DOI: 10.3897/folmed.68.e169836

Authors: Sonakshi Sharma, Amol Patil, Shruti Biyani, Shivangini Swarnkar, Meydha Gera

Abstract: Aim: Functional mandibular advancement appliances are widely used in orthodontics, but their molecular and histological effects on masticatory muscles remain underexplored. This study evaluated gene expression and tissue-level adaptations in response to mandibular advancement and a subsequent recovery period in young male Wistar rats. Materials and methods: Thirty rats were randomly assigned to three groups: control (Group A), functional mandibular advancement for four weeks (Group B), and functional mandibular advancement followed by a one-month recovery period (Group C). The expression of myostatin and myosin-1c genes was determined using quantitative real-time reverse transcription polymerase chain reaction. Histological analyses were performed to examine muscle fiber morphology in the masseter and lateral pterygoid muscles. Results: Mandibular advancement produced a significant downregulation of myostatin and upregulation of myosin-1c (p<0.05), most prominent in the lateral pterygoid muscle. Histological evaluation revealed hypertrophic changes in muscle fibers consistent with increased mechanical loading. After the recovery phase, altered gene expression and hypertrophic features persisted partially, indicating sustained molecular and structural adaptations. The masseter and lateral pterygoid muscles exhibited distinct, muscle-specific responses at both the genetic and histological levels. Conclusion: Mandibular advancement induces molecular and histological adaptations in masticatory muscles, with partial persistence following a one-month recovery period. These results suggest the potential for long-term functional and morphological changes after orthodontic intervention and provide biological evidence to inform personalized treatment and retention strategies in growing individuals.

HTML

XML

PDF

DOI: 10.3897/folmed.66.e130813

Authors: Swapnil Junnarkar, Anand Sabane, Amol Patil, Meenal Tepan, Tanisha Rout, Sonakshi Sharma, Arati Gholap

Abstract: Aim: We aim to assess and contrast the mechanical stability of two mini-implant designs, featuring larger diameters and shorter lengths, for orthodontic anchorage against a conventional group of implants. Materials and methods: Three groups of mini-implant underwent testing: the implants in Group 1 were 2.5 mm in diameter and 4 mm in length; the implants in Group 2 were 3 mm in diameter and 3 mm in length; and the conventional group implants were 1.3 mm in diameter and 7 mm in length. Both types were Abso Anchor mini-implants (Dentos Inc.). The implants’ mechanical stability was assessed using the maximum insertion torque (MIT), the maximum removal torque (MRT), and the angulated lateral displacement tests for compression and tension force vectors. Fourteen mini-implants of each design were used to measure MIT and MRT. Seven mini-implants of each design were tested for lateral displacement. Results: Torque tests - Group 2 mini-implants showed superior primary stability with higher MIT and MRT values compared to Group 1 and the conventional group implants. Lateral displacement tests - Group 2 mini-implants required significantly greater compressive force than those in Group 1 and the conventional group. Tension force for lateral displacements was similar between the three groups. Conclusion: Group 2 mini-implants, with larger diameters and shorter lengths, demonstrated superior primary stability over Group 1 implants. Despite the differences in compressive force, all three groups performed similarly under tension in lateral displacement tests.

HTML

XML

PDF

DOI: 10.3897/folmed.66.e119060

Authors: Harpreet Singh, Pinaki Roy, Raj Kumar Maurya, Poonam Sharma, Pranav Kapoor, Tanmay Mittal

Abstract: Skeletal class III malocclusion is a therapeutic challenge in orthodontic practice. Reverse functional appliances such as reverse twin block (RTB) are used to correct class III skeletal and occlusal disharmonies associated with functional anterior shift in growing patients. However, treatment options become limited with increasing age, especially when patients desire nonsurgical and nonextraction camouflage treatment. This report illustrates the successful nonsurgical treatment of class III malocclusion during adolescence and adulthood, exacerbated by a functional anterior shift that resulted in overclosure of the mandible. A modified fixed RTB was utilized to posture the mandible backwards, thereby inducing active clockwise rotation of the mandible. After treatment, patients demonstrated significantly improved maxillomandibular relationships, well-maintained stable occlusion, and facial esthetics. Satisfactory occlusal, esthetic, and functional outcomes achieved in the present cases underline the fact that dentoalveolar changes induced by fixed RTB can be utilized even past a patient’s peak pubertal growth period to obtain changes that aid in correcting a class III malocclusion. A synergistic combination of modified fixed RTB therapy accompanied by comprehensive fixed mechanotherapy is a viable treatment alternative for the correction of aptly selected mild to moderate skeletal class III malocclusions associated with functional anterior shift, anterior crossbites, and mandibular overclosure.

HTML

XML

PDF

DOI: 10.3897/folmed.66.e129047

Authors: Anish Doke, Anand Sabane, Amol Patil, Jayesh Rahalkar, Tulsi Subramaniam, Monali Nikalje

Abstract: Introduction: Mandibular prognathism (MP) patients present with aesthetic concerns and functional issues, including difficulties in mastication and pronunciation. Studies revealed that mandibular prognathism had definitive Mendelian inheritance patterns. This study aimed to ascertain distinct genetic markers associated with mandibular prognathism in individuals of Indian descent, focusing on exploring the prevalent genetic variations associated with certain genes. This study sought to identify the association of the following gene markers with mandibular prognathism: 1) Matrilin-1 (MATN1) (rs1065755), 2) Bone morphogenic protein 3 (BMP-3) (Tyr67Asn), 3) Homeobox protein hox-A2 (HOXA2) (Val327Ile), 4) Rho-GTPase activating protein (ARHGAP 21) (Gly1121Ser), 5) Myosin 1H (MYO1H) (rs10850110) Materials and methods: Forty subjects (age group 18–30 years) were chosen based on their clinical examination, study model, and lateral cephalogram. Ten subjects had normal skeletal jaw-base relationships, and 30 had prognathic mandibles (skeletal class III jaw-base relationships). Two milliliters of blood were taken from each person. The genes, as mentioned above, associated with mandibular prognathism were studied. To assess the association between genetic markers and mandibular prognathism, the following statistical tests were used: an unpaired t-test was used to compare the mean values of continuous variables between the normal and prognathic groups; a chi-square test was used to evaluate the association between genetic markers and the jaw-base relationship; and an odds ratio was used to assess the strength of association between genetic markers and the prognathic mandible. Statistical analyses were conducted using SPSS software. Results: Out of five single nucleotide polymorphisms (SNP) selected in the study, namely rs10850110, rs1065755, rs111419738, rs143043350, and rs74764079, three SNPs—rs111419738, rs143043350, and rs74764079—did not show differences in the genotypes among the study and control samples. Thus, this indicates that these three SNPs may be related to mutations seen in MP in other populations but do not exhibit any association with the people covered in this study. The other two SNPs, rs10850110 and rs1065755, showed variant genotypes in control and study samples. Conclusions: Our research found that rs10850110 and rs1065755 positively correlated with mandibular prognathism. Further studies are needed to see the association between these two restriction sites in MP subjects.

HTML

XML

PDF

DOI: 10.3897/folmed.65.e85525

Authors: Manoela Kalaydzhieva, Silviya Krasteva, Mariya Stoilova-Todorova, Katya Todorova-Plachyiska, Konstantin Georgiev

Abstract: Introduction: The main goal of orthodontic retention is to keep the teeth in their corrected positions. Fixed or removable retainers are the most common types of retainers used during the retention phase. For the maxilla, various types of retainers have been described, including the vacuum-formed retainers and Hawley retainers. Fixed retainers are used for the lower jaw. Aim: The aim of the present study was to assess the retention characteristics of Hawley retainers, vacuum-formed retainers, and fixed retainers in preserving dental arch dimensions and tooth alignment. Materials and methods: Seventy subjects were examined and distributed into two retention groups. One of the groups received maxillary Hawley retainers and bonded retainers in the mandible. The other group received maxillary vacuum-formed retainers and bonded retainers in the mandible. The mean retention period was two years. Maxillary and mandibular casts were analyzed at pretreatment, debonding, and two years in retention. The assessed measurements were the arch length, intercanine width, interpremolar width, intermolar width and Little’s irregularity index. Results: Vacuum-formed retainers maintained maxillary anterior teeth alignment more effectively than Hawley retainers did. No differences in transversal dimensions were found between the two retention protocols. Hawley retainers showed superior retention characteristics in maxillary arch length preservation compared to vacuum-formed retainers. Even with bonded retainers, relapse could still happen. All measured variables showed a tendency to relapse to the pretreatment values in the two groups. Conclusions: Vacuum-formed retainer maintained maxillary incisor position more effectively than Hawley retainers did. No differences were observed in the transversal dimensions between the two groups. A greater decrease in the mandibular intermolar width was measured between T1 and T2 in both groups where bonded retainers were used.

HTML

XML

PDF

DOI: 10.3897/folmed.65.e67782

Authors: Zeinab Imani, Ahmad Sodagar, Maryam Pourhajibagher, Armin Hosseinpour Nader, Abbas Bahador

Abstract: Aim: The present study aimed to assess the antimicrobial effects of orthodontic primer containing nano-propolis against the cariogenic bacteria in а rat model. Materials and methods: Transbond XT orthodontic primer containing 0%, 1%, 5%, and 10% nano-propolis was experimentally prepared in-house. The Wistar rats we used in the study were randomly divided into four groups and their oral cavities were colonized with Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus. After anesthetizing the rats, one drop (10 µL) of primer containing different concentrations of nano-propolis was applied to the labial surface of the maxillary incisor and light-cured. The orthodontic composite was applied on the primer and light-cured. One drop (10 µL) of primer containing the same concentrations of nano-propolis was again applied on the surface of composite and light-cured. The number of S. mutans, S. sanguinis, and L. acidophilus colonies in the saliva of rats was quantified at 24 h, at days 4 and 7 using plate counting. Results: Primer containing 1%, 5%, and 10% of nano-propolis significantly reduced the S. mutans colony count at 24 h compared with the control group (p<0.05). At day 4, the mean S. mutans colony counts in the 5% and 10% nano-propolis groups were significantly lower than that in the control group (p<0.05). Primer containing 1%, 5%, and 10% (all (p<0.05) of nano-propolis significantly reduced the L. acidophilus at 24 hours. Also, at day 4 the mean L. acidophilus colony counts in the 5% and 10% nano-propolis groups were significantly lower than that in the control group (p<0.05). At 24 h and 4 days, the mean S. sanguinis colony count in the 1%, 5%, and 10% nano-propolis group was significantly lower than that in the control group (p<0.05). No significant difference was observed in the presence of all concentrations of nano-propolis at day 7 (p>0.05). Conclusions: Orthodontic primer containing nano-propolis significantly reduced the colony count of cariogenic bacteria in a rat model.

HTML

XML

PDF

DOI: 10.3897/folmed.63.e53716

Authors: Maryam Pourhajibagher, Abbas Bahador

Abstract: Introduction: In fixed orthodontics, formation of white spot lesions, enamel demineralization, and tooth decay around appliances are common complications which mar the outcome.Aim: The aims of this study were the determination of the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic adhesive doped with N-GO, as well as the assessment of antimicrobial activities of the modified orthodontic adhesive against Streptococcus mutans.Materials and methods: N-GO was characterized by a scanning electron microscope (SEM), Fourier transformation infrared (FTIR), X-ray diffraction (XRD), and Zeta potential. The SBS and ARI of modified orthodontics adhesive containing different concentrations of N-GO (0, 1, 2, 5, and 10 wt%) were then measured. The influences of adding N-GO on antimicrobial properties of orthodontic adhesive were determined against S. mutans by disc agar diffusion (DAD) testing and biofilm formation inhibition assay.Results: The SEM, FTIR, XRD, and Zeta potential analysis indicated the successful synthesis of N-GO. Orthodontics adhesive doped with 5 wt% N-GO showed the highest concentration of N-GO and SBS value (21.71±7.45 MPa, p<0.05) simultaneously with no significant differences in adhesive remnant index compared with the control group. SBS in the 1, 2, and 5% N-GO were significantly higher than that in 10% N-GO (p=0.025, p=0.036, p=0.041, respectively). The disinfection ability of the modified orthodontic adhesive doped with N-GO against S. mutans in the DAD and biofilm formation inhibition assays were positively associated with increased in N-GO concentrations (p<0.05). However, the 5 and 10 wt% N-GO showed a statistically significant decrease the CFU/mL of the test microorganisms in biofilm structures (p<0.05).Conclusions: It could be concluded that 5 wt% of N-GO can be considered as an orthodontic adhesive additive to reduce the microbial count and biofilm with no adverse effect on SBS and ARI.

HTML

PDF

DOI: 10.3897/folmed.63.e52165

Authors: Harshal Santosh Patil, Sangeeta Golwalkar, Kishor Chougule, Nishita Rajeev Kulkarni

Abstract: Introduction: Facial soft tissue thickness is important not only for plastic surgeons but also for orthodontists to plan the treatment procedure. Genioplasty, an orthognathic surgery in combination with orthodontic treatment is indicated to restore adequate shape and projection of the chin in the face. It has been performed to enhance soft tissue contours related to disproportion between soft and hard tissue. These treatments require the critical information regarding the relation between soft and hard tissues for proper treatment plan-ning. However, there is very minimal documentation on comparison of soft tissue characteristics particularly in Class II malocclusion. Aim: To evaluate and compare soft tissue chin thickness in class II subjects with various growth patterns. To evaluate soft tissue chin thickness difference in males and females and compare the results with previous studies. Materials and methods: The study comprised 150 adults aged between 18 and 26 years (mean age 21 years). Based on FH/MP angle the study sample was allocated into three groups: group I - low (hypodivergent), group II – average, and group III - high (hyper-divergent). Radiographs were traced manually. Angular measurements were computed to determine the vertical position of the maxilla and mandible in relation to anterior cranial base, to true horizontal and to each other. Soft tissue chin thickness was measured at three different levels. Results: Hyperdivergent group showed greater soft tissue chin thickness at Pog-Pog’ than the hypodivergent and average angle groups. Hypodivergent group showed greater soft tissue chin thickness at Me-Me’ and Gn-Gn’ as compared to average and hyperdivergent groups. Males showed greater soft tissue chin thickness at hypodivergent, average and hyperdivergent group than females. Conclusions: Soft tissue thickness measurements were smaller in adult patients of hyperdivergent group compared to adult patients in clinically average and hypodivergent groups. All STC measurements were greater in men than in women. The findings suggested that STC thickness in hyperdivergent pattern should be considered differently at its most anterior point (Pog) relative to its inferior landmarks (Gn and Me).

HTML

PDF