Proclination Of Upper Incisors Research Articles

Effects of upper-molar distalization using clear aligners in combination with Class II elastics: a three-dimensional finite element analysis

IntroductionThe effects of upper-molar distalization using clear aligners in combination with Class II elastics for anchorage reinforcement have not been fully investigated yet. The objective of this study is to analyze the movement and stress of the whole dentition and further explore guidelines for the selection of traction methods.MethodsThree-dimensional (3D) finite element models are established to simulate the sequential molar distalization process, including the initial distalization of the 2nd molar (Set I) and the initial distalization of the 1st molar (Set II). Each group set features three models: a control model without Class II elastics (model A), Class II elastics attached to the tooth by buttons (model B), and Class II elastics attached to the aligner by precision cutting (model C). The 3D displacements, proclination angles, periodontal ligament (PDL) hydrostatic stress and alveolar bone von Mises stress in the anterior area are recorded.ResultsIn all of the models, the maxillary anterior teeth are labial and mesial proclined, whereas the distal moving molars exhibit distal buccal inclination with an extrusion tendency. With the combination of Class II elastics, the anchorage was effectively reinforced; model C demonstrates superior anchorage reinforcement with lower stress distribution in comparison with model B. The upper canines in model B present an extrusion tendency. Meanwhile, the mandibular dentition in models B and C experience undesired movement tendencies with little discrepancy from each other.ConclusionsClass II elastics are generally effective for anchorage reinforcement as the upper-molar distalization is performed with clear aligners. Class II elastics attached to an aligner by precision cutting is a superior alternative for maxillary anchorage control in cases that the proclination of upper incisors and extrusion of upper canines are unwanted.

Combined Orthodontic and Surgical Management for Treatment of Severe Class III Malocclusion with Anterior and Posterior Crossbites

Severe class III malocclusion can be a great challenge, especially in adult patients. This case report describes an adult patient with severe skeletal class III malocclusion and with an obvious maxillary deficiency and mandibular excess causing both anterior and posterior crossbites in addition to a shift in the upper and lower midlines to the left concerning the facial midline. This was complicated by compensatory mechanisms such as the proclination of upper incisors and retroclination of lower incisors. Decompensation of the upper and lower arches was performed combined with upper arch expansion to relieve crowding in the upper arch and correct the posterior crossbite. This was followed by double jaw surgeries, including Le Fort I osteotomy in the maxilla and bilateral sagittal split osteotomy (BSSO) in the mandible. Orthodontic finishing procedures were then used to correct any other dental discrepancies. Remarkable esthetic and functional results were achieved with high patient satisfaction.

Analyzing the contribution of the dental components and abnormal habits in the development of dental open bite in growing children: A cross sectional study

Dental Open bite malocclusion could be caused by either aberrant dental development or abnormal oral habits. Aim: The current study aimed at analyzing the causative factors of dental open bite in a group of growing female subjects having normal vertical growth pattern. Materials and methods: Dental measurements were performed on lateral cephalometric radiographs and study models of 176 growing females with an age range of 9-12 years and average vertical skeletal growth pattern. They were divided into 2 equal groups; group 1 consisted of subjects with dental open bite and group 2 consisted of subjects with normal overbite. The existence of oral habits was also recorded for each patient in the 2 groups Results: The flattened curve of Spee and the proclination of the upper incisors were statistically higher in the open bite group. The ratios of occurrence of thumb sucking, tongue thrusting and mouth breathing habits in the open bite group were statistically higher than in the control group. Conclusions: The flattened curve of Spee, and the proclination of upper incisors, together with some oral habits should be cautiously addressed by the orthodontic clinician during the treatment planning process of open bite malocclusions. This could help in resolving the causative factor of the malocclusion.

A correlative study to evaluate the effect of various skeletal and dentoalveolar parameters on smile esthetics in different malocclusion groups

Introduction: The smile is one of the most effective means by which people convey their emotions and from a social standpoint, it is viewed frontally more often than in profile. Smiles can be either posed or spontaneous. Peck and Peck classified smiles as Stages I and II, and Ackerman et al . classified smiles into two basic types: the social smile and the enjoyment smile. Each type involves a different anatomic presentation of the elements of the display zone. Smile characteristics are determined by the interplay of static and dynamic relationships between the dentoskeletal and soft-tissue components of the face. Hence, a study was planned to understand the influence of various skeletal and dentoalveolar parameters on smile esthetics in different malocclusion groups. Materials and Methods: Sixty subjects in the age range of 17–25 years were selected and skeletally divided into Groups I and II on the basis of beta angle, ANB angle, and Wits appraisal. Group II was further subdivided into two groups on the basis of Angle's classification of the malocclusion. Various skeletal and dental parameters were measured on cephalogram and smile measurements were made on facial photographs in Adobe Photoshop. Various statistical tests were applied for assessment and comparison of various skeletal and dentoalveolar parameters and their correlation with smile esthetics were in different malocclusion groups. Results: Upper lip length was maximum in Class II div 2 malocclusion patients and least in Class I malocclusion patients. It was maximum in horizontal growth pattern patients. It decreased with the increase in proclination of upper incisors. Maxillary incisal display at rest and smile was maximum in Class II div 1 malocclusion patients and least in Class II div 2 malocclusion patients. It was maximum in vertical growth pattern individuals. It increased with the increase in proclination of upper incisors. A similar tendency was shown by the Morley ratio and modified smile. Lip competency was maximum in Class II div 2 patients and minimum in Class II div 1 patients. It was maximum in horizontal growth pattern patients. Proclination of the incisors decreased the lip competency. Conclusions: Different skeletal patterns exhibit their characteristic smile features. Orthodontic treatment should be planned considering the correlation of skeletal and dental effects on smile esthetics.

Maxillary protraction by reverse headgear treatment in patients with unilateral cleft lip and palate: A cephalometric evaluation

Objective: This investigation was undertaken with the primary aim of evaluating the effects of reverse headgear therapy in patients with unilateral cleft lip and palate (UCLP) using lateral cephalograms and to compare the results of the reverse headgear treatment in these patients with other patients with UCLP who did not receive any orthopedic/orthodontic treatment. Materials and Methods: The treated group comprised 17 patients (13 male, 4 female; mean age 9.28 ± 2.78 years) with repaired complete UCLP and untreated group consisted of 5 subjects (4 male, 1 female; mean age 8.25 ± 2.25 years) with repaired complete UCLP. All patients in treated group received maxillary protraction with a Delaire type reverse headgear along with a customized intraoral splint worn for 16–18 h daily with force in the range of 420–480 g. Subjects in the untreated group did not receive any orthopedic/orthodontic treatment. Average treatment/observation period was 11.62 months for the treated and 12.40 months for the untreated group. Changes were evaluated at the end of the treatment and observation period by comparing pre- and post-lateral cephalograms. Results: Treatment effects of reverse headgear therapy were significant for anterior positioning of maxilla, clockwise rotation of mandible, proclination of upper incisors, and forward movement of upper molars as shown by cephalometric analysis. The untreated group did not show any significant changes, for the same measurements. Conclusions: Reverse headgear treatment is an effective method of improving the maxillomandibular relationship in patients with UCLP.

Incisor inclination and perceived tooth colour changes.

Social attractiveness is influenced by a variety of different smile-related factors. We evaluated whether the degree of upper central incisor proclination can result in tooth colour change. Forty young adult subjects (20-25 years) in good health with a complete sound dentition were selected. The subjects were seated in standardized light conditions with an above-directed light source. Their natural head position was stated as 0 degrees. To mimic the range of possible anterior torque movements they were asked to tilt their heads upward +15 degrees (upward tilting) and downward -15 degrees (downward tilting). Frontal macro photographs, parallel to the Frankfort plane of the patient's natural head position were taken at the three head angulations (+15, 0, and -15 degrees ). Photographs were analysed for colour differences at the centre of the incisor clinical crowns with a CIE L*a*b* colour model based software. A paired t-test was used to test for significance between each value for each inclination. Differences were found between the CIE L*a*b* colour values for: upward tilting, downward tilting, and -15 to +15 degrees (total tilting) except for b* values for downward tilting. As the inclination of the subject's head changed downward, the upper incisors were retroclined and the CIE L*a*b* values indicated a darker and less green but redder colour component. As the inclination of the subject's head changed upwards the upper incisors were proclined and the L*a*b* values indicated a lighter and less green and yellow but redder and bluer colour component. Proclination of upper incisors caused lighter tooth colour parameters compared to retroclined incisors and colour changes. Orthodontic change of upper incisor inclination may induce alterations on how tooth colour is perceived.

Facial asymmetry correction with surgical-orthodontic treatment. Case report

A case report of a 19-year-old female patient who attendedthe Orthodontics Department, Faculty of Dentistry, NationalAutonomous University of Mexico without any apparent pathological data is hereby presented. Upon interrogation, the patient referred to have had a previous surgical replacement of the left ear lobe. Physical examination revealed a severe facial asymmetry with mandibular deviation to the left side, straight profile, upper lip retrusion and gibbous nose. Intraorally the patient showed crowding, non-coincident dental midlines, squared arches and class III molar and canine relationship with left crossbite. Radiographically all dental organs were present and mandibular asymmetry could beobserved. Cephalometric analysis showed skeletal a class III due to maxillary retrusion, vertical growth pattern, left laterognathia, proclination of upper incisors and upper lip retrusion. Treatment consisted of three phases: 1 presurgical orthodontics with 0.018” slot Alexander appliances and an archwire sequence suitable to the problem that the patient presented. Subsequently, surgical phase 2 was initiated with a sagittal osteotomy for bilateral laterognathia correction. During phase 3, postsurgical orthodontics, the case was detailed, muscular patterns were corrected and the occlusion was settled. Treatment was completed in 36 months. The profile and facial harmony were improved, the positive smile was maintained and the crossbite corrected. Bilateral canine and molar class I was obtained, the dental midlines were centered and arch form was improved as were the overbite and overjet.

Orthopedic Treatment of Skeletal Class III Malocclusions With Maxillary Deficiency

ABSTRACT Objective: The purpose of this study was to compare the treatment effects of a double-plate appliance (DPA) and a double-plate appliance and facemask combination (DPA-FM) in correcting Class III malocclusions. Materials and Methods: The material consisted of lateral cephalometric radiographs of 40 children with skeletal and dental Class III malocclusion. In the first treatment group, 13 patients (mean age: 10 years 3 months) were treated with DPA. In the second treatment group, 15 patients (mean age: 10 years 9 months) were treated with DPA-FM. In the third group, 12 patients (mean age: 10 years 6 months) were observed without treatment for 9 months. Statistical evaluation was made by ANOVA, Duncan, and paired t tests. Results: The increases in SNA and ANB angles were significantly greater in the DPA-FM group than in the DPA group. The proclination of upper incisors (U1/NA) and retroclination of lower incisors (L1/NB) were significantly greater in the DPA group than in the DPA-FM group. The retro...

Camouflage treatment of skeletal Class III malocclusion with multiloop edgewise arch wire and modified Class III elastics by maxillary mini-implant anchorage

To evaluate the effect of the multiloop edgewise arch wire (MEAW) technique with maxillary mini-implants in the camouflage treatment of skeletal Class III malocclusion. Twenty patients were treated with the MEAW technique and modified Class III elastics from the maxillary mini-implants. Twenty-four patients were treated with MEAW and long Class III elastics from the upper second molars as control. Lateral cephalometric radiographs were obtained and analyzed before and after treatment, and 1 year after retention. Satisfactory occlusion was established in both groups. Through principal component analysis, it could be concluded the anterior-posterior dental position, skeletal sagittal and vertical position, and upper molar vertical position changed within groups and between groups; vertical lower teeth position and Wits distance changed in the experimental group and between groups. In the experimental group, the lower incisors tipped lingually 2.7 mm and extruded 2.4 mm. The lingual inclination of the lower incisors increased 3.5°. The mandibular first molars tipped distally 9.1° and intruded 0.4 mm. Their cusps moved 3.4 mm distally. In the control group, the upper incisors proclined 3°, and the upper first molar extruded 2 mm. SN-MP increased 1.6° and S-Go/N-ME decreased 1. The MEAW technique combined with modified Class III elastics by maxillary mini-implants can effectively tip the mandibular molars distally without any extrusion and tip the lower incisors lingually with extrusion to camouflage skeletal Class III malocclusions. Clockwise rotation of the mandible and further proclination of upper incisors can be avoided. The MEAW technique and modified Class III elastics provided an appropriate treatment strategy especially for patients with high angle and open bite tendency.

Preliminary study of non-surgical treatment of severe Class III malocclusion in 18 patients of 12-20 years old

To analyze effects of non-surgical treatment on subjects of 12-20 years old with severe skeletal Class III deformity and to directly evaluate dental and facial profile changes. Eighteen patients with severe skeletal Class III malocclusion (male 5, female 13), diagnosed as indication for orthognathic surgery, were included in the study. The average age was 14.6 +/- 2.5 years old., with age range from 12 years old to 20 years old. 12 cases were treated with Tip-Edge straight-wire technique and 6 cases with Begg light wire technique. The average treatment time was 2.5 +/- 0.8 years. The selection criteria included: (1) mesial or superior mesial Class III molar relationship, with maxillary first molar occlude the buccal groove of the mandibular second molars (2) no mandibular shift (3) ANB < -1.5 degrees (4) high angle cases with average value of SN-MP 34.9 degrees +/- 5.9 degrees, 4 cases present with openbite (5) concave facial profile (6) originally classified as surgery cases. Lateral cephalometric films taken at the beginning and the end of the treatment were analyzed with traditional cephalometric analysis. The arithmetic mean (Mean) and standard deviation (SD) were calculated for each variable. Paired t-test was performed to evaluate the significant treatment change. Normal overjet and overbite were established with proclination of upper incisors and retroclination of lower incisors. Inclination of upper incisors was increased 5.9 degrees when measured with the angle of upper incisor to SN plane (P < 0.01). Inclination of lower incisors was decreased 6.6 degrees when measured with the angle of lower incisor to mandibular plane (P < 0.001). Negative value of the distance difference of upper lip and lower lip to Sn-Pg' at the beginning of treatment changed to positive value with significant difference (P < 0.001). Successful treatment effects could be obtained with non-surgical therapy in severe skeletal Class III malocclusion in permanent dentition. Remarkable soft-tissue change was noted after the treatment and concave facial profile changed to straight profile.

Long-term effect of the chincap on hard and soft tissues.

The short- and long-term effects of the chincap used in combination with a removable appliance to procline upper incisors were analysed cephalometrically in 23 patients with Class III malocclusions. The overall changes were compared with growth changes in a closely matched control sample of untreated Class III patients. There was no evidence that the chincap retarded growth of the mandible. During treatment, there was an increase in mandibular length and facial height. The lower incisors retroclined and the upper incisors proclined. The incisor relationship was corrected. Soft tissue changes included an increase in nasolabial angle and improvement in soft-tissue profile, including the nose. Skeletal post-treatment changes included further mandibular growth associated with an increase in angle SNB and Wits measurement. Facial height also increased significantly. The Class I overjet was maintained, although slightly diminished. The soft tissue nose, upper and lower lip, and chin moved anteriorly, and the nasal tip and chin moved inferiorly. At the end of the study period there were no significant skeletal or soft tissue differences between the treated and control groups. The only significant contrasts were in the overjet and the overbite. Chincap therapy combined with an upper removable appliance to procline the upper incisors is effective in producing long-term correction of the incisor relationship by retroclination of lower incisors, proclination of upper incisors, and redirection of mandibular growth in a downward direction. The direction of growth at the chin is maintained subsequent to treatment, as are the changes in incisor inclination, although in diminished form. There are corresponding improvements in the soft tissue profile.

Early Treatment of pseudo Class III malocclusion in mixed dentition

Aim To illustrate a simple effective method for early treatment of pseudo Class III in the mixed dentition and to highlight the advantages of early treatment by showing a 4-year follow-up of the treatment effects. Subjects Twenty-one consecutive southern Chinese patients with a mean age of 9.6 years were included in the early treated group with pseudo Class III malocclusion. Methods Lateral cephalometric films taken at the beginning and at the end of treatment were analysed. The arithmetic mean and standard deviation (SD) were calculated for each cephalometric variable and paired t-tests were performed to assess the statistical significance of the treatment effects. Results Anterior crossbites and mandibular displacements were eliminated after the treatment. The angulation of the upper incisors to the maxillary plane showed an increase by a mean of 9.5° (P < 0.001), while the angulation of the lower incisors to the mandibular plane showed a decrease by a mean of 4.9° (P < 0.001). Conclusion In pseudo Class III malocclusion, proclination of upper incisors and/or retroclination of lower incisors with simple fixed appliances contribute to the correction of anterior crossbite and the elimination of mandibular displacement. Proclination of upper incisors, use of Leeway space and arch width increase provide space required for the eruption of the premolars and canines.

Management of pseudo Class III malocclusion in southern Chinese children.

To illustrate a simple effective method for early treatment of pseudo Class III in the mixed dentition and to highlight the advantages of early treatment by showing a 4-year follow-up of the treatment effects. Twenty-one consecutive southern Chinese patients with a mean age of 9.6 years were included in the early treated group with pseudo Class III malocclusion. Lateral cephalometric films taken at the beginning and at the end of treatment were analysed. The arithmetic mean and standard deviation (SD) were calculated for each cephalometric variable and paired t-tests were performed to assess the statistical significance of the treatment effects. Anterior crossbites and mandibular displacements were eliminated after the treatment. The angulation of the upper incisors to the maxillary plane showed an increase by a mean of 9.5 degrees (P < 0.001), while the angulation of the lower incisors to the mandibular plane showed a decrease by a mean of 4.9 degrees (P < 0.001). In pseudo Class III malocclusion, proclination of upper incisors and/or retroclination of lower incisors with simple fixed appliances contribute to the correction of anterior crossbite and the elimination of mandibular displacement. Proclination of upper incisors, use of Leeway space and arch width increase provide space required for the eruption of the premolars and canines.

Postpubertal growth and development of the face in unilateral cleft lip and palate as compared to the pubertal period: A longitudinal study: Smahel Z.; Mullerova Z.J. Craniofac. Genet. Dev. Biol. (CZE) (1996) 16/3 (182–192)

X-ray cephalometry was used for the assessment of 22 boys and 23 girls with complete unilateral cleft lip and palate who were treated with the same surgical method. They were examined at the age of 10 years and in adulthood. In the group of 13 boys and 15 girls, examined also at the age of 15 years, were analysed intersexual differences of facial growth and development during the postpubertal period and the results were compared with those obtained during the pubertal period. The data showed that in boys facial growth persists after the age of 15 years and in the region of the upper face attains about half the values recorded in the period of puberty, while mandibular growth attains almost the same values as during puberty. In girls the growth is almost terminated but for the lower jaw, where it is still significant though several times slighter than during puberty. In both sexes there is only a minimum growth of maxillary depth and of upper lip height during the postpubertal period, as well as during the pubertal period. The highest growth rate shows the depth of the nose. Because of the intersexual differences in the amount of postpubertal growth, developmental changes in facial configuration do not occur in girls during this period, while in boys a further deterioration of maxillary protrusion, of sagittal jaw relations, and of the upper lip prominence continues, as well as an increase of the flattening of the face. In contrast to the pubertal period in both sexes, a proclination of upper incisors and an improvement of overjet was not attained. Contrary to the pubertal period, in the postpubertal period, intersexual differences in the amount of growth and of the developmental changes in the shape and position of facial characteristics were recorded. Therefore during studies of the growth and development of the face, it is not possible to pool both sexes without some reservations. This holds true in particular in the postpubertal period.

Facial Growth and Development in Unilateral Cleft Lip and Palate during the Period of Puberty: Comparison of the Development after Periosteoplasty and after Primary Bone Grafting

X-ray cephalometry was used in studies of facial growth and development carried out in 32 males with complete unilateral cleft lip and palate. They underwent primary periosteoplasty and were examined at the ages of 10 and 15 years. The results were compared with the development of the face in a longitudinal study of 20 males with the same type of cleft who were operated with a primary bone graft. The series with periosteoplasty showed a more marked proclination of the upper dentoalveolar component with the restoration of a positive overjet, as compared to a persistent anterior crossbite in the males with bone grafts. The lower jaw showed a larger protrusion, while individuals with bone grafts were characterized at the ages of 10 and 15 years by a larger posterior rotation of the mandible. The growth of the maxilla did not differ between series. In both series, there was a marked reduction in the growth of maxillary depth and of upper lip height, while the highest growth rate showed parameters of nasal prominence. An increasing mandibular protrusion and maxillary retrusion resulted in an impairment of sagittal jaw relations and in the flattening of the face, both of which occurred in almost all patients. The rotation of the lower jaw was not correlated with either the convexity of the face, sagittal jaw relations, or an overjet. The independence of developmental changes of selected characteristics at their initial state documented the impossibility of predicting the development of the face on the basis of a single x-ray examination at a given stage of development. Fixed appliances promoted a more marked proclination of upper incisors and the alveolar process than removable appliances, but they exerted no direct action on the other facial parameters studied.

Early treatment of Class III incisor relationship using the chincap appliance.

Twenty-three patients (10 male, 13 female), with Class III relationships of the incisor teeth at the mixed dentition stage, were treated with the chincap appliance associated, where appropriate, with an upper removable appliance to procline upper incisors and to free the occlusion. Cephalometric analyses at the beginning and at the end of active treatment were compared with those in a carefully matched untreated control group selected from the Belfast Growth Study. At the beginning of treatment patients differed significantly from the controls in the SNB was larger, ANB was negative, Wits' analysis was negative, and the intermaxillary angle significantly reduced. The overjet was reversed, the lower incisors were ahead of A-Po, and the upper lip was far behind the E line. Significant changes brought about by the treatment were improvement in the Wits' relationship (but there was no significant change in the ANB angle), increases in the intermaxillary angle and lower facial height, improvement in the overjet, proclination of upper incisors and retroclination of lower incisors, backward movement of the lower incisors in relation to A-Po, and backward movement of the lower lip. The efficacy of the chincap appliance can be attributed to retroclination of lower incisors and downward movement of the mandible which may improve the jaw relationship without affecting the ANB angle. There were marked changes in the lip posture.

Spontaneous Changes in the Incisor Relationship following Extraction of Lower First Permanent Molars

The spontaneous changes in overbite, overjet and incisor inclinations during the first year following extraction of both lower first permanent molars were investigated in 43 (19M, 24F) patients whose ages ranged from 8–14 years at the time of extraction. The changes were measured on 90° left lateral cephalometric radiographs taken before extraction and approximately 12 months later. On average, there was a tendency for the overbite and overjet to increase with associated retroclination of lower and proclination of upper incisors. The range of the changes was relatively large. When the overbite showed an appreciable increase during the period of observation, pre-existing proclination of upper or lower incisors and an increased overbite or overjet were the most frequent findings. Remarkably, a previously increased overjet seemed to be a better indicator of an overbite that would increase than was the Previous overbite itself. In most cases showing a previously normal overbite or overjet, the overjet after extraction remained stable. Correlation of the overbite and overjet together against the changes in overbite proved disappointing from the prognostic standpoint except that previously incomplete overbites almost invariably increased.