Alberto Di Blasio

Success of miniscrews used as anchorage for orthodontic treatment: analysis of different factors

OBJECTIVES To examine factors involved in clinical success of miniscrew implants used for orthodontic anchorage in the upper jaw. MATERIALS AND METHODS One hundred and forty-four patients (93 females and 51 males) were fitted with a total of 324 miniscrew implants of two different morphologies (cylindrical and conical), and of different lengths and diameters. The clinical factors examined were screw length, side of insertion, miniscrew shape and diameter, bone quality, skeletal type, and relationship between bone quality and skeletal type and patient age. RESULTS The mean overall success rate of the implants was 91.4%. The length and shape of the miniscrews significantly influenced the success rate, whereas side of insertion (left or right), screw diameter and skeletal type showed no significant effects. Poor (soft) bone quality and good (hard) bone quality are risk factors for miniscrew failure, with the best results obtained when the screws are inserted into bone of medium quality (10-15Ncm). CONCLUSION In the posterior areas of the upper jaw, long, conical miniscrews showed a significantly greater success rate. An insertion torque of 10 Ncm to 15 Ncm is also a significant index of higher success rate.

How does the mandible grow after early high condylectomy

AbstractThe early high condylectomy (HC), removing the overgrowing area of the condyle, may be indicated for condylar hyperplasia. However, in young patients, when the HC removes the pathological overgrowing tissue the contralateral condyle is still growing. May this surgical procedure, in these growing patients, stop the operated side growth creating the conditions for an opposite asymmetry? Authors investigate the way the operated mandible develops after the early HC, both as a symmetry percentage and in an absolute value related to the unaffected side. A sample of 8 consecutive growing patients, 1 male and 7 females, referred to the Maxillofacial Surgery Department of Parma University for HC were investigated. Patients were longitudinally studied with 3 orthopantomographies at: T0 (diagnosis: mean age, 13 years; range, 11 years 2 months to 13 years 8 months), T1 (after surgery: mean age, 15; range, 13–18 years) and T2 (follow-up: mean age, 18 years; range, 17–20 years). The x-ray is used to study the condyle, ramus, and total vertical structures length by Mattila tracing method. The data were analyzed by the Student t test and Wilcoxon matched pairs test; P value was set at 0.5. The operated side was overcorrected by HC and; during the investigated period, its growth decreased from T0 to T1 and restarted from T1 to T2. The whole T0–T2 growth of the operated side was not statistically different from the one of the healthy side (P < 0.05). These results suggest that the operated side growth may continue in a more normal way after condylectomy.

Combined photographic and ultrasonographic measurement of the ANB angle: a pilot study

ObjectiveThis study was performed to evaluate the feasibility of noninvasive measurement of the ANB angle using photographic and ultrasonographic methods.MethodsTwenty consecutive orthodontic patients were evaluated. The ANB angle and soft tissue thickness covering the N, A, and B cephalometric points were measured by lateral teleradiography; these measurements were made by two expert operators. The soft tissue thickness covering the N, A, and B cephalometric points was measured by ultrasonography; these measurements were also made by two expert operators. On a 1:1 photographic profile print on which the ultrasonographic points were marked, the ANB ultrasonographic angle was measured. The following comparisons were considered: averaged and single measurements of N, A, and B points by first versus second ultrasonographer; averaged and single ultrasonographic versus radiographic soft tissue thickness covering the N, A, B points; and averaged and single ultrasonographic versus radiographic measurements of ANB angle.ResultsHigh correlation and concordance of the averaged and single measurements, but no significant difference, was found between the two ultrasonographers. No statistically significant difference was found between the two methods for measuring averaged soft tissue thickness, but a 20% difference was found for the single measurements. High correlation and concordance between the ultrasonographic and radiographic measurements, but no significant difference, was found between the single and averaged ANB angle measurements.ConclusionUltrasonography seems to be a noninvasive and reliable technique for measurement of the ANB angle and may replace radiographic measurement in some cases.

Pre- and Postsurgical Orthodontics in Patients with Moebius Syndrome

The authors report a combined orthodontic-surgical correction of an adult patients malocclusion affected by Moebius Syndrome (MS). The treatment was conducted at the Dentistry Unit and the Maxillofacial Surgery Unit of the University Hospital of Parma. Treatment of malocclusion was performed after the correction of facial mimic mobility with smile surgery. The postoperative stability and orthodontic results were good and the correction of the morphological problems related to the syndrome was very satisfactory.

Dentoalveolar Effects of Early Orthodontic Treatment in Patients With Cleft Lip and Palate

Abstract No agreement exists on the most appropriate timing of orthodontic treatment in patients with cleft lip and palate. The aim of this study is to investigate the effect of early orthodontic treatment on development of the dental arches and alveolar bone. A dental casts analysis was performed on 28 children with cleft lip and palate before orthodontic treatment (T0; mean age, 6.5 ± 1.7) and at the end of active treatment (T1; mean age, 9.2 ± 2.1 years). The considered variables were: intercanine and intermolar distances; dental arch relationships, evaluated according to the modified Huddart/Bodenham system. The study group was divided into 2 samples according to the age at T0: Group A (age < 6 years) and Group B (age ≥ 6 years). A statistical comparison of the treatment effects between the 2 samples was performed. Patients in Group A exhibited a greater increase of intercanine distance (8 mm versus 2.7 mm; P<0.001), intermolar distance (7.2 mm versus 5 mm; P = 0.06), and Huddart/Bodenham score (7.1 versus 3; P < 0.05) when compared with patients in Group B. Early orthodontic treatment strongly improved the dental arch relationship, since subjects starting the therapy before the age of 6 had a better response in terms of anterior maxillary expansion.

Asymmetric Expansion with a Modified Quad Helix for Treatment of Isolated Crossbite

Unilateral posterior crossbite often involves only one tooth, especially upper first molar; in these cases it is never easy to obtain an asymmetrical movement of a molar and a proper planning of the orthodontic device with its anchorage is necessary to avoid arch overexpansion. Thanks to its simplicity and efficacy, the modified Quad Helix here described represents a valid therapeutic tool in cases of isolated posterior crossbite.

Functional Treatment of a Child with Extracapsular Mandibular Fracture

Condylar fractures are among the most frequent fractures in the context of traumatic lesions of the face. The management of condylar fractures is still controversial, especially when fractures occur in children: if overlooked or inappropriately treated, these lesions may lead to severe sequelae, both cosmetic and functional. The therapy must be careful because severe long-term complications can occur. In this case report, the authors present a case of mandibular fracture in which the decision between surgical therapy and functional therapeutic regimen may be controversial due to the particular anatomy of the fracture line and the age of the patient.

The integration of orthodontic miniscrews under mechanical loading: a pre-clinical study in rabbit

Introduction Orthodontic miniscrews are an increasingly popular choice to achieve absolute anchorage. The temporary use of miniscrews and their recent introduction have limited the debate over the biological aspect of the materials to that of the surface that permeates the field of dental implants. The aim of the present study was to investigate the integration of grade 5 titanium mini-implants with machined or sand blasted acid etched surface (SAE) under mechanical load in a rabbit tibia model of implant integration. Methods A total of 64 miniscrews (Ti6Al4V) of 1.5 mm diameter and 6.5 mm length were inserted in the proximal medial surface of each tibia in eight male rabbits aged 6 months. Each tibia received four miniscrews. A 100 g nickel-titanium coil spring (Neosentalloy) was applied between two miniscrews along the main axis while two miniscrews were left unloaded. The removal torque was measured for loaded and unloaded miniscrews after 12 weeks. Two miniscrews were harvested for histology. Results Removal torque was significantly higher for SAE mini-implants than for machined screws, under both loading conditions. Although no difference in bone to implant contact was observed among the groups, cortical area significantly decreased with both surfaces under loading. Conclusions Our data indicate that SAE miniscrews have higher bone retention than MA miniscrews, although the effects of mechanical loading of these devices on cortical bone require further investigations.

Early Orthopaedic Treatment of Hemifacial Microsomia

The aim of this paper is to report treatment effects of functional therapy in a growing patient affected by hemifacial microsomia (HM). According to Kabans classification, the patient was classified as grade IIa as she presented all mandibular and temporomandibular joint components and a normal shaped, hypoplastic mandible. The therapeutic approach included the use of an asymmetrical functional activator (AFA) to stimulate the growth of the affected side and consequently to improve symmetry of the mandible and maxillary deficiency. Further effects were the lengthening of the mandibular ramus, restoration of occlusion, and expansion of soft tissues.

Virtual Planning of a Complex Three-Part Bimaxillary Osteotomy

In maxillofacial surgery, every patient presents special problems requiring careful evaluation. Conventional methods to study the deformities are still reliable, but the advent of tridimensional (3D) imaging, especially computed tomography (CT) scan and laser scanning of casts, created the opportunity to better understanding the skeletal support and the soft tissue structures. Nowadays, virtual technologies are increasingly employed in maxillofacial surgery and demonstrated precision and reliability. However, in complex surgical procedures, these new technologies are still controversial. Especially in the less frequent cases of three-part maxillary surgery, the experience is limited, and scientific literature cannot give a clear support. This paper presents the case of a young patient affected by a complex long face dentofacial deformity treated by a bimaxillary surgery with three-part segmentation of the maxilla. The operator performed the surgical study completely with a virtual workflow. Pre- and postoperative CT scan and optical scanning of plaster models were collected and compared. Every postoperatory maxillary piece was superimposed with the presurgical one, and the differences were examined in a color-coded map. Only mild differences were found near the osteotomy lines, when the bony surface and the teeth demonstrated an excellent coincidence.