The effects of extraction and nonextraction treatment on the mandibular position

Treatment of Dental Class-II, Division 2 Malocclusion Associated with a Deep Anterior Overbite: A Case Report Orthodontic Camouflage

AIM

This study sought to correct the assessment of orthodontic camouflage treatment to provide a harmonized soft-tissue profile, consistent occlusion, and a pleasant smile.

BACKGROUND

Class-II, division 2 malocclusions can be treated through dental compensation and growth modification methods instead of surgical-orthodontic treatment, which can be determined by the growth and age of the patient.

CASE DESCRIPTION

This case report was of a 14-year-old Chinese female whose chief complaint was crowding of anterior teeth and required treatment for the same. On necessary clinical and radiographical examination, diagnosis of convex facial profile with class-II, division 2 malocclusion was arrived and hence treated with orthodontic camouflage. On treatment completion of 33 months, cephalometric assessment revealed that the anterior maxillary teeth had been successfully intruded and substantially distalized, with a slight counterclockwise rotation of the mandible. The treatment results and profile changes were demonstrated with good patient cooperation.

CONCLUSION

Using a utility arch with orthodontic camouflage treatment can help to reinforce molar anchoring and improve a deep bite in the maxillary dentitions. The patient was treated with the devised treatment plan and acceptable results were obtained with patient satisfaction as recorded after 1 year of follow-up.

CLINICAL SIGNIFICANCE

To correct a maxillomandibular discrepancy, an orthodontist may conduct a process known as camouflage therapy without necessity of surgery. However, patient selection forms a crucial role, and hence systematic arrival of the diagnosis and treatment protocol is a pivotal factor.

Evaluating the Lower Anterior Facial Height in Patients Treated with Extraction Versus Non-extraction Fixed Mechanotherapy: “A Systematic Review and Meta-analysis”

Objective:

The objective of this study was to evaluate the effects of the four first premolars extraction compared with a non-extraction treated control group on the lower anterior facial height.

Methods:

Electronic search was conducted on PubMed, Cochrane, Scopus, Lilacs, Scielo, clinical trials, and opengrey.eu databases; only article published in English were included. The eligibility criteria were extraction of four first premolars compared with a non-extraction control group treated with fixed mechanotherapy. Anterior Nasal Spine to Menton (ANS-Me) (mm) was taken as the primary outcome; Frankfurt mandibular plane angle (FMA) and Nasion to Menton (N-Me) were selected as secondary outcomes. Non-randomized Studies-of Intervention (ROBINS-I) tool was used for the quality assessment and risk of bias. Heterogeneity was analyzed using statistical tests, including chi-squared-based Q-statistic, tau-square, and I-squared statistics. Review Manager was used for quantitative assessment and meta-analysis.

Results:

Five retrospective studies were included for quantitative assessment and three were included in the meta-analysis due to certain missing data. Extraction of four first premolars did not affect both primary and secondary outcomes with P = .65, P = .93, and P = .91, respectively, for ANS-Me, FMA, and N-Me.

Conclusion:

This review and meta-analysis concluded that there was no statistically significant effect of extraction of four first premolars on lower anterior facial height.

Considerations for vertical control with microimplants in a idiopathic condylar resorption patient: A case report

Idiopathic condylar resorption (ICR) is a rare, destructive temporomandibular joint disease characterised by progressive resorption of the condyles. This case report presents a record of an orthodontically treated patient with ICR with favourable posttreatment remodelling of the condyles. An 18-year-old woman sought treatment for ICR. A severe Class II high-angle facial pattern with resorption of bilateral condyles was evident. The treatment plan was determined after careful examination of condylar radiographs and comprised forward rotation of the mandible through full-arch intrusion with microimplants after extraction of the four premolars. The treatment was completed in 35 months, and the patient was noted to have a straight profile, good interdigitation and slightly increased condylar volume. Two years after retention, the condyles were stable, and the patient's profile and occlusion remained acceptable despite a mild relapse of the mandibular position. ICR was successfully corrected with orthodontic treatment. Counter-clockwise mechanics applied during the ICR remission period not only improved facial aesthetics but were also suitable for condylar unloading.

Dissipating tooth-mass discrepancy caused by a set of mandibular incisor anomalies

Dental anomalies are complicating factors of orthodontic treatment, especially when 1 or more anterior teeth are affected. In this case report, a girl, aged 12.5 years with a retrognathic chin; number, size, and position anomalies of the mandibular incisors; and bilateral Class I molar relationship sought orthodontic treatment. Tooth-size ratio discrepancy was dissipated without extraction or prosthetic rehabilitation, and the initial molar relationship was maintained, as well as the straight soft tissue profile. Tipping of maxillary and mandibular incisors, crown torque of canines, restoration of anomalous incisor, and maxillary interproximal enamel reduction were key points for successful treatment. After 18 months, the orthodontic records showed stable results, excellent static and functional occlusion, and good smile esthetics and facial appearance, in addition to a high degree of patient satisfaction with the achieved results.

Mesiodistal angulation of posterior teeth in orthodontic patients with different facial growth patterns

Background. Mesiodistal and buccolingual angulations of teeth are variable in different malocclusion classes. This study aimed to assess the mesiodistal angulation of posterior teeth in orthodontic patients with vertical, normal, and horizontal facial growth patterns. Methods. This descriptive, cross-sectional study evaluated 150 lateral cephalograms of orthodontic patients. According to cephalometric analysis, facial growth patterns were divided into three groups of normal, horizontal, and vertical (n=50). The angulation of maxillary and mandibular posterior teeth was then measured. Data were analyzed using SPSS 22. Results. The results showed an increase in the mean angle of maxillary and mandibular posterior teeth relative to palatal and mandibular planes in patients with a vertical facial growth pattern. Conversely, their angulation decreased relative to the bisected occlusal plane (BOP). The angulation of posterior teeth decreased relative to palatal and mandibular planes and increased relative to the occlusal plane with an increase in overbite. The mean angle of all maxillary teeth relative to the palatal plane was significantly greater in open bite patients compared to normal and deep bite patients. This value in patients with normal bite was significantly greater than that in deep bite patients (P<0.05). Conclusion. The current results revealed that in patients with a vertical growth pattern, all the posterior teeth had a forward inclination. Conversely, in patients with a horizontal growth pattern, the teeth had a backward inclination.

Common errors observed at the American Board of Orthodontics clinical examination

The American Board of Orthodontics has developed tools to help examinees select patients to be used for the Board examination. The Case Management Form can be used to evaluate aspects of a patient's treatment that cannot be measured by other tools. The Case Management Form is a structured treatment-neutral assessment of orthodontic objectives and outcomes associated with a patient's treatment. Despite the availability of this form, examiners continue to see problems, including lack of attention to finishing details, inappropriate treatment objectives, excessive proclination of mandibular incisors due to treatment mechanics, excessive expansion of mandibular intercanine width, closing skeletal open bite with extrusion of anterior teeth leading to excessive gingival display, and failure to recognize the importance of controlling the eruption or extrusion of molars during treatment. In addition, some examinees exhibit a lack of understanding of proper cephalometric tracing and superimposition techniques, which lead to improper interpretation of cephalometric data and treatment outcomes.

Premolar extraction in orthodontics: Does it have any effect on patient's facial height?

Objectives:

Facial esthetics is an important part of the orthodontic treatment. Many cases frequently require premolar extraction, either for relief of crowding or for profile change. Supposedly, extraction provides some vertical reduction. This investigation challenges the clinical effects of such treatment protocols.

Patients and Methods:

This was a retrospective and quasi-experimental study. Records of 60 patients in their post-pubertal age were randomly selected for this study. The criteria for case selection were: Class II Division I malocclusion with either two upper or four upper and lower first premolars extraction. Patients were not vertical-sensitive type of face. Pre- and post-treatment X-rays were scanned and digitized with Dolphin V 10.0 software. The X-rays of both groups were compared based upon the following cephalometric measurements: Lower anterior facial height (LAFH), Me–PP, Pal-MeGe, LAFH/total anterior facial height (TAFH) × 100, upper anterior facial height (UAFH)/TAFH × 100, U6 to PP, L6 to MP, and U6D–PTV.

Results:

In the four bicuspid group, a statistically significant increase was observed in all measurements: 2.53 mm increase in LAFH (P ≤ 0.04), 2.92 mm increase in Me–PP (P ≤ 0.01), 0.65° increase in Pal-MeGe (P ≤ 0.02), 0.66° increase in LAFH/TAFH × 100 (P ≤ 0.01), 1.26 mm increase in U6 to PP (P ≤ 0.02), 1.96 mm increase in L6 to MP (P ≤ 0.002), and 3.06 mm increase in U6D–PTV (P ≤ 0.0001). But a decrease of 0.66° in UAFH/TAFH × 100 (P ≤ 0.01) was observed. In the two bicuspid group, a significant increase was generally recorded: 2.06 mm increase in LAFH (P ≤ 0.05), 1.19° increase in Pal-MeGe (P ≤ 0.02), 1.39 mm increase in L6 to MP (P ≤ 0.002), and 2.37 mm increase in U6D–PTV (P ≤ 0.004).

Conclusions:

The results of this study are indicative of no change in patient's facial height with bicuspid extraction. In fact, extrusive effect of all types of tooth movement mostly overcomes the benefits of “wedging effect concept.”

Long-term mandibular skeletal and dental effects of standard edgewise treatment

INTRODUCTION

The purpose of this investigation was to examine the effect of Tweed edgewise treatment on the expression of mandibular growth in the horizontal direction through maintenance of vertical control.

METHODS

We studied 36 patients who had 4 premolars extracted during treatment. Pretreatment, posttreatment, and postretention records of these patients were matched by age (± 6 months), sex, malocclusion, and treatment interval (± 6 months) to untreated controls from the Bolton-Brush Growth Study Center, Cleveland, Ohio. The cephalograms of the 2 samples were traced, digitized, and analyzed by descriptive cephalometric analysis and detailed regional superimposition.

RESULTS

Tweed edgewise treatment can prevent clockwise rotation but was not observed to enhance the normal forward rotation of the mandible. The mandible did not rotate forward in the treated patients who underwent a greater chin advancement.

CONCLUSIONS

The pattern of skeletal change was favorable both during treatment and in later years. A feature of this effect was an improved pattern of mandibular growth displacement, when mandibular change was compared with maxillary change.

Cephalometric comparison of vertical changes between Begg and preadjusted edgewise appliances

The purpose of this retrospective study was to quantify and compare the vertical dimensional changes in bialveolar dental protrusion patients undergoing extraction of all four first premolars between the preadjusted edgewise appliance (PEA) and the Begg appliance. The cephalometric records of 55 patients (14 males and 41 females) with Class I bimaxillary protrusion were selected and divided into two groups based on the appliance used, i.e Begg or PEA mechanotherapy. To minimize the effects of growth, the subjects were at least in stage VI of skeletal maturation. The mean age was 18.25 ± 3.2 years for the Begg group and 18.03 ± 3.5 years for the PEA group. Skeletal and dental changes were analysed in both groups on lateral cephalograms taken pre- (T1) and post- (T2) treatment. A Student's t-test was used to analyse the treatment changes. Within group results showed a significant increase in face height and extrusion and mesial movement of the upper and lower molars for both groups. However, no significant differences were observed when the groups were compared. A significant correlation was found between the change in lower molar to mandibular plane angle and lower anterior face height for both groups. No significant difference was found when the Begg mechanotherapy was compared to the PEA technique on vertical dimensional changes. It can be speculated that mesial movement of the molars tended to keep pace with their extrusion and negated any bite opening effect with both mechanotherapies.

Surgical correction of a Class II skeletal malocclusion associated with anterior open bite and temporomandibular joint pain

This case report describes the treatment of a 25-year-old woman with anterior open bite, Class II skeletal malocclusion, and a history of temporomandibular joint pain and sounds. She also had significant anteroposterior and vertical discrepancies and a convex profile with protrusive lips. Intraorally, she had an anterior open bite of 3 mm and an overjet of 5 mm. Mandibular surgical rotation, associated with mandibular incisor extraction, was performed to reduce the protrusion, close the open bite, and minimize the temporomandibular joint disorder.

Effects of camouflage treatment on dentofacial structures in Class II division 1 mandibular retrognathic patients

The aims of this study were to determine the changes in the dentofacial structures of Class II division 1 mandibular retrognathic patients treated with bilateral extraction of the upper first premolars, and to compare pre- and post-treatment values with the cephalometric norms of Anatolian Turkish adults. The Class II division 1 subjects included 20 males and 33 females (mean age: 17.08 +/- 1.03 years). All received comprehensive orthodontic treatment using an edgewise appliance and appropriate headgear. Lateral cephalograms were taken at the beginning and end of treatment. Twenty-five (14 linear and 11 angular) measurements were analysed on each radiograph. Each cephalogram was traced and digitized. For statistical evaluation, paired and independent-samples t-tests were performed. When the pre- and post-treatment measurements were compared, statistically significant differences were found for nine of 25 measurements. During treatment the facial axis, U1-SN ( degrees ), U1-NA (mm), U1-NA ( degrees ), H angle and upper lip to E plane measurements decreased, while N-ANS, interincisal angle and upper lip to Steiner S line increased. No statistically significant gender differences were found. Significant improvements were determined in ANS-Me and L1-APo measurements compared with Turkish norms. However, statistically significant deterioration was found in values related to point A, upper incisor and lower lip measurements. The findings demonstrates that camouflage treatment in Class II, mandibular retrognathic subjects has characteristic skeletal, dental and soft tissue effects on the dentofacial complex.

Influence of extraction and nonextraction orthodontic treatment in Japanese-Brazilians with class I and class II division 1 malocclusions

BACKGROUND

The primary objective of this retrospective, longitudinal, cephalometric investigation was to study the influence of extraction and nonextraction orthodontic treatment on the facial height of Japanese-Brazilian children with Class I and Class II Division 1 malocclusions.

METHODS

The sample included 59 mesocephalic patients distributed into 4 groups: group 1: Class I patients treated with 4 first premolar extractions; group 2: Class I patients treated nonextraction; group 3: Class II Division 1 patients treated with 4 first premolar extractions; group 4: Class II Division 1 patients treated nonextraction. The overall initial mean age of the groups was 12.14 years, and all groups were treated with standard edgewise appliances for a mean period of 2.49 years. The pretreatment and posttreatment stage comparison and the intergroup comparison of the treatment changes were conducted between extraction and nonextraction groups in the Class I and Class II malocclusion samples with t tests.

RESULTS

The amounts of changes in the absolute magnitude of posterior and anterior facial heights and in the ratios of lower posterior facial height/lower anterior facial height and lower anterior facial height/total anterior facial height were similar between extraction and nonextraction treatment in both Class I and Class II malocclusions.

Treatment of open bite with microscrew implant anchorage

Open bite treatment with microscrew implant anchorage is discussed in relation to vertical control of the posterior dentoalvelar dimension. Maxillary microscrew implants provided anchorage for intruding the posterior teeth and retracting the anterior teeth; mandibular microscrew implants were used to apply intrusion force distal to the mandibular first molars to prevent mesial tipping of the posterior teeth during space closure. Closing the mandibular plane after intruding the maxillary posterior teeth and bodily mesial movement of the mandibular posterior teeth contributed to facial profile improvement. The efficacy and potency of microscrew implants in open bite treatment are discussed.

The effect of cervical headgear on patients with high or low mandibular plane angles and the "myth" of posterior mandibular rotation

The purpose of this retrospective survey was to compare the magnitude of posterior mandibular rotation during orthodontic treatment with edgewise appliances and cervical headgear in patients with high or low Frankfort-mandibular plane angles (FMA). The files of a private orthodontic practice were searched, and the records of growing patients with Class II Division 1 malocclusion were selected. These were divided into 2 groups, according to FMA: the hypodivergent (FMA < 22 degrees ) or low-angle group consisted of 29 patients with a median FMA of 19.80 degrees, and the hyperdivergent (FMA > 28 degrees ) or high-angle group consisted of 31 patients with a median FMA of 32.70 degrees. All patients had nonextraction treatment with full edgewise appliances (Roth prescription), including second molars, by the same clinician. Cervical headgear and Class II elastics were used, and several patients also had fixed or removable anterior biteplanes for short periods. Pretreatment and posttreatment cephalometric tracings were superimposed on internal basic structures of the mandible. There was no difference in FMA changes between the 2 groups, nor were there statistically significant differences in changes during treatment, with 2 exceptions: the angle SN-GoGn showed a very small (0.86 degrees ) mean differential change between groups, generated mostly by the counterclockwise mandibular rotation of the low-angle patients. This was verified with structural superimpositions to evaluate vertical changes. In addition, posterior face height increase was significantly greater in the low-angle group. Structural superimposition of the mandible after treatment showed marked counterclockwise rotations in relation to the anterior base of the skull in both groups, with the high-angle group rotating significantly less. On average, growth and treatment resulted in improvements in the high-angle patients but aggravated the problems in the low-angle patients with deep bite malocclusions.

Buccolingual inclinations of posterior teeth in subjects with different facial patterns

This study compared the buccolingual inclination of the posterior teeth in subjects with a horizontal growth pattern (proportionally short lower anterior face height) with that of subjects with a vertical growth pattern (proportionally long lower anterior face height). Seventy subjects with permanent dentition were divided into 2 groups. Group I comprised 35 subjects (16 male, 19 female) with Class II Division 2 malocclusion with a horizontal growth pattern, and group II comprised 35 subjects (15 male, 20 female) with a vertical growth pattern. Buccolingual inclinations of the first molar and second premolar were indirectly assessed on photocopies of buccolingual sections of these teeth by measuring their occlusal surface (represented by an imaginary line connecting the lingual and buccal cusps) inclination. The groups were compared with t tests (P <.05). The maxillary posterior teeth of subjects with a vertical growth pattern had a significantly greater buccal inclination compared with those of subjects with a horizontal growth pattern. However, there were no statistically significant differences in the inclinations of the mandibular posterior teeth between the 2 groups.

Class II treatment success rate in 2- and 4-premolar extraction protocols

This study compared the occlusal success rate of Class II orthodontic treatment results with either 2- or 4-premolar extraction protocols. Group 1 comprised dental study models of 81 patients treated with 2 premolar extractions, and group 2 comprised dental study models of 50 patients treated with 4 premolar extractions. The initial mean ages of the groups were 13.9 and 12.9 years, respectively. Grainger's treatment priority index (TPI) was used to assess the initial and final occlusal status of each patient. Individual variables, such as maxillary canine anteroposterior positioning, overjet, and overbite improvements were also evaluated. Independent t tests were used to compare the variables at the pretreatment and posttreatment stages and their improvement between the groups. The results showed a statistically significant difference in most of the variables and in their improvement at the end of treatment between the groups. The variables showed a better dental relationship in group 1, and the improvements in group 1 were larger than in group 2. Treatment of Class II malocclusion with 2 premolar extractions gives a better occlusal success rate than treatment with 4 premolar extractions.

Longitudinal assessment of vertical and sagittal control in the mandibular arch by the mandibular fixed lingual arch

The purpose of this investigation was to determine and quantify vertical changes in the position of the mandibular molars while maintaining arch perimeter with a fixed lingual arch. Twenty-three patients with a mean age of 10.4 +/- 0.6 years were selected to receive fixed lingual arch treatment as the only appliance in the mandibular arch. Average treatment time was 18.3 +/-+/- 0.6 months. Longitudinal records for 12 and 24 months of 24 individuals matched by ethnic origin, age, gender, and mandibular plane inclination were used as controls. Pretreatment and posttreatment cephalograms were used to determine positional changes. Statistically significant differences between the fixed lingual arch and control groups were found. The results of this investigation indicated that the mandibular fixed lingual arch is a useful tool to control the vertical development of the mandibular molars.

Early treatment of vertical skeletal dysplasia: the hyperdivergent phenotype

This cephalometric study evaluated an early nonextraction treatment approach for patients with severe vertical skeletal dysplasia and maxillary transverse constriction. Thirty-eight patients, 8.2 years (+/- 1.2 years) of age, were treated for 1.3 years (+/- 0.3 years) with lip seal exercises, a bonded palatal expander appliance, and a banded lower Crozat/lip bumper. The bonded palatal expander functioned as a posterior bite-block and was fixed in place throughout treatment. Patients with poor masticatory muscle force (79%) wore a high-pull chincup 12 to 14 hours per day. A control group was matched for age, sex, and mandibular plane angle. Treatment changes for chincup and other patients were not significantly different. Overall, treatment significantly enhanced condylar growth, altered it to a more anterosuperior direction, and produced "true" forward mandibular rotation 2.7 times greater than control values. Posterior facial height increased significantly more in patients than in controls, and the maxillary molars showed relative intrusion. In treated patients, articular angle increased, gonial angle decreased, and the chin moved anteriorly twice as much as in controls. Treatment also led to increased overbite and decreased overjet. Maxillary and mandibular expansion did not cause the mandibular plane angle to increase. The 16 patients with openbite malocclusions exhibited a 2.7 mm increase in overbite and inhibition of growth in anterior lower facial height. The aggregate of individual changes demonstrates a net improvement, indicating this treatment approach may be suited for hyperdivergent patients with skeletal discrepancies in all 3 planes of space.

The influence of extraction orthodontic treatment on craniofacial structures: evaluation according to two different factors

The purpose of this study was to evaluate the effects of different growth pattern and treatment type factors on craniofacial structures in cases treated with fixed mechanics and premolar extractions. A total of 41 cases with a mean chronologic age of 14 years 7 months and skeletal age of 14 years 6 months was included in the study. These cases were treated with fixed Edgewise mechanics and with extraction of four first premolars. The growth pattern factor was assessed in two levels as mesiodivergent and hyperdivergent, and the treatment type factor was assessed as with and without headgear. The results were analyzed by two-way analysis of variance. In the assessment of differences between the two types of growth patterns at the end of treatment; the changes in N-ANS and N-M were found to be statistically significant (P <.05). In comparison of cases treated with and without headgear, changes in SNA and ANB angles were found to be statistically significant (P <.01). Interaction was found to be nonsignificant for all measurements. It was observed that treatment with fixed appliances and premolar extractions does not change significantly the growth pattern.