Objective: To evaluate the position of hyoid bone in the subjects treated with Twin block appliance. Materials and Methods: The sample consisted of 40 Angle's Class II division 1 subjects treated with Twin block appliance. Lateral radiographs were taken before and after treatment. According to Schudy's facial divergence angle (SN-MP), the subjects were classified in to three groups: group I (hypodivergent, SN-MP: <31° (27°-30°), n=15), group II (normodivergent, SN-MP: 31°-34°, n=15), and group III (hyperdivergent, SN-MP: >34° (35°-38°), n=10). Lateral cephalograms were traced and analyzed manually. After measurements of variables, Student's t-test and one-way analysis of variance (ANOVA) were performed. Results: Post treatment with Twin block therapy, hyoid bone shifted significantly (P<0.01) forward in horizontal dimension in all three groups, although it was highest in group III. However, there was no significant difference amongst the groups. In vertical dimension, hyoid bone shifted in upward direction in all three groups; however, the shift was significant (P<0.01) only in group I and there was a significant difference between group I and rest of the two groups. Width of upper airway significantly (P<0.01) increased and ANB angle significantly (P<0.001) decreased in all three groups with forward movement of mandible. Conclusions: After treatment with Twin block appliance, significant changes occurred in horizontal dimension (anterior displacement), which resulted in significant increase in width of upper pharynx in all three groups.

Objectives: To assess the effects of bimaxillary surgery on Class III subjects with mandibular asymmetry, and to compare the effects of the type of surgery performed in the mandible on the facial profile especially in the presence of facial asymmetry. Materials and Methods: Thirty-six patients in whom imbalance between the maxilla and the mandible were corrected by Le Fort I osteotomy combined with bilateral intraoral vertical ramus osteotomy (BIVRO group, n=9), bilateral sagittal split ramus osteotomy (BSSRO group, n=14), or a combination of intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) (IVRO + SSRO group, n=13). Cephalograms were taken before surgery (T1), and 1 year after surgery (T2). Hard and soft-tissue changes were compared. Results: The postsurgical findings showed that greater mandibular backward displacement and greater upper lip forward movement were more pronounced among BIVRO group when compared with BSSRO group. Upper lip relation to E-line showed greater improvement in BIVRO group than BSSRO and IVRO + SSRO groups. The ratios of corresponding mandibular soft to hard tissue movements were higher than that of maxillary movements and were more pronounced in IVRO + SSRO and BSSRO groups when compared with BIVRO group. Conclusion: IVRO surgical technique appears to be more effective in positioning the mandible more posteriorly and improving upper and lower lips position and competence.

Aim: To evaluate the effect of the application of either fluoride varnish (FV) or amorphous calcium phosphate (ACP) as preventive method on shear bond strength (SBS) at the same time of their bonding in vitro using self-etching primer (SEP) as an agent for enamel pre-treatment FV. Materials and Methods: Sixty human bicuspids were randomly divided into five groups: G1 was rubbed by SEP for 5 s, G2 for 5 s by SEP and ACP, G3 for 10 s by SEP and ACP, G4 for 5 s by SEP and FV, and G5 for 10 s by SEP and FV. Stainless steel metal brackets were bonded. A Zwick/Roell Z020 Universal Testing Machine (Zwick GmbH and Co, Germany) with a 500 N load cell was used to test SBS. SBS values were analyzed using one-way analysis of variance (ANOVA) and Tukey's post hoc tests (P≤0.05). Differences in adhesive remnant index (ARI) values between groups were calculated. Results: The mean SBS values were 10.00±4.48 MPa, 5.71±4.3 MPa, 7.47±4.44 MPa, 4.4±2.39 MPa, and 3.98±0.83 MPa for groups 1-5, respectively. Significant differences in SBS values between all groups were found. The mean SBS values of groups 2, 4, and 5 were significantly lower than that of the G1. No significant difference was found between G3 and G1. Significant difference in ARI between the groups was found (P<0.001) and G1 had a significantly higher ARI. Conclusion: The results suggested that the application of ACP at the same time of using SEP for 10 s has no effect on SBS.

During the 20 ^th century, functional appliances evolved from night time wear to more flexible appliances for increased day time wear to full time wear with Twin Block appliances. The current trend is toward fixed functional appliances and this paper introduces the Fixed Twin Block, bonded to the teeth to eliminate problems of compliance in functional therapy. TransForce lingual appliances are pre-activated and may be used in first phase treatment for sagittal and transverse arch development. Alternatively, they may be integrated with fixed appliances at any stage of treatment.

This case report describes the treatment of a Saudi female patient, aged 13 years 8 months at the start of treatment, with a Class I bimaxillary dentoalveolar protrusion and extracted maxillary first molars. Miniscrews were placed bilaterally in the interdental space between both the upper and the lower posterior teeth. The treatment plan consisted of extraction of both lower first permanent molars, distalization of upper and lower premolars using miniscrews followed by en masse retraction of the upper and lower six anterior teeth. The active treatment period was 2 years 8 months. Arch retention was done using upper wrap-around retainer and lower fixed 3-3 retainer. The use of miniscrews helped to resolve the bimaxillary protrusion regardless of extraction pattern used.

Background: There is limited data about current utilization of miniscrews in orthodontic practices in India. The purpose of this survey was to obtain information on clinical utilization of miniscrews among orthodontists in India. Materials and Methods: A survey questionnaire was prepared and mailed to 2100 qualified and registered orthodontists in India. Results: A total of 1691 orthodontists responded to the survey, with a response rate of 80.52%. Among them, 952 (56.3%) had never used miniscrews in their clinical practice. Seven hundred and thirty-nine (739) (43.7%) had utilized miniscrews in their treatment, at some point of time. Among the orthodontists who used miniscrews, 463 (62.65%) used a surgical guide for positioning the miniscrews and 276 (37.35%) placed miniscrews without a surgical guide. Six hundred and thirty-four (634) (85.79%) orthodontists placed the miniscrews personally while 105 (14.21%) utilized the help of other specialists for placing the miniscrews. Among the orthodontists who used miniscrews, 76 (10.28%) utilized the help of oral surgeon to place the miniscrews while 29 (3.93%) utilized the help of periodontists to do the procedure. Conclusion: Miniscrews are a useful addition to the orthodontic armamentarium. The major indication for miniscrew was indirect anchorage in critical anchorage cases. The most important factors in determining the clinical utilization of miniscrews as a part of the treatment modality depends upon operator training and skill; fear of complications, patient refusal to accept miniscrews and the clinician's preference for conventional methods without unnecessary invasive procedure.

Objectives: The aims of this study were to determine the mean mesiodistal tooth size width and Bolton's anterior and overall ratios, find any possible sex differences, and study the frequency of tooth size discrepancies among Yemeni population and if there is a difference in tooth size between the right and left sides. Materials and Methods: 176 subjects aged 13-25 years (94 females and 82 males) with different types of malocclusions (94 Angle Class I, 37 Class II division 1, 36 Class II division 2, and 9 Class III) were included in the present study. The mean mesiodistal tooth size width and Bolton's ratios were determined. Results: The results showed that males had significantly larger teeth than females. The prevalence rates of clinically significant discrepancy greater than 2 SD were 29.53% and 14.20% in the anterior and overall tooth size ratios, respectively. Further, the results revealed that there were no significant differences in the tooth size width between right and left sides. Conclusion: The findings of the present study indicate that there was no significant difference between Bolton's ratio and that of Yemeni population.

Background: One of the common types of oro-dental morphopathologic relationship is the Class II Division 1 malocclusion. Therefore, the study of tongue position in Class II Division 1 may reveal a role of the tongue in the etiology or diagnosis of malocclusion. Aims: Present study was done with the aim to evaluate the tongue position radiographically in centric occlusion and rest position in the subjects with Angle's Class 1 normal occlusion and subjects with Angle's Class II Division 1 malocclusion and to find out any differences in tongue position between Angle's Class 1 normal occlusion and Angle's Class II Division 1 malocclusion group. Materials and Methods: The present study was conducted on lateral cephalogram of 40 subjects between the age ranges of 16 to 22 years. The samples were divided into the Angle's Class 1 normal occlusion group (Group I) and the Angle's Class II Division 1 malocclusion group (Group II) with the 20 in each groups. The study involved the evaluation of tongue position at rest position and centric occlusion on the lateral head cephalogram. Results: This study for the evaluation of the tongue position from the rest position to the centric occlusion showed no statistically significant changes in both groups. However, there were greater changes in various parameters (From the rest position to the centric occlusion) in the subjects with Angle's Class II Division 1 malocclusion as compared to the subjects with the Angle's Class I normal occlusion group. Conclusion: From the present study following conclusion can be drawn: with the closure of mandible from the rest position to centric occlusion the tongue moved antero-superiorly in the tip region, superiorly in the dorsum region, and antero-superiorly in the posterior region in normal occlusion and postero-superiorly in Class II Division 1 malocclusion.

The purpose of this article is to report the management of a transmigrated mandibular canine with emphasis on saving the tooth as natural part rather than surgical removal of the transmigrated tooth. There are several treatment options proposed for impacted mandibular canines including surgical removal, exposure and orthodontic alignment, intra-alveolar tooth transplantation (surgical repositioning of a tooth in its alveolar socket) and observation. The technique, surgical repositioning of a tooth involves the surgical extraction of impacted tooth and fixation in the correct position in the dental arch after surgical preparation (correction) of the alveolar socket. It is especially valuable in cases of difficult-to-treat impaction. A repositioned tooth is better substitute than fixed or removable prostheses, and the technique is more cost effective than other methods. Patients with excellent oral hygiene should be considered as preferred candidates for surgical repositioning of tooth. Disadvantages include the invasiveness of surgery, the difficulty of projecting long term stability due to chances of root resorption and loss of gingival attachment.

Objectives: To investigate the reliability of mechanical and adhesive methods of fixing rectangular wires in the cross-slot of a mini-implant. Materials and Methods: A twin-hooked wire element was placed and fixed in the slot of a mini-implant via a NiTi spring under tension, or by means of an adhesive. For the purpose of mechanical anchorage, the wire was crimped with a special crimping tool to increase its thickness and prevent it from slipping through the slot. Before applying the adhesive, there were four possible methods of preparation: Untreated Wire (Adh. 1); ROCATEC-Pre (Adh. 2); ROCATEC-PRE + Espe Sil (Adh. 3); ROCATEC-PRE + ROCATEC-PLUS + Espe Sil (Adh. 4). The mechanical fixing and two adhesive fixings were aged by means of temperature change (500 cycles). A Zwick universal testing machine was used to measure the maximum strength of the coupling. Results: In all tests, the untreated wire + adhesive withstood the lowest maximum load (Ø 3 N and 10.8 N respectively) and failed the aging test after a maximum of eight cycles. The wires in test group Adh. 4 withstood the highest maximum load (Ø 43.3 N; 41.5 N; 45.9 N after aging) in all tests. The average load withstood by the crimped ligature was 38.7 N. Conclusion: The adhesive method of fixation performs best when the rectangular wire is sand blasted and silanized before application. The mechanical coupling using the crimped ligature is reliable.

Background: A review of literature indicates the Arab cephalometric pattern compared to the Caucasian cephalometric pattern is skeletally bimaxillary retrusive, dentally bimaxillary protrusive, and more divergent palatal and mandibular planes. Objective: The aim of this study was to clarify the cephalometric features of Emirates adults with Class I malocclusion and pleasing soft tissue profile and to evaluate for gender differences. The null hypothesis tested was no differences in lateral cephalometric measurements as a function of gender. Materials and Methods: The lateral cephalometric radiographs of adult Emirati nationals with Class I malocclusion were analyzed in order to characterize an indigenous Class I malocclusion population in the United Arab Emirates. Lateral cephalometric radiographs of 30 males with average age of 24.52±6.09 years and 31 females averaging 23.57±5.52 years were analyzed using Dolphin Imaging software. Twenty-two hard and soft tissue measurements comprised the cephalometric analysis. Results: Only one gender difference was demonstrated out of the 22 cephalometric analysis measurements used in the study; SN-PP mean for females (10.74±3.44 degrees) subjects averaged a 2.3 degree higher mean value than the males (8.43±3.95 degrees, P=0.018). The cephalometric study results were compared to published norms from Steiner and Eastman. Conclusions: Based upon the conditions of the present study, it may be concluded that adult Emirati males and females seeking orthodontic treatment with Class I malocclusion present similar cephalometric profiles with the exception that measurement SN-PP may be steeper in females than males. Moreover, Emiratis are likely to present greater incisor proclination and protrusion than Caucasians and may be generally considered as more bimaxillary protrusive.

Orthodontic force elicits a biological response in the tissues surrounding the teeth, resulting in remodeling of the periodontal ligament and the alveolar bone. The force-induced tissue strain result in reorganization of both cellular and extracellular matrix, besides producing changes in the local vascularity. This in turn leads to the synthesis and release of various neurotransmitters, arachidonic acid, growth factors, metabolites, cytokines, colony-stimulating factors, and enzymes like cathepsin K, matrix metalloproteinases, and aspartate aminotransferase. Despite the availability of many studies in the orthodontic and related scientific literature, a concise integration of all data is still lacking. Such a consolidation of the rapidly accumulating scientific information should help in understanding the biological processes that underlie the phenomenon of tooth movement in response to mechanical loading. Therefore, the aim of this review was to describe the biological processes taking place at the molecular level on application of orthodontic force and to provide an update of the current literature.