[Comparison of the application of micro-implant screw support and flat guide plate in the treatment of excessive deep overbite of lower anterior teeth].

PURPOSE: To compare and analyze the orthodontic effects of micro-implant screw support and flat guide plate on excessive deep overbite of lower anterior teeth. METHODS: Eighty-two patients with excessive deep overbite of the lower anterior teeth who were treated from January to December 2022 were selected and randomly divided into two groups (41 in each group) by random number table method. Both groups were treated with straight wire arch orthodontic technology, and the anterior teeth were supported by micro-implant screws (micro-implant screw group) and flat guide plates (flat guide plate group), respectively. The effect of upper anterior tooth compression, changes in occlusal plane, and apical absorption were compared between the two groups. SPSS 25.0 software package was used for statistical analysis. RESULTS: There were no significant changes in SNA angle, SNB angle, ANB angle, U1-PP, U6-PP, and L6-MP before and after treatment between the two groups (P＞0.05). L1-MP significantly increased in both groups after treatment than before treatment(P＜0.05). There was no significant difference in bite opening, Spee curve depth, U1 depression, L1 depression, U6 elongation, L6 elongation and occlusal opening time between the two groups before and after treatment(P＞0.05). The root apex absorption of the mandibular central incisors and lateral incisors in the micro-implant screw group was significantly lower than that in the flat guide plate group(P＜0.05), while there was no significant difference in root apex absorption between the two groups of canines(P＞0.05). CONCLUSIONS: Both micro-implant screw support and flat guide plate can effectively lower the mandibular anterior teeth in the treatment of deep overbite in adults, with good orthodontic effects. However, the latter can lead to increased root resorption.

[Improvement of the mastication function of orthodontics combined with restoration in the treatment of deep overbite with severe lower anterior teeth attrition].

PURPOSE: To observe the effect of orthodontics combined with restoration on masticatory function in deep overbite patients with severe lower anterior teeth attrition. METHODS: From January 2018 to January 2022, a total of 164 deep overbite patients with severe lower anterior teeth attrition were collected and divided into two groups according to different treatment plans: control group(72 patients, with restoration treatment) and experimental group(92 patients, with orthodontics combined with restoration treatment). The chewing efficiency of the two groups was evaluated, temporomandibular joint dysfunction index (DI), muscle palpation index (PI) and cranio-mandibular index (CMI) were calculated. The satisfaction with facial esthetic, the Chinese version of Oral Health Impact Scale-14(OHIP-14) and the repair satisfaction score were evaluated, the occurrence of adverse events between the two groups was compared. SPSS 23.0 software package was used for statistical analysis. RESULTS: After treatment, the chewing efficiency of the experimental group was significantly improved compared to the control group, while the DI, PI, and CMI were significantly reduced compared to the control group(P＜0.05). Compared with the control group, the satisfaction degree with facial esthetic and restoration in the experimental group was significantly higher, while the OHIP-14 score was significantly lower after treatment(P＜0.05). The incidence of adverse events in the experimental group was significantly decreased compared with the control group (6.52% vs 25.00%, P＜0.05). CONCLUSIONS: Combination of orthodontics and restoration treatment can enhance the effectiveness of restoration treatment for deep overbite with severe lower anterior teeth attrition, improve the mastication function and temporomandibular joint balance,satisfaction and quality of life of patients, as well as reduce the risk of adverse events.

Evaluating malocclusion patterns in children with autism spectrum disorder using the index of complexity, outcome and need: a cross-sectional study.

BACKGROUND: The purpose of this study was to evaluate the complexity of malocclusion and existing patterns in children with autism spectrum disorders (ASD) using the index of complexity, outcome and need (ICON). METHODS: This cross-sectional study included children diagnosed with ASD, aged 9-15 years. A group of healthy children with the same demographic characteristics was randomly selected as the control group. Malocclusion was assessed according to ICON scoring protocol. The following parameters were recorded: dental aesthetics, upper arch crowding/spacing, presence of crossbite, anterior-vertical relationship (open and deep bite) and buccal segment anterior-posterior relationship. Finally, an overall ICON score was derived and reported for each patient. Descriptive analysis was performed for all investigated variables. Significance level was set at p < 0.05. RESULTS: A total of 324 children, divided into ASD (162) and control (162) groups, comprised the study population. Our results demonstrated that the average overall ICON score was significantly higher in the ASD group compared to the control group (38.77 vs. 27.43, p < 0.001). ASD children also obtained significantly higher scores regarding the dental aesthetics component (3.84 vs 2.78, p < 0.001). Study groups were significantly different in terms of the prevalence of incisor overbite and open bite (p = 0.002 and p < 0.001, respectively). Patients in the ASD group showed a higher prevalence of Class II and Class III malocclusions (p < 0.001). CONCLUSION: ASD children obtained significantly higher overall ICON scores, indicating more complex and severe malocclusions. These children also exhibited a greater tendency towards Class II and III malocclusions.

Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners.

AIM: The purpose of this study was to evaluate the mandibular growth and/or projection following maxillary incisor proclination, overbite correction, and maxillary dentoalveolar expansion without the use of any class II mechanics, in growing class II division 2 patients treated with clear aligners. MATERIALS AND METHODS: Before and after treatment cone-beam computed tomographic (CBCT) generated lateral and posteroanterior cephalograms of thirty-two patients with skeletal class II division 2, 16 in the treatment group and 16 in the untreated group, were reviewed to evaluate treatment-related changes. Upper incisors were proclined and protruded, as well as upper arch expansion and overbite correction were performed as part of their regular treatment. Cephalometric analysis was performed to evaluate skeletal and dental changes. Unpaired statistical t-tests were performed to determine if significant skeletal class II correction was achieved in the treatment group. RESULTS: In the treatment group, after treatment, the upper incisors became more proclined and protruded, and the inter-molar width increased while the overbite was reduced compared to the control group. An increase in skeletal mandibular growth and forward projection was also observed, thus contributing to an improvement of the sagittal skeletal relationship as evidenced by ANB and Wits values compared to the control group. CONCLUSION: A combination of upper incisor proclination, correction of deep overbite, and maxillary dentoalveolar expansion using clear aligners appears to contribute to an improvement of the skeletal class II relationship in growing patients with class II division 2. CLINICAL SIGNIFICANCE: This study shows that unlocking the mandible by correcting a deep overbite, proclining upper incisors, and expanding the upper arch in growing class II division 2 patients can improve skeletal class II using clear aligners. How to cite this article: Mirzasoleiman P, El-Bialy T, Wiltshire WA, et al. Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners. J Contemp Dent Pract 2024;25(4):295-302.

A comprehensive national survey on malocclusion prevalence among Palestinian children.

BACKGROUND: This study aims to evaluate the prevalence of malocclusion and orthodontic features among schoolchildren in the West Bank, Palestine. METHODS: A stratified cluster sample of 1278 schoolchildren (620 males, 658 females, mean age 12 years and 5 months (± 0.5)) were examined. Candidates who had not received any previous orthodontic treatment were only included. Dental anomalies like missing and ectopic teeth were recorded. The anteroposterior occlusal relationship was assessed based on Angle classification. Overjet and overbite were measured. Crowding and spacing were recorded subjectively. In addition, crossbite, openbite, and midline displacement were recorded. The chi-square test and descriptive analysis were used statistically. RESULTS: The study found Angle Class I molar relationship in 65%, Class II div 1 in 17%, Class II div 2 in 6%, and Class III in 12% of the sample. An overjet (OJ) of more than 4 mm was present in 17%, and 4% had OJ of more than 6 mm; an OJ of at least 0 mm or less in 36%, and 6% had a reverse OJ. A normal overbite was observed in 53%, while 28% had an increase and 19% had a decreased overbite. An anterior openbite (AOB) was present in 9%, and a scissor bite or anterior crossbite in 6% and 14%, respectively. A posterior crossbite was observed in 12% (9% unilateral and 3% bilateral). Midline displacement was found in (9%). Crowding was observed in 35% and 31% and spacing in 24% and 15% of the maxillary and mandibular arches, respectively. A statistically significant relationship between gender and midline shift, a diastema, spacing in the upper arch, and most dental anomalies was found; males were more affected (p < 0.05). CONCLUSION: This study reported a high prevalence of malocclusion among schoolchildren in Palestine. A collaborative effort should be directed to obtain more monitoring and surveillance of malocclusion more frequently to prevent and control the exacerbation of the problem.

Analysis of prefabricated myofunctional appliances with different overjet and bumper designs: a three-dimensional finite element analysis.

BACKGROUND: Prefabricated myofunctional appliance can guide tooth eruption, improve dentition alignment, correct myofunctional disorders and harmful oral habits. However, its application to skeletal discrepancy may result in unsatisfactory tooth inclination. This study aimed to construct a novel appliance with overjet design to avoid this side effect and investigated its shape and mechanical changes under occlusion using three-dimensional finite element method. METHODS: We established three samples of prefabricated myofunctional appliances. The first one was edge to edge without overjet, and the outer shield of both jaws were flattened. The second one was 3 mm overjet with stepped the outer shield. The last one was 3 mm overjet, and the outer shield of both jaws were flatted, which meant the front wall of lower jaw was strengthened with bumper, termed as lower bumper. A complete dentition model was applied to the study. 150 N occlusal force was applied to each type of appliance and the deformation displacement and the changes in stress was recorded. RESULTS: The deformation was significant in the incisors regions, especially in the vertical and lateral dimensions. The maximum displacements of 3 mm overjet with step shield group were 7.08 mm (vertical), 3.99 mm (lateral), and 2.90 mm (sagittal), while it decreased to 3.92 mm(vertical), 1.94 mm (lateral), and 1.55 mm (sagittal) in overjet with bumper group. Moreover, the upper molar regions exhibited higher vertical and sagittal displacement in 3 mm overjet with step shield group, which were 3.03 mm (vertical) and 1.99 mm (sagittal), and the bumper design could decrease the maximum displacement to 1.72 mm (vertical) and 0.72 mm (sagittal). In addition, the Von Mises stress of appliances was analyzed, and results indicated that 3 mm overjet with step shield generated higher stress than other groups, with the maximum Von Mises stress was 0.9387 MP, which were 0.5858 and 0.5657 MP in edge to edge group and 3 mm overjet with lower bumper group, respectively. CONCLUSION: The prefabricated myofunctional appliances may cause deformation during occlusion. Compared to step shield group, the application of lower bumper exhibited better resistance to occlusal force.

Planned and achieved overjet and overbite changes following an initial series of Invisalign® aligners: A retrospective study of adolescent patients.

OBJECTIVE: The aim of the present study was to compare the changes in overjet and overbite measurements achieved in adolescent patients following an initial series of Invisalign® aligners (Align Technology, San Jose, California) with those planned by orthodontists via its ClinCheck® digital treatment planning facility. METHODS: Data provided by Align regarding patients who had completed an initial series of Invisalign® aligner treatment and were less than 18-years old were assessed in relation to pre-treatment, planned and achieved overjet and overbite measurements. Descriptive statistics, Wilcoxon rank-sum, Mann Whitney calculations were computed. RESULTS: A total of 290 patients satisfied inclusion criteria. The median (interquartile range (IQR)) age was 14.17 (13,15.42) years. The median achieved overjet and overbite changes were less than those planned (p<0.01) with 53.33% of the planned median overjet increase achieved and 52.94% of planned median overjet reduction achieved. Additionally, 58.33% of the planned median overbite increase was achieved and 55.55% of the planned median overbite reduction was achieved. A total of 21.52% patients recorded no change or an increase from pre-treatment to the achieved overjet where reduction was planned, whereas 41.67% recorded no change or a reduction in overjet where increase was planned. A total of 18.72% recorded no change or an increase in overbite where reduction was planned, whereas 20.75% recorded no change or a reduction in overbite where increase was planned. CONCLUSIONS: Less than 60% of the planned overjet and overbite changes per patient were achieved. Between 18.72 and 41.67% of patients experienced no change or changes in overjet and overbite in the opposite direction to that planned. This is likely to be clinically significant.

Effects of eruption guidance appliance in the early treatment of Class III malocclusion.

OBJECTIVES: To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition. MATERIALS AND METHODS: The experimental group comprised 22 patients with Class III malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05). RESULTS: In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group. CONCLUSIONS: The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.

Skeletal, dentoalveolar and soft tissue changes after stabilization splint treatment for patients with temporomandibular joint disorders.

BACKGROUND: Temporomandibular disorder (TMD) is a grouping of heterogeneous disorders with multifactorial origins. Stabilization splints (SS) have demonstrated an acceptable treatment effect in TMD. The possible changes at the skeletal, dental, and soft tissue levels need to be addressed to evaluate the benefit/risk ratio of this therapeutic procedure. Accordingly, this study aimed to three­dimensionally evaluate skeletal, dentoalveolar and soft tissue changes after SS treatment for patients with TMD. METHODS: This retrospective study included 74 adult patients with myofascial and/or intra-articular disorders (25 males and 49 females), with an average age of 22.88 ± 4.8 years, who underwent SS treatment. Pre- and post-treatment Cone beam computed tomography were analysed using Invivo 6.0.3 software. The primary outcome was the vertical skeletal and dentoalveolar changes, while the secondary outcomes were the anteroposterior skeletal, dentoalveolar and soft tissue changes. Paired t-test and Wilcoxon rank sum test were used for statistical analyses. RESULTS: For the primary outcome; skeletally, there was a significant increase in mandibular plane inclination (difference: 0.82°±1.37), decrease facial height ratio (difference: 0.45%±1.07) and at the dentoalveolar level, the inclination of the functional (FOP-SN, FOP-FH) and bisecting (BOP-SN, BOP-FH) occlusal planes exhibited a significant increase too (difference: 0.38 ± 1.43°, 0.49 ± 1.62°, 0.44 ± 1.29° and 0.41 ± 1.17°, respectively) and also a decrease in the overbite (difference: -0.54 ± 0.83). For the secondary outcomes; there was a significant decrease in mandibular position (SNB) (difference: 1.60 ± 1.36°) and increase in the overjet (difference: 0.93 ± 1.04, p < 0.001) and a significant lower lip retrusion (difference: 0.33 ± 1.01 mm p < 0.01), was observed too. CONCLUSIONS: SS therapy resulted in significant vertical skeletal and dentoalveolar changes that were manifested mainly by facial height ratio, mandibular and occlusal plane changes, and to a lesser extent, significant anteroposterior skeletal, dentoalveolar, and soft tissue changes in the form of mandibular position, increased overjet and a more retrusive lower lip. These changes should be considered during patients' selection prior to initiating SS therapy.

Prevalence of malocclusion and oral health-related factors among pre-school children in Northern Albania.

The aim of the present study was to investigate prevalence and association between malocclusion and caries among pre-school children aged 4-6 years frequenting public kindergartens in Shkodër, the largest city in North Albania. The sample for this descriptive and cross-sectional study included 389 pre-school children aged 4-6 years frequenting 20 public kindergartens in Shkodër, the largest city in North Albania. The participants were divided into two groups according to their caries experience evaluated, as determined by decayed-missing-filled index dmf (World Health Organization criteria) score. Those with dmf score of zero were considered to be free of caries. The prevalence of children with at least one malocclusion trait was 89%. The prevalence of caries was 66% (mean dmf score: 3.63). Increased overbite (43%), followed by increased overjet, were the most prevalent malocclusion traits observed in children with a dmf of zero. Among children with caries, the most prevalent trait was increased overjet (42%) and increased overbite. Almost half of the entire study population had a straight terminal plane and class I canine relationship. There was a similar prevalence of bilateral crossbite. Significant changes (p = 0.008) were observed between the groups with regards to the absence of spacing in the maxillary anterior region. Regression analysis further revealed that children with an absence of maxillary spacing were 2.564-fold more likely to have caries; those with a deepbite were 0.814-fold more likely to have caries. More than half of the children had caries. Increased overjet, overbite, crossbite and maxillary crowding were malocclusion traits observed in the population included in this study. A positive association was identified between maxillary crowding, deepbite and caries. The association between malocclusion and caries, highlights the necessity for an increased awareness of these two conditions that are commonly found among children of pre-school age.

Noninvasive conservative management of anterior open bite treated with TADs versus clear aligner therapy.

OBJECTIVES: Anterior open bite can be treated non-surgically via molar intrusion using temporary skeletal devices (TAD). Clear aligner therapy (CAT) is recognized as a viable therapeutic modality for non-extraction treatment of adults with mild open bite. This study aimed to compare the treatment effect and mechanisms of open bite closure between patients treated with braces and TADs double arch intrusion and those treated with CAT. Treatment success at T3 was based on 1- positive overbite on ceph; 2- Change in the vertical dimension 3- post treatment POSI score equal to zero. MATERIAL AND METHODS: The TAD group includes 18 consecutively treated patients from the main author. The CAT group consisted of 16 selected patients from three different orthodontists. The observation time points were as follows: pretreatment (T1), end of molar intrusion and positive overbite achieved (T2), end of treatment (T3), at least 6-month follow-up (T4). Treatment changes were assessed by cephalometric analysis and frontal intraoral photo. RESULTS: At the end of treatment, 100% of the patient of the TAD group and 78,6% of the CAT group had a posi score of 0. The TAD group showed a significant reduction in vertical measurements (SN-MPA: -1,55° ± 0.41, LAFH: -3,05 ± 0.51 mm, U6-PP: -1.48 ± 0.30 mm), but the CAT group did not have significant changes for these variables. Both groups had significant increases in overbite from T1 to T3 (TAD: 4,32 ± 0,5 mm; CAT: 2,33 ± 0.56 mm), and overbite remained stable at T4. The CAT group did not have a significant upper molar intrusion, but a significant extrusion of 1.22 ± 0.42 mm of the lower incisor occurred. CONCLUSION: The TAD group achieved bite closure by upper molar intrusion, lower molar and incisors vertical control, and mandibular plane counterclockwise rotation, resulting in an improved AP and vertical relationship. The CAT group achieved bite closure through the lower incisor extrusion without significant change in the vertical dimension. CLINICAL RELEVANCE: This study provides relevant information about the skeletal and dental changes of open bite treatment with TADs double arch intrusion. The comparison with a control group treated with CAT confirms known information.

Occlusal characteristics in modern humans with tooth agenesis.

Non-syndromic permanent tooth agenesis affects a significant proportion of the population, especially if third molars are considered. Although tooth agenesis has been linked to a smaller craniofacial size, reduced facial convexity and a shorter skeletal face, the occlusal characteristics of individuals with tooth agenesis remain largely unexplored. Therefore, this study investigated potential associations between tooth agenesis and metric occlusal traits in 806 individuals (491 with 4.1 missing teeth per subject, including third molars, and 315 without any tooth agenesis). Dentoskeletal morphology was defined through anatomical landmarks on pre-treatment cephalometric radiographs. Multivariate regression models, adjusted for sex and age, showed that tooth agenesis was significantly associated with a reduced overjet, an increased interincisal angle, and shorter upper and lower dental arch lengths, but not with overbite. Moreover, apart from reduced tooth length and dentoalveolar effects, as the number of missing teeth increased the upper front teeth were progressively retruded according to the craniofacial complex and to the face. Thus, tooth agenesis has a substantial influence on dental and occlusal characteristics, as well as on the sagittal position and inclination of anterior teeth. These findings emphasize the necessity for personalized, multidisciplinary approaches in individuals with multiple agenesis to successfully meet treatment goals.

Does aligner refinement have the same efficiency in deep bite correction?: A retrospective study.

BACKGROUND: Refinements are very common in clear aligner treatments. The aim of this study is to assess whether the predictability of deep overbite correction is similar over several refinements using clear aligners (Invisalign, Align Technology, San Jose, Calif) and examine the accuracy of vertical movement and inclination change of individual teeth. METHODS: This retrospective study included 20 deep bite patients (7M and 13F; 32.63 ± 11.88 years old; an initial overbite of 5.09 ± 0.98 mm), consecutively treated from September 2016 and March 2023, who completed at least two sets of aligners, including refinements. The initial, predicted, and achieved models were exported from ClinCheck or OrthoCAD (Cadent Inc, Carlstadt, NJ) and superimposed via best-fit surface-based registration using SlicerCMF (version 4.9.0; cmf.slicer.org). We also examined 15 out of 20 patients who completed treatments. The overbite correction and changes in vertical movement and inclination for individual teeth were measured. Descriptive statistics and a paired t-test or Wilcoxon signed-rank test were performed. P < 0.05 was considered statistically significant. RESULTS: The mean accuracy of overbite correction was 37.63% after 1st set, followed by 11.19%, 6.32%, and 13.80% (2nd-4th sets), respectively. There were statistically significant differences between the predicted and achieved vertical movements and inclination changes for all teeth for the 1st and 2nd sets. For the completed cases, the mean overbite correction was 38.54% compared to the initially planned overbite correction, which is similar to one of the 1st set. Still, the vertical movements and inclination changes of all teeth present statistically significant differences between the initially planned and finally achieved movements except for maxillary lateral incisor torque. CONCLUSIONS: The most overbite correction occurs during the 1st set of aligners, and refinement treatment does not significantly improve the deep bite correction.

Retrospective comparison of two different miniscrew-supported molar distalization methods applied in the buccal and palatal regions.

BACKGROUND: To compare dentofacial effects of distalization with miniscrew-supported pendulum and infrazygomatic crest miniscrews. METHODS: The study included 36 patients whose lateral cephalometric radiographs were obtained before (T0) and after (T1) distalization. Patients were divided into two groups according to the treatment methods: 1) distalization with miniscrew-supported pendulum (MSP) (n = 19; 14 girls and 5 boys; mean age 16.9 ± 1.46 years) and 2) distalization with infrazygomatic crest (IZC) miniscrews (n = 17; 8 girls and 9 boys; mean age 17.0 ± 1.68 years). Dental, skeletal and soft tissue measurements were performed on lateral cephalograms taken from individuals. RESULTS: A significant molar distalization was achieved both in the MSP group (3.52 ± 0.76 mm at 8.71 ± 2.02 months) and the IZC group (3.5 ± 0.74 mm at 9.7 ± 2.5 months) (P < 0.001 for both). Premolar distalization was significantly lower in the MSP group (1.73 ± 1.09 mm) than in the IZC group (2.81 ± 0.79 mm) (P < 0.01). Significant molar tipping was observed in both groups (P < 0.001), while no significant difference was found between the groups (P > 0.05). Retrusion of maxillary incisors were significantly higher in the IZC group (2.75 mm) than in the MSP group (0.98 mm) (P < 0.01). A significant difference was found between the two groups with regard to the changes in overjet and overbite (P < 0.05). CONCLUSIONS: Both distalization methods were found to be effective in achieving a Class I molar relationship in patients with Class II malocclusion.

Oro-facial function and quality of life in children and adolescents with large horizontal maxillary overjet-A case-control study.

BACKGROUND: Large horizontal maxillary overjet (overjet) is associated with reduced bite force (BF) and number of contacts, which influence the chewing effectivity (CE). Oral health, oro-facial function (OF) and malocclusion have great impact on psychological well-being and quality of life (QoL). OBJECTIVES: The aims of the study were to examine OF, temporomandibular disorders (TMD), BF, CE, QoL and well-being in children and adolescents with large overjet. METHODS: The study was a case-control study including healthy children with large overjet in the study group compared to a control group of healthy children with neutral occlusion, all 9-14 years old. OF was examined by use of Nordic Orofacial Test-Screening (NOT-S), Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and registration of morphological and functional occlusion. QoL and well-being were examined using KIDSCREEN-10 and Strengths and Difficulties Questionnaire. RESULTS: The study and control groups included 37 and 32 participants, respectively. Significantly increased NOT-S score (p < .001) and reduced BF (p = .011), numbers of contacts (p < .001) and CE (p = .005) were found in the study group. BF, numbers of contacts and CE were negatively associated with erupting canines and premolars. No significant difference was found in age, gender, dental eruption, TMD diagnosis or QoL between the groups. Significantly increased emotional symptoms (p = .007), hyperactivity (p = .043) and total difficulties score (p = .009) were found in the study group. CONCLUSION: The study group showed higher NOT-S score and reduced BF, number of contacts and CE. No difference in QoL were found between the groups, although reduced well-being and increased emotional symptoms, hyperactivity and total difficulties were found in the study group.

Long-term stability of curve of Spee depth among orthodontically treated patients: A retrospective longitudinal study.

OBJECTIVE: The curve of Spee is deemed important characteristic of the dentition for a balanced occlusion and distribution of masticatory forces, while orthodontic levelling of an accentuated curve of Spee is generally included as a treatment goal for deepbite correction. However, relapse is often seen and can be problematic. METHODS: A retrospective longitudinal study of predominantly young patients with a deep curve of Spee, who had been treated orthodontically with 0.018"-slot Edgewise fixed appliances, was performed. The depth of the curve of Spee was digitally measured before treatment (T1), at debond (T2), and an average of 7 years post-debond (T3) and analysed statistically at 5%. RESULTS: A total of 157 patients were included (56.7% female; 11.6-year-old at T1), 16.6% of which were treated with premolars extractions. Non-extraction treatment reduced the curve of Spee at the first premolar from 1.87 mm (T1) to 0.22 mm (T2), which relapsed 0.12 mm (T3; P = .04). The respective depths for the second premolar were 2.0 mm (T1), reduced to 0.80 mm (T2). No significant relapse was seen for the second premolar (0.08 mm; P > .05) or the first permanent molar (0.06 mm; P > .05). No overall significant differences in absolute relapse were seen between extraction and non-extraction patients, but premolar extractions were associated with less clinically relevant relapse at the first molar (odds ratio 0.27; 95%-confidence interval 0.08-0.88; P = .003). CONCLUSION: Steep curves of Spee can be satisfactorily levelled orthodontically with satisfactory stability in the long term, while premolar extractions might be associated with less relapse.

Unplanned tooth movement in deepbite correction with Invisalign: A retrospective study.

BACKGROUND: This study aimed to investigate unplanned tooth movements in deepbite correction with Invisalign. METHODS: The sample consisted of 34 adult patients with deepbite malocclusion treated with Invisalign. Pretreatment and predicted digital models were exported from ClinCheck software, while the post-treatment model was obtained from an intraoral scan taken at the end of the first set of aligners. Digital models' superimposition was done using the eModel "Compare" software. Frequency and percentage of occurrence of unplanned linear and angular movements, their magnitude, and direction were then determined. In addition, comparison of unplanned movements was performed between anterior and posterior teeth as well as between linear and angular measurements. RESULTS: The percentage of unplanned movements ranged from 1.68% to 25.63% in the maxilla and 3.36% to 23.95% in the mandible, being most evident in the first and second molars. Unplanned movements were statistically significantly more frequent in posterior teeth compared with the anterior teeth (P > 0.05). In addition, the frequency of angular movements was statistically significantly higher for each tooth than linear movement (P < 0.05) with a higher mean value. Unplanned mesiodistal movements were the least frequent. CONCLUSIONS: Unplanned linear as well as angular movements were evident in almost all teeth. Unplanned faciolingual inclination and mesiodistal angulation movements were the most frequently observed. Unplanned vertical movements can affect the predictability of deepbite correction and thus merit particular attention in those cases.

Comparison of posttreatment stability after total mandibular arch distalization with mini-implants and mandibular setback surgery.

OBJECTIVES: To compare posttreatment stability in skeletal Class III patients between those treated by total mandibular arch distalization (TMAD) with buccal mini-implants and those by mandibular setback surgery (MSS). MATERIALS AND METHODS: The samples included 40 Class III adults, 20 treated by TMAD using buccal interradicular mini-implants and 20 treated with MSS. Lateral cephalograms were taken at pretreatment, posttreatment, and at least 1-year follow-up, and 24 variables were compared using statistical analysis. RESULTS: Mandibular first molars moved distally 1.9 mm with intrusion of 1.1 mm after treatment in the TMAD group. The mandibular incisors moved distally by 2.3 mm. The MSS group exhibited a significant skeletal change of the mandible, whereas the TMAD group did not. During retention, there were no skeletal or dental changes other than 0.6 mm labial movement of the mandibular incisors (P < .05) in the MSS group. There was 1.4° of mesial tipping (P < .01) and 0.4 mm of mesial movement of the mandibular molars and 1.9° of labial tipping (P < .001) and 0.8 mm of mesial movement of the mandibular incisors in the TMAD group. These dental changes were not significantly different between the two groups. CONCLUSIONS: The TMAD group showed a slightly decreased overjet with labial tipping of the mandibular incisors and mesial tipping of the first molars during retention. Posttreatment stability of the mandibular dentition was not significantly different between the groups. It can be useful to plan camouflage treatment by TMAD with mini-implants in mild-to-moderate Class III patients.

Thirteen-year-old female patient with Class II division 1 malocclusion and hypodivergent facial pattern treated with buccal fixed appliance. Case report no 230052. European College of Orthodontics. Commission of affiliation and titularisation.

DATE OF BIRTH: 24/09/1998; sex: female. PRE-TREATMENT DOCUMENTS: 13 years 5 months old; 07/03/2012. DIAGNOSIS: Skeletal Class I with biretrusion, hypodivergent facial pattern; angle's Class II division 1 with overbite; moderate dento-maxillary discrepancy; maxillary incisor malposition. TREATMENT PLANNING: Bimaxillary buccal fixed appliance with Class II elastics. Active treatment duration: 25 months. POST-TREATMENT DOCUMENTS: 15 years 7 months old; 09/05/2014. POST-RETENTION DOCUMENTS: (minimum 1 year) 16 years 9 months old; 08/07/2015. Retention period: unlimited.