Buccal Segment Research Articles

Final Posttreatment Occlusion in Patients With Unilateral Cleft Lip and Palate.

Objective:To evaluate final posttreatment occlusion in patients with complete unilateral cleft lip and palate (cUCLP) by comparing (1) 3 treatment centers, (2) males and females, (3) cleft and noncleft sides, (4) right- and left-sided clefts, and (5) orthodontic treatment with/without orthognathic surgery (OS).Design:Retrospective cohort study.Patients:Blinded posttreatment dental casts of 56 patients (19.4 ± 1.4 years) with cUCLP from 3 centers in Switzerland.Main Outcome Measure:Occlusal assessment using the modified Huddart/Bodenham (MHB) index.Results:Our sample comprised 35 males and 21 females, 46 with left- and 10 with right-sided clefts, of which 32 had undergone OS. The final posttreatment occlusion showed a median MHB score of 0 (interquartile range: −1.0 to 2.0) in the total sample and did not seem to depend on treatment center, sex, or OS. The MHB scores for the anterior buccal and the buccal segments were more negative on the cleft than on the noncleft side (P = .002 and P = .006, respectively). When the cleft was on the left side, the MHB score tended to be more positive in the labial (P = .046) and anterior buccal segments (P = .034).Conclusions:This study shows a very satisfactory final posttreatment occlusion in patients with cUCLP. The more constricted buccal occlusion on the cleft side emphasizes the attention that should be given in correcting the more medially positioned lesser maxillary segment. The influence of cleft-sidedness should be analyzed further on a sample including more patients with right-sided clefts.

Efficacy of Theobromine and Sodium Fluoride Solutions for Remineralization of Initial Enamel Caries Lesions

Objectives: This study investigated the efficacy of theobromine in comparison with 0.05% sodium fluoride solution for remineralization of initial enamel caries lesions (IECLs). Materials and Methods: Ninety non-carious extracted premolars were sectioned longitudinally into buccal and lingual segments. Caries-like lesions were induced in each segment using acidified gel. Forty-five buccal segments were used for surface microhardness (SMH) test, and 45 buccal segments were used for energy-dispersive X-ray spectroscopy (EDS). The lingual segments were used as the control group for EDS and SMH test. The baseline SMH was measured with a Vickers hardness tester, and the baseline calcium content was analyzed by EDS. Each test group was divided into three subgroups for treatment with (1) artificial saliva, (2) 1.1 mol/L theobromine, and (3) 0.05% sodium fluoride. Remineralization and demineralization were done by daily pH cycling to simulate the oral environment. Samples in each group were immersed in treatment solutions for 1 min before and after the remineralizing cycle. After a 7-day cycle, the SMH test and EDS analysis were performed again. Data were analyzed using one-way ANOVA, Tukey’s post-hoc test, and paired sample t-test (P<0.05). Results: All treatments effectively remineralized the IECLs (P<0.05), and theobromine caused the maximum increase in SMH, which was significantly higher than the value in sodium fluoride group (mean value of 36.56±4.95 versus 23.25±3.92; P=0.000). EDS showed the highest calcium deposition in theobromine group (3.82±1.83wt%). Conclusion: Theobromine is an effective cariostatic agent, and can be considered as a safe alternative to fluoride in preventive dental care.

The stability of Class II correction with functional appliance therapy and orthodontic camouflage: A retrospective cohort study

The aim of this study was to compare the stability of overjet reduction in adolescents treated with either orthodontic camouflage involving extraction of premolar units or functional appliance therapy. A retrospective cohort study was undertaken with data collected at pre-treatment (T0), debond (T1) and 12 months post-treatment (T2). The primary outcome measure was stability of overjet reduction, and secondary outcome measures included Angle's molar relationship, and Little's Irregularity Index score. Forty-two Class II participants, 18 treated with a functional appliance and 24 with camouflage, were included with a mean pre-treatment age of 13.07 years (SD 1.72), with 23 (55%) being female. Mean overjet reduction during treatment in the functional appliance group was 6.99mm with relapse of just 0.62mm present at 12 months post-treatment. In the orthodontic camouflage group, there was a mean overjet reduction of 3.54mm with relapse of 0.27mm at 12 months post-treatment. Linear regression analysis confirmed no statistical difference (P=0.501) in overjet relapse between both treatment groups at 12 months post-treatment, adjusting for overjet at baseline. A further regression analysis revealed no significant association between overjet relapse and pre-treatment skeletal discrepancy, labial segment crowding, retention regime or compliance with the retention protocol. Both functional appliance and orthodontic camouflage therapies appear to have good antero-posterior occlusal stability, with minor degrees of overjet relapse occurring over a 12-month follow-up period. There was no significant difference between the treatments in relation to overjet relapse, buccal segment interdigitation or anterior irregularity.

Effects of conventional and herbal irrigants on microhardness and flexural strength of root canal dentin: An in vitro study.

Aim:The aim of this in vitro study was to compare the effects of herbal irrigants with conventional irrigants on microhardness and flexural strength of root dentin.Materials and Methods:Sixty extracted permanent maxillary canines were selected. Decoronated roots were sectioned longitudinally into buccal and lingual segments to get 120 specimens. These were embedded in auto polymerizing acrylic resin and further grounded with fine emery papers under distilled water. Of these, 100 root segments without any defects were selected, further divided into four test groups and a control group according to the irrigants used (n = 20). Group 1: 2.5% Sodium hypochlorite, Group 2: Miswak stick extract, Group 3: Cashew leaves extract. Group 4: Mango leaves extract and Group 5: Normal saline (control). All specimens were treated with 5 ml of each irrigant for 10 minutes and rinsed immediately. Dentin microhardness was measured with a Vickers indenter, and the flexural strength test was done using a universal testing machine. The data were analyzed using one-way ANOVA and the intergroup comparison by student t-test.Results:The experimental groups showed a significant reduction in microhardness values when compared with the control group. Intragroup comparison among experimental groups, herbal irrigants showed the least reduction in microhardness values at cervical, middle, and apical thirds. When compared to the control group, the flexural strength values decreased significantly with experimental groups.Conclusion:Within the limitation of this study, it was concluded that herbal irrigants were least detrimental to root dentin microhardness when compared with conventional irrigant. But the flexural strength was equally reduced by both conventional and herbal irrigants.

Effects of fixed twin-block and forsus fatigue resistant device on mandibular third molar angulation – A comparative study

INTRODUCTION: Fixed functional appliances such as fixed twin-block (FTB) and forsus fatigue resistant device (FRD) improve Class II skeletal relationships by increasing the length of the mandible, which subsequently leads to an increase in the retromolar space. This would bring about a positional and angular change in the mandibular third molar. These appliances also produce forward movement of the mandibular buccal segments, which has also been cited as an important factor providing space and therefore improving the angulation and eruption potential of the third molars. OBJECTIVE: To evaluate and compare the effects of FTB and forsus FRD treatment on mandibular third molar angulation. MATERIALS AND METHODS: Pretreatment and posttreatment lateral cephalograms and orthopantomograms of 25 patients with Class II division 1 malocclusion treated with FTB were compared with those of 25 patients treated with forsus FRD. Sagittal and vertical skeletal relationships and mandibular length were assessed on lateral cephalogram, whereas linear parameters such as retromolar space; space width ratio (SWR); distance of Xi point from the distal surface of the lower second molar; and angular parameters such as α, β, and ϒ; and gonial angles were measured using orthopantomograms. Intragroup comparison was done using paired t-test, while unpaired t-test was done for intergroup comparison of the observed changes. RESULTS: Mandibular length increased significantly in the FTB group, whereas mesialization of the mandibular dentition was significantly high in the FRD group. Both groups showed a significant increase in retromolar space, SWR, Xi point to 7 distance, α angle, and a decrease in β angle. These changes were significantly more pronounced in the FTB group. CONCLUSION: There was a significant improvement in the third molar angulation following treatment with fixed functional appliances, which was comparatively more in the FTB group than that in the FRD group, owing to an increase in mandibular length.

ROLE OF SOCKET SHIELD TECHNIQUE IN IMMEDIATE IMPLANTS PLACED IN THE ESTHETIC ZONE – A CASE REPORT

Immediate implant is a valuable treatment of choice to replace non restorable teeth in the esthetic zone with a success rate of 87.5 to 100%. It has several advantages like minimizing the total treatment time, cost effective, and psycosocial benefits. In spite of the exceptional success rates, horizontal buccal bone resorption of about 56% and corresponding palatal bone resorption of 30% has been documented with respect to immediate implants (1) . These morphometric changes negatively influence the aesthetic outcome of dental implants. The use of modified surgical procedures such as the flapless technique, various hard tissue augmentation procedures, guided bone regeneration (GBR) and titanium reinforced barriers as well as various bone promoting molecules have been tried for bone preservation, with each method having its own benefits and drawbacks. Recently socket-shield technique (SST) otherwise called partial extraction therapy by Hurzeler et al in 2006 was described where buccal segment of the root is retained as a shield in situ, which aids in preserving periodontal attachment apparatus thus preserving the vascularity of buccal bone when compared to other conventional techniques. Here we present a case of non-restorable tooth in the maxillary aesthetic zone managed with placement of immediate implant using socket shield technique and evaluating the hard tissue health and aesthetic outcome (2).

EVALUATION OF VARIATION IN SLOT SIZE BETWEEN COMMERCIALLY AVAILABLE BRACKET SYSTEMS

Immediate implant is a valuable treatment of choice to replace non restorable teeth in the esthetic zone with a success rate of 87.5 to 100%. It has several advantages like minimizing the total treatment time, cost effective, and psycosocial benefits. In spite of the exceptional success rates, horizontal buccal bone resorption of about 56% and corresponding palatal bone resorption of 30% has been documented with respect to immediate implants (1) . These morphometric changes negatively influence the aesthetic outcome of dental implants. The use of modified surgical procedures such as the flapless technique, various hard tissue augmentation procedures, guided bone regeneration (GBR) and titanium reinforced barriers as well as various bone promoting molecules have been tried for bone preservation, with each method having its own benefits and drawbacks. Recently socket-shield technique (SST) otherwise called partial extraction therapy by Hurzeler et al in 2006 was described where buccal segment of the root is retained as a shield in situ, which aids in preserving periodontal attachment apparatus thus preserving the vascularity of buccal bone when compared to other conventional techniques. Here we present a case of non-restorable tooth in the maxillary aesthetic zone managed with placement of immediate implant using socket shield technique and evaluating the hard tissue health and aesthetic outcome (2).

Cadaveric Dissections to Determine Surface Landmarks Locating the Facial Artery for Filler Injections.

The facial artery is a high-risk structure when performing filler injections at the nasolabial fold, buccal, and mandibular regions. This study aimed to establish reference landmarks locating the course of the facial artery and its essential branches. Thirty-one embalmed cadavers were enrolled in this study. The course of the facial artery was observed in regard to the following reference points: masseter insertion, oral commissure, and common bony landmarks. The corner of the mouth was utilized as the landmark to measure the turning point of the facial artery. Seven points were established to identify the course and turning point of the facial artery. These included the anterior masseteric, lateral mental, infraorbital, medial canthal, basal alar, post-modiolar (PMP), and supra-commissural (SCP) points. The course of the facial artery deviates at least twice at the lateral mental points and at the SCP or PMP. The facial artery appeared more medially when the artery turned at the PMP and SCP. It presented through the lateral channel if the turning point was solely at the PMP. Wherever the facial artery deviates, it can be divided into 3 segments: the mandibular, buccal, and nasolabial segments. The arterial course may deviate laterally from the mouth corner towards PMP. The nasolabial segment may also deviate laterally to the basal alar point at the alar grove for 0.5 to 1 cm. The deviation of facial artery closely relates with mandibular, buccal, and nasolabial segments. It is essential in avoiding arterial injury for physicians and surgeons who perform procedures in these areas.

Force magnitude as a variable in maxillary buccal segment intrusion in adult patients with skeletal open bite.

To compare the effects of two different force magnitudes on maxillary posterior segment intrusion using mini-screws. The null hypothesis was that there would be no difference between the two force magnitudes. Adult patients with skeletal open bite and a dental open bite ranging from 3 to 8 mm were recruited for this trial. The comparator group had 200 g of intrusive force applied for posterior segment intrusion, whereas 400 g of force was applied in the intervention group. Primary outcomes were the amount of posterior teeth intrusion and anterior open bite closure. Twenty-two subjects were randomized to include 11 participants in each group. One participant dropped out in each group, leaving us with 10 subjects to be analyzed per group. There was statistically significant posterior teeth intrusion of 2.42 ± 2.06 and 2.26 ± 1.87 mm for the comparator and intervention groups, respectively, with no difference between them. Statistically significant open bite closure was achieved in both groups, measuring 2.24 ± 1.18 and 3.15 ± 1.06 mm in the comparator and intervention groups, respectively, with no difference between them. Both the 200 g and 400 g intrusive forces yielded similar outcomes in terms of posterior teeth intrusion and anterior open bite closure.

A prospective evaluation of factors affecting occlusal stability of Class II correction with Twin-block followed by fixed appliances

Modified Twin-block therapy followed by fixed appliances (TBFA) is a standard treatment modality in Class II malocclusion; however, there is little information regarding the stability of this approach. We aimed to assess the stability of Class II correction with TBFA and to evaluate factors that may affect stability. A prospective evaluation involving convenience sampling of 64 participants treated with TBFA was undertaken over 12months. Study models and lateral cephalometric radiographs were obtained to record overjet and molar relationship, Peer Assessment Rating score, and skeletal parameters, and a new objective buccal segment interdigitation scoring system was developed. Multivariate logistic regression analysis was used to assess the stability of anteroposterior occlusal correction and the degree of buccal interdigitation, pretreatment skeletal discrepancy, and change in overjet during treatment. Mean overjet reduction of 6.22mm arose during treatment, with the canine and molar relationships improving by 3.34mm and 2.67mm, respectively. In the 12months posttreatment, a relapse of 0.67mm and 0.06mm in overjet and molar relationship, respectively, was observed, with 25% of subjects having overjet relapse of>1mm. There is weak evidence that the treatment-induced change in overjet is linked with overjet relapse (P=0.05; odds ratio, 0.67; 95% confidence interval, 0.44, 1.01). No significant relationship was observed, however, between anteroposterior stability and buccal segment interdigitation (P=0.99), pretreatment skeletal discrepancy (P=0.10) or prescribed retention regime (P=0.63). Overall, acceptable levels of stability were observed, although appreciable relapse was noted in 25% of participants. Neither the degree of buccal segment interdigitation nor pretreatment skeletal discrepancy was predictive of anteroposterior occlusal stability.

Prevalence of Bimaxillary Protrusion among UiTM Orthodontic Patients

Objective: To determine the prevalence of bimaxillary protrusion in general and the prevalence of skeletal Class I and dental Class I bimaxillary protrusion/ proclination among orthodontic patients attending postgraduate orthodontic clinic at Faculty of Dentistry, Universiti Teknologi MARA (UiTM), Sungai Buloh, Malaysia. Materials and Methods: This is a cross sectional study which was carried out in two stages. The first part involves a random selection of 100 extra-oral profile photographs taken from postgraduate orthodontic residents’ patient list. The photographs were taken using Canon digital SLR camera EOS 70D with macro lens EF 100mm (Canon Inc., Tokyo, Japan) with patients in natural head position. The photographs were visually analysed for its bimaxillary protrusion features by two operators. The second part comprises of analyses of extra-oral profile photographs as well as intra-oral photographs of right buccal segment view which was conducted in two separate sittings. In the first sitting, five assessors analysed 259 extra - and intra-oral photographs followed by 40 photographs assessed in the second sitting for skeletal and dental Class I bimaxillary protrusion/ proclination. Statistical analysis for Kappa score was performed to assess the agreement between assessors using SPSS version 23 and Stata version 13. Results: The first part of the study showed an average prevalence of 34% with bimaxillary protrusion in 100 orthodontic patients. Whilst in the second part, prevalence of skeletal and dental Class I bimax ranging from 28-33 per cent and 38-40 percent respectively with very good and good inter-reliability agreement for both component. Conclusion: The prevalence of bimaxillary protrusion in general among UiTM orthodontic patients was found to range from 31 percent to 37 percent. Whilst the prevalence of skeletal and dental Class I bimax ranging from 28-33 percent and 38-40 percent respectively.

Comparison of Friction in Sliding Mechanics Using Different Ligation Methods on Ceramic Bracket with Metal Slot and Epoxy Resin-Coated Stainless Steel Esthetic Wire: An in Vitro Study

Introduction: The friction generated during orthodontic treatment seems of concern in terms of anchorage and treatment duration. Different ligation methods have been developed to reduce the friction as compared with regular elastic modules. This study aimed to evaluate and to compare static and kinetic friction generated in ceramic brackets with metal slot and epoxy resin-coated stainless steel esthetic wire by using different ligation materials in wet condition (artificial saliva). Materials and Methods: A total of 40 epoxy-coated stainless steel wires and metal slot ceramic brackets were divided into 4 groups of 10 each and ligated using 4 different methods as follows: (1) super slick elastic modules, (2) slide elastic modules, (3) Teflon-coated esthetic stainless steel wire, and (4) regular elastic modules. They were then immersed in artificial saliva for 1 hour before testing their static and kinetic friction using a universal testing machine. Results: The intergroup comparison showed statistically significant differences for static and kinetic friction among all the 4 groups, where group 2 (slide modules) showed the least static as well as kinetic friction as compared with the other 3 groups. Conclusions: (1) Slide modules produced the least amount of friction compared with all other methods of ligation when epoxy resin-coated stainless steel archwire was used in ceramic bracket with 0.22˝ metal slot in wet condition. (2) Super slick modules produced the least friction in comparison with regular elastomeric and Teflon-coated ligature groups but produced greater friction than slide modules. (3) Teflon-coated stainless steel ligature produced the highest friction; however, it was not statistically significant when compared with the conventional elastic ligature. (4) In all clinical situations during the retraction stage, a large amount of friction is created in the buccal segment; hence, it is advisable to use slide modules in the buccal segment to reduce static and kinetic friction.

Evaluation of Nanomechanical Properties, Surface Roughness, and Color Stability of Esthetic Nickel-Titanium Orthodontic Archwires.

Objectives:The objective of the study is to evaluate the surface roughness, nanomechancial properties the color stability of three brands of coated (rhodium, epoxy, and Teflon) nickel-titanium (NiTi) esthetic archwires.Materials and Methods:Three brands of coated (rhodium, epoxy, and Teflon) esthetic NiTi archwires and three brands of uncoated (NiTi) archwires from the same manufactures were evaluated for the surface roughness, nanomechanical properties, and color stability. The specimens with 20 mm length (n = 5) were cut from the straight buccal segments of the coated and uncoated archwires. The specimens with 20 mm length (n = 10) were subjected to color measurement after immersion in a coffee staining solution. The color measurement was evaluated after 7, 14, 21, and 28 days after immersion in staining solution using color eye 7000 spectrophotometer. The experimental data were analyzed using descriptive statistics, analyses of variance, and Tukey's post hoc test.Results:Epoxy (1.517 ± 0.071) and rhodium (0.297 ± 0.015) coated archwires showed the highest and lower value of surface roughness. All the intergroup comparisons showed a significant difference (P < 0.05) in surface roughness except between rhodium and control group (P = 0.998). There were significant differences between control and the experimental groups for both nanohardness and elastic modulus was observed. All the three NiTi-coated esthetic archwires demonstrated trace” (extremely slight change) color changes as measured by the National Bureau of Standards units after 4 weeks of immersion.Conclusion:Surface roughness of rhodium-coated archwires was almost similar to that of uncoated wires. Whereas Teflon and epoxy coated archwires showed a significant difference in surface roughness compared to uncoated archwires. Uncoated archwires showed higher nanohardness values compared to the coated archwires. Teflon-coated archwires demonstrated significantly slight color change after 4 weeks of immersion in staining solution.

Bilateral dentoalveolar asymmetries in female patients with adolescent idiopathic scoliosis

The aim of this cross-sectional research was to quantify left-right dentoalveolar fluctuating (FA) and directional asymmetries (DA) in patients with adolescent idiopathic scoliosis and to assess the relationship between these asymmetries and the side, location, and severity of scoliosis. The study group comprised of 60 females aged 12-16 years, with idiopathic scoliosis, and 54 healthy controls. Measurements were made with the use of digital caliper on full-mouth dental casts. The following variables were measured from each subject: a shift of the incisor midline, left and right incisor overjet, deviation of canine and buccal segment relation as well as maxillary and mandibular arch chords. The data were statistically analyzed with significance taken as p < 0.05. Statistically significant differences in the mean shift of the incisor midline, buccal segment relation on the left and canine deviation on the left between the control group and the study group were detected ( p = 0.0419, p = 0.0.458 and p = 0.0204, respectively). FA of the midline deviation and canine deviation were statistically significantly higher for subjects with IS, compared to healthy controls ( p = 0.0315 and p = 0.0415, respectively). Neither direction of the curve nor apical vertebra's location or apical translation significantly affected the magnitude of dentoalveolar asymmetries. Our results confirmed that bilateral asymmetries are a common feature of the young females' occlusion. Individuals with IS show higher tendency to Angle Class II malocclusion, as well as higher FA of incisor midline discrepancy and canine deviation, compared to the controls.

Socket-shield technique: the influence of the length of the remaining buccal segment of healthy tooth structure on peri-implant bone and socket preservation. A study in dogs

ObjectiveThe aim of this study was to evaluate the influence of the location and length of root pieces on buccal peri-implant bone width and socket preservation in socket shield technique. Material and methodsForty-eight dental implants (24 narrow and 24 regular platform internal hex implants) were placed in six dogs. The clinical crowns of teeth P2, P3, P4 and M1 were detached horizontally and removed from the underlying roots. Then the mesial root of each tooth was extracted and the distal root was degraded using a high-speed hand-piece with round bur, creating a concave shell of dentin cementum and periodontal ligament (PDL) connected to the buccal aspect of the socket. Remaining root fragments of different lengths were created: coronal (1/3); middle and coronal (2/3); full length (3/3). These were positioned all around the bone crest. Implants were placed at the center of the root sockets, 1–3mm deeper than the original root apex. RFA and histological evaluations were made at 4 and 12 weeks. Data underwent statistical analysis (p<0.05). ResultsAll 48 implants osseointegrated satisfactorily. On both buccal and lingual sides, the coronal (1/3) radicular fragment was attached to the buccal bone plate by physiologic periodontal ligament with less crestal bone resorption compared with middle (2/3) and whole root (3/3) groups for narrow and standard implants. ConclusionsWithin the limitations of this study, the results demonstrate that a small piece of root in the coronal part of the alveolus can protect the buccal, mesial and distal bone crest following the immediate placement of NeO narrow or NeO Standard Internal Hex implants.The thickness of peri-implant bone and the remaining root fragment together will provide a total thickness of >2mm. The technique would appear to be highly predictable, maintaining bone volume and reducing the risk of crestal bone resorption

Effect of orthodontic treatment and comorbidity risk factors on interdental alveolar crest level: A radiographic evaluation.

Alveolar bone loss is regarded as a potential adverse event during orthodontic treatment, especially in adults. The purposes of this study were to evaluate the prevalence and severity of interdental alveolar crest height loss in adult orthodontic patients compared with an untreated control group and to identify comorbidity risk factors for such bone loss (high BMI score, high blood pressure, high cholesterol levels, and smoking). Standardized bitewing radiographs of patients' buccal segments were taken before and after treatment of 34 consecutive adults treated in an orthodontic clinic. The control group included 29 patients from the operative dental clinic matched according to age and sex. Mean ages of the participants before treatment were 35.7±6.7 and 35.6±7.3years for the control and treatment groups, respectively. Before orthodontic treatment, the patients were evaluated, treated as needed, and approved by a periodontist. They were periodontically healthy before treatment. Interdental alveolar crest height loss was calculated by subtracting the distance on a bitewing x-ray from the cementoenamel junction to the interdental alveolar crest at each interproximal tooth surface from the mesial aspect of the first premolar to the distal aspect of the secondmolar (8 sites per quadrant). Changes in interdental alveolar crest height were calculated by subtracting the cementoenamel junction-interdental alveolar crest distance before treatment from the corresponding distance after treatment. The mean individual bone losses of all interproximal surfaces were 0.130±0.192 and 0.072±0.280mm in the treatment and control groups, respectively. These differences did not reach statistical significance (P=0.353). Twenty-two patients (65%) from the treatment group and 10 patients (34%) from the control group had an increase in the cementoenamel junction-interdental alveolar crest distance of more than 1mm in at least 1 site, with borderline significance between the groups (P=0.079). Notably, no association was observed between bone loss with any comorbidity factor. The results of this study correspond to the conventional understanding in the orthodontic and periodontal literature that orthodontic tooth movement per se does not cause attachment loss. However, orthodontists should always be aware of the possibility of periodontal deterioration during orthodontic treatment. Therefore, comprehensive periodontal examination is necessary during orthodontic treatment, especially in adults.

Permanent maxillary central incisor and first molar rotations in the mixed dentition in repaired complete unilateral cleft lip and palate and their relationship with absence of teeth in their vicinity.

To describe qualitatively and quantitatively the directions and magnitudes of rotations of permanent maxillary central incisors and first molars in the mixed dentition in repaired complete unilateral cleft lip and palate (UCLP) and study their associations with absence of teeth in their vicinity. Dental casts and orthodontic records taken prior to orthodontic preparation for alveolar bone grafting of 74 children with repaired UCLP (53 male, 21 female; aged 8.9 ± 1.0 years) were studied. Directions and magnitudes of permanent maxillary central incisor and first molar rotations were recorded. Tooth absence was confirmed from longitudinal radiographic records. Incisor and molar rotations were analyzed in relation to the absence of teeth in their vicinity. Distolabial rotation of the permanent maxillary central incisor was noted in 77.14% on the cleft side, while distopalatal rotation was noted in 82.19% on the noncleft side. Incisor rotation was greater when a permanent tooth was present distal to the cleft side central incisor, in the greater segment. The permanent maxillary first molar showed mesiopalatal rotation, which was greater on the cleft side and when there was absence of one or more teeth in the buccal segment. Presence and absence of teeth were associated with the severity of incisor and molar rotations in UCLP. Crowding of anterior teeth in the greater segment was associated with a greater magnitude of rotation of the cleft side permanent central incisor. Absence of one or more buccal segment teeth was associated with greater magnitude of rotation of the molar.

Longitudinal eruptive and posteruptive tooth movements, studied on oblique and lateral cephalograms with implants

The purpose of this study was to investigate the eruptive and posteruptive tooth displacements of untreated growing subjects longitudinally and the potential connections between posteruptive displacement of the maxillary and mandibular first molars and skeletal facial growth. The sample comprised 11 series of right 45° oblique cephalograms and lateral cephalograms of untreated children with metallic implants of the Björk type obtained from the archives of a growth study. Cephalograms generated at approximately 2-year intervals between the ages of 8.5 and 16years were selected and traced. Superimpositions of serial tracings of oblique cephalograms on stable intraosseous implants were made to determine the displacements of buccal segment teeth in both arches, and superimpositions of serial tracings of lateral cephalograms were used to evaluate growth of the jaws. Continuous mesial tipping of the maxillary molars was observed from 8.5 to 16years of age, averaging 8.2° ± 5.5° for the first molars and 18.3°± 8.5° for the secondmolars. Compared with the maxillary molars, the mandibular first molars showed less change in angulation except in the later mixed dentition when more than half of the subjects had accelerated forward tipping of the first molar in the late mixed dentition associated with migration into the leeway space. Average amounts of cumulative eruption from 8.5 to 16years of age were 12.1±2.1mm downward and 3.8±1.7mm forward for the maxillary first molar. The mandibular first molar showed 8.6±2.3mm of eruption and 4.4±1.9mm of mesial migration. Peak velocity of vertical eruption of the maxillary and mandibular first molars corresponded to the skeletal vertical growth spurt. The maxillary canines and first premolars showed remarkable and continuous uprighting migration during eruption, averaging 9.5° ± 5.0° and 10.5° ± 6.7°, respectively. However, when they erupted into the occlusion, their changes in angulation reverted to forward tipping. The same tendency was also found in themandibular canines and first premolars. Remarkable eruption and migration occur to the teethof both arches during childhood and adolescence. Rates of first molar eruption during adolescence follow the general pattern of somatic growth. We infer that maintaining the original distal crown angulation of the maxillary molars may be an effective protocol for preservation of anchorage.

Influence of Lateral Cephalometric Radiographs on Orthodontic Treatment Planning of Class II Patients.

Background:Lateral Cephalometric Radiographs (LCR) are a common decision-making aid in orthodontic treatment planning and are routinely used in clinical practice. The aim of this present study was to test the null hypothesis that LCR evaluation does not alter specific components of orthodontic treatment planning in Class II patients.Materials and Methods:Records of 75 patients, who had been treated at the Department of Orthodontics, Centre of Dental Medicine, University of Zurich comprised the study material. Inclusion criteria were: (1) adolescents between the age of 12-15, (2) permanent dentition with Class II buccal segment relationship (3) absence of craniofacial and dento-alveolar malformations. Fifteen orthodontists from the dental faculties of Istanbul University, Istanbul and Ege University, Izmir filled out Likert-type linear scale questionnaires without knowing that they would repeat the same procedure with and without LCRs at two different time points. Equivalence and clinical relevance were assessed using (%95 CI) Wilcoxon signed rank tests.Results:Extraction decision did not differ between groups (p=0.68). Preference of functional appliance use (p=0.006) and inter-maxillary fixed functional appliance (p=0.043) was different among groups.Conclusion:LCR evaluation has minor influence on treatment planning procedure of Class II patients. It might be beneficial to consider its prescription not in a routine manner but as a supplementary tool considering possible reduction of radiation exposure.

Extraction Planning in Orthodontics

Planning extraction of teeth for orthodontic treatment is one of the challenging factors for successful functional and esthetic orthodontic results and for the long-term stability. The aim of this study is to document possible extraction guidelines for planning of orthodontic treatment for space deficiency cases related to excess tooth material. The guidelines are written as patterns to facilitate the decision of extraction of teeth for class I, class II division 1, class II division 2, and class III malocclusions, for crowding, overjet reduction, or correcting the buccal segment relationship. The decision for extraction of teeth for orthodontic treatment is enforced by the oral hygiene, carious teeth, periodontal involvement, impacted teeth, supernumeraries, hypodontia, or for orthognathic purposes. Also, planning the decision for accurate extraction pattern is the main factor in the success of the orthodontic treatment and for the long-term stability of the results. Orthodontic tooth extraction should always be planned with consideration of the width and length of the face, the oral hygiene, carious activity, periodontal involvement, malformed crowns, length and health of the root of the teeth, prognosis of impacted teeth, supernumeraries, and hypodontia. Accurate diagnosis and treatment planning following orthodontic extraction guidelines lead to a long-term stability of the corrected results.