Marco Portelli

TOOTH ORTHODONTIC MOVEMENT AFTER MAXILLOFACIAL SURGERY

The purpose of this study is to compare the rate of orthodontic tooth movement in regenerated bone, created after mandibular Distraction Osteogenesis (DO), with the rate of orthodontic tooth movement in patients who had extractions. The sample group (treated subjects) was composed of 14 Class II patients (5 males and 9 females, mean age 25.0±1.1years) treated with a Distraction Osteogenesis appliance; the control group (extraction cases) was composed of 14 subjects (mean age 21.9±3.1 years). Both groups were followed by conventional orthodontic treatment for space closure. Teeth movements (amount and fate) were evaluated by measuring the distance between the distal wing of the canine bracket and the mesial wing of the first or the second premolar bracket, depending on the group, using Vernier callipers (Dentaurum). Readings were noted every 2 weeks until space closure was completed. In this study the mean duration of the post-distraction orthodontic treatment was 12±0.3 months. Our study showed that the space created by distraction was closed in 10±1 months; while with conventional orthodontic treatment the average time to complete space closure was 5.90±0.9 months. The average space closure was 6.50±0.10 mm with conventional orthodontic treatment and 7.90±0.38 mm in the patients treated with DO. The mean rate of tooth movement was 1.27±0.23 mm/month in the group with conventional orthodontic treatment and 0.68±0.20 mm/month in the group treated with DO. Unpaired t test showed a significant difference between tooth movement in the study sample and in the control group (p<.05). As suggested by most scientific literature, in our sample dental movement was started at the end of the consolidation phase. However, the rate of space closure in the distraction area was higher than with conventional orthodontic treatment. Undoubtedly, this approach can be used for the treatment of very severe skeletal malocclusions and maxillofacial deformities, but it cannot be considered an alternative to conventional orthodontic surgery to accelerate treatment because tooth movement in edentulous spaces created by osteodistraction requires more time.

Low-dose protocol of the spiral CT in orthodontics: comparative evaluation of entrance skin dose with traditional X-ray techniques

BackgroundThe aim of this study was to evaluate the amount of radiation doses absorbed by soft tissues (entrance skin dose) with a low-dose spiral computed tomography (CT) protocol compared to conventional X-ray techniques commonly used in orthodontics.MethodsThe amount of skin dose has been evaluated using a tissue-equivalent head-neck radiotherapy humanoid phantom with thermoluminescent dosimeters placed at the level of eye lens, parotid glands, and thyroid glands. CT images have been taken using a Sensation 16 Siemens CT scan and a low-dose protocol (15 mAs, 1 pitch, 2.5 mGy (CTDIvol), 80 kV, 1-mm slice thickness).ResultsThe difference in image quality between traditional X-ray techniques and low-dose spiral CT was statistically significant (P < 0.05). The difference in mean absorbed dose instead was not statistically significant.ConclusionsOur protocol allows a more accurate orthodontic diagnosis without an increase of radiological risk for the patients in comparison to traditional X-ray techniques.

Delayed progressive haematoma after Le Fort I osteotomy: A possible severe complication in orthognatic surgery

Although the Le Fort I osteotomy is a safe surgical technique, many complications have been reported. We present a case of an extended cervico-facial haematoma due to delayed bleeding from the terminal branches of the maxillary artery after orthognatic surgery. A 23-year-old man was referred to our observation for the surgical correction of a class III asymmetric malocclusion. The patient underwent a Le Fort I osteotomy, with impaction of the maxilla, associated with an Epker mandibular bilateral sagittal split osteotomy, with maxillary advancement and rigid internal fixation of the mandible with four miniplates and another four for the upper maxilla as well. The first post-surgery day, the patient developed a gradual dispnea together with neck swelling. By second postoperative day, the patients general condition improved with a progressive normalization of laboratory tests values. The Computerised Axial Tomography (CAT) scan confirmed a decrease in the parapharyngeal thickening. Total recovery was achieved within two months, the final clinical check showed a healthy appearance with good occlusion. An increased knowledge of the basic biology of the Le Fort I osteotomy, the development of instruments specially designed for the Le Fort I procedure and the use of hypotensive anaesthesia could reduce the morbidity and duration of this procedure.

Histomorphometric Evaluation of Two Different Bone Substitutes in Sinus Floor Augmentation Procedures.

The aim of this study is to compare the histomorphometric data of deproteinized bovine bone (DBB) and a fully synthetic bone substitute, poly (lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA) applied for sinus floor augmentation technique. Twelve maxillary atrophic ridges of 8 patients requiring major maxillary sinus floor augmentation were studied; the sites were randomly assigned to the study groups and reexamined at 6 months after grafting using cone beam computed tomography scans and biopsy samples harvested during dental implant placement. Total bone volume, residual graft material volume, and new bone volume were assessed. Measurable biopsies were available from 67% of test sites and 100% of control sites. Poly (lactic-co-glycolic) acid/hydroxyapatite grafts showed no trace of graft material, whereas DBB grafts had a mean graft area of 16.60%. Mean percent of newly formed bone tended to be greater for PLGA/HA than for DBB group. Mean total bone volume percent did not differ significantly: PLGA/HA = 44.45% (CI, 16.42-72.48), DBB = 44.11% (CI, 36.61-51.60). Deproteinized bovine bone and PLGA/HA produced similar total bone volumes. Poly (lactic-co-glycolic) acid/hydroxyapatite appeared to be completely replaced by newly formed bone, whereas DBB presented significant amounts of residual graft material. Poly (lactic-co-glycolic) acid/hydroxyapatite necessitates of more clinical trials to be considered suitable for sinus floor augmentation.

No Compliance Correction of Class II Malocclusion in Growing Patients Whit HERBST Appliance: A Case Report

Background: Class II malocclusion is the most common sagittal skeletal discrepancy, with a prevalent skeletal pattern of mandibular retrusion. The correction of mandibular retrusion with functional removable appliance needs a good patient’s compliance; for this reason, some clinicians prefer to use no compliance apparatus. Objective: Objective of the present therapy note is to demonstrate that the use of no compliance apparatus can provide a good correction of skeletal class II malocclusion. Methods: In the present study, authors report a therapy note referred to a 10 years old patient, woman, affected by Class II, with mandibular retrusion and deep bite, treated in 2013 at the Dep. of Orthodontics of Messina University. An orthodontic treatment has been planned with the aim of stimulating mandibular growth; an Herbst appliance with a cantilever design, bonded on first maxillary and mandibular molars, has been used. After eleven months of functional therapy a bilateral molar class I have been obtained. Results: In the therapy note proposed, authors obtained a resolution of mandibular retrusion, a correction of overjet, overbite and dental crowding in both arches, and a bilateral molar and canine class I has been achieved. Conclusion: Herbst appliance seems to be efficient in the correction of II Class Malocclusion, independently from patient’s cooperation; moreover , early correction of Class II malocclusion with functional appliances produces several clinical advantages.

Oxidative Stress Evaluation in Patients Treated with Orthodontic Self-ligating Multibracket Appliances: An Case-Control Study

Objective: Oxidative stress is a pathologic event induced by a prevalence of oxidant agents on the antioxidant ones, with a consequent alteration of oxide-reducing balance. Introduction: Freeradicals produce damages both in cellular and extra-cellular components; phospholipid membranes, proteins, mitochondrial and nuclear DNA, are the target of the oxidative stress, that can finally cause cellular death due to apoptosis. Materials & Methods: Orthodontic appliances such as brackets, wires, resins and soldering have some components that can be considered as potential allergen, carcinogenic, cytotoxic and gene mutation factors. The primary aim of this research is to evaluate oxidative stress in the saliva of patients treated with multibracket self-ligating vestibular orthodontic appliances; the secondary purpose is to investigate the influence of orthodontic multibracket therapy on oral hygiene and the consequent effect on oxidative stress. Salivary specimens has been collected in a sample of 23 patients were enrolled (12 Female, 11 Male) between 12 and 16 years of age (mean age 14.2). For each patient has been collected a salivary specimen at the following time points; before orthodontic bonding (T1), five weeks (T2) and ten weeks (T3) after orthodontic appliance bonding. Results: Samples has been analysed with a photometer due to SAT Test (Salivary Antioxidant Test). Data obtained show a mean of 2971 mEq/l of anti-oxidant agents before orthodontic treatment, and after five weeks from the bonding the mean was decreased to 2909 mEq/l, instead at ten weeks was increased to 3332 mEq/l. Repeated measures ANOVA did not reveal statistically significant differences between the time points (P = 0.1697). The study did not reveal any correlation between the level of dental hygiene and that of oxidative stress (Pearson Correlation Coefficient R = 0). Conclusion: Orthodontic treatment with multibrackets vestibular metallic appliance seems to be not able to affect oxidative stress during the first ten weeks of therapy.

Effects of rapid vs slow maxillary expansion on nasal cavity dimensions in growing subjects: A methodological and reproducibility study

AIM To evaluate the methodological feasibility of a RCT comparing skeletal changes of nasal cavity size obtained with RME and SME, assessed via CBCT. MATERIALS AND METHODS Twenty Caucasian children with a mean age of 10.4 years were recruited and allocated to receive RME (10 subjects, mean age 10.4 years) or SME (10 subjects, mean age 10.5 years). INCLUSION CRITERIA constricted maxillary arch, upper and lower first molars erupted, unilateral or bilateral posterior crossbite. EXCLUSION CRITERIA age above 15 years, history of previous orthodontic treatment, periodontal disease, systemic disease affecting craniofacial growth, or craniofacial congenital syndrome. CBCT examinations were performed before treatment (T0) and 7 months after expander removal (T1). Changes of nasal width (NW), palatal width (PW) and total nasal volume (TNV) were assessed; palatal and nasal expansion was also calculated as a percentage of the increase of intermolar width IMW (PW% and NW%). RESULTS The correlation between the first and the second readings ranged from 0.991 to 0.995 for linear measurements and was of 0.915 for volumetric measurements. The method error, as described by the value of ?, was in general less than 0.3 mm for linear measurements and 0.372 cm³ for volumetric measurements. All linear transverse skeletal and dental measurements and the nasal volume increased with both RME and SME protocols. CONCLUSION The reported methodology can be reasonably used to investigate the transverse dimension of nasal cavity. The PW% and NW% parameters more accurately described the efficacy of the two expansion protocols as compared to their corresponding absolute measurement (PW and NW).