Changes in temporomandibular joint disc position and form following Herbst and fixed orthodontic treatment

Abstract

; Má rcio Abrahã o d ABSTRACT Objective: To determine the changes in the position and form of the temporomandibular joint articular disc in adolescents with Class II division 1 malocclusion and mandibular retrognathism treated with the Herbst appliance (phase I) and fixed orthodontic appliance (phase II). Materials and Methods: Thirty-two consecutive adolescents went through phase I of treatment and 23 completed phase II. The temporomandibular joints were evaluated qualitatively by means of magnetic resonance images at the beginning of treatment (T1), during phase I (T2), at the end of phase I (T3), and at the end of phase II (T4). Results: Significant changes in disc position were not observed with the mouth closed between T1 3 T3 (P 5 .317), T3 3 T4 (P 5 .287), or T1 3 T4 (P 5 .261). At T2, on average, the disc was positioned regressively. With the mouth open, no difference was observed between T1 3 T3 (P 5 .223) or T1 3 T4 (P 5 .082). We did observe a significant difference between T3 3 T4 (P , .05). Significant changes in the disc form were found with the mouth closed between T1 3 T2 (P , .001) and T2 3 T3 (P , .001). Conclusions: At the end of the two-phase treatment, in general terms, the position and form of the initial articular discs were maintained; however, in some temporomandibular joints some seemingly adverse effects were observed at T4. (Angle Orthod. 2010;80:843-852.)

Impact of functional mandibular advancement appliances on the temporomandibular joint - a systematic review

“…The use of a mandibular advancement appliance to correct skeletal malocclusions associated with mandibular retrognathism is indicated during the first stage of orthodontic treatment (1). The objective is to stimulate mandibular growth and correct the sagittal misalignment by bringing the condyles forward and downward within the glenoid fossa (2,3), as well as remodelling the condyle and glenoid fossa, causing anterior rotation of the mandible and consequently projecting it forwards (4).…”

Morphological Changes of Condyles and Helkimo Clinical Dysfunction Index in Patients Treated with Herbst - Orthodontic Appliance

“…When necessary, supplementary advances of 2 to 3 mm were achieved in the third month. In all 32 adolescents, treatment with the Herbst appliance (1,7,8) resulted in Class I or overcorrected Class I dental arch relationships.…”

“…Functional analyses of the masticatory system (12,13) by means of clinical evaluations, combined with morphological changes in the TMJs diagnosed using imaging tests, have been included in some studies (1,(6)(7)(8)(9) to elucidate the effects of treatment using the Herbst appliance.…”

“…Class II malocclusion associated with mandibular retrognathism may be treated using orthopedic functional appliances in the first phase of treatment to advance the mandible and to improve its anteroposterior adjustment during growth (1)(2)(3)(4)(5)(6)(7)(8)(9). In the second phase of treatment, fixed orthodontic appliances are used to refine occlusion (1,9).…”

“…In the second phase of treatment, fixed orthodontic appliances are used to refine occlusion (1,9). The responses of the temporomandibular joints (TMJs) treated using this method are controversial, which has led to the conduction of studies using the three-dimensional finite element method (10) as well as analyses in groups of experimental animals (11) or humans beings (1)(2)(3)(4)(5)(6)(7)(8)(9).…”