Assessment of the changes in the dimensions of the soft palate following orthognathic surgery in class three patients

Statement of Problem: Adaptation of the soft palate and its morphological alterations do occur to some extent after different surgical strategies of class III patients including mandibular setback, maxillary advancement and bimaxillary surgery. The precise changes in soft palate morphology are not well understood yet

Purpose: The aim of this study was to conduct a detailed cephalometric evaluation of the alterations taking place in position and morphology of the soft palate after treatment of class III skeletal deformity via different surgical procedures [i.e. mandibular setback, maxillary advancement, bimaxillary surgery]

Materials and Method: 120 consecutive patients who were diagnosed as having skeletal class III deformity were evaluated. All patients included in this study were adults who had completed their growth and had cephalograms within a month prior to operation [T1] and 1 month to 9 months post-surgery [T2] taken in the natural head position. Patients were divided according to the type of surgery undertaken in three groups: group 1 combination of mandibular and maxillary [bimaxillary], group 2 [mandibular setback] and group 3 [maxillary advancement] surgery. Soft palate length, depth and thickness were evaluated at both T1 and T2 in each group. The results were compared by paired t and oneway ANOVA tests

Results: Soft palate length increased significantly in groups I and III [p <0.05]. Soft palate depth changed significantly in group II [p <0.05]. Soft palate thickness did not changed in any groups [p >0.05]

Conclusion: Soft palate morphology was changed after class III surgeries. Palatal length was increased after maxillary advancement or bimaxillary surgery whereas its depth was increased after mandibular setback or bimaxillary surgery

Comparison of dental arch changes and patients' discomforts between newly designed maxillary expansion screw and slow expansion procedures

Statement of Problem: One fourth of orthodontic patients can benefit from maxillary expansion but traditional expansion screws produce unfavorable heavy interrupted forces. A new spring- loaded expansion screw was designed which created light and continuous forces

Purpose: The purpose of this study was to compare the treatment effects and patients, discomfort with removable slow maxillary expansion and newly designed spring loaded expansion screw

Materials and Method: 35 healthy Iranian children were divided randomly to two groups: group I [25 patients] treated by removable expansion appliance and group II [10 patients] treated by spring- loaded expansion appliance. The active phase of expansion was monitored and arch sizes of the upper dental arches [inter- canine, inter- premolar, inter- molar and arch perimeter] were measured with a caliper on casts monthly. The patients requested to mark the intensity estimation of their discomforts during wearing of appliance on questionnaires which comprised 12 statements. The scores of individual question were added up to obtain a total score. The independent ttest and Mann- Whitney U-test were applied to analyze the data

Results: There were no significant differences in both groups in the mean of arch size changes in each appointment [p >0.05]. There was no significant difference in both groups in terms of the mean of scores of questionnaires [p =0.352]

Conclusion: There was no significant difference in terms of patients, discomfort and arch size changes in spring- loaded and removable expansion appliances. Since the newly designed expansion appliance does not need to be activated by patients, it might be assumed a proper substitute for traditional expansion appliances

[Evaluation of the students' attitude and satisfaction of educational situation in Shiraz dental school]

Statement of problem: Awareness of clinical dental students' points of view about the educational situation of different departments will help faculty members and those in charge of educational affairs to improve the students' qualitative as well as quantitative scientific skills. Being so, to achieve such a goal, it seems necessary to conduct a research on evaluation of educational condition of different dental departments from students' points of view

Purpose: The aim of this study was to evaluate the weak and strong points of different departments of Shiraz Dental School as determined by dental students' points of view in order to present new methods to improve future educational policies of dental departments

Materials and Method: In this cross-sectional study, a questionnaire made of seventeen standard questions was used. After confirmation of the validity of the questions, the questionnaires were distributed among 43 fifth and sixth year students of Shiraz Dental School. After completion of the questionnaires, the data were analyzed by Kruskall- Wallis and Mann- Whitney tests, using SPSS software

Results: Based on the results of this study, although there was a low rate of fluctuation in the students' rate of satisfaction from educational situation of different departments, the highest satisfaction rate was belonged to pedodontics and periodontics departments respectively, and the least satisfaction rate belonged to oral surgery department

Conclusion: In spite of the difference in answers given to similar questions such as scientific capability of faculty members, equipment of departments and behavior of personnel and faculty members to students, generally speaking, the rate of students' satisfaction from different departments was almost similar to each other and had a low fluctuation rate [ p > 0.05]

[In vitro comparison of load activation rate of a designed screw with other common expansion screws]

Expansion screws such as Hyrax and Hass have high load-activation rate and their force system is somehow far from ideal for moving teeth. Hence, activation of such screws produces heavy forces that decay rapidly. Also, rapid reactivation of the appliance has the potential of damaging the teeth and periodontium. Moreover, lack of patient's cooperation in activation of screw could be considered as one of its main disadvantages. The purpose of this investigation was to assess and compare the force- activation curve of a designed screw with those of the commonly used expansion screws. In this experimental study, a screw was designed and manufactured in similar size as the other screws with the potential of 8 millimeter expansion in 2 times activation. The screw was embedded in acrylic material in a removable appliance and fixed on its plaster cast. The compression test machine was used to depict its load-activation curve. The curve was compared with other screws' curves. The results of this study showed that the designed screw had a lower load-deflection rate than other screws. It generated a light continuous force of 2- 3.5 pounds for 4 millimeter expansion. Compared with other screws which produce heavy and interrupted forces, the designed screw generated a light continuous force

[Radiographic and CT scan evaluation of root resorption of permanent incisors maxillary impacted carises]

Resorptions of permanent incisors are a rare complication of ectopically erupting maxillary canines but when they occur they may lead to extraction, orthodontic treatment or both. The purpose of this study was to assess the incisor root resorption adjacent to impacted maxillary canines using conventional radiographs and CT scan. Fourteen patients [13-20 years] with 18 impacted canines were studied. Upper alveolar bone CT scans of the patients and their periapical and panoramic images were analyzed for detecting incisor root resorption caused by impacted canines. Degree of root resorption was assessed on CT scans on the basis of the self-designed classification. Buccolingual, mesiodistal and superioinferior location of resorption of incisors' roots and their longitudinal extension were assessed using CT scans in regard to the number of CT cuts showing the resorption. All of the teeth adjacent to impacted maxillary canines showed resorption. The most prevalent resorption site [84.6%] was detected in lateral incisors. 61.5% of involved teeth in CT scan did not show any resorption in the conventional radiographs and the others [38.5%] were questionable. In 77% of cases, resorption of palatal and distopalatal surfaces of involved roots were not detectable in conventional radiographs. Assessment of canine eruption angle in panoramic radiography revealed that this angle did not have any significant role in developing root resorption of adjacent teeth. Conventional radiographs are not able to detect root resorption of the incisors adjacent to impacted canines. Therefore, in cases which intensity and extension of root resorption has an effect on treatment plan and prognosis, CT scan is strongly recommended

[Comparison of the rate of maxillary incisors apical root resorption in 13-18 years old patients with Cl I, Cl II and Cl III malocclusions, before and after fixed orthodontic treatment]

Apical root resortpion of maxillary incisors is relatively a common phenomenon at the end of orthodontic treatment. Therefore, recognizing risk factors in root resorption before starting the treatment is very important. The aim of this study was to compare the amounts of apical root resorption in different malocclusion groups. The amount of apical root resorption in 219 fixed orthodontic [70 Cl 1, 76 Cl II and 73 Cl III patients] with first or second maxillary premolars extraction and with mean age of 15 +/- 0.5 years were evaluated through the examination of parallel radiographies [long cone] before and after treatment. The amount of apical root resorption was measured in groups by using Photoshop program [Version 7.0]. Then, the groups were compared and analyzed by t-test and one way ANOVA. One hundred percent of patients [84.96% of teeth] showed first degree resorption, 18%, zero degree resorption; 1.37%, third degree and 12.8% showed second degree resorption. The greater resorption of second degree was observed in Cl II patients. Left and right incisors and central and lateral incisors had no significant differences among all the three groups. The comparison between apical root resorption in CI, Cl II and Cl III groups indicated that the resorption in Cl II group was more than Cl I and Cl III groups [p<0.001]

[Dento-skeletal characteristics of 8-13 year-old boys and girls with class ii division 1 malocclusion in Fars province; a cephalometric study]

The dentoskeletal characteristics of the Class II Division 1 patients dictate their treatment plan and mechanotherapy. This study was undertaken to describe the dentofacial characteristics of this type of malocclusion in 8-13 year-old children in Fars Province. The materials examined included 693 lateral head radiographs comprising two series of 213 films of normal occlusion children and 480 films of Class II Division 1 patients reffered to Orthodontic Department of Shiraz Dental School, taken during the years 2002 to 2004. The controls and the Class II Division 1 subjects were each divided into three groups according to age including 10-11, 12-13 and 14-15 and then divided into two subgroups according to gender. The radiographs were converted into computer-readable X and Y coordinate data and 36 linear and 15 angular measurements in the cranial base, maxilla, mandible and dentition, were provided [based on 35 points] and compared. The statistical analysis showed that the anterior cranial base was larger and more protrusive, with an increase in cranial base angle compared with controls. The mandible was smaller and its form and position was different from controls whereas, the maxilla [at the level of palate and alveolus] and the dentition were protrusive. The palate was inclined superiorly at its anterior half. The vertical maxillary exess and the increase of mid-facial convexity were visible. Various factors ranging from mandibular deficiency to maxillary protrusion with different dental configurations were responsible for the presence of Class II Division 1 malocclusion in our patients

Comparison of the antibacterial effects of persica mouthwash with chlorhexidine on streptococcus mutans in orthodontic patients

Chlorhexidine mouthwash has shown the highest antimicrobial effects in orthodontic patients, however, some complications have limited its widespread use. The goal of this study was to compare the antimicrobial effects of persica mouthwash with chlorhexidine in fixed orthodontics patients. Sixty patients [13-18 years old] on fixed orthodontic treatment, with desirable oral health were randomly divided into three equal groups of control, clorhexidine and persica. Patients were educated to properly use these mouthwashes. The control group was asked to wash their mouth with water twice a day. The numbers of streptococcus mutans colonies available in the elastic rings around the two bracket bases were determined in culture mediums before and immediately after a single application of water or mouthwashes and also following their daily uses for three weeks. The number of bacterial colonies then were compared at these three graps. The use of persica resulted in a significant [p<0.001] reduction in the number of streptococcus mutans colonies, albeit it was not as potent as chlorhexidine. Thirteen and fourty percent of patients using persica mouthwash experienced tooth discoloration and changes in taste respectively. The corresponding figures for chlorhexidine were 86% and 73% respectively. Significant reduction of streptococcus mutans colonies by persica as well as its lower tooth discoloration effects and unpleasant taste relative to chlorhexidine might give credence to the use of complementary herbal compounds in orthodontics patients

Soft tissue and dentoskeletal changes in class II division 1 patients following extraction and non-extraction treatment

Treatment with or without extraction in class II division 1 cases and their effect on the skeletodental and soft tissues in orthodontic treatment are in debate. Assessing the changes of hard and soft tissues in class II division 1 patients can evaluate facial esthetics following different treatment plannings. The purpose of this study was to compare the changes in subjects with class II division I malocclusions treated with and without extraction. Lateral cephalograms, photographic pictures, OPG radiographic and dental casts of 80 class II division 1 patients aged 12-17 [mean age: 13.6 +/- 1.7], among 900 referred patients to private office, were evaluated at two stages: Pretreatment and posttreatment. 40 patients [20 males and 20 females] had premolar extraction and 40 patients [20 males and 20 females] were treated non-extraction using head gear. All of them were treated with classic edgewise [0.22] system. Eighteen hard and 10 soft tissue landmarks were identified on each cephalogram. All landmarks were identified and checked. Thirty-six skeletal, dental and soft tissue linear and angular measurements were derived. Pearson Rank correlation and student t tests were used to analyze the data and compare the incremental changes between the groups before and after treatment. Absolute dimension within each sex and in extraction group were recorded before and after the treatments. Significance level for statistical comparisions was predetermined at p

Comparison of the antibacterial effects of persica and matrica, two herbal mouthwashes with chlohexidine mouthwash

Fixed orthodontic appliances are considered to be a clinical risk factor in terms of gingival and enamel integrity, because of plaque accumulation around the bracket bases which increases the levels of microorganisms. Although chlorohexidine significantly reduces plaque accumulation, but its side effects prevents its common use. The purpose of this in vivo study was to compare the antibacterial effects of two herbal mouthwashes of persica and matrica with chlorhexidine in fixed orthodontic patients. A total of 68 orthodontic patients of 13-19 years old [who referred to a private clinic in 2002] with good oral hygiene were randomized into 4 groups. Group 1 [control] used water, group 2 used Chlorhexidine, group 3 used Persica and group 4 used matrica, twice a day for 3 weeks. The number of all bacterial colonies around the ring elastics of the upper canine and premolar growing in the culture media were counted before [T[1]] immediately after [T[2]] and 3 weeks after [T[3]] the use of the mouthwashes and water in all 4 groups and analyzed. Chlorhexidine, Persica and Matrica mouthwashes significantly reduced the amount of bacteria around the brackets immediately and after 20 days after their use. The inter group comparison showed that persica and matrica at T[2] and T[3] had significant differences with chlorhexidine group. So, Chlorhexidine was the most effective antibacterial mouthwash in T[2] and T[3]. Persica and Matrica groups showed no significant differences both in T[2] and T[3], but had significant difference with the control group. The use of herbal mouthwashes such as Persica and Matrica in orthodontic patients can significantly reduce the amount of microorganisms around the bracket bases without any side effect such as tooth discoloration which is seen with Chlorhexidine