Mandibular Growth Stimulation Research Articles

Current Trends of Nanotechnology in Orthodontics.

The branch of science known as nanotechnology studies the manipulation of matter at the nanoscale. The field of nanotechnology is expanding daily and has shown great promise in all areas of medicine, including dentistry. Because of its many uses, including nanocoatings in brackets and archwires, orthodontic bonding, antimicrobial qualities, and atomic force microscopy, it has also become more significant in the field of orthodontics. Some of its potential uses in the future include shape-memory polymers, gene therapy-induced stimulation of mandibular growth, accelerating orthodontic movement, and biomechanical sensors. The capacity of nanotechnology to improve material qualities, particularly antimicrobial properties, has led to its increased prominence in recent years. Many areas of orthodontics can benefit from the application of nanotechnology. This paper focuses onthe impact of nanomaterials on orthodontic appliances and treatment.

Impact of initial lip competence on the outcome of class II functional appliances therapy

ObjectivesThe aim of this prospective clinical study was to evaluate the impact of initial lip position on class II functional appliance therapy.Materials and methodsIn total, 34 class II division 1 patients (23 females, 19 males; mean age 12.4 ± 0.9 years) that met the inclusion criteria (> ½ class II molar relationship, overjet > 6 mm, ANB > 4°, neutral or horizontal growth pattern, cervical vertebral maturation stage (CVMS) II – III, mean wear-time > 10 h/day) were consecutively divided into two groups (lip incompetence (LI); lip competence (LC)). All patients were treated with the Sander bite jumping appliance (BJA). Wear time was microelectronically measured. Lateral cephalograms were taken at the beginning (T0) and after 1 year of treatment (T1). An untreated class II group served as a control (CG). Inter-group comparisons were determined with Mann–Whitney U tests for independent samples.ResultsSignificant skeletal treatment effects were found in both treated groups when compared to the CG with significantly more pronounced mandibular skeletal effects in the LI than in the LC group (mandibular base length p < 0.001, composite mandibular base length p < 0.001, condylar head growth p = 0.002, co-pg p < 0.00, go-pg p = 0.003, reduction of the ANB angle p = 0.009, and Wits appraisal p < 0.001).ConclusionThe more pronounced mandibular effects in the LI group were composed of the functional orthopedic effect plus harmonization of the lip competence.Clinical relevanceFunctional harmonization of lip incompetence with BJA enhances mandibular growth stimulation. Lip incompetence seems to impede mandibular growth and its harmonization seems to be a preventive approach.

An overview of nanotechnological advances in orthodontics

Nanotechnology is the field of science dealing with the manipulation of the matter at the nanoscale level. The science of nanotechnology has emerged as a promising concept in all fields of medicine including dentistry and its scope is increasing everyday. It has also gained relevance in the field of orthodontics owing to its wide range of applications ranging from nanocoatings in archwires and brackets, orthodontic bonding, antimicrobial properties, atomic force microscopy to some future applications such as shape memory polymers, mandibular growth stimulation with gene therapy, acceleration of orthodontic movement, and use as biomechanical sensors. The enormous range of application of nanotechnology in orthodontics demands an intensive research into its current and future usages. This article aims to review and discuss the various applications and its potential usage in orthodontics.

Results of orthodontic treatment of a child with asymmetrical micrognathia and the congenital mandibular condylar hyperplasia

Aim. To analyze the results of orthodontic treatment of a child with asymmetrical micrognathia and mandiblar condylar hyperplasia.&#x0D; Methods. The configuration of a face in the photos was evaluated and diagnostic models of the jaws were analyzed by using the Ponts and Korkhaus methods in treatment dynamics. The physiological status of bone tissue, temporomandibular joints and teeth was studied by using orthopantomography and computed tomography. Functional disorders were detected by using special tests, including EschlerBittner's test and Ilyina-Markosyans test. Orthodontic treatment and stimulation of mandibular growth in the mixed dentition stage were undertaken with the single jaw removable appliances and the appliance improved by us for correction of the distal occlusion. The Damon Q bracket system with archwires was used in permanent dentition period.&#x0D; Results. The child's convex facial profile was typical for distal occlusion and micrognathia. The facial asymmetry, increasing with mouth opening, and a decrease in mandibular range of motion indicated lesion of the right temporomandibular joint. The right condyle was enlarged on the orthopantomogram. The computed tomography showed that it was asymmetrically enlarged and had a cellular structure. There was detected asymmetric micrognathia. The comprehensive rehabilitation plan included orthodontic treatment, myotherapy, speech therapy, mechanotherapy. The use of removable orthodontic appliances led to the normal size of the dentition and their relation, significantly reduced functional disorders and improved facial aesthetics. Five years after completion of orthodontic treatment, the physiological occlusion and amplitude of the mandibular movements remained, but the right mandibular angle was flattened.&#x0D; Conclusion. The comprehensive rehabilitation of a child with asymmetrical micrognathia and mandibular condylar hyperplasia started in mixed dentition stage provided conditions for the formation of normal permanent dentition and the improvement of functional disorders and facial aesthetics; our results allow us to suggest the positive effect of our tactics for treatment of the patient.

Skeletal effects in Angle Class II/1 patients treated with the functional regulator type II : Cephalometric and tensor analysis.

The purpose of this work was to employ both cephalometric and tensor analysis in characterizing the skeletal changes experienced by patients with Angle Class II/1 malocclusion during functional orthodontic treatment with the functional regulator type II. A total of 23 patients with Class II/1 malocclusion based on lateral cephalograms obtained before and after treatment with the functional regulator type II were analyzed. Another 23 patients with Angle Class II/1 malocclusion who had not undergone treatment were included as controls. Our cephalometric data attest to significant therapeutic effects of the functional regulator type II on the skeletal mandibular system, including significant advancement of the mandible, increases in effective mandibular length with enhancement of the chin profile, and reduction of growth-related bite deepening. No treatment-related effects were observed at the cranial-base and midface levels. In addition, tensor analysis revealed significant stimulation of mandibular growth in sagittal directions, without indications of growth effects on the maxilla. Its growth-pattern findings differed from those of cephalometric analysis by indicating that the appliance did promote horizontal development, which supports the functional orthodontic treatment effect in Angle Class II/1 cases. Tensor analysis yielded additional insights into sagittal and vertical growth changes not identifiable by strictly cephalometric means. The functional regulator typeII was an effective treatment modality for Angle Class II/1 malocclusion and influenced the skeletal development of these patients in favorable ways.

Effects of miniplate anchored and conventional Forsus Fatigue Resistant Devices in the treatment of Class II malocclusion.

To compare the skeletal, dentoalveolar, and soft tissue effects of the miniplate anchored Forsus Fatigue Resistant Device (FRD) and the conventional Forsus FRD in the treatment of Class II malocclusion. The study was carried out with 30 patients (10 girls, 20 boys). In the MA-Forsus group, 15 patients (2 girls, 13 boys) were treated with a miniplate anchored Forsus FRD for 9.40 ± 2.25 months. In the C-Forsus group, 15 patients (8 girls, 7 boys) were treated with a conventional Forsus FRD for 9.46 ± 0.81 months. A total of 16 measurements were calculated and statistically analyzed to find intragroup and intergroup differences. Statistically significant differences were found between the groups in IMPA, SN/Occ, SN/GoGn, overjet, overbite, and Li-S measurements (P < .05). In the C-Forsus group, a substantial amount of lower incisor protrusion was observed, whereas retrusion was found in the MA-Forsus group (P < .001). The mandible rotated backward in the MA-Forsus group, whereas it remained unchanged in the C-Forsus group (P < .05). Reductions in overjet (P < .001) and overbite were greater in the C-Forsus group (P < .05). Stimulation of mandibular growth and inhibition of maxillary growth were achieved in both treatment groups. In the C-Forsus group, a substantial amount of lower incisor protrusion was observed, whereas retrusion of lower incisors was found in the MA-Forsus group. The MA-Forsus group was found to be more advantageous as it had no dentoalveolar side effects on mandibular dentition.

Skeletal Effects in Class II Treatment with the Functional Mandibular Advancer (FMA)?

The aim of this clinical study was to reveal skeletal effects during the treatment of Class II malocclusions in adolescents and young adults using a protrusive-acting fixed, rigid functional orthodontic appliance, and to quantify them in comparison with an untreated control group. We aimed to determine whether, and if so, to what extent skeletal effects diminish with increasing age, and whether inter-individual differences can be observed. To correct their intermaxillary jaw relationship, the functional mandibular advancer (FMA) was inserted in 16 adolescents and young adults (eight males, eight females, aged from 12 years, 3 months to 18 years, 7 months) presenting with a skeletal Class II malocclusion. The course of treatment was documented cephalometrically. In all patients, the FMA treatment led to neutroclusion or overcorrected neutroclusion and a marked reduction in overjet. The occlusion's improvement in the sagittal dimension (overjet reduction by 4.43 +/- 2.10 mm, molar relationship improvement by 3.88 +/- 1.12 mm) was achieved by a combination of dental effects (distalization of upper teeth, mesialization of lower teeth) and skeletal effects (mandibular growth stimulation). Excepting the position and morphology of the maxillary base and the condyle's dorsal position in the fossa, all sagittal skeletal and dental changes induced by the FMA treatment were statistically significant. There was a mean increase of 1.71 +/- 1.11 mm in sagittal length of the mandible, in the sagittal-diagonal dimension of 1.42 +/- 1.51 mm and 1.53 +/- 2.15 mm, as well as a slight, significant increase in the gonial angle area. Whereas the condylar position remained stable, a forward positioning of the chin and thus significant increase in distance length was recorded from the posterior condylar margin to the anterior mandibular margin. Treatment with a fixed functional appliance in Class II patients effected significant changes in mandibular growth and correction of the distal intermaxillary relationship even after the pubertal growth spurt in adolescents and young adults. While the proportion of the orthopedically-induced skeletal share is subject to substantial inter-individual variability in adolescents, the overall conclusion can be drawn that skeletal effects (= stimulation of mandibular growth) in general clearly lessen with increasing patient age. In young adult patients, the correction of a distal intermaxillary jaw relationship is manifested primarily as a dento-alveolar compensation for the skeletal malocclusion.

When is the ideal period for Herbsttherapy—early or late?

The present article aims at answering the question whether an early or late treatment approach is the ideal period for Herbst therapy. This topic will be discussed by summarizing and evaluating the short- and long-term effects of the Herbst appliance on the dentofacial complex. Special emphasis will be given to the treatment outcome in relation to the patient's somatic and skeletal maturity at the time of therapy. Furthermore, the long-term stability of the treatment results will be addressed. The available knowledge in the literature demonstrates that the ideal period for Herbst treatment is in the permanent dentition at or just after the peak of pubertal growth corresponding to the skeletal maturity stages FG to H of the middle phalanx of the third finger (implying the pre-capping to pre-union stages of the ephiphysis and metaphysis). As mandibular growth stimulation is also possible in postadolescent young adult subjects a new concept of Class II therapy is presented in which the Herbst appliance is used as an alternative to orthognathic surgery in older Class II subjects.

Current concepts on functional appliances and mandibular growth stimulation.

The mode of action of functional appliances, particularly in relation to stimulating mandibular growth, is a controversial subject. Many of the reports concerning growth effects of functional appliances have been characterized by poor methodology. In assessing functional appliances, results from prospective randomized clinical trials should be given prominence. On the basis of available evidence, it cannot be concluded that functional appliances are effective in stimulating and increasing mandibular growth in the long term. Although favourable growth changes have been reported following phase 1 therapy, they are generally not substantial and long term stability appears to be poor.

Endocrine regulation of craniofacial growth.

This paper presents an updated review of the role of endocrine factors in craniofacial and dental development. Some unpublished results of the author's own studies are presented. Longitudinal growth studies have shown the similarity of facial and somatic growth rates, whereas dental development has been found to be independent. The increased therapeutic use of the growth hormone (GH) has focused attention on the dental and craniofacial effects of GH. Whereas delayed and advanced cranial base and facial growth is obvious in conditions with either lack or excess of GH, the effect of GH on the dentition is less clear. Thyroid hormones seem to be necessary for the eruptive movement of teeth. Sex steroids clearly have an effect on facial and cranial base growth and are also odontogenic, but the effects have not been much studied. The growth-inhibiting effect of corticosteroids is explained partly by the reduced response of cartilage cells to insulin-like growth factor-1. Experimentally, the effect is also seen in the condylar cartilage, but clinical studies have not been published. In tooth eruption an accelerating effect has been noted in experimental animals. The role of androgenic hormones in mandibular growth stimulation is discussed.

A cephalometric, tomographic, and dental cast evaluation of Fränkel therapy

The purpose of this study was to evaluate the skeletal, dental, and condylar positional changes induced by Fränkel FR-2 therapy. The pre- and posttreatment cephalometric, tomographic, and dental cast records of 25 consecutively treated cases were evaluated. Results showed little Class II skeletal correction with no headgear-type restraining effect on the maxilla or mandibular growth stimulation noted. Significant amounts of maxillary incisor retraction and mandibular incisor proclination were observed. The maxillary intermolar width along with the mandibular intercanine and intermolar widths were significantly increased during treatment. No significant changes in condylar position were found during Frankel therapy and only a small increase in mandibular plane angle was noted.