Mahidol Dental Journal

Management of temporomandibular joint osteochondroma with facial asymmetry: a case report

2023-01-24T09:01:27+07:00

Osteochondroma is rare in the facial region and osteochondroma of the mandible typically causes facial asymmetry and malocclusion. Resection of the affected condyle and orthognathic surgery has been frequently reported as the treatment of choice. The aim of this study was to manage a case of osteochondroma of the temporomandibular joint (TMJ) causing facial asymmetry. After extensive treatment plan discussions between the surgeon and the patient, the patient was reluctant to undergo the surgeries and chose to wait and see if there was cessation of the condylar hyperplasia instead of undergoing orthognathic surgery and condylectomy. Thus, this case was followed up by performing clinical examinations, radiographs, CT, and bone scintigraphy for approximately eight years. Subsequently, the facial asymmetry and the skeletal discrepancy became more severe. Furthermore, the bone scan revealed evidence of ongoing condylar hyperplasia. Based on these findings, the patient chose to undergo surgery. Low condylectomy with bimaxillary orthognathic surgery were selected for this case. The intraoperative sequence, however, differed from other studies in that the maxilla orthognathic surgery was performed prior to resecting the condyle and bilateral sagittal split osteotomy (BSSRO). The histopathologic results indicated that the tumor was consistent with osteochondroma. His facial asymmetry and malocclusion had been appropriately corrected. The patient did not experience restricted mouth opening, whereas postoperative complications, such as lip paresthesia and facial weakness were reported after three months. However, three months later, these complications had resolved. Moreover, the radiographic evaluation demonstrated no recurrence of the osteochondroma.

A Novel saliva ejector for effective orthodontic bonding: a laboratory investigation

2023-02-22T08:23:31+07:00

Objective: To use computer-aided design and computer-aided manufacturing (CAD-CAM) to design a customized saliva ejector in order to investigate the performance of the new saliva ejector compared to the conventional saliva ejector with regards to shear bond strength, adhesive remnants, and bonding time.

Materials and Methods: Forty maxillary human premolars were mounted on acrylic dental models, with four teeth per side. Three-dimensional (3D) scans of the models were made using an intraoral scanner (iTero Element; Align Technologies, San Jose, Calif), then imported into an orthodontic software (OrthoAnalyzer; 3Shape, Copenhagen, Denmark) for bracket placement. The new saliva ejector was fabricated using ethylene-vinyl acetate (EVA) thermoplastic sheets. Orthodontic brackets were bonded on one side of the model using the new saliva ejector, and on the other side using the conventional saliva ejector. The effectiveness of the new saliva ejector was assessed by the duration of the bonding, shear bond strength, and adhesive remnant index (ARI).

Results: No statistically significant differences in shear bond strength were found between the new saliva ejector group (24.73 ± 9.93 MPa) with the conventional saliva ejector group (21.72 ± 1.45 MPa). Bonding time and ARI score did not differ significantly between the two groups either. (p >0.05)

Conclusion: The performance of the new saliva ejector was at least comparable to the conventional type with regard to shear bond strength, adhesive remnants, and bonding time.

Long-term effect of nasoalveolar molding on skeletal and dental development in patients with oral clefts; a systematic review and meta-analysis

2023-03-13T12:14:48+07:00

Objective: This study aimed to analyze the treatment effects of pre-surgical nasoalveolar molding (PNAM) on cephalometric characteristics and dentoalveolar outcome for patients with non-syndromic unilateral cleft lip and palate by conducting a systematic review and meta-analysis.

Materials and Methods: Five electronic databases and two journals were searched up through October 2021. Studies comparing treatment results between PNAM and non-PNAM treatment protocols were selected for analyses. Cephalometric characteristics and dentoalveolar outcome were outcomes of interest. Data extraction, methodological quality assessment, risk of bias assessment, and meta-analysis were performed.

Results: Four retrospective cohort studies were selected for a qualitative review and meta-analysis. The risk of bias assessment was moderate for all studies. Treatment results from patients who underwent PNAM were not significantly different from other treatment protocols.

Conclusion: This study found that PNAM does not improve cephalometric characteristics and dentoalveolar outcomes.

Effectiveness of different coated materials on root caries prevention under simulated tooth brushing: an in vitro study

2023-04-19T22:01:08+07:00

Objective: Sealing tooth root surfaces with coating material is expected to represent an effective approach to preventing root caries. The aim of this study is to investigate the effect of tooth brushing on the efficacy of different coating materials in root caries prevention.
Materials and Methods: The experiment was conducted on root dentin specimens under simultaneous demineralization conditions. Fifty specimens were used in this study. The specimens were divided into 5 groups: Group 1 (control group), no treatment; Groups 2-3, Clinpro White Varnishapplication with or without brushing; and Groups 4-5, PRG Coat Barrierapplication with or without brushing. A multispecies biofilm model was formed on specimens that were exposed to 1% sucrose for 10 days. Then, the % cell viability, bacterial density, % surface microhardness loss, and lesion depth were assessed using a confocal laser scanning microscope, microcomputed tomography, and Knoop microhardness tester, respectively.
Results: The Kolmogorov–Smirnov test revealed a normal distribution of all data. Differences within and between mean values for groups were statistically analyzed using one-way ANOVA and Dunnett’s T3 post hoc test, respectively. No significant differences in bacterial density and biofilm thickness were found among the groups. A difference in the %surface microhardness loss was noted in the control group with relatively higher %cell viability compared with the other groups. The deepest carious lesion was found in the control group. The shallowest carious lesion was found in the PRG Coat Barrier-coated dentin-without brushing group. Brushing only increases the lesion depth on Clinpro White Varnish-coated dentin.
Conclusions: Applying either Clinpro White Varnish or PRG Coat Barrierhas the benefits of reducing the depth of root caries and increasing the hardness of demineralized root dentin. Brushing reduces the efficacy of Clinpro White Varnish.