Md Mahdi Kashani Aragh Bidi, Dr Mahdi Jabari Jahromi, Dr Sepide Bagheri Hosein Abadi, Dr Mohammadreza Shokuhifar,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: The vertical growth pattern of the face depends on several factors. One of these factors can be the muscle strength of the jaw. Maximum occlusal force (MOF) can be considered as an index to measure the function of the muscles of the masticatory system. Despite the various studies, the relationship between the facial pattern and muscle function is still controversial. According to soft tissue paradigm theory, muscle can affect the shape and form of bones of the jaw, face and head. The aim of this study was to determine the relationship between the maximum occlusal force and head and face growth pattern in dental students of Shahed University in Tehran.
Materials and Methods81 dental students (40 males and 41 females) were participated. MOF was measured with a loadcell designed for this purpose, and the anthropometric points of the face and head were measured with digital caliper. Two-way ANOVA and Tukey HSD tests were used to determine the effect of facial and head patterns on the maximum occlusal force. Statistical analysis was performed by SPSS23.
Results: The mean MOF in males was 480 N and in females 320 N. Head forms in our sample research were 54.32% Brachycephale, 32.09% Mesocephale, and 13.58% Dolicocephale. The form of the face was 23.45% euprosopic, 39.5% mesoprosopic, and 37.03% leptoprosopic. According to the statistical analysis, the relationship between the maximum occlusal force and leptoprosopic form of face was statistically significant (P=0.02). However, there was not significant relationship between the maximal occlusal force and none of the three type of head forms (P=0.813).
Conclusion: MOF was related to the leptoprosopic pattern of face, and these individuals had less bite power. No relationship between the maximum occlusal force and head forms and neither between the head pattern and facial pattern was found in this study. The maximum occlusal force in men was higher in all three facial patterns than that of women, although this relationship was not significant.
Pedram Abedi, Maysam Mirzaee, Sahba Amini, Mohammad Mehdi Naghibi Sistani,
Volume 33, Issue 4 (1-2021)
Abstract
Background and Aims: Information collection about the malocclusion and oral health in blind children is essential to plan for their education in schools. Therefore, this study aimed to evaluate the status of malocclusion and oral health among blind children and teenagers in Mazandaran, Iran.
Materials and Methods: The population of this included 150 blind children and teenagers aged from 10 to 18 years who were referred to the public and private centers cities including Sari, Babol, Freydoonkenar, and Babolsar in Mazandaran, Iran in 2019. Information on maxillary occlusion status, oral hygiene index, and DMFT index was extracted through clinical examination. Data were analyzed using SPSS23 software by ANOVA and Chi-square tests in addition to the descriptive statistics.
Results: The mean DMFT was 10.25 (SD 4.67). Oral hygiene status was good in 16% of participants, moderate in 82%, and poor in 2%. There was no significant difference between girls and boys in terms of oral hygiene status (P=0.5). In all cases, 35.8% had class I malocclusion, 29.8% had class II malocclusion, and 14.6% had class III malocclusion. Class II malocclusion was more common in girls and class I in boys (P=0.01).
Conclusion: Dental caries and occlusal abnormalities were common among blind children and adolescents living in Mazandaran province. Addressing the oral and dental needs of the blind should be a priority for health policymakers in this province in Iran.
Elahe Soltanmohamadi Borujeni, Ali Bavi, Mohammad Aghaali, Ali Saleh, Aida Mehdipour,
Volume 37, Issue 0 (3-2024)
Abstract
Background and Aims: Strong bond between the ceramic brackets and ceramic veneers has an important role in cosmetic treatment. The purpose of this study was to investigate the effect of aging on the shear bond strength (SBS) of ceramic brackets bonded to zirconia after surface preparation by Neodymium-doped Yttrium Aluminum Garnet (Nd: YAG) laser or sandblasting with alumina.
Materials and Methods: This experimental study was conducted on 24 zirconia blocks and these blocks were randomly divided into two groups for surface preparation and each was sub-divided into three time intervals. Surface preparation was done by sandblasting with alumina: in SG1 (Immediately after sandblasting), SG2 (2 weeks after sandblasting), and SG3 (3 months after sandblasting) groups. For the Nd: YAG laser (1/5W, 20Hz, 10s) with non-contact mode: in LG4 (Immediately after laser), LG5 (2 weeks after laser), and LG6 (3 months after laser) groups. The ceramic brackets were bonded to the zirconia blocks. The SBS and adhesive remnant index (ARI) were evaluated and compared among test groups. Dara were analyzed using Mann Whitney test.
Results: There was no significant difference between the SBS of SG1 and LG4 (P=0.430), SG2 and LG5 (P=0.382) and SG3 and LG6 (P=0.326) groups. LG4 group showed the highest shear bond strength. After aging (2 weeks and 3 months), the laser groups showed higher SBS. There was no significant difference in the ARI between SG1 and LG4 (P=0.220), SG2 and LG5 (P=0.154), SG3 and LG6 (P=0.527) groups.
Conclusion: No significant difference was observed between the Nd: YAG laser and sandblasted groups in terms of SBS and ARI over time. Therefore, Nd: YAG laser could be used as a surface treamnet method in Zirconia crowns for bonding to ceramic brackets.