Noninvasive interdisciplinary treatment of a dischromic partially worn dentition.

According to the classic concepts of prosthodontics the treatment of a patient presenting severely worn and dischromic dentition would involve a complex and demolitive treatment including periodontal surgery, endodontic therapy, posts and cores, and crowns; nowadays these problems can be solved with noninvasive procedures that allow preservation of dental and periodontal tissues. This article describes the interdisciplinary team approach (orthodontist, dental technician, prosthodontist) for the treatment of a patient showing attrition of the mandibular incisors in a deep bite relationship, contraction of the posterior sextants of both arches, diastemas in the anterior region of the maxilla, and highly dischromic teeth. The gingival tissue levels and the tooth malposition were corrected by orthodontic therapy, the abraded and the healthy dischromic teeth were restored with 20 additional veneers (the molars were the only teeth not involved in the restorative phase); tooth structure, tooth vitality, and bone level were maintained. No provisional restorations were delivered and no anesthesia was necessary either for tooth preparation or final impression. A protocol is shown to treat in a conservative and comfortable manner the structural and esthetic problems in a patient presenting highly dischromic teeth, worn mandibular incisors, and diastemas on the maxillary sextant.

Measuring 3D-orthodontic actions to guide clinical treatments involving coil springs and miniscrews.

The understanding of the phenomena at the base of tooth movement, due to orthodontic therapy, is an ambitious topic especially with regard to the "optimal forces" able to move teeth without causing irreversible tissue damages. To this aim, a measuring platform for detecting 3D orthodontic actions has been developed. It consists of customized load cells and dedicated acquisition electronics. The force sensors are able to detect, simultaneously and independently of each other, the six orthodontic components which a tooth is affected by. They have been calibrated and then applied on a clinical case that required NiTi closed coil springs and miniscrews for the treatment of upper post-extraction spaces closure. The tests have been conducted on teeth stumps belonging to a plaster cast of the patient's mouth. The load cells characteristics (sensor linearity and repeatability) have been analyzed (0.97 < R 2 < 1; 6.3*10 -6 % < STD < 8.8 %) and, on the basis of calibration data, the actions exerted on teeth have been determined. The biomechanical behavior of the frontal group and clinical interpretation of the results are discussed.

A comparative study of two different clear aligner systems.

BACKGROUND: This study aims to compare the 'Nuvola®' system with 'Fantasmino®' system, examine their material properties, and define the indications for use of the aligners. METHODS: Two groups of patients were selected and were respectively treated with Nuvola® aligner and Fantasmino® system. RESULTS: The goal of treatment has been achieved with the two systems. CONCLUSIONS: The two types of aligners have shown differences during the treatment. Fantasmino® system has elastic properties of high performance, but its size does not encourage compliance throughout the day. Nuvola® system determines good tooth movement and its size facilitates the patient's collaboration. In both aligner systems, difficulties were found in the correction of torque information and rotations.

Mini-implants and the efficiency of Herbst treatment: a preliminary study.

BACKGROUND: The purpose of this study is to present the use of a modified Herbst appliance in association with temporary anchorage devices (TADs) in order to enhance the correction of skeletal class II malocclusions. METHODS: Ten consecutive adolescents scheduled for Herbst treatment were assigned to two treatment groups. Five cases were treated with a modified miniscrew-supported Herbst appliance (experimental group (EG)) and five cases with a conventional cast Herbst appliance (control group (CG)). In all cases, the Herbst was kept in place for 9 months and was followed by fixed appliances until class I relationships were achieved. The initial (T1) and final (T2) lower incisor inclination on lateral headfilms were analyzed for each case, and the mean increase for the five EG patients and the five CG patients were compared. RESULTS: The mean increase in lower incisor inclination at the end of treatment was 1° (range 0° to 2°) for the EG and 7° (range 4° to 10°) for the CG. CONCLUSIONS: The rational association of TADs with the Herbst appliance can optimize treatment efficiency and skeletal response by reducing the occurrence of excessive lower incisor proclination.

[Skeletal Class II treatment with the miniscrew-anchored Herbst]. / Traitement de la classe II squelettique au moyen d'un appareil de Herbst à ancrage osseux.

No-compliance orthodontic treatment has recently become very popular. Unlike removable appliances requiring patient compliance, the Herbst appliance is a widely used fixed functional bite-jumping device generating predictable results in the treatment of skeletal class II malocclusions. The main problem associated with tooth-borne bite-jumping appliances is the generation of unavoidable dental movements, especially proclination of lower incisors, in addition to the skeletal effect. These dento-alveolar compensations can, when uncontrolled, compromise treatment results. This article describes two cases managed with a new treatment protocol based on the association of a modified Herbst appliance and temporary skeletal anchorage devices (TSADs) for efficient treatment of skeletal class II malocclusions.

Inter- relationships between orthodontics and posture: basic theories.

The first part of the present report deals mainly with the concept of posture - both in static and in dynamic sense - its relationships with equilibrium, weight balance and motion, its phylogenic origin, reasons why any orthodontic professional should be aware of it; moreover, different profile types and their connections with one's own skeletal class are briefly discussed. Two more papers are following on the subject.

Immediate loading of orthodontic mini-implants: a histomorphometric evaluation of tissue reaction.

Although immediate loading of orthodontic mini-implants can be clinically successful, a lack of histological data exists. The present investigation was performed to evaluate, in an animal model, tissue reaction to immediate loading. Fifty orthodontic titanium mini-implants were inserted in four adult male monkeys at four time intervals. Forty-two devices were loaded with 50 cN super-elastic coil springs immediately after insertion while eight were left unloaded and served as the controls. After euthanasia, the following histomorphometric parameters were evaluated: bone volume (BV/TV), bone-to-implant contact (BIC), mineralizing surface (MS/BS), and erosion surface (ES/BS). Statistical analysis was performed by means of non-parametric tests. Four devices were removed because of loss of stability. A wide variation between animals was found for all parameters. BV/TV: slightly higher values were found in the unloaded sample. Although no particular trend was observed, at 3 months higher values were found in the lower jaw. BIC: a trend to a decrease between 1 week and 1 month followed by a significantly progressive increase was observed. Implants that showed some sections with as little as 3 per cent BIC successfully resisted loading. MS/BS: higher values were found in the lower jaw. MS/BS increased significantly between 1 week and 1 month, followed by a progressive decrease. ES/BS: there was a decrease between 1 week and 1 month, followed by a progressive re-increase. BV/TV did not show any particular trend while BIC was a time-dependent factor. MS/BS and ES/BS demonstrated opposite trends during the healing period. Immediate loading with light forces did not negatively affect the bone healing pattern.

A prospective clinical investigation of the failure rate of immediately loaded mini-implants used for orthodontic anchorage.

AIM: To evaluate the failure rate of immediately loaded mini-implants used for orthodontic anchorage. MATERIALS AND METHODS: 140 mini-implants were inserted in 98 patients and immediately loaded with 50cN super-elastic coil springs. 99 devices were inserted in the lower jaw and 41 in the upper jaw in the following sites: mandibular symphusis (n=17), mandibular alveolar process (n=72), maxillary alveolar process (n=32), retromolar area (n=10), and palate (n=9). The mini-implants were used to perform the following dental movements: molar uprighting, molar uprighting and mesial movement, molar mesial movement, incisor intrusion and proclination, incisor retraction, premolar intrusion, midline correction, premolar distal movement, and molar intrusion. All devices that showed complete absence of mobility after 120 days of continuous load were scored as successful. Those that showed minimum mobility but stayed in place and could resist further load were scored as partial failures, while those that were lost were scored as failures. RESULTS: 13 of the mini-implants failed (9.3%), 9 were partial failures (6.4%). The upper jaw had a greater failure rate (12.2%) than the lower jaw (8.0%). The palate was the anatomic location with the greatest risk of failure, while in the mandibular alveolar process the lowest failure rate was observed. CONCLUSIONS: The overall failure rate was similar to other investigations where a healing period had been performed, suggesting that immediate loading with light forces should not be considered a risk factor. Other factors such as inflammation of the surrounding soft tissues, bone characteristics, thickness of the mucosa and incorrect surgical procedure should be considered determinants of clinical failure.