[Cone beam computed tomography analysis of the bony structure of the temporomandibular joint during two phase treatment with Herbst appliance].
OBJECTIVE
This study assessed the effects of two-phase treatment with Herbst appliance on the bony structure of the temporomandibular joint via cone beam computed tomography (CBCT) analysis.


METHODS
This study selected 15 patients exhibiting early permanent dentition and classⅡmalocclusion combined with mandibular retrusion treated by a two phase treatment (Herbst and fixed appliance). The CBCT scans of the patients were obtained at the following stages: 2 weeks before Herbst treatment (T1), at the start of treatment when the Herbst appliance was set in place (T2), immediately after removal of the Herbst appliance (T3), and immediately after removal of the edgewise appliance (T4). Three-dimensional reconstruction and related measurements were performed using InvivoDental software, and the acquired data were statistically analyzed.


RESULTS
1) CBCT showed a crescent-shaped hyperplasia at the posterior-superior border of the condyles that the outer edge was highly dense and the inner region was lowly dense in T3 in 14 patients (28 condyles). 2) In T3-T2 and T4-T1, the diameters of the anteroposterior condyles increased by 0.62 and 0.66 mm, respectively (P<0.01), and the condylar head height correspondingly increased by 0.54 and 0.53 mm (P<0.01).


CONCLUSIONS
Condylar growth remodeling occurs during Herbst treatment. .
Dept. of Stomatology, Traditional Chinese Medicine and Western Medicine Combination Hospital of Nanchang City, Nanchang 330006, China.
Chen
C
Weiwei
Dept. of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University, Nanchang 330006, China.
Sang
S
Ting
Dept. of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University, Nanchang 330006, China.
Huang
H
Zhen
Dept. of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University, Nanchang 330006, China.
Wu
W
Jun
D001842:Bone and Bones; D054893:Cone-Beam Computed Tomography; D006801:Humans; D017289:Orthodontic Appliances, Functional; D063173:Retrognathia; D013704:Temporomandibular Joint
Herbst appliance; cone beam computed tomography; temporomandibular joint; two phase treatment