The impact of dental midline angulation towards the facial flow curve on the esthetics of an asymmetric face: Perspective of laypeople and orthodontists.

PURPOSE: The objective of the present article was to evaluate the impact of dental midline angulation in asymmetrical faces. MATERIALS AND METHODS: A full-portrait image was used to create a set of digitally modified images with a different degree of facial asymmetry, towards the right and the left side of the face respectively. Half of the images were designed with an equivalent angulation of the dental midline in respect to the curve of the lower third of the face and half of them without. Through a web survey, 250 laypeople and 250 orthodontists were asked to assess the attractiveness of each image separately. RESULTS: As the asymmetry of the face was increased, facial attractiveness was further decreased both for laypersons and orthodontists. For each one of the modified images, when the dental midline was following the curve that was formed from the inclination of the simulated asymmetry of the face, the smile attractiveness scores were significantly higher compared to a straight dental midline. CONCLUSION: Facial asymmetries derived from the inclination of the nose, the chin and the commissural line of the lips can significantly affect the smile attractiveness. An orientation of the dental midline towards the facial asymmetry in order to follow the facial curve, can be beneficial for the smile attractiveness compared to a perpendicular to the face dental midline. During the design of a smile, clinicians have to take into consideration deviations in facial midline, in order their restorations to be in harmony with the rest of the face. CLINICAL SIGNIFICANCE: During the design of a smile, clinicians have to take into consideration deviations in the facial midline, in order their restorations to be in harmony with the rest of the face.

Perception of smile attractiveness among laypeople and orthodontists regarding the buccal corridor space, as it is defined by the eyes. An innovated technique.

OBJECTIVE: To investigate whether there is a relationship between the distance between the iris and pupil with the ideal size of buccal corridors. MATERIALS AND METHODS: A full-portrait image of a male Caucasian was used to create a set of 11 digitally modified images with different buccal corridor space. A web-based cross-sectional study was designed and distributed via an online survey to 200 laypeople and 200 orthodontists to assess image attractiveness, using a Visual analogue scale. For the statistical analysis, Wilcoxon signed-rank and Mann-Whitney U tests were used. The significance level was set at p < 0.05. RESULTS: The response rate for laypeople was 70% (n = 139), while the rate for orthodontists was 73% (n = 146). For the layperson group, the maximum smile attractiveness score was 10% of buccal width reduction, compared to the iris-pupillary distance, while for the orthodontists, it was 20%. The attractiveness of the smile was significantly reduced in both groups when the buccal corridor width was increased in comparison to the iris-pupillary distance. CONCLUSION: The length between the mesial part of the iris and the distal of the pupil, may constitutes a landmark for the estimation of the desired width of the buccal corridor. CLINICAL RELEVANCE: Inter iris-pupillary distance can be the starting point in the smile designing process, in order to perform a facial driven selection of buccal corridor size.

Comparison between orthodontic and surgical uprighting of mandibular molars: a systematic review.

OBJECTIVES: To evaluate and compare the efficiency of orthodontic treatment and surgical uprighting of first and second mandibular molars. MATERIALS AND METHODS: An electronic literature search in PubMed, Science Direct, Embase, Scopus, Web of Science, Cochrane Library, LILACS, and Google Scholar, as well as a hand search was conducted by two independent researchers to identify relevant articles up to January 2022. In addition, a manual search was done that included article reference lists, grey literature, and dissertations. The risk of bias of the included prospective and retrospective studies was assessed with the Risk Of Bias Tool In Non-randomized Studies of Interventions (ROBINS-I) assessment tool. RESULTS: A total of six nonrandomized clinical trials (non-RCT) evaluating the efficiency of mandibular molar orthodontic and/or surgical uprighting were included. The quality analysis showed certain defects of the Non-RCTs included and, according to the criteria used, the majority of the articles were judged to be of moderate quality. CONCLUSIONS: Based on the evidence, orthodontic and surgical uprighting appear to be effective treatment methods for mandibular molars. Surgical uprighting may be associated with more complications than orthodontic uprighting. However, the existing literature on the subject is limited, heterogeneous, and methodologically limited. Therefore, the outcomes should be interpreted carefully.

Lip sucking habit and associated craniofacial differences in a set of monozygotic twins.

OBJECTIVE: The objective of this study was to evaluate the influence of lip sucking on dentofacial development in a pair of 6.5-year-old monozygotic twins. BACKGROUND: Lip sucking, which causes an imbalance in splanchnocraniums soft tissues pressures, can influence the hard tissues development, and contribute to orthodontic anomalies. METHODS: Analysis of lateral cephalometric X-rays was performed by 9 orthodontists. Data were compared using the Mann-Whitney and Kruskal-Wallis tests. Statistical significance was defined as p<0.05. RESULTS: SNA, A-NPog, and Cond-A values suggested an anterior shift of the maxilla. The 1u to SN, 1u to A-Pog, 1u to A-Pog angle, and 1u-Avert values indicated an upper incisor protrusion. While the 1l to A-Pog, 1l to A-Pog angle and 1l to Go-Me values showed a retrusion of the lower incisors, the NL-NSL implied a hard palate rotation counterclockwise. The SNA-Me indicated that the mandible of the lip-sucking patient was in a more inferior position. CONCLUSION: Lip sucking can influence the skeletal development of maxilla, the position of upper and lower incisors and the position of mandible. Skeletal development of mandible seems to be unaffected (Tab. 3, Fig. 1, Ref. 26).

Temporomandibular Disorders: Fundamental Questions and Answers.

This review aimed to present the current evidence-based answers to a questionnaire which was developed to evaluate the beliefs and knowledge of dental professionals concerning temporomandibular disorder (TMD). A literature review was conducted using the PubMed/Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane, Google Scholar, and Scopus search engines from January 1980 to June 2020 corresponding to TMD diagnosis, causes, management, and consequences. A total of 50 articles were considered relevant and selected for full review. The etiology of TMD is multifactorial and complicated and involves several direct and indirect factors. Orthodontic treatment does not appear to either prevent or relieve TMD to a great degree. Nevertheless, condylar and occlusal stability reduces the risk of TMD development. As a result, an assessment of the function of masticatory system prior to beginning orthodontic therapy is fundamental. If signs and symptoms of TMD are significantly present, they should be managed before any orthodontic intervention. Moreover, psychological disorders are strongly associated with joint and facial pain. Thus, professionals who work with chronic TMD patients need to be aware of the psychological aspects of chronic pain and refer the patient for psychological evaluation when warranted. Future research elucidating a cause-effect relationship and neurobehavioral processes underlining chronic pain should be performed.