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ABSTRACT Objective: The aim of the study was to investigate the influence of facemask treatment with skeletal anchorage on the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI), in patients with Class III malocclusion, accompanied by maxillary retrusion. Methods: Fifteen patients with a mean age of 12.1±1.43 years were included in the study. All patients were treated using facemask with skeletal anchorage after eight weeks of Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol. Magnetic resonance imaging was performed before and immediately after facemask treatment for TMJ evaluation. Disc position, condylar translation, degenerative changes of the condyles, and joint effusion were evaluated. To assess whether the alterations associated with the treatment were statistically significant, McNemar and marginal homogeneity tests were used. Results: After facemask treatment, a statistically significant change was observed in the disc position (an anterior disc displacement with/without reduction in five TMJs) (p<0.05). The alteration in the condylar translation was not statistically significant (p>0.05). This treatment did not cause degenerative changes of the condyles or effusion in any of the TMJs. Conclusion: Facemask treatment with skeletal anchorage following the Alt-RAMEC protocol had a minimal influence on the TMJ, only by means of disc position, which was not negligible. Long-term results of such treatment are required for following up the changes observed in the TMJs.
RESUMO Objetivo: O objetivo desse estudo foi investigar a influência do tratamento com máscara facial com ancoragem esquelética na articulação temporomandibular (ATM), por meio de ressonância magnética (RM), em pacientes com má oclusão de Classe III acompanhada de retrusão maxilar. Métodos: Quinze pacientes com idade média de 12,1±1,43 anos foram incluídos no estudo. Todos os pacientes foram tratados com máscara facial com ancoragem esquelética após oito semanas de protocolo de Expansão Rápida da Maxila e Constrição Alternadas (Alt-RAMEC). Os exames de ressonância magnética foram realizados antes e imediatamente após o tratamento com máscara facial, para avaliação da ATM. Foram avaliados posição do disco, translação condilar, alterações degenerativas dos côndilos e derrame articular. Os testes de McNemar e de homogeneidade marginal foram utilizados para avaliar se as alterações associadas ao tratamento foram estatisticamente significativas. Resultados: Após o tratamento com máscara facial, uma mudança estatisticamente significativa foi observada na posição do disco (deslocamento anterior do disco com/sem redução em cinco ATMs) (p<0,05). A alteração na translação condilar não foi estatisticamente significativa (p>0,05). Esse tratamento não causou alterações degenerativas dos côndilos ou derrame em qualquer das ATMs. Conclusão: O tratamento com máscara facial com ancoragem esquelética ápós o protocolo Alt-RAMEC teve uma influência mínima na ATM, apenas quanto à posição do disco, que não foi desprezível. Resultados em longo prazo desse tratamento são necessários para acompanhar as mudanças observadas nas ATMs.
ABSTRACT
OBJECTIVE: The aim of this retrospective study was to evaluate and compare the changes in the pharyngeal airway (PA), maxillary sinus volume, and skeletal parameters after rapid maxillary expansion (RME) and alternate rapid maxillary expansion and constriction (Alt-RAMEC) followed by facemask (FM) therapy. METHODS: The records of 40 patients with skeletal Class III malocclusion due to maxillary retrognathism were collected, and the patients were assigned into two groups. The first group comprised 8 male and 12 female patients (mean age, 10.0 ± 1.1 years) treated using RME/FM for an average of 10 months. The second group comprised 10 male and 10 female patients (mean age, 9.64 ± 1.3 years) treated using Alt-RAMEC/FM for an average of 12 months. Cone-beam computed tomography images acquired before (T0) and after treatment (T1) were evaluated. RESULTS: Regarding the skeletal effects, significant differences between the groups were the increase in ANS-HRP (perpendicular distance of ANS to the horizontal reference plane, 0.99 mm, p <0.05) in the Alt-RAMEC/FM group and the decrease in PP-SN (palatal plane to Sella-Nasion plane, 0.93°, p < 0.05) in the RME/FM group. Maxillary sinus volumes increased significantly in both the groups, and the increase was statistically significantly higher in the Alt-RAMEC/FM group. Although no significant intergroup differences were observed in PA volumes, both lower (1,011.19 mm3) and total (1,601.21 mm3), PA volume increased significantly in the Alt-RAMEC/FM group. CONCLUSIONS: The different expansion devices and protocols used with FM therapy do not seem to affect the forward movement of the maxilla and PA volumes. In contrast, the increase in maxillary sinus volume was greater in the Alt-RAMEC/FM protocol.
Subject(s)
Female , Humans , Male , Cone-Beam Computed Tomography , Constriction , Malocclusion , Maxilla , Maxillary Sinus , Palatal Expansion Technique , Retrognathia , Retrospective StudiesABSTRACT
OBJECTIVE: The purpose of this study was to analyze initial displacement and stress distribution of the maxillofacial complex during dentoskeletal maxillary protraction with various appliance designs placed on the palatal region by using three-dimensional finite element analysis. METHODS: Six models of maxillary protraction were developed: conventional facemask (Type A), facemask with dentoskeletal hybrid anchorage (Type B), facemask with a palatal plate (Type C), intraoral traction using a Class III palatal plate (Type D), facemask with a palatal plate combined with rapid maxillary expansion (RME; Type E), and Class III palatal plate intraoral traction with RME (Type F). In Types A, B, C, and D, maxillary protraction alone was performed, whereas in Types E and F, transverse expansion was performed simultaneously with maxillary protraction. RESULTS: Type C displayed the greatest amount of anterior dentoskeletal displacement in the sagittal plane. Types A and B resulted in similar amounts of anterior displacement of all the maxillofacial landmarks. Type D showed little movement, but Type E with expansion and the palatal plate displayed a larger range of movement of the maxillofacial landmarks in all directions. CONCLUSIONS: The palatal plate served as an effective skeletal anchor for use with the facemask in maxillary protraction. In contrast, the intraoral use of Class III palatal plates showed minimal skeletal and dental effects in maxillary protraction. In addition, palatal expansion with the protraction force showed minimal effect on the forward movement of the maxillary complex.
Subject(s)
Finite Element Analysis , Palatal Expansion Technique , TractionABSTRACT
OBJECTIVE: To evaluate the effects of facemask therapy, which was anchored from the zygomatic buttresses of the maxilla by using two miniplates, in skeletal Class III patients with maxillary deficiency. METHODS: Eighteen skeletal Class III patients (10 girls and 8 boys; mean age, 11.4 ± 1.28 years) with maxillary deficiency were treated using miniplate-anchored facemasks, and their outcomes were compared with those of a Class III control group (9 girls and 9 boys; mean age, 10.6 ± 1.12 years). Two I-shaped miniplates were placed on the right and left zygomatic buttresses of the maxilla, and a facemask was applied with a 400 g force per side. Intragroup comparisons were made using the Wilcoxon test, and intergroup comparisons were made using the Mann-Whitney U-test (p < 0.05). RESULTS: In the treatment group, the maxilla moved 3.3 mm forward, the mandible showed posterior rotation by 1.5°, and the lower incisors were retroclined after treatment. These results were significantly different from those in the control group (p < 0.05). No significant anterior rotation of the palatal plane was observed after treatment. Moreover, changes in the sagittal positions of the maxillary incisors and molars were similar between the treatment and control groups. CONCLUSIONS: Skeletally anchored facemask therapy is an effective method for correcting Class III malocclusions, which also minimizes the undesired dental side effects of conventional methods in the maxilla.
Subject(s)
Female , Humans , Gravitation , Incisor , Malocclusion , Mandible , Maxilla , Methods , Molar , OrthopedicsABSTRACT
Abnormality in the relationship of the maxillary and mandibular jaw bases is one of the commonly encountered problems, which when treated within the period of growth with the help of orthopaedic appliances help in the attainment of correct jaw relationship. This timely use of several orthopaedic appliances like chin cup, head gear, face mask also called as reverse pull head gear, assists in preventing a more complex and compromised treatment options like camouflage or surgical correction. Orthopaedic malrelation, which occurs due to deficient maxilla, while the patient is in mixed dentition stage are the best candidates for the use of facemask therapy.
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The developing class III malocclusion is one of the most challenging problems for the practicing orthodontist to manage clinically. True class III malocclusion is rare in our region as compared to Class II and Class I malocclusion. With adults, orthognathic surgery and dental camouflage is the viable treatment option. A variety of treatment alternatives exists for patients in the developing stages of a Class III malocclusion. In the past much of the therapy has focused on restriction of mandibular growth with chin cups and functional appliances. This is based on the traditional thought that developing Class III malocclusions were the result of prognathic mandible. Recently, however, there has been a growing awareness that the majority of patients with a developing Class III skeletal pattern exhibit a maxillary deficiency with a normal or only slightly prognathic mandible. Therefore, considerable attention has been given to early treatment using maxillary protraction therapy. Using facemask therapy in conjunction with maxillary expansion has been shown in clinical reports to be a successful and predictable treatment option. Treatment should be carried out as early as possible with the aim to prevent it from becoming severe. A case treated with biphasic therapy – orthopaedic appliance followed by fixed orthodontic treatment is presented here.
ABSTRACT
The objective of the study is to evaluate treatment effects of orthopedic facemask on Class III preadolescents depending on the vertical facial pattern. This study was based on 30 patients aged 9–12 years, and were diagnosed as skeletal Class III with maxillary deficiency. They were divided into 2 groups (low and high angle groups) depending on gonial angle and the SNMP (GoGn) angle, respectively. Pretreatment and post-treatment lateral cephalograms were used to compare the effects of facemask and the following conclusions were obtained:1) A significantly large amount of backward movement of the point B was observed in patients with a low SNMP angle. Those with a high SNMP angle had significant forward movement at point A. (2) The patients with low gonial angle had the least forward movement at the point A, and those with a high angle had more forward movement. In comparing the horizontal and vertical movement of the point A, the high angle group showed more horizontal movement while the low angle group showed more vertical movement.
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OBJECTIVE: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. METHODS: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. RESULTS: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. CONCLUSIONS: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.
Subject(s)
Humans , Incisor , Malocclusion , Mandible , Maxilla , Overbite , Palatal Expansion Technique , Retention, PsychologyABSTRACT
Preadolescent children with deficient maxillae are suitable candidates for the maxillary protraction appliance(MPA). The theoretical effect of the MPA is protraction or anterior displacement of the maxilla. However, it is known that complex effects such as anterior displacement of the maxillary teeth, downward and backward rotation of the mandible, linguoversion of the mandibular anterior incisors, are known to play a role in improving the Cl III malocclusion. There have been much studies with regard to maxillary protraction, but the different effects of MPAs depending on the vertical facial pattern are not known precisely. This study was based on 67 patients (31 males, 36 females) aged from 6 years 6 months to 13 years 3months, who visited the Dept. of Orthodontics at Yonsei Univ., Dental Hospital and diagnosed as skeletal Class III with maxillary deficiency. They were divided into 3 groups (low, average, high angle groups) depending on gonial angle and the SNMP (Go-Gn) angle, respectively. Pretreatment and post-treatment lateral cephalograms were used to compare the effects of MPA and the following conclusions were obtained: 1) A significantly large amount of backward movement of the B point was observed in patients with a low SNMP angle. Those with a high SNMP angle had significant forward movement at A point. 2) The patients with low gonial angle had the least forward movement at the A point, and those with a high angle had more forward movement. 3) In comparing the arcTan of the A point, the high angle group showed more horizontal movement while the low angle group showed more vertical movement. 4) There was no significance between the treatment duration of the SNMP and the Gonial angle groups.