Treatment and posttreatment effects of Herbst appliance therapy on trabecular structure of the mandible using fractal dimension analysis

Abstract

Objectives This controlled study aimed to evaluate the effects of Herbst therapy on the trabecular structure of the condyle and angulus mandible using fractal dimension analysis (FD-A) accompanied by skeletal cephalometric changes. Material and method The panoramic and cephalometric radiographs of 30 patients with skeletal Class II malocclusion treated with the Herbst appliance (C II-H group, mean age: 15.23 ± 1.08), 30 patients with skeletal Class II malocclusion that received fixed orthodontic treatment (C II-C group, mean age: 15.73 ± 1.38), and 30 patients with skeletal Class I malocclusion (C I-C group, mean age: 15.90 ± 1.30) were selected. FD-A was performed on the superoposterior region (C-SP) and centre of the condyles (C-C) and the mandibular angulus (Ang) on the panoramic radiographs taken at the pretreatment (T0), intermediate stage of treatment (T1), and posttreatment (T2) timepoints just like cephalometric analysis. Results Herbst therapy provided a statistically significant increase in SNB, ANS-Me, Na-Me, S-Go, Co-Gn and a decrease in ANB and overjet (P < 0.05). All skeletal changes remained stable during the fixed appliance treatment after Herbst. The FD values in C-C increased (P < 0.05), and C-SP values decreased (P < 0.05) during Herbst therapy, while after removal of the Herbst appliance, no significant change was observed despite an increase in C-SP. The Ang value did not change during Herbst treatment, but then increased significantly (P < 0.05). There was no significant change in the FD values of the C I-C and C II-C groups at any stage of treatment. The C-C and C-SP changes at T1–T0 period, C-SP and Ang changes at T2–T1 period, and C-C, C-SP, and Ang values at T2–T0 period were found higher in C II-H group compared with the C II-C group significantly (P < 0.05). Conclusion Herbst therapy changed the trabecular structure of the condyles in different directions at the superoposterior and central regions of the condyles, while the structural complexity of the angulus mandible, which did not change during the Herbst treatment, increased during the fixed orthodontic treatment after Herbst.

Effects of reverse headgear therapy on mandibular trabecular structure: A fractal analysis study

“…The decrease in the complexity of the bone structure was associated with the presence of erosive changes. It can be said that pathological conditions cause changes in the normal formation and destruction mechanism of bone 12 . In our study, no significant changes in FD values were observed in the mandibular condyle after treatment with RME + RHG.…”

“…It can be said that pathological conditions cause changes in the normal formation and destruction mechanism of bone. 12 In our study, no significant changes in FD values were observed in the mandibular condyle after treatment with RME + RHG. Therefore, it can be inferred that this treatment does not have pathological or destructive effects on the temporomandibular condyle.…”

“…As it is a routinely obtained patient record in orthodontics, a panoramic radiograph is a suitable assessment tool for the investigation of the changes in the mandibular trabeculation. It is a reliable measurement method that gives valid findings and has previously been used to evaluate the trabecular structure of the mandible in many different dental studies 10–12 …”

“…It is a reliable measurement method that gives valid findings and has previously been used to evaluate the trabecular structure of the mandible in many different dental studies. [10][11][12] Although various studies have investigated the cephalometric and occlusal effects of RME + RHG treatment on the dentoskeletal complex, there are no studies to evaluate its effects on the mandibular trabecular structure to our knowledge. Therefore, we aimed to assess the effects of RME + RHG treatment on mandibular bony architecture and compare these effects with an untreated control group in Class III patients using FD analysis.…”

Evaluation of architectural changes in mandibular trabecular and cortical bone pattern after functional treatment

“…30 In a recent study, Ok and Kaya 31 used fractal analysis to assess the skeletal and dental effects of rapid maxillary expansion. Amuk et al, 32 in an investigation of the effects of the Herbst appliance on mandibular trabecular structure by fractal analysis, found that the supero-anterior and central parts of the condyles were affected differently but the structural complexity of the mandibular angle did not change. Recently, Cesur et al conducted a similar study to test the effectiveness of functional treatment using FD measurement of the condyle, mandibular angle and mandibular corpus to compare with a Class I control group.…”