sensitivity of MRI was 100% [95% CI 1.0-1.0] and specificity was 75% [95% CI 0.326-1.174]. Sensitivity of SPECT was 100% [95% CI 1.0-1.0] and specificity was 50% [95% CI 0.01-0.99]. CONCLUSIONS: MRI is accurate in predicting bone involvement. The addition of SPECT and CT to routine MRI staging protocols seems no longer indicated. CT may be useful in some selected cases to determine maxillary involvement due to the thinner cortex of the maxilla.     

Can radiological examination of mandibular bone invasion accurately predict the need for mandibular resection in oral squamous cell carcinoma?

Bone invasion by oral squamous cell carcinoma necessitates jaw resection, with preoperative imaging ideally able to guide the resection. A retrospective review of 109 patients with oral squamous cell carcinoma who underwent mandibular resection was performed. Eighty-three had preoperative computed tomography (CT) imaging and 72 underwent magnetic resonance imaging (MRI). The presence of bone invasion on imaging was compared to histopathology. Bone invasion was detected in 44 of 109 resection specimens (40.4%) and was identified on CT in 31 of 83 cases (37.4%) and on MRI in 35 of 72 cases (48.6%). The sensitivity and specificity of CT for detecting bone invasion was 69.0% and 79.6%, respectively, while for MRI was 87.1% and 80.5%, respectively. Histological detection of bone invasion was associated with greater disease-specific mortality (P = 0.002), as was MRI detection of bone invasion (P = 0.027). CT detection was not significant (P = 0.240). Negative prediction of bone invasion was 95% accurate for both modalities in clinically non-invaded mandibles. Survival was reduced in patients who underwent marginal mandibular resection when bone invasion was detected histologically (33.3% vs. 70.5%, P = 0.277) and with CT, although this was not statistically significant. More data are required to determine whether more aggressive resection is warranted when bone invasion is detected preoperatively.     

Is there a role for the use of volumetric cone beam computed tomography in periodontics?

Volumetric computed cone beam tomography offers a number of significant advantages over conventional intraoral and extraoral panoramic radiography, as well as computed tomography. To date, periodontal diagnosis has relied heavily on the assessment of both intraoral radiographs and extraoral panoramic radiographs. With emerging technology in radiology there has been considerable interest in the role that volumetric cone beam computed tomography might play in periodontal diagnostics. This narrative reviews the current evidence and considers whether there is a role for volumetric cone beam computed tomography in periodontics.     

Iatrogenic mandibular fracture associated with third molar removal. Can it be prevented?

Removal of third molars is the most common procedure in oral surgery. It may be associated with complications, such as sensory damage , dry socket, infection and iatrogenic damage. A case of mandibular angle fracture during third molar extraction in a 37-year-old female is reported. Literature review on the possible etiologies and ways of prevention were recorded. The reason is believed to be multifactorial and include: age, gender, degree of impaction, relative volume of the tooth in the jaw, preexisting infection or bone lesions, failure to maintain a soft diet in the early postoperative period and the surgical technique. It is possible to reduce the risk of this complication by adoption of preventive measures.     

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

Aim

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

Materials and Methods

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle–Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

Results

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR?=?2.39; 95% CI: 1.62–3.53; p?<?0.00001; I² = 55%). An apical filling extension of 0–2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR?=?1.49; 95% CI: 1.15–1.94; p?=?0.003; I² = 2%).

Conclusion

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

Clinical relevance

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.

     

How useful is intraoperative cone beam computed tomography in maxillofacial surgery? An overview of the current literature

Intraoperative imaging is increasingly used by surgeons and has become an integral part of many surgical procedures. This study was performed to provide an overview of the current literature on the intraoperative use of cone beam computed tomography (CBCT) imaging in maxillofacial surgery. A bibliographic search of PubMed was conducted in March 2020, without time limitation, using “intraoperative imaging” AND “maxillofacial surgery” AND “cone beam computed tomography” as key words. Ninety-one articles were found; after complete reading, 16 articles met the eligibility criteria and were analysed. The results showed that the majority of the indications were related to maxillofacial trauma, particularly zygomaticomaxillary complex fractures. Final verification with intraoperative CBCT before wound closure was the most common use of this device. However, innovative uses of intraoperative CBCT are expanding, such as CBCT coupling with mirror computational planning, and even the combined use of initial intraoperative CBCT acquisition with navigation. Immediate, fast, and easy evaluation of bone repositioning to avoid the need for further surgical revision is the main advantage of this technique. Imaging quality is comparable to that of multi-slice computed tomography, but with lower radiation exposure. Nevertheless, CBCT is still not widely available in maxillofacial centres, probably because of its cost, and perhaps because not everyone is aware of its advantages and versatility, which are reported in this review.