Retrospective 25-year follow-up of treatment outcomes in angle Class III patients : Early versus late treatment.

OBJECTIVES: To assess early versus late treatment of Class III syndrome for skeletal and dental differences. METHODS: Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Baseline data were obtained by reviewing pretreatment (T0) anamnestic records, cephalograms, and casts. The cases were assigned to an early or a late treatment group based on age at T0 (up to 9 years or older than 9 years but before the pubertal growth spurt). Both groups were further compared based on posttreatment data (T1) and long-term follow-up data collected approximately 25 years after treatment (T2). RESULTS: Early treatment was successful in 74% and late treatment in 67% of cases. More failures were noted among male patients. The late treatment group was characterized post therapeutically by significantly more pronounced skeletal parameters of jaw size relative to normal Class I values; in addition, a greater skeletal discrepancy between maxilla and mandible, higher values for mandibular length, Cond-Pog, ramus height, overjet, anterior posterior dysplasia indicator (APDI), lower anterior face height, and gonial angle were measured at T1. The angle between the AB line and mandibular plane was found to be larger at T0, T1, and T2, as well as more pronounced camouflage positions of the lower anterior teeth at T0. The early treatment group was found to exhibit greater amounts of negative overjet at T0 but more effective correction at T1. CONCLUSIONS: Early treatment of Class III syndrome resulted in greater skeletal changes with less dental compensation.

Skeletal and dental effects of Class III orthopaedic treatment: a systematic review and meta-analysis.

To summarise the skeletal, dental and soft tissue effects of orthopaedic treatment on growing skeletal class III patients compared with a concurrent untreated similar control group and to evaluate whether the design of the primary studies may affect the results. A literature search was performed up to the end of February 2016. No restrictions were applied concerning language and appliances. Once the quality score was assessed, a meta-analysis was performed for the appliances used in more than three studies. A moderator analysis for study design was performed. The level of evidence was evaluated by means of the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) tool. The search resulted in 21 papers. The quality of most of the studies was medium. Each study reported skeletal sagittal improvement and overjet correction. Fourteen studies reported a significant increase in lower facial height. Follow-up data showed slight relapses in about 15% of patients. Meta-analyses were performed for the facemask and chin cup. The two appliances were efficient for correcting the sagittal discrepancy, increasing the divergence. In the analysis for study design, the retrospective studies showed a more efficient appliance than RCTs for 6 of 13 variables. The level of evidence was between very low and moderate. There is very low to low evidence that orthopaedic treatment is effective in the correction of Class III skeletal discrepancies and moderate evidence for the correction of the overjet. A common side effect is mandibular clockwise rotation in older subjects.

Retrospective 25-year follow-up of treatment outcomes in Angle Class III patients : Success versus failure.

OBJECTIVES: Despite recommendations for early treatment of hereditary Angle Class III syndrome, late pubertal growth may cause a relapse requiring surgical intervention. This study was performed to identify predictors of successful Class III treatment. MATERIALS AND METHODS: Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Data were collected from the data archive, cephalograms, and casts, including pretreatment (T0) and posttreatment (T1) data, as well as long-term follow-up data collected approximately 25 years after treatment (T2). Each patient was assigned to a success or a failure group. Data were analyzed based on time (T0, T1, T2), deviations from normal (Class I), and prognathism types (true mandibular prognathism, maxillary retrognathism, combined pro- and retrognathism). RESULTS: Compared to Class I normal values, the data obtained in both groups yielded 11 significant parameters. The success group showed values closer to normal at all times (T0, T1, T2) and vertical parameters decreased from T0 to T2. The failure group showed higher values for vertical and horizontal mandibular growth, as well as dentally more protrusion of the lower anterior teeth and more negative overjet at all times. In adittion, total gonial and upper gonial angle were higher at T0 and T1. A prognostic score-yet to be evaluated in clinical practice-was developed from the results. The failure group showed greater amounts of horizontal development during the years between T1 and T2. Treatment of true mandibular prognathism achieved better outcomes in female patients. Cases of maxillary retrognathism were treated very successfully without gender difference. Failure was clearly more prevalent, again without gender difference, among the patients with combined mandibular prognathism and maxillary retrognathism. Crossbite situations were observed in 44% of cases at T0. Even though this finding had been resolved by T1, it relapsed in 16% of the cases by T2. CONCLUSION: The failure rate increased in cases of combined mandibular prognathism and maxillary retrognathism. Precisely in these combined Class III situations, it should be useful to apply the diagnostic and prognostic parameters identified in the present study and to provide the patients with specific information about the increased risk of failure.

Relationship between Orthodontic Treatment Plan and Goslon Yardstick Assessment in Japanese Patients with Unilateral Cleft Lip and Palate: One-stage vs. Two-stage Palatoplasty.

The present study targeted patients with unilateral cleft lip and palate (UCLP) undergoing either one - (Wardill technique) or two-stage palatoplasty (Perko technique). Correlations between Goslon Yardstick scores and orthodontic appliances used and whether an osteotomy was performed were investigated. No differences were observed between the two types of palatoplasty in terms of Goslon Yardstick scores. A palatal expander and protraction facemask were used in Phase I of orthodontic treatment. The palatal expander was selected for most patients with UCLP in Phase I, regardless of the surgical technique used. A protraction facemask was used in patients undergoing the Wardill procedure who had a Goslon Yardstick score placing them in Group 3 or 4. In contrast, a protraction facemask was used in patients undergoing the Perko procedure who had a Goslon Yardstick score placing them in Group 4. No significant differences were observed in the Goslon Yardstick scores yielded by either type of procedure. The Goslon Yardstick score in relation to whether an osteotomy was performed in Phase II as part of orthodontic treatment was determined, focusing on the relationship between that score and the palatoplasty method used. A protraction facemask was used in patients undergoing the Perko procedure, which eliminated the need for an osteotomy at a future date. However, a protraction facemask was also used in patients undergoing the Wardill option, and those patients were likely to require an osteotomy. In other words, the results suggest that the type of palatoplasty selected will determine the effectiveness of any orthodontic appliances used.

Outcomes of different Class II treatments : Comparisons using the American Board of Orthodontics Model Grading System.

OBJECTIVE: The aim of this study was to evaluate the clinical outcomes of three different Class II treatment modalities followed by fixed orthodontic therapy, using the American Board of Orthodontics Model Grading System (ABO-MGS). MATERIALS AND METHODS: As a retrospective study, files of patients treated at postgraduate orthodontic  clinics in different cities in Turkey was randomly selected. From 1684 posttreatment records, 669 patients were divided into three groups: 269 patients treated with extraction of two upper premolars, 198 patients treated with cervical headgear, and 202 patients treated with functional appliances. All the cases were evaluated by one researcher using ABO-MGS. The χ (2), Z test, and multivariate analysis of variance were used for statistical evaluation (p < 0.05). RESULTS: No significant differences were found among the groups in buccolingual inclination, overjet, occlusal relationship, and root angulation. However, there were significant differences in alignment, marginal ridge height, occlusal contact, interproximal contact measurements, and overall MGS average scores. The mean treatment time between the extraction and functional appliance groups was significantly different (p = 0.017). CONCLUSION: According to total ABO-MGS scores, headgear treatment had better results than functional appliances. The headgear group had better tooth alignment than the extraction group. Headgear treatment resulted in better occlusal contacts than the functional appliances and had lower average scores for interproximal contact measurements. Functional appliances had the worst average scores for marginal ridge height. Finally, the functional appliance group had the longest treatment times.

Evidence-based practice and barriers to compliance: Face bow transfer.

PURPOSE: To recapitulate a 2003 study inquiring of US dental schools whether they teach the face bow transfer by means of a survey in order to determine if compliance with clinical evidence has improved. METHODS: The same 54 dental schools surveyed in 2003 were asked the same question regarding whether they teach the use of the face bow transfer in the complete denture curriculum. RESULTS: Teaching of the face bow transfer has increased in prevalence from 84% of surveyed schools in 2003 to 93.75% of surveyed schools in 2015. CONCLUSIONS: This finding is especially interesting in light of the fact that there is no compelling evidence supporting the use of the face bow transfer with regard to improving patient outcomes. With respect to the continued unjustified teaching of the face bow transfer, some possible reasons for non-compliance with best available evidence are presented using the medical literature for reference.

Efeitos do tratamento térmico em arcos ortodônticos de aço CrNi / Effects of heat treatment on orthodontic CrNi steel arches

O objetivo deste trabalho é avaliar o efeito do tratamento térmico em arcos odontológicos de aço inoxidável de CrNi de seção retangular" 0,019x0,025 através do tratamento realizado em uma maquina elétrica de solda a ponto e em lamparina, no sentido de contribuir sobre a eficácia do uso dessa técnica. Foram utilizadas 48 arcos divididos em três grupos com 16 arcos cada, sendo o primeiro grupo sem tratamento térmico, o segundo com tratamento térmico realizado em lamparinas e o terceiro com tratamento técnico realizados em maquinas de solda a ponto. posteriormente, foram realizados em uma maquina de solda a ponto. Posteriormente, foram realizados mensurações nas regiões anterior e posterior do arco por meio de um microscópio Mitutoyo TM. As medições foram realizadas 24h após a confecção dos arecos de 30 dias após a primeira. Os resultados foram submetidos á análise estatística com tese de variância ANOVA com pós- testes de Tukey em nivel de 5% ( p<0,05). Com os resultados obtidos na elaboração deste trabalho é possível concluir que o tratamento térmico ou ausência dele não exerce influência significtiva nas dimensões dos arcos no decorrer de 30 dias. Não foram encontradas entre os três grupos. As amostras do grupo com tratamento térmico realizados em maquinas de solda a ponto, comparadas as amostras dos demais grupos, apresentam uma contração da região posterior dos arcos, porém, provavelmente, sem relevância cínica

The aim of study is to analize the effect of the heat treatment in orthodontic wires of chrome nickel CrNi stainless steel of rectangular section of 0.019x0,25 though the efficacy of this technique. 48 arches were divided into theree groups with 16 arches each. the first group did not go through any heat treatment; the second was done with a heat treatment performed on the electric spot welding machine. Afterwards measurements were made in the anterior and posterior regions of the arch with the help of miroscope Mituloio TM. The measures were taken 24h after the making of the arches and 30 days after- the first. The results were statistically analyzed with ANOVA test and TUKEY POST- TEST AT 5% level (p<0,05). With the obtained results in elaboration of this study it can be concluded that the heat treatment or the lack of it does not exert significant influence on the dimensione of significtiva arcs during 30 days. They were found between the three groups. The samples of the group with heat treatment performed in maquinasd spot welding, compared samples from the other groups, show a contraction of the posterior region of the arches, but probably not relevant cynical

The use of fixed appliances in the UK: a survey of specialist orthodontists.

OBJECTIVE: To investigate the use of fixed appliances in the UK. DESIGN: Prospective postal questionnaire. SETTING: UK. PARTICIPANTS: All members of the General Dental Council Specialist List in Orthodontics still in active practice and not in training posts. METHOD: A preemptive letter of explanation was sent inviting orthodontists to participate in the survey. The questionnaire was subsequently posted to 935 specialists. Data analysis investigated differences in clinical practice related to varying provider groups, level of operator experience and geographical region. RESULTS: The response rate achieved was 66.3%. A majority of orthodontists routinely used the 0.022 inch pre-adjusted edgewise system, standard size Siamese pattern stainless steel brackets, conventionally ligated and bonded using standard etch and light cured composite. Nickel titanium and stainless steel were the most popular archwire materials. Anchorage was supported routinely by palatal and lingual arches in up to 25% and by headgear in over a third of respondents. Newer innovations showed variable popularity. Self-etching primer was used routinely by one-third of respondents with 11% use of self-ligating brackets. Banding of first molars was preferred by over 60% of clinicians. Bone screw implants were used by only 0.2% of respondents. Clinicians with less than 10 years experience used more headgear, light curing, MBT prescription and molar bonding. Operators with over 20 years experience used more chemically cured bonding, Roth prescription, banded first molars, 0.018 inch slot size and Tip-Edge(TM), with less use of headgear. Fixed appliance use differed from that reported in the US with lower use in the UK of standard edgewise and Roth systems, aesthetic, miniaturised and 0.018 inch slot brackets and rapid maxillary expansion. CONCLUSION: Most UK orthodontic specialists routinely used the 0.022 inch pre-adjusted edgewise system with standard size Siamese steel brackets bonded using standard etch and light cured composite with conventional ligation. Variations were seen between different provider groups, types of treatment funding, levels of operator seniority and geographical regions. Differences were noted particularly in the use of bracket prescription and design, types of molar attachment and anchorage control.

Craniofacial displacement in response to varying headgear forces evaluated biomechanically with finite element analysis.

INTRODUCTION: The aim of this study was to evaluate biomechanically the displacement patterns of the facial bones in response to different headgear loading by using a higher-resolution finite element method model than used in previous studies. METHODS: An analytical model was developed from sequential computed tomography scan images taken at 2.5-mm intervals of a dry skull of a 7-year-old. Different headgear forces were simulated by applying 1 kg of posteriorly directed force in the first molar region to simulate cervical-pull, straight-pull, and high-pull headgear. Displacements (in mm) of various craniofacial structures were evaluated along the x, y, and z coordinates with different headgear loading. RESULTS: All 3 headgears demonstrated posterior displacement of the maxilla with clockwise rotation of the palatal plane. The distal displacement of the maxilla was the greatest with the straight-pull headgear followed by the cervical-pull headgear. The high-pull headgear had better control in the vertical dimensions. The midpalatal suture opening was evident and was more pronounced in the anterior region. The articular fossa and the articular eminence were displaced laterally and postero-superiorly with each headgear type. CONCLUSIONS: The high-pull headgear was most effective in restricting the antero-inferior maxillary growth vector. Midpalatal suture opening similar to rapid maxillary expansion was observed with all 3 headgear types. The center of rotation varied with the direction of headgear forces for both the maxilla and the zygomatic complex. A potential for chondrogenic and osteogenic modeling exists for the articular fossa and the articular eminence with headgear loading.

Comparison of treatment outcomes between skeletal anchorage and extraoral anchorage in adults with maxillary dentoalveolar protrusion.

INTRODUCTION: The goal of this retrospective cephalometric study was to compare orthodontic outcomes in patients with maxillary dentoalveolar protrusion malocclusion treated with extraoral headgear or mini-implants for maximum anchorage. MATERIALS: Forty-seven subjects with Angle Class II malocclusion or Class I bimaxillary dentoalveolar protrusion were treated by retracting the maxillary dentoalveolar process by using the extraction space of the bilateral maxillary first premolars. Two anchorage systems were used. Group 1 (n = 22) received traditional anchorage preparation with a transpalatal arch and headgear; group 2 (n = 25) received mini-implants (miniplates, miniscrews, or microscrews) for bony anchorage. Pretreatment and posttreatment lateral cephalograms were superimposed to compare the following parameters between groups: (1) amount of maxillary central incisor retraction, (2) reduction in maxillary central incisor angulation, (3) anchorage loss of the maxillary first molar, (4) movements of the maxillary central incisor and first molar in the vertical direction, and (5) changes in skeletal measurements representing the anteroposterior and vertical jaw relationships. RESULTS: The skeletal anchorage group had greater anterior tooth retraction (8.17 vs 6.73 mm) and less maxillary molar mesialization (0.88 vs 2.07 mm) than did the headgear group, with a shorter treatment duration (29.81 vs 32.29 months). Translational movement of the incisors was more common than tipping movement, and intrusion of the maxillary dentition was greater, in patients receiving miniplates than in those receiving screw-type bony anchorage, resulting in counterclockwise rotation of the mandible and a statistically significant decrease in the mandibular plane angle. Cephalometric analysis of skeletal measurements in patients with low to average mandibular plane angles showed no significant difference between groups, although greater maxillary incisor retraction and less mesial movement of the first molar were noted in the mini-implant group. In patients with a high mandibular plane angle, those receiving skeletal anchorage had genuine intrusion of the maxillary first molar and reduction in the mandibular plane angle, whereas those receiving headgear anchorage had extrusion of the maxillary first molar and an increase of mandibular plane angle. In contrast to the posterior movement in the headgear group, anterior movement of Point A was noted in the mini-implant group. CONCLUSIONS: In both the anteroposterior and vertical directions, skeletal anchorage achieved better control than did the traditional headgear appliance during the treatment of maxillary dentoalveolar protrusion. Greater retraction of the maxillary incisor, less anchorage loss of the maxillary first molar, and the possibility of counterclockwise mandibular rotation all facilitated the correction of the Class II malocclusion.

Response of headgear release mechanisms to nonaxial force application.

Safety products have been developed to help reduce the incidence of trauma caused by headgear. Previous studies have reported the characteristics of breakaway-type headgear release mechanisms with axial force application. Not all accidental releases are triggered by an axial force and it is necessary to understand the characteristics of these mechanisms with nonaxial force application. Thirteen headgear release mechanisms were tested as part of a complete headgear system. With the system attached to a plaster head and neck model a tensile force was applied to the system at 30 degrees to the sagittal plane at 2 rates. The force of activation at release and the distance traveled were determined and analyzed statistically. Force values ranged from 4.6 to 36.7 pounds and face bow travel before release ranged from 0.97 to 3.42 inches. No consistent pattern of rate dependence was observed. Several devices demonstrated the desirable combination of low force and face bow travel at release.

Facial profile and dental changes before, during and after treatment with Hansaplate/Headgear.

In this prospective study the changes of facial profile and dentition in 19 boys and 19 girls treated for 1 year with Hansaplate/Headgear were analyzed yearly over a 4-year period. On average the boys were 10.2 and the girls 9.2 years old at the first recording, i.e., 1 year pretreatment. The actual values are compared with standard growth data presented by Bathia and Leighton (1993). Irrespective of the initial face morphology, the Hansaplate/Headgear appliance straightened the facial hard and soft tissue profiles favorably. The upper lip became more retruded while the lower lip was unaffected by therapy. During the 2-year post-treatment period these changes continued, probably as a consequence of growth. The overjet was reduced by 5 mm during treatment and was found to be quite stable 2 years after treatment.

Maxillary protraction and chincap appliance treatment effects and long-term changes in skeletal class III patients.

The purpose of this study was to investigate the orthopedic effects of combined maxillary protraction appliance (MPA) and chincap therapy on growing Japanese girls and the posttreatment changes after growth is complete. To estimate the actual effects of treatment and posttreatment changes, we used a series of templates that had been constructed from semilongitudinal data of Japanese girls with normal occlusion. During treatment, forward movement of the maxilla with counterclockwise rotation, and backward and downward movement of the mandible with clockwise rotation and growth retardation were observed. The forward movement of the maxilla persisted until growth was complete. During the posttreatment period, the mandible maintained its improved position but showed excessive growth, which could be a rebound change. These results indicate that combined MPA and chincap treatment is effective for correcting skeletal Class III malocclusion.

The effectiveness of protraction face mask therapy: a meta-analysis.

This study examined the effectiveness of maxillary protraction with orthopedic appliances in Class III patients. A meta-analysis of relevant literature was performed to determine whether a consensus exists regarding controversial issues such as the timing of treatment and the use of adjunctive intraoral appliances. An initial search identified 440 articles relating to Class III malocclusion. Among those articles, 11 studies in English and 3 studies in foreign languages met the previously established selection criteria. Data from the selected studies were categorized by age and appliance groups for the meta-analysis. The sample sizes were comparable between the groups. The statistical synthesis of changes before and after treatment in selected cephalometric landmarks showed no distinct difference between the palatal expansion group and nonexpansion group except for 1 variable, upper incisor angulation, which increased to a greater degree in the nonexpansion group. This finding implies that more skeletal effect and less dental change are produced in the expansion appliance group. Examination of the effects of age revealed greater treatment changes in the younger group. Results indicate that protraction face mask therapy is effective in patients who are growing, but to a lesser degree in patients who are older than 10 years of age, and that protraction in combination with an initial period of expansion may provide more significant skeletal effects. Overall mean values and corresponding standard deviations for the studies selected can also be used to estimate mean treatment effects expected from the use of protraction face mask.

Design and fabrication of a modified protraction headgear for Class III long face patients.

Treatment of children with long face and with Class III malocclusions is difficult because most of the available appliances treat one of the two problems at the cost of aggravating the other one. In this article, we present the steps of design and fabrication of a modified protraction headgear that can be useful for such a patient. A patient treated with this approach is presented.

Cervical headgear therapy as a factor in obstructive sleep apnea syndrome.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) has been a subject of increasing interest from the orthodontic point of view, but less attention has been paid to the possible influence of orthodontic treatment on its occurrence. The aim here was to study possible associations between the use of cervical headgear and nocturnal cessations of airflow and the severity of the latter. METHODS: The subjects were 30 children (12 boys, 18 girls, mean age 8.2, sd 1.61 years), divided into three groups: a group of 10 children undergoing headgear therapy, selected for this examination because of symptoms of OSAS while using headgear, an age-matched control group of 10 healthy children and a group of 10 with OSAS. Standard cephalograms of the headgear group prior to the orthodontic therapy and the corresponding cephalograms of healthy controls were analysed. A polygraphic (PG) sleep evaluation was used to assess the tendency for OSAS. Apnea and hypopnea periods were summated as apnea index (AI) and number of desaturations as desaturation index (ODI). All the subjects spent one night sleeping under laboratory conditions, those with orthodontic treatment spending the first half of the night with the headgear and the latter half without. RESULTS: The position of the mandible was found to be slightly more posterior in the headgear group than in the control group. The children in the headgear group were found to have significantly more apnea/hypopnea periods during the hours when the appliance was used, and the ODI-index showed increased values in this group. CONCLUSIONS: We suggest that headgear therapy may contribute to the occurrence of sleep apnea, when a strong predisposition, such as mandibular retrognathia to the development of upper airway occlusion already exists.

An experimental evaluation of effects and side effects of asymmetric face-bows in the light of in vivo measurements of initial tooth movements.

By using a magnetic sensing system, the translational and rotational molar movements under the application of various asymmetric face-bows were measured two-dimensionally in human subjects to evaluate their primary effects and side effects. The asymmetric face-bow designs tested were three types of power arm face-bows, swivel offset face-bow, and internal hinge face-bow. Although all face-bow designs were considered to be effective in achieving asymmetric distalizations of the molars, they generated lateral displacements that may lead to an undesirable crossbite. The swivel offset face-bow may produce unexpected results and its fabrication is complicated. The internal hinge face-bow is remarkably effective for asymmetric molar distalizations. Unfortunately, it causes a strong crossbite tendency on the molar to be more distalized. Therefore the use of the power arm face-bow is thought to be relatively recommendable because it showed an acceptable asymmetric effect and is easily fabricated from a commercially available face-bow. It is concluded that all asymmetric face-bows generate lateral forces as side effects as long as the force delivery system with a combination of an asymmetric face-bow and a neck strap or head cap is applied. The current study suggests a method whereby the side effect of asymmetric face-bows can be eliminated.