Evaluation of anterior teeth crown-root morphology and alveolar bone structure in patients with closed deep overbite using cone beam computed tomography.

This retrospective study used cone-beam computed tomography to investigated the crown-root morphology and alveolar bone structure in incisors region in subjects with closed deep overbite and comparison the difference between gender and age. The CBCT images for 40 subjects (group C) with Angle II division 2 were selected from patients of the HeFei Stomatological Hospital from November 2023 to March 2024.20 individual normal occlusion subjects (group A),20 patients with Angle II division 1(group B) were included. The crown-root ratio of the maxillary and mandibular anterior teeth, crown-root angle and alveolar bone structure were measured on the CBCT images, the data were statistically analyzed. In addition to mandibular lateral incisor, the crown-root ratio of maxillary and mandibular anterior teeth in the Class II division 2 group was higher than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The crown-root angle of maxillary anterior teeth in the Class II division 2 group was smaller than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The alveolar bone thickness of the maxillary central incisor was comparatively smaller, while the alveolar bone height was relatively higher in the Class II division 2 group. Age and gender were associated with change in root lengths and crown-root angle for the Class II division 2 group (P < 0. 05). Patients with closed deep overbite malocclusion exhibit a significant difference compared to the controls for most measurements. The patients presenting with Class II division 2 malocclusion exhibit excessive inward positioning of the anterior teeth, resulting in evident crown-root angle, a large crown-root ratio, and minimal labial alveolar bone. In order to keep the tooth movement within the safe range of alveolar bone movement, it is necessary to strictly control the torque and use appropriate orthodontic force to reduce the risk of bone fenestration, bone dehiscence, gingival recession and root resorption.

Clinical Insights Into Lower Incisor Extraction for Orthodontic Treatment: A Case Report.

Extracting a single lower front tooth can be an appropriate treatment for class I malocclusions when the alignment of the upper teeth is normal and there is an adequate overlap of the teeth. This approach is particularly effective in cases of significant crowding in the lower front teeth, especially when the space deficiency exceeds 4-5 mm and the combined width of the lower front teeth surpasses 83 mm. It is also a viable option for malocclusions resulting from discrepancies in tooth size, such as narrower upper front teeth or larger lower front teeth. Research suggests that this method leads to better post-treatment stability compared to the conventional approach of premolar extraction. The success of this treatment is contingent upon meticulous diagnosis, comprehensive planning, and the expertise of the orthodontic professional. This method not only addresses specific issues of space and alignment but also provides a more stable and predictable long-term outcome for patients with these particular orthodontic challenges.

A 3D finite element analysis of biomechanical effects on teeth and bone during true intrusion of anteriors using miniscrews.

PURPOSE: The primary objective of this study was to investigate the biomechanical effects and stresses on bone, periodontal ligament (PDL), cementum and displacement along X-, Y- and Z-axis during true intrusion of incisors using mini-implants with Finite Element Analysis; the secondary objective of the study was to find out the best method for anterior intrusion in clinical practice to treat anterior deep bite malocclusions. MATERIALS AND METHODS: A 3D finite element method was used to simulate true anterior intrusion with sliding mechanics using mini-implants. Two groups were modelled with mini-implants placed distal to lateral incisors for Model 1, and below the anterior nasal spine (ANS) for Model 2, to achieve intrusion. von Mises stress, principal stress on PDL and alveolar bone, displacements in all 3 planes were determined. RESULTS: Amongst the modalities compared in the present study, the stresses on bone and PDL were showing best behavior for mini-implants placed distal to lateral incisors (Model 1). The teeth showed controlled tooth movement in Model 1. CONCLUSION: Maximum stress was found in the cortical bone and in the PDL. Nature of the stress changed from compressive to tensile from cervical area to root apex, concentrating mainly at the apical area. Amongst the modalities compared, the best controlled tooth movements for anterior intrusion to treat anterior deep bite malocclusions, was for mini-implants placed distal to lateral incisors (Model 1).

Comparison between effects of reverse curve of Spee nickel titanium archwire and stainless steel archwires with and without torque on the lower incisors in deep overbite treatment: a randomized control study.

OBJECTIVES: To compare the effect between three different reverse curve of Spee (RCOS) archwires: 0.016 × 0.022-inch Nickel-Titanium and 0.019 × 0.025-inch stainless steel (SS) with and without crown labial torque (CLT) on lower incisors during deep overbite treatment. MATERIALS AND METHODS: Eighty subjects with deep overbite were randomly divided into three groups: the first group (mean age: 20.5 years) received SS RCOS with CLT, the second group (mean age: 19.4 years) was treated with 0.019 × 0.025-inch SS RCOS with zero CLT, the third group (mean age: 18.2 years) was treated with rocking-chair nickel-titanium (NiTi) 0.016 × 0.022-inch with RCOS. Two lateral cephalometric images were taken for each patient, one after alignment and the second after deep bite correction. These images were superimposed using the corpus axis to study the lower incisor horizontal and vertical changes. RESULTS: The lower incisor angular change was significantly smaller in Group II (-0.3°) compared to Group I (4.8°) and Group III (6.0°, P ≤ .001). Lower incisor anterior movement was reduced in Group II compared to Group I (P = .014) and Group III (P = .008). Group III showed significantly more downward movement of the lower Incisors (P ≤ .001). The three groups showed comparable amounts of true intrusion (1 mm, P = .536). CONCLUSIONS: 0.016 × 0.022-inch NiTi and 0.019 × 0.025-inch SS with crown labial torque RCOS archwires resulted in similar proclination and forward movement of the lower incisors. Removal of anterior crown labial torque from the 0.019 × 0.025-inch SS RCOS archwire prevents lower incisor proclination and forward movement.

Is occlusal contact re-established within 6 months after bonding of a fixed anterior bite plane in adolescents with a Class II division 2 incisor relationship? A randomised controlled trial.

OBJECTIVE: To determine if re-establishment of occlusal contact was achieved within 6 months after insertion of a fixed anterior bite plane in individuals with Class II division 2 incisor relationship, and to evaluate the occlusal and vertical skeletal changes and acceptance of the intra-oral scanner and bite plane. DESIGN: Single-centre two-arm parallel group randomised controlled trial with 1:1 allocation to intervention and control groups. SETTING: Dundee Dental Hospital and Research School, UK. PARTICIPANTS: A total of 38 participants aged 9-16 years (11 males, 27 females) with Class II division 2 incisor relationship and increased overbite (greater than one-third incisor overlap). METHODS: Participants were randomised to intervention (n = 19) and control (n = 19) groups using block randomisation. The intervention group had a fixed anterior bite plane, and the occlusion and vertical facial dimensions were monitored with intra-oral scans, lateral cephalograms and photographs. The control group received no treatment and occlusal and vertical facial dimensions were monitored with scans and photographs. Questionnaires were completed by participants and parents/carers. An intention-to-treat analysis was planned. RESULTS: The overbite reduced in all participants in the intervention group (mean initial overbite: 5.07 mm, 95% confidence interval [CI] = 4.15-6.00; mean overbite after 6 months: 2.45 mm, 95% CI = 1.93-2.96). There was a mean incisor intrusion of 0.29 mm (95% CI = 0.17-0.42) and mean eruption of the first molars of 0.23 mm (95% CI = 0.09-0.37). There was no significant change in incisor inclination or vertical skeletal change. Feedback from participants and their parents/carers were generally positive. CONCLUSION: Fixed anterior bite planes effectively reduce an increased overbite in adolescents with a Class II division 2 incisor relationship, due to a combination of incisor intrusion and molar eruption with no change in incisor inclination or vertical skeletal change. Intra-oral scanning and fixed anterior bite planes are acceptable in adolescents.

Treatment of Vertical Maxillary Excess and Skeletal Class II Malocclusion: A Case Report.

Class II malocclusion is a recurrent problem that may occur at a young age. If treated initially, the malocclusion can be corrected by redirecting the growth without invasive modalities and avoiding orthognathic surgeries. A female patient aged 10 years three months came to the department of orthodontics having a complaint of upper front teeth placed forwardly, diagnosed with skeletal class II due to retrusive mandible and vertical maxillary excess with hyper divergent growth pattern with increased anterior facial height, with Angle's molar class II division 1 malocclusion, increased overjet of 13 mm and overbite of 7 mm, acute nasolabial angle, deep mentolabial sulcus, and hyperactive mentalis. It was treated using an activator with medium-high-pull headgear (modified Herren activator) passing through the maxillary center of resistance. A fixed mechanotherapy with high-pull headgear was given using the anterior inclined plane acrylic plate in the maxilla and McLaughlin, Bennett, and Trevisi (MBT). Begg's wrap was used for the retention plan. This case report shows the significance of proper treatment results obtained due to correct identification and planning in treating malocclusion. This case report shows the significance of proper treatment results obtained due to correct identification and planning in treating malocclusion.

Anterior Open Bite Treated With Palatal Crib and Myofunctional Therapy: A Case Report.

The most prevalent oral habit and one of the most often habitual behavioral patterns in preschool-aged children is thumb-sucking. This behavior is crucial to the development of malocclusion and must be addressed carefully since it may cause a secondary tongue thrust that worsens the issue. Developing an effective treatment plan requires determining the underlying cause, which may include psychological, physiological, and or anatomical factors. Overall prevention of behavior needs to be planned for successful outcomes. One such device for treating tongue-thrusting and thumb-sucking habits is the palatal crib. The present case shows the possible effectiveness of palatal crib use in conjunction with myofunctional therapy for a child whose diagnosis involves habitually holding the tongue low and sucking the thumb that causes an anterior open bite (AOB). An 11-year-old boy with flared and spaced upper and lower incisors also had an AOB. Myofunctional therapy was combined with palatal cribs to help the tongue reposition itself and discourage the habit of sucking. The AOB was successfully corrected with an appropriate overjet and overbite after a total of three months of treatment.

Behind the Smile: Managing Class I Malocclusion and Protrusive Upper Incisors With Kalra Simultaneous Intrusion and Retraction (K-SIR) Mechanics.

Malocclusion is defined as any deviation from the ideal occlusal positions and the position of the specific teeth. Those that are common are numerous and affect a patient's stomatology and dental structures in appearance and utility. Class I is the most common type and favors the anterior relationship of both jaws, which lies between the second and third quartiles. Its cause is still unknown at the moment. It is even more frequent than usual occlusion. Class I malocclusion with an overjet of upper incisors less than 4 mm accompanied by type 2 of Dewey's modification also displays protruded upper incisors and a deep overbite. This case report's focus is to provide an extensive evaluation of the diagnostic process, management plan, and outcome for a patient who had presented with this specific dental abnormality and simultaneous intrusion and retraction mechanics for an anterior segment with Kalra Simultaneous Intrusion and Retraction (K-SIR) loops.

Effectiveness of removable anterior bite planes with varied mealtime protocols in correcting deep bites among growing patients: a randomized clinical trial.

OBJECTIVES: To compare effectiveness of two protocols for correcting deep bite in growing patients using a removable anterior bite plane (RABP): full-time wear with appliance on during meals (F + M) vs off during meals (F - M) and to explore the relationship between average daily duration of wear and overbite (OB) correction rate, stratified by the wear protocol. MATERIALS AND METHODS: Thirty-two growing patients with deep bite (mean age = 10.94 ± 2.17 years) were randomly assigned to the F + M (n = 16) or F - M (n = 16) group. Cephalometric radiographs were taken at baseline (T0) and when normal OB was achieved (T1). Duration of wear was recorded by a TheraMon microsensor within the appliance. A best-fit regression model for the relationship between daily duration of wear and OB correction rate was determined (α = 0.05). RESULTS: Both groups exhibited similar baseline characteristics and cephalometric changes, ie, molar extrusion, and incisor intrusion and proclination in both arches (P < .05), and intergroup differences were not significant. Here, F + M exhibited significantly faster rates of deep bite correction (1.83 ± 1.18 vs 1.08 ± 0.62 mm/month; P < .05) and mandibular molar extrusion (0.46 ± 0.25 vs 0.30 ± 0.18 mm/month, P < .05) compared with F - M. Best-fit regression models for relationship between daily duration of wear and OB correction rate were exponential for both F + M (R2 = 0.53) and F - M (R2 = 0.74). CONCLUSIONS: Here, F + M and F - M protocols resulted in comparable cephalometric changes among deep bite growing patients. However, the F + M group exhibited a faster correction rate. Daily duration of wear positively correlated with OB correction rate in an exponential manner.

Effect of Early Orthodontic Treatment on Long-Term Stability of Class II Malocclusions.

Background: Class II malocclusions are a common orthodontic problem, often requiring comprehensive treatment to achieve proper occlusion and facial harmony. Early orthodontic intervention in the mixed dentition phase has been advocated to address these issues. Materials and Methods: A retrospective analysis was conducted on a cohort of 150 patients with class II malocclusions who underwent early orthodontic treatment between the ages of 7 and 10 years. The treatment included fixed or removable appliances, headgear, and functional appliances, depending on individual needs. Records of their initial malocclusion severity, treatment modalities, and long-term follow-up data (mean follow-up duration of 10 years) were collected and analyzed. Stability was assessed by evaluating overjet and overbite changes from post-treatment to the long-term follow-up. Results: The initial mean overjet and overbite values were 8.5 mm and 4.0 mm, respectively. Following early orthodontic intervention, these values were significantly reduced to 3.0 mm and 1.5 mm, respectively (P < 0.001). At the long-term follow-up, the mean overjet and overbite remained stable at 3.2 mm and 1.6 mm, respectively. Analysis revealed that 85% of patients maintained their corrected class II occlusion within clinically acceptable limits, while 15% experienced minor relapse requiring minimal additional treatment. Conclusion: Early orthodontic treatment in class II malocclusions can lead to significant improvements in overjet and overbite, and these corrections tend to remain stable over the long term.

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.

Correlation between Depth of the Curve of Spee and Some Specific Malocclusion Characteristics in a Population from Sibiu County, Romania-A Cross-Sectional Study.

Background: This study aimed to investigate the relationship between the Curve of Spee (COS) depth and malocclusion characteristics in a population from Sibiu County, Romania. The research sought to understand how the COS's anatomical dimensions correlate with different classes of malocclusion and the position of the frontal teeth. Methods: A total of 265 participants from the Dentistry Ambulatory of the Military Hospital of Sibiu were included in this study. It employed digital intraoral scanning technology to measure the COS, overjet, and overbite, with malocclusion classification. Statistical analyses, including correlation and regression, were conducted to examine the relationships between COS depth, frontal teeth position, and malocclusion characteristics. Results: The average COS depth measured was 1.0564 mm, presenting variability when compared to existing literature. Most of the study participants had Class I malocclusion. A significant positive correlation between COS depth and overjet was identified, with no notable gender-based differences in these occlusal parameters. Conclusions: The findings affirm the integral role of COS in occlusal dynamics and malocclusion diagnosis. The COS measurement of a mean of 1.0564 mm, when compared to other results emphasizes the differences in occlusal curvature among various populations. The results contribute to a refined understanding of occlusal relationships, supporting the need for personalized orthodontic and prosthetic treatments based on precise anatomical measurements.

Effectiveness of Invisalign Treatment on Open Bite Correction.

Background: Open bite is a common orthodontic malocclusion that can have functional and aesthetic implications. Traditional orthodontic treatments have been used to correct open bites, but the effectiveness of Invisalign, a clear aligner therapy, in open bite correction remains a topic of interest. Materials and Methods: A retrospective analysis was conducted on a cohort of 50 patients with open bites who underwent Invisalign treatment. Pre-treatment and post-treatment records, including cephalometric radiographs, dental models, and clinical photographs, were assessed. The open bite was defined as a negative overbite greater than 2 mm. Treatment duration, number of aligners used, and patient compliance were also recorded. Statistical analysis, including paired t-tests and subjective patient feedback, was employed to evaluate the treatment outcomes. Results: The mean pre-treatment open bite was -3.5 mm (SD = 1.2), and the mean treatment duration was 18 months (SD = 2.5). On average, patients received 24 sets of aligners (SD = 4.1) during the treatment. Post-treatment evaluation showed that the mean overbite improved to + 1.5 mm (SD = 0.8), indicating successful open bite correction. The paired t-test revealed a statistically significant difference between pre-treatment and post-treatment open bite measurements (P < 0.001). Patient satisfaction was high, with 90% of participants reporting improved aesthetics and comfort. Conclusion: Invisalign treatment demonstrates effectiveness in correcting open bites, with statistically significant improvements in overbite measurements.

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.

An evaluation of cephalometric predictors of anterior open bite; An assessment of dental and skeletal parameters in an orthodontic population.

BACKGROUND: Anterior open bite (AOB) malocclusion is one of the highly challenging malocclusions. Cephalometric radiographs have been used for the diagnosis of occlusal anomalies in the vertical and anteroposterior directions. This study aims to compare skeletal and dental features in open and non-open bite subjects to identify factors that help predict and categorize open bites in a Nigerian population. MATERIALS AND METHODS: Pretreatment cephalometric radiographs of 82 patients were recruited into this study. This study comprised 41 AOB patients and 41 (Class 1 malocclusion) patients (control group). The radiographs were obtained from the orthodontic unit, Department of Child Dental Health of the Lagos University Teaching Hospital, Idi-Araba Lagos. Cephalometric tracing and analysis of the obtained radiographs were used to identify and compare the skeletal and dental differences between the two groups. RESULTS: The mean age of the participants was 20.47 ± 8.05 years. The patients consisted of 26 (31.7%) males and 56 (68.3%) females. There was a significant difference in the open bite depth indicator (ODI) of the open bite (P value < 0.001). There was a statistically significant increase in the vertical skeletal parameters - lower facial height (LFH), total facial height (TFH), posterior facial height (PFH), Frankfort-mandibular plane angle (FMA), mandibular-maxillary angle (MMA), and gonial angle in the AOB group compared to the control group. The vertical height of the dentoalveolar segments measured was all significantly increased in the open bite group compared to the control group. CONCLUSION: The results suggest that the skeletal and dental vertical parameters, including ODI of the open bite subjects, varied compared with the non-open bite subjects in the Nigerian population studied and could be used to predict AOB tendency.

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders: A case report and review of literature.

BACKGROUND: The relation between orthodontic treatment and temporomandibular disorders (TMDs) is under debate; the management of TMD during orthodontic treatment has always been a challenge. If TMD symptoms occur during orthodontic treatment, an immediate pause of orthodontic adjustments is recommended; the treatment can resume when the symptoms are managed and stabilized. CASE SUMMARY: This case report presents a patient (26-year-old, female) with angle class I, skeletal class II and TMDs. The treatment was a hybrid of clear aligners, fixed appliances and temporary anchorage devices (TADs). After 3 mo resting and treatment on her TMD, the patient's TMD symptom alleviated, but her anterior occlusion displayed deep overbite. Therefore, the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves. After the levelling, the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion. After careful examination of temporomandibular joints (TMJ) position, the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion. Eventually, the improved facial appearance and relatively stable occlusion were achieved. The 1-year follow-up records showed there was no obvious change in TMJ morphology, and her occlusion was stable. CONCLUSION: TMD screening and monitoring is of great clinical importance in the TMD susceptible patients. Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

Predicted and achieved overjet and overbite measurements with the Invisalign appliance: a retrospective study.

OBJECTIVES: To determine whether achieved outcome regarding overjet and overbite matched the predicted outcome following treatment with Invisalign (Align Technology, San Jose, Calif) aligner appliances. MATERIALS AND METHODS: Data including pretreatment, predicted and achieved overjet, and overbite measurements provided by Align's digital treatment facility, ClinCheck Pro, were evaluated. Descriptive statistics, Mann-Whitney U-test, and Wilcoxon rank-sum intraclass correlation (ICC) test results were calculated. RESULTS: From an initial sample of 600, 355 adult patients satisfied the inclusion and exclusion criteria. ICC scores for data input were excellent. Median (interquartile range [IQR]) age was 30.14 (23.33, 39.92) years and most (n = 259; 72.95%) were women. Almost one-third (n = 101; 28.45%) had undergone extraction as part of their treatment. More aligners were prescribed in the initial digital treatment plan for patients (median, 44; IQR: 35, 51.5; minimum, 17; maximum, 92) undergoing extractions as part of their orthodontic treatment than those who were not (median, 24; IQR: 18.25, 32; minimum, 13; maximum, 85) (P < .0001). Planned changes in overjet differed significantly from achieved outcomes (P < .001). Planned increases in overbite resulted in up to more than twice (222.72%) as much increase than predicted. Planned reduction of overbite achieved 8.69% of its predicted reduction in extraction cases. CONCLUSIONS: Achieved overjet and overbite measurements differed significantly from the predicted outcomes at the end of an initial sequence of aligners. Planned increases in overbite resulted in greater overbite correction than predicted, particularly in extraction cases. Planned overbite reduction was challenging, especially in patients with extractions.

The effect of vertical skeletal proportions on overbite changes in untreated adolescents: a longitudinal evaluation.

OBJECTIVES: To evaluate the change in overbite within an untreated cohort from 9 to 18 years of age and to compare age-related changes in overbite depth based on vertical skeletal proportion. MATERIALS AND METHODS: Lateral cephalograms were obtained from the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection Project. All cephalometric outcome measures were assessed at ages 9-11 (T1), 13-15 (T2), and 17-19 (T3) years. Generalized estimating equation (GEE) regression models were fit to examine the effect of MP-SN on overbite adjusted for age and gender. RESULTS: A total of 130 subjects from the Denver, Bolton Brush, and Oregon Growth Studies were included. Overbite was relatively constant from T1 to T3 irrespective of facial type, with a minor decrease (0.15 mm) being observed overall. There was a transient increase between T1 and T2 (0.31 mm) that was canceled out by changes during later adolescence. Based on the GEE regression model adjusted for time and gender, a minor but statistically significantly greater reduction in overbite arose as MP-SN increased (coefficient = -0.080; 95% confidence interval -0.12, -0.04; P < .01). CONCLUSIONS: In hyperdivergent subjects, a marginal decrease in overbite was observed from 9 to 18 years of age, with a transient increase from the period spanning 9-11 years to 13-15 years, which was negated in later adolescence. There are limited data to suggest that observation of vertical growth is required in most patients with marginally increased vertical facial proportions in the juvenile and pubertal phases.

Predicted overbite and overjet changes with the Invisalign appliance: a validation study.

OBJECTIVES: To investigate whether the predicted changes in overbite (OB) and overjet (OJ) in Align Technology's (Santa Jose, Calif) digital treatment plan for the prescribed course of treatment with the Invisalign appliance were consistent with those same changes in OB and OJ measured with the Geomagic Control X (Geomagic US, Research, Triangle Park, NC) metrology software system. MATERIALS AND METHODS: Geomagic Control X software was used to determine OB and OJ differences between the pretreatment and predicted outcome. STL files for patients satisfying inclusion criteria and undergoing nonextraction orthodontic treatment with the Invisalign appliance. The differences were compared, using the Bland-Altman analysis, to the corresponding data provided by Align Technology's digital treatment-planning interface, ClinCheck. RESULTS: Data regarding 76 adult patients who satisfied strict inclusion criteria were assessed. The Shapiro-Wilks test indicated normality (P > .05). The Bland-Altman analysis showed high levels of agreement between the two measurements, with a bias range of -0.131 to 0.111 for OB and -0.393 to 0.03 for OJ recorded. CONCLUSIONS: Clinicians and researchers can be confident that measurement data provided by Invisalign's ClinCheck digital treatment-planning facility concerning OB and OJ changes from the initial to the predicted treatment outcome are valid.

Does age influence deep overbite correction with Invisalign? A prospective study evaluating mandibular incisor intrusion in adolescents vs adults.

OBJECTIVE: To compare the accuracy of mandibular incisor intrusion with Invisalign (Align Technology, Santa Clara, Calif) in adolescents to that in adults. MATERIALS AND METHODS: This prospective clinical study included 58 patients treated with either Invisalign Teen or Invisalign Full. Mandibular central and lateral incisors were measured on digital models created from intraoral scans. Predicted values were determined by superimposing the initial and final ClinCheck models, and achieved values were determined by superimposing the initial ClinCheck models and the digital models from the final scans. Individual teeth were superimposed with a best-fit analysis and measured using Compare software (version 8.1; GeoDigm, Falcon Heights, Minn). RESULTS: The mean accuracies of mandibular incisor intrusion were 63.5% in adolescents and 45.3% in adults, and this difference was statistically significant. The amounts of achieved intrusion were 1.7 mm in adolescents and 0.9 mm in adults, and this difference was also statistically significant. Overall, there was a weak negative correlation between age and accuracy; as age advanced, the accuracy of mandibular incisor intrusion diminished slightly. CONCLUSIONS: Mandibular incisor intrusion with Invisalign is significantly more accurate in adolescents than in adults. Orthodontists could contemplate reducing the degree of overcorrection for mandibular incisor intrusion in adolescents with deep overbites undergoing Invisalign Teen but still implementing the reverse curve of Spee mechanics.