Effects of Mandibular Third Molar Angulation and Position on Crowding

Objective:To test the hypothesis that there are no statistically significant differences between mandibular dental crowding and angulation and impaction depth of mandibular third molars.Materials and Method:In this study, the lateral cephalograms, panoramic radiographs, and dental casts of 48 patients (11 boys, 37 girls, mean age 17.10 ± 3.20 years) were evaluated. All patients had class 1 molar relationship, mild and moderate dental crowding, and no tooth loss or size anomaly. Three groups were established according to the mandibular third molar impaction depth on a panoramic radiograph. Group 1 (8 patients, mean age 22.3 ± 2.13 years), the occlusal surface of the impacted tooth is level or nearly level with the second molar; group 2 (16 patients, mean age 17 ± 2.33 years), the occlusal surface is between the occlusal plane and the cervical line of the second molar; and group 3 (24 patients, mean age 15.4 ± 1.76 years), the occlusal surface is below the cervical line of the second molar. Third molar angulation was measured with reference to the anterior angle between the occlusal plane of the first and second premolars and a line drawn through the occlusal surface of the third molar. Angulation and impaction depth of all right and left molars were compared with the mandibular dental crowding. Pearson correlation and 1-way ANOVA statistical analyses were used.Results:There were no statistically significant differences between impaction depth and total mandibular dental crowding (p> 0.05). In addition, no statistically significant differences were found between both left and right third molar angulation and left or right dental crowding in all groups (p > 0.05).Conclusion:The present study indicated that mandibular third molar angulation and impaction depth have no effect on mandibular dental crowding

Yeni doğan dudak damak yarıklı bebeklerin alçı modellerinin değerlendirilmesi

Amaç: Dudak ve damak yarıkları baş-boyun bölgesinin sık görülen konjenital malformasyonları arasındadır. Bu çalışmada Gaziantep Üniversitesi Diş Hekimliği Fakültesi Ortodonti Anabilim Dalı’nda tedavi edilen dudak damak yarıklı hastalarının cinsiyet, yaş, yarık tipi, anterior yarık genişliği, midpalatal ve posterior palatal genişliklerine göre değerlendirilmesi amaçlanmıştır.Gereç ve Yöntemler: Çalışmada kliniğimize gelen 39 dudak damak yarıklı hastanın kayıtları kullanıldı ve yaş, cinsiyet, yarık tipleri değerlendirildi. Analiz için alçı modeller üzerinde ölçümler yapıldı. Kullanılan referans noktaları; c, c’ noktaları (kaninler bölgesi), t, t’ noktaları (tüber noktaları), g, g’ noktaları (c ve t noktaları arası mesafenin orta noktası) olarak belirlendi.Bulgular: Çalışmaya dâhil edilen bireylerin %24ü (n=9) çift taraflı dudak damak yarıklı, %20si (n=8) izole damak yarıklı, %56sı (n=22) tek taraflı dudak damak yarıklı idi. Çift taraflı dudak damak yarıklı bireylerin yaş ortalaması 24.33±24.69 gün, izole damak yarıklı bireylerin yaş ortalaması 68.37±58.04 gün, tek taraflı dudak damak yarıklı bireylerin yaş ortalaması ise 31±30.11 gündü. Çift taraflı dudak damak yarıklı bireylerin %66.7si (n=6) erkekti. Grubun anterior yarık genişliği ortalama olarak 13.23±3.06, midpalatal genişliği 32.67±3.58, postpalatal genişliği 29.25±2.78 mm idi. İzole damak yarıklı bireylerin %37.5’i (3kişi) erkekti. Grubun anterior yarık genişliği bulunmamaktaydı. Midpalatal yarık genişliği 30.71±2.11, postpalatal genişliği 27.17±2.42 mm idi. Unilateral yarıklı bireylerin %54.5i (12kişi) erkekti. Grubun anterior yarık genişliği 10.14±3.12, midpalatal genişlik 35.74±3.05, postpalatal genişlik ise 31.35±3.22 mm idi.Sonuç: Tek ve çift taraflı dudak damak yarıkları erkeklerde, izole damak yarıkları ise kızlarda daha çok görüldü. Anterior yarık genişliği miktarı çift taraflı dudak damak yarıklı grupta tek taraflı dudak damak yarıklı gruptan daha fazla olduğu görüldü. Ancak midpalatal genişliğin ve posterior palatal genişliğin tek taraflı dudak damak yarıklı bireylerde daha fazla olduğu görüldü. Kliniğimize en erken başvuran grubun çift taraflı dudak damak yarıklı bireyler, en geç başvuran grubun ise izole damak yarıklı bireyler olduğu tespit edildi. Kliniğimize başvuran, gerek Hotz plağı gerek nazal molding aygıtlarıyla tedavilerine başlanan hastaların uzun dönem takiplerinin yapılarak başlangıç değerleriyle karşılaştırılması düşünüldü

Does the Seating Force Affect the Shear Bond Strength of Brackets? An InVitro Study

Objective:The purpose of this study was to observe two different seating forces on conventional and self-ligating brackets using shear bond strength (SBS).Methods:The study material consisted of 48 recently extracted human premolars divided into four groups: Group I, conventional bracket (Master series, AO) 100 g seating force applied; Group II, conventional bracket (Master series, AO) 200 g seating force applied; Group III, self-ligating bracket (Empower, AO) 100 g seating force applied; and Group IV, self-ligating bracket (Empower, AO) 200 g seating force applied. All teeth were bonded with Transbond XT by the same operator. Following the bonding procedure, all teeth were stored in deionized water at 37°C for 30 days, and they were thermal cycled. A universal testing machine was used to obtain the SBS records. The Kruskal–Wallis statistical test was used to determine the significant differences in SBS between the four groups, and the Mann–Whitney U test with Bonferroni correction was used to compare the subgroups.Results:The mean shear bond strength was 15.70 MPa for Group I, 13.97 MPa for Group II, 8.38 MPa for Group III, and 8.31 MPa for Group IV. Significant differences in the SBS values were recorded between the self-ligating groups and conventional bracket groups. Seating forces on the brackets did not show any differences among the groups.Conclusion:Within the limitations in this study, 100 g and 200 g forces can be applied because both seating forces showed acceptable SBS results

Temperature Changes of Pulp Chamber during In Vitro

The use of lasers has been suggested for orthodontists to fabricate or repair orthodontic appliances by welding metals directly in the mouth. This work aimed to evaluate the temperature changes in the pulp chamber during welding of an orthodontic wire to an orthodontic molar band using Nd : YAG laser in vitro. A freshly extracted human third molar with eliminated pulpal tissues was used. J-type thermocouple wire was positioned in the pulp chamber. A conductor gel was used in the transferring of outside temperature changes to the thermocouple wire. An orthodontic band was applied to the molar tooth and bonded using light cured orthodontic cement. Twenty five mm length of 0.6 mm diameter orthodontic stainless steel wires was welded to the orthodontic band using Nd : YAG laser operated at 9.4 watt. Temperature variation was determined as the change from baseline temperature to the highest temperature was recorded during welding. The recorded temperature changes were between 1.8 and 6.8°C (mean: 3.3 ± 1.1°C). The reported critical 5.5°C level was exceeded in only one sample. The results of this study suggest that intraoral use of lasers holds great potential for the future of orthodontics and does not present a thermal risk. Further studies with larger samples and structural analysis are required

Effects of Edentulism on Mandibular Morphology: Evaluation of Panoramic Radiographs

Purpose. The objective of this study was to evaluate morphological changes of the mandible in edentulous and dentate subjects using panoramic radiographs. Materials and Methods. Panoramic radiographs were divided into the following three groups: Group I (completely edentulous group), Group II (old dentate group) and Group III (young dentate group). The research parameters of gonial angle, condylar height, ramus height, ramus notch depth, and antegonial notch depth were measured on panoramic radiographs. The Kruskal-Wallis statistical test was used to determine significant differences in mandibular morphological parameters among the three groups. The Mann-Whitney U test was used to compare the subgroups. Results. Significant differences were found only in ramus height between three groups. According to the Mann-Whitney U test, a significant difference was exhibited among Groups I and II in the ramus height parameter. No significant differences were found in the gonial angle, condylar height, ramus notch depth, or antegonial notch depth when comparing the young dentate, old dentate, and completely edentulous subjects. Conclusions. Significant differences were found only in ramus height between the groups. Ramus height may be an indicator that changed by years and tooth loss. It must be considered that ramus height can be decreased in edentulism

Does the Panoramic Radiography Have the Power to Identify the Gonial Angle in Orthodontics?

Purpose. The objective of this study was to assess gonial angle under the angle classification by comparing panoramic radiograph and lateral cephalometric radiograph. Materials and Methods. 49 patients (25 males, 24 females) with an age range of 12–29 years participated in the present study. Subjects were retrospectively selected among those categorised as skeletal and dental Class I, II, and III malocclusion group. Using lateral cephalometric radiograph, mandibular and ramal planes were drawn and based on these planes. Gonial angle was determined from two tangents which were drawn from the inferior border of the mandible and posterior borders of the condyle and ramus of both sides in the panoramic radiographs. Multiple comparison tests (ANOVA) were used to determine differences between the three angle groups. Results. There were no significant differences between Class I, II, and III malocclusion group values of gonial angles determined by lateral cephalometric radiograph and panoramic radiographs (). Conclusion. Panoramic radiograph results were shown to be as reliable as lateral cephalometric radiograph in all angle classifications. Panoramic radiography can be used as an alternative radiographic technique to detect gonial angle in orthodontic patients

The Relationship between Dental Follicle Width and Maxillary Impacted Canines’ Descriptive and Resorptive Features Using Cone-Beam Computed Tomography

Objectives. To assess the relationship between dental follicle width and maxillary impacted canines’ descriptive and resorptive features with three-dimensional (3D) cone-beam computed tomography (CBCT). Methods. The study comprised 102 patients with cone-beam computed tomography 3D images and a total of 140 impacted canines. The association between maxillary impacted canine dental follicle width and the variables of gender, impaction side (right and left), localization of impacted canine (buccal, central, and palatal), and resorption of the adjacent laterals was compared. Measurements were analyzed with Student’s t-test, Kruskal-Wallis test, and Mann–Whitney U statistical test. Results. According to gender, no statistically significant differences were found in the follicle size of the maxillary impacted canine between males and females (p>0.05). Widths of the follicles were determined for the right and left impaction sides, and no statistically significant relation was found (p>0.05). There were statistically significant differences between root resorption degrees of lateral incisors and maxillary impacted canine follicle width (p<0.05). Statistically significant higher follicle width values were present in degree 2 (mild) resorption than in degree 1 (no) and degree 3 (moderate) resorption samples (p<0.05). Conclusions. No significant correlation was found between follicle width and the variables of gender, impaction side, and localization of maxillary impacted canines. Our study could not confirm that increased dental follicle width of the maxillary impacted canines exhibited more resorption risk for the adjacent lateral incisors