Evaluation of an open access generic 3D software for Orthodontic diagnosis and treatment planning

Aim: To evaluate the accuracy and the validity of orthodontic diagnostic measurements, as well as virtual tooth transformations using a generic open access 3D software compared to OrthoAnalyzer (3Shape) software; which was previously tested and proven for accuracy. Methods: 40 maxillary and mandibular single arch study models were duplicated and scanned using 3Shape laser scanner. The files were imported into the generic and OrthoAnalyzer software programs; where linear measurements were taken twice to investigate the accuracy of the program. To test the accuracy of the program format, they were printed, rescanned and imported into OrthAnalyzer. Finally, to investigate the accuracy of editing capabilities, linear and angular transformation procedures were performed, superimposed and printed to be rescanned and imported to OrthoAnalyzer for comparison. Results: There was no statistically significant difference between the two groups using the two software programs regarding the accuracy of the linear measurements (p>0.05). There was no statistically significant difference between the different formats among all the measurements, (p>0.05). The editing capabilities also showed no statistically significant difference (p>0.05). Conclusion: The generic 3D software (Meshmixer) was valid and accurate in cast measurements and linear and angular editing procedures. It can be used for orthodontic diagnosis and treatment planning without added costs

Enamel Deproteinization: Will It Save The Shear Bond Strength For The Sake Of Preventing White Spot Lesions? / Desproteinização do esmalte: salvará a resistência ao cisalhamento para prevenir lesões de manchas brancas?

Objective: This study attempted to investigate the effect of enamel deproteinization using citric acid, PEG 400 and NaOCL on the shear bond strength of orthodontic brackets to enamel using nano-silver modified resin for the prevention of white spot lesions. Material and Methods: 68 premolars were used in the study; nano-silver modified adhesive resin was used to bond orthodontic brackets to the enamel. Specimens were divided into 4 groups according to the applied surface treatment before bonding. Group I (control): acid etching with 37% phosphoric acid. Group II: deproteinization using 5.25% sodium hypochlorite (NaOCl) before acid etching. Group III:deproteinization using 10% citric acid before acid etching. Group IV:deproteinization using 5% polyethylene glycol (PEG 400) before acid etching. The specimens were then thermo- cycled for 6000 cycles. They were examined for surface roughness, shear bond strength and using electron microscope. Results: In both surface roughness and shear bond strength tests, Group III (citric acid) showed the highest values, followed by Group II (sodium hypochlorite); (p < 0.001). The least values were shown for Groups I (control) and IV (PEG 400), with no statistically significant difference between them (p = 0.948). SEM revealed etching pattern type 1 and 2 in the citric acid group while PEG 400 showed shallower micro- porosities. Conclusions: Deproteinization of enamel using either NaOCl or citric acid increased the bond strength of nano-sliver modified resin to enamel, with citric acid showing greater increase in bond strength. Deproteinization using PEG 400 did not increase the bond strength. (AU)

Objetivo: Este estudo buscou investigar o efeito da desproteinização do esmalte utilizando ácido cítrico, PEG 400 e NaOCl na resistência ao cisalhamento de braquetes ortodônticos ao esmalte usando resina modificada com nanoprata para a prevenção de lesões de manchas brancas. Material e Métodos: 68 pré-molares foram usados no estudo; resina adesiva modificada com nanoprata foi usada para colar os braquetes ortodônticos ao esmalte. Os corpos-de-prova foram divididos em 4 grupos de acordo com o tratamento de superfície aplicado antes da colagem. Grupo I (controle): condicionamento ácido com ácido fosfórico a 37%. Grupo II: desproteinização com hipoclorito de sódio a 5,25% (NaOCl) antes do condicionamento ácido. Grupo III: desproteinização com ácido cítrico a 10% antes do condicionamento ácido. Grupo IV: desproteinização com polietilenoglicol 5% (PEG 400) antes do condicionamento ácido. As amostras foram então termocicladas por 6.000 ciclos. Eles foram examinados quanto à rugosidade da superfície, resistência ao cisalhamento e usando microscópio eletrônico. Resultados: Nos testes de rugosidade superficial e resistência ao cisalhamento, o Grupo III (ácido cítrico) apresentou os maiores valores, seguido do Grupo II (hipoclorito de sódio); (p <0,001). Os menores valores foram apresentados para os Grupos I (controle) e IV (PEG 400), sem diferença estatisticamente significativa entre eles (p = 0,948). A microscopia eletrônica revelou padrão de ataque tipo 1 e 2 no grupo de ácido cítrico, enquanto PEG 400 mostrou microporosidades mais rasas. Conclusões: A desproteinização do esmalte com NaOCl ou ácido cítrico aumentou a força de união da resina modificada com nanoprata ao esmalte, com o ácido cítrico apresentando maior aumento na força de união. A desproteinização usando PEG 400 não aumentou a resistência de união. (AU)

Facial analysis using a new clinical device: The Kattan Facio-meter.

BACKGROUND: The aim of the study was to attempt to set average faciometric standards for Egyptians using the Kattan Facio-meter. MATERIAL AND METHODS: The sample consisted of 180 faculty students with age range 17-25 years. It was divided into three groups; Angle Class I, II and III. Class II was further subdivided into divisions 1 and 2. Linear and angular facial measurements in relation to K plane were taken using the Kattan facio-meter. The measurements were correlated to Angle's classification and between genders. RESULTS: On comparing the different classes, Class II division 1 showed the statistically highest mean value for Orbitale-soft tissue A; p=0.042, Class II divisions 1 and 2 for Orbitale- Labrale superius; p=0.002 and soft tissue ANB; p<0.001. Females showed significantly higher mean value than males for the upper incisor/K plane; p=0.031. Males showed significantly higher mean value for the inter-incisal angle than females; p=0.001. CONCLUSIONS: Within the limitations of the current study, it was found that both linear and angular soft tissue measurements conformed to the antroposterior skeletal relation of the jaws and that Class II division 1 was due to protruded maxilla. Males had more prominent lips and deeper mentolabial sulcus. Egyptians had less prominent noses than Caucasians. The Kattan Facio-meter was a valuable tool for clinical analysis without the hazards of irradiation. Key words:Kattan Facio-meter, Angle Class I, II and III.

A New Horizontal Plane of the Head.

AIM: This study aimed to attempt to introduce a new extracranial horizontal plane of the head (K plane that extends from SN to SAE bilaterally) that could act as a substitute to the Frankfurt horizontal intracranial reference plane; both clinically and radiographically. MATERIAL AND METHODS: The new K plane depended on three points of the head. The first was the soft tissue nasion (NS) on the interpupillary line when the subject looked forward at a distant point at eye level. The other two points were the superior attachments of the ears (SAE). RESULTS: The student "t" test comparing mean values of K/V and FH/V was not significant; -0.21. The coefficient of correlation between different variables was highly positively significant (r = 0.98 with probability = 0.001). CONCLUSION: Within the limitations of this prospective study, the new K plane was found to be both reliable and reproducible. It can be used as a reliable reference plane instead of Frankfort horizontal plane both clinically and radiographically; as it is an accurate tool for head orientation in the natural head position.

Buccal Corridors: A Fact or a Myth in the Eyes of Laymen?

AIM: This study aimed to investigate laymen knowledge of the existence of the buccal corridor and whether it was an important factor for them in judging smile attractiveness and the effect of introducing the knowledge to them on their further judgment. MATERIALS AND METHODS: Nine subjects were randomly selected with variable buccal corridor percentages. They were coached to smile in a posed fashion and full face smile photographs were taken from a standardised distance. The photographs were randomly arranged in a power point presentation and displayed to a panel of thirty-nine randomly selected laymen judges. The judges made their beauty judgment on a visual analogue scale (VAS) and filled a questionnaire. After their education about the buccal corridor, they were asked to make a second judgment on a second sheet with VAS and with a different random sequence of the photographs. RESULTS: Intra-class correlation agreement for all the judges between the first and second scores was 0.713. The Spearman's rho Correlation coefficient indicated a positive correlation for all the photos. For the male judges, the agreement between the ratings was 0.839, and the correlation was positive for all the photos. For the female judges, the agreement between the ratings was 0.510, and the correlation was positive for all the photographs. Hundred percent of the judges were not familiar with the buccal corridor. Eighty percent of the female judges and 44.4% of the male judges mentioned that it would affect their further judgment. CONCLUSION: Laymen build their esthetic judgments on what we teach them, and modifying treatment plans to include corrections of buccal corridors for esthetic reasons only is a myth.