Histological evaluation of periodontal ligament in human after orthodontic treatment with piezosurgery and monolateral tooth dislocation and ligament distraction technique: a first morphologic and histologic evaluation.

Traditional orthodontic tooth movement is based on the concept that application of a protracted force causes alveolar bone remodelling and adaptive changes in periodontal and dental tissues. Thus, if orthodontic tooth movement is described as a biological bone reaction to orthodontic forces mediated by the periodontal ligament (PDL), this event involves a series of sophisticated signal transduction processes that allows the PDL compression with specific histologic and biomolecular modifications. However, the preservation of the integrity of the PDL is generally difficult to achieve when it is associated with a long duration of orthodontic treatment. A total of 20 Caucasian patients with different dental-skeletal were treated using the Monocortical Tooth Dislocation and Ligament Distraction (MTDLD) technique with Piezosurgery associated with morphologic and histological evaluation of the PDL. The histological results obtained, confirm a good clinical outcome with an improvement of the speed on orthodontic treatment without any signs of tissue injury of PDL fiber without areas of hyalinization. The data suggests that MTDLD with Piezosurgery seems to be a valid alternative to the traditional orthodontic movement in adult patients preserving the anatomy and the integrity of PDL.

Piezoelectric surgery inserts vs conventional burst: a clinical investigation.

Piezosurgery is a new technique that can be used to cut mineralized structures without damaging adjacent soft tissues. This device has a lot of advantages: reduced surgical time, blood loss, and inferior alveolar nerve injury in bimaxillary osteotomy. Fifty patients underwent different surgical operations (orthognathic surgery, traumatic surgery, reconstructive surgery, aesthetic procedures) with 7 different kind of piezosurgery inserts in a period of 8 months. The same two surgeons performed all the procedures. All the procedures were carried out in order to improve the precision of the osteotomy and the comfort of the surgeon. Piezoelectric devices provide an innovative ultrasonic technique for safe and effective osteotomy compared with methods that use rotating instruments. Different inserts have been developed in order to achieve the utmost advantages.

[Computer-based preoperative planning for breast reconstruction in the woman with unilateral breast hypoplasia]. / Pianificazione computerizzata per la ricostruzione mammaria in donne affette da ipoplasia mammaria unilaterale.

BACKGROUND: Aim of this paper is to describe a computer program which can provide objective and quantitative data useful for the selection of the proper implant in order to obtain the symmetry with the contralateral breast in case of unilateral breast reconstruction by tissue expansion, especially for the surgeon without experience or for the occasional operator. METHODS: Our C++ program provides the final implant volume using the measurements of the semi-circumference and projection of the contralateral breast performed on the supine patient. The aim is the symmetry of the two breasts. RESULTS: According to our experience in breast reconstruction by tissue expanders, this program allows non invasive and simple measurements of the breast volume, useful to obtain the mammary symmetry. CONCLUSIONS: In case of breast reconstruction by tissue expansion, the preoperative evaluation is usually based on the surgeon's experience and on empirical observations without knowing the correct volume to reach. For this reason our program is useful to know the necessary volume for breast reconstruction, and therefore it allows the surgeon to obtain a better plastic result.

[Experimental model for the evaluation of topical application of a solution to help myocutaneous flap transposition]. / Modèle expérimental pour l'évaluation d'une solution topique améliorant la survie des lambeaux myocutanés.

The aim of this article is the evaluation of the topical application of a solution of hydrogen peroxide (H2O2) 8% and dimethyl sulphoxide (DMSO) 50% in order to reduce ischaemic failure in random skin flaps. This study was performed using a rabbit model. Two parallel, cephalad-based para-midline random cutaneous flap (10 cm x 2.5 cm) were elevated and resutured in place on the dorsum of 40 New Zealand rabbits. The 80 flaps thus obtained were then randomly divided into one control group and three experimental groups of 20 flaps each. Flaps from the control group (group A) were topically treated with saline, while flaps from experimental group B were treated with H2O2 8%, flaps from experimental group C with DMSO 50%, and flaps from experimental group D with a solution of 50% DMSO + 8% H2O2. Each solution was topically applied, 20 cc per three times a day, on the flaps for seven days, starting on the immediate postoperative period. Transcutaneous oxygen tension (Ptc O2) measurements were carried out in all flaps, 72 h after flap elevation. The percentage of surviving skin area of each flap was determined by planimetry 7 days after flap elevation. The mean surviving area of the group A (control) flaps was 71%. The mean surviving area of the group B (H2O2-treated) flaps was 72%. The mean surviving area of the group C (DMSO-treated) flaps was 76%, and that of the group D (DMSO + H2O2-treated) flaps was 92%. While no statistically significant differences were found between the survival rates of both the flaps treated with H2O2 or DMSO alone and that of the control group, the mean surviving rate of the DMSO + H2O2 treated flaps (+20%) was statistically higher than that of the control flaps. Similarly, a statistically significant difference has been found between the mean Ptc O2 values of the DMSO + H2O2 flaps and those of the other three groups of flaps.

[Computer-aided preoperative planning of tissue expansion]. / Pianificazione preoperatoria dell'espansione tissutale supportata dal computer.

OBJECT: The aim of this paper is to introduce a computer program developed to provide objective and quantitative data useful to provide proper expander selection when a rectangular tissue expander has to be used. METHODS: The program has been developed to calculate the volume of a rectangular tissue expander to obtain the exact amount of yield necessary to allow for reconstruction of a determined defect. The only data to be supplied are the length and the width of the defect to be reconstructed. RESULTS: The accuracy of the results obtained by the computer program was tested clinically comparing preoperative data with volume measurements obtained at the end of the expansion procedure. In our study the resulting data did not show any statistically significant difference (p<0,05) between the two groups. CONCLUSIONS: In our opinion, although its use is not aimed at replacing clinical judgment based on experience and careful observation, this program may be considered a simple and useful adjunct for the inexperienced surgeon (or the occasional operator) planning to use a rectangular tissue expander.

[Computer planning for postmastectomy breast reconstruction by tissue expansion]. / Pianificazione computerizzata per la ricostruzione mammaria postmastectomia mediante espansione tissutale.

Aim of this paper is to present a computer program able to provide objective and quantitative data useful to guarantee the selection of the proper implant in order to obtain symmetry with the contralateral breast, in case of unilateral breast reconstruction by tissue expansion, especially for surgeons without experience or for occasional operators. Our C++ program provides the final implant volume using the measurements of the semi-circumference and projection of the contralateral breast performed on the supine patient. The aim is the symmetry of the two breasts. According to personal experience in breast reconstruction by tissue expanders, this program allows non invasive and simple measurements of the breast volume, useful to obtain the mammary symmetry. In case of breast reconstruction by tissue expansion, the preoperative evaluation is usually based on the surgeon experience and on the empirical observation without knowing the correct volume to reach. Since this program is useful to know the precise necessary volume for breast reconstruction, it allows the surgeon to obtain a better plastic result.

Quantitative benefits provided by acute tissue expansion: a biomechanical study in human cadavers.

The aim of this study was to test the ex vivo biomechanical properties of acutely expanded cutaneous flaps to quantitatively assess the efficacy of intraoperative tissue expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (15 x 8 cm), proximally based flap was designed on each side of the body, in three different locations: lateral arm, anterior thorax, anterior thigh. In each cadaver, one randomly selected flap per each body region underwent acute-intermittent expansion, whereas the contralateral flap served as control. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer. The obtained data showed that the biomechanical benefits provided by acute tissue expansion were statistically different (P< 0.05) from those obtained by simple subcutaneous undermining. While no changes of length have been observed in the acutely expanded skin flaps as compared to control cutaneous flaps, a statistically significant gain in the compliance of the former has been recorded as compared to the biomechanical behaviour of the latter.

[Intraoperative expansion of scalp flaps. Quantitative assessment]. / Espansione intraoperatoria di lembi di scalpo. Valutazione quantitativa.

BACKGROUND: The aim of this study was to test the ex-vivo biomechanical properties of acutely expanded scalp flaps, in order to quantitatively assess the efficacy of acute scalp expansion. METHODS: A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally-based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly-selected flap per each scalp underwent acute-intermittent expansion (3-minute expansion-3-minute rest cycle per three times with the maximal expansion achievable), while the contralateral flap served as control. After the expansion process, the acutely-expanded flaps were measured to assess if the applied biomechanical stress have determined any changes in their dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer. RESULTS: The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. Neither any change of length nor any gain in the compliance have been observed in the acutely-expanded flaps as compared to control scalp flaps. CONCLUSIONS: In our opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that inelastic galea aponeurotica did not allow the mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Cleft lip: a histochemical and ultrastructural analysis of lip muscles.

AIMS: In order to evaluate the pathogenesis of cleft-lip in relation to both the anatomical and structural anomalies of the mesenchymal tissues, the authors concluded that the presence of structural anomalies in the examined tissues could not explain the malformation, but might be a consequence of it. Delayed muscular development, asymmetrical distribution of the muscular fibres and their anomalous insertion suggest that the anatomical/functional loss clinically detectable in the orbicular muscle could be the result of a perinatal dysmorphological process rather than of a simple mesenchymal hypoplasia. METHODS: Schendel et al. suggested that a metabolic defect in the mitochondrial function could cause a deficiency in cell migration and proliferation responsible for the malformation in question. To establish whether the pathogenesis of the cleft-lip is associated with an alteration in mitochondrial functionality, eight patients affected by unilateral cleft-lip were subjected to a biopsy of the orbicular muscle during the course of reparative surgery. RESULTS: The results obtained showed: 1) a great variation in the size of muscle fibres; 2) the absence of ragged red fibres; 3) a normal oxidative function in the muscle fibres examined; 4) the absence of typologically significant groupings positive for myofibral ATPases. Furthermore, the morphology of the mitochondria was preserved in all cases and neither inclusions nor morphological or volumetric changes were detected. CONCLUSIONS: This preliminary data did not confirm the constant presence of mitochondrial pathology responsible for the malformation in question. In our opinion, the growth deficiency of the maxillary segment could be ascribed to the cicatrization of the surgical repair of the cleft-lip.