Research Spotlight

Wolford, L. M. (2019). “Comprehensive Post Orthognathic Surgery Orthodontics: Complications, Misconceptions, and Management.” Oral Maxillofac Surg Clin North Am Nov 1. pii: S1042-3699(19)30076-7. [Epub ahead of print].

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Post orthognathic surgery patient management is critical for high-quality and predictable outcomes. Surgeons and orthodontists must have the knowledge and ability to implement postsurgical management protocols and strategies to provide the best care and outcomes possible. This article presents basic concepts, philosophies, treatment protocols, risks, and potential complications associated with postsurgical patient management. Postsurgical orthodontic goals are to maximize the occlusal fit and provide predictable means to retain the occlusion. Aggressive orthodontic mechanics may be required to provide the best occlusal fit. Complications can occur, but early recognition of complications and implementation of corrective tactics should minimize adverse outcomes.

Trivedi, B., M. J. Kesterke, R. Bhattacharjee, W. Weber, K. Mynar and L. V. Reddy (2019). “Craniofacial Injuries Seen With the Introduction of Bicycle-Share Electric Scooters in an Urban Setting.” J Oral Maxillofac Surg 77(11): 2292-2297.

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PURPOSE: Standing electric scooters (e-scooters) are rapidly becoming popular modes of transportation in many urban areas across the United States. However, this increase in popularity has resulted in an increase in traumatic injuries associated with these modes of expedient travel. The purpose of the present study was to determine the types of craniofacial trauma directly related to e-scooter use in a major urban center (Dallas, TX). MATERIALS AND METHODS: We performed a retrospective case series and examined the medical records of the patients who had presented to the emergency department (ED) for trauma related to e-scooter use. Descriptive statistics were calculated for all variables on patient presentation, including incident notes and patient interviews, demographic information, diagnostic tests, trauma (ie, location, type, severity), treatment (ie, type, admission, outpatient referral, follow-up data), and contributing factors (ie, reported or detected alcohol use, use of protective equipment). RESULTS: A total of 90 patients (56 males, 34 females; mean age, 31.8 years) had presented with scooter-related trauma to the ED during the first 7 months of scooters after their introduction to the metropolitan area. A total of 52 admissions (58% of all admissions) involved injuries of the head and face. The patients had presented with a myriad of craniofacial trauma, ranging from abrasions, lacerations, and concussions to intracranial hemorrhage and Le Fort II and III fractures. Of the 52 craniofacial injuries, 30 (58%) were considered severe (ie, fracture, internal hemorrhage, concussion, loss of consciousness), and 22 (42%) were considered minor (ie, lacerations, contusion, abrasion, dental). Alcohol use had been involved in 18% of all scooter-related trauma admissions, and no rider had reported wearing a helmet. CONCLUSIONS: Injuries to the head and face were commonly found with e-scooter admissions in this sample, and the high prevalence of extremity injuries suggested that patients were breaking their fall during the crash. Craniofacial trauma related to e-scooter use could be significantly reduced by the wearing of a protective helmet.

Revilla-Leon, M., M. Umorin, M. Ozcan and W. Piedra-Cascon (2019). “Color dimensions of additive manufactured interim restorative dental material.” J Prosthet Dent Oct 22. pii: S0022-3913(18)30841-2. [Epub ahead of print].

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STATEMENT OF PROBLEM: Interim dental restorations can be fabricated by using additive manufacturing (AM) technologies. Although dental restoration contours can be easily and accurately fabricated by using computer-aided design (CAD) procedures, protocols for creating predictable color dimensions of AM interim restorations are lacking. PURPOSE: The purpose of this in vitro study was to measure and compare color dimensions of different AM and conventional interim restorative materials. MATERIAL AND METHODS: Disks (N=420) were fabricated by using either conventionally (CNV group) or additively manufactured (AM group) materials. The CNV group was further divided into the subgroups CNV-1 (Protemp 4; 3M ESPE) and CNV-2 (Anaxdent new outline dentin; Anaxdent). AM subgroups included AM-1 (FreePrint temp; Detax), AM-2 (E-Dent 400; Envisiontec), AM-3 (NextDent C&B; NextDent), AM-4 (NextDent C&B MFH; NextDent), and AM-5 (Med620 VEROGlaze; Stratasys). Color measurements in the CIELab coordinates were made by using a spectrophotometer (VITA EasyShade Advance 4.0; VITA) with a standardized photography gray card as a background under room light conditions (1003 lux). Color difference (DeltaE*) values were calculated by using the CIE76 and CIEDE2000 formulas. The data were analyzed by using the Kruskal-Wallis test with nonparametric pairwise comparisons. RESULTS: Owing to a software error, the spectrophotometer was unable to measure the color of any specimens in the AM-5 subgroup, which was consequently excluded from further analysis. Significant differences (P=.001) between 2 manufacturing groups were found based on the L* variable. All subgroups were significantly different from each other for all 3 variables (P<.001). Pairwise comparisons revealed that all groups were significantly different from each other, except for the AM-1 and AM-2 subgroups, compared with the CNV-1 subgroup for the L* color dimension. The DeltaE* values calculated by using the CIE76 formula varied from 6.63 to 23.1 and by using the CIEDE2000 formula from 3.43 to 10.21, suggesting a perceptible and unacceptable color mismatch between the CNV and AM groups. CONCLUSIONS: None of the additively manufactured interim materials tested matched the conventional interim materials in all 3 CIELab color dimensions.

Revilla-Leon, M., M. J. Meyer, J. J. Barrington, A. Sones, M. P. Umorin, M. Taleghani and A. Zandinejad (2019). “Perception of occlusal plane that is nonparallel to interpupillary and commissural lines but with the maxillary dental midline ideally positioned.” J Prosthet Dent 122(5): 482-490.

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STATEMENT OF PROBLEM: How disparities in parallelism between the occlusal plane and the interpupillary (IP) or commissural facial front lines are perceived is unclear. PURPOSE: The purpose of this observational study was to examine the perceptions of laypersons, dental students, and dentists regarding disparities of the anterior occlusal plane (AOP) and posterior occlusal plane (POP) with respect to the IP and commissural line (CL) with the maxillary dental midline ideally positioned. MATERIAL AND METHODS: A model of a symmetric female face was digitally created with the IP and CL parallel and the facial midline coincident with the maxillary dental midline. Two groups of images were created, one with the POP modified in 1-degree increments, in which both the maxillary dental midline and the position of the maxillary central incisors were not manipulated, and the other with the POP modified in the same increments but with the position of both maxillary central incisors lengthened to follow the inclination of the occlusal plane. Participants (N=312) were asked to rate the images on a 1-to-6 scale. The Kruskal-Wallis medians test and ordinal logistic regression were used to analyze the ratings. RESULTS: Group median ratings for different occupations gradually decreased with increased inclination of the occlusal plane. Significant differences were found for inclinations from 2 to 5 degrees. Significant odd ratios were found for age and sex. CONCLUSIONS: Dental professionals detected smaller POP disparities. The dentist and dental student groups gave lower ratings in proportion to the amount of POP inclination. Laypersons gave lower ratings only after 3 degrees of POP inclination but still graded all the images as esthetically pleasant. Older people and men tended to give higher ratings to the same image.

Li, S., Y. Sun, T. Tian, X. Qin, S. Lin, T. Zhang, Q. Zhang, M. Zhou, X. Zhang, Y. Zhou, H. Zhao, B. Zhu and X. Cai (2019). “MicroRNA-214-3p modified tetrahedral framework nucleic acids target survivin to induce tumour cell apoptosis.” Cell Prolif Oct 23:e12708. [Epub ahead of print].

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OBJECTIVES: Due to the instability of microRNAs, the applications of microRNA are currently limited. Thus, we utilized tetrahedral framework nucleic acids and a targeted microRNAs to form a stable nanocomposite to explore whether this nanocomposite can promote apoptosis of tumour cells. MATERIALS AND METHODS: In our study, the survivin gene, which is expressed only in tumour cells and embryonic cells, was selected as the target gene; miRNA-214-3p, which can reduce the expression of survivin, was modified onto tetrahedral framework nucleic acid, thereby producing a reduction in the expression of survivin upon intracellular delivery and eventually leading to tumour cell apoptosis. RESULTS: By comparing the stability of microRNAs with that of microRNA-tetrahedral framework nucleic acid, we proved the superiority of this carrier system. The results of flow cytometry showed that after treated with this complex, the ratio of A549 cells in both late and early period of apoptosis in miRNA-214-3p-tetrahedral framework nucleic acid group had doubled and the cell cycle in the G2-M phase had declined. The decrease in the expression of anti-apoptotic protein and the increase in the expression of pro-apoptotic protein indicate that the ability of this complex to function in cells also makes it attractive as a new targeted therapy for cancer. CONCLUSION: The unique expression of survivin in tumour cells and embryonic cells makes microRNA-tetrahedral framework nucleic acid a new targeted therapy. In addition, due to the functional diversity of microRNAs, this delivery system approach can be applied to a wide variety of fields, such as targeted therapy and tissue regeneration.