Biological effect of resorbable plates on normal osteoblasts and osteoblasts derived from Pfeiffer syndrome

Mechanical Behaviour and Primary Stability of a Self-Condensing Implant: A Laboratory Critical Simulation of a Severe Maxillary Atrophy on Polyurethane Lamina

Background: Posterior maxillary atrophies could emerge after the loss of teeth, trauma, infections, or lesions that often require regenerative approaches. In these critical conditions, the achievement of implant primary stability represents a clinical challenge in the operative practice. Therefore, a two-stage approach is often preferred with a delay of the rehabilitation time and a consistent increasing of the biological and the operative costs. The aim of this study was to evaluate the mechanical behaviour of a self-condenser implant compared to a standard implant in a critical simulation on different thicknesses and densities of polyurethane lamina. Materials and methods: A total of two implant models were tested: a self-condensing device (test) and a standard implant (control). The study evaluated the insertion torque and the pull-out strength values of the test and control implants inserted in different sizes (1, 2, and 3 mm) and density polyurethane lamina (10, 20, and 30 pcf) for a total of 320 experimental sites. Results: In total, 320 experimental sites were produced in the polyurethane samples. A statistically significant difference of insertion and pull-out torque values between the test and control Implants was found in the different bone densities (p < 0.05). The insertion and pull-out torque values were always higher for the test implants in all experimental conditions. In all bone densities, the insertion torque values were higher than the pull-out torque values. The self-condenser dental implant design evaluated in this in vitro study showed a high level of stability in all experimental conditions. Conclusions: The test implant could represent a useful tool for a one-stage surgical approach in the presence of limited residual native bone as an alternative to a delayed technique.

Midpalatal Suture Density Evaluation after Rapid and Slow Maxillary Expansion with a Low-Dose CT Protocol: A Retrospective Study

Background and objectives: The aim of the present paper is to use low-dose computed tomography (CT) to evaluate the changes in the midpalatal suture density in patients treated with rapid maxillary expansion (RME) and slow maxillary expansion (SME). Materials and Methods: Thirty patients (mean age 10.2 ± 1.2 years) were retrospectively selected from the existing sample of a previous study. For each patient, a low-dose computed tomography examination was performed before appliance placement (T0) and at the end of retention (T1), seven months later. Using the collected images, the midpalatal suture density was evaluated in six regions of interest. Results: No significant differences were found between the timepoints in the rapid maxillary expansion group. Three out of six regions of interest showed significant decreases between the timepoints in the slow maxillary expansion group. No significant differences were found in comparisons between the two groups. Conclusions: The midpalatal suture density showed no significant differences when rapid maxillary expansion groups were compared to slow maxillary expansion groups, suggesting that a similar rate of suture reorganization occurs despite different expansion protocols.

Molecular mechanisms underlying nuchal hump formation in dolphin cichlid, Cyrtocara moorii

East African cichlid fishes represent a model to tackle adaptive changes and their connection to rapid speciation and ecological distinction. In comparison to bony craniofacial tissues, adaptive morphogenesis of soft tissues has been rarely addressed, particularly at the molecular level. The nuchal hump in cichlids fishes is one such soft-tissue and exaggerated trait that is hypothesized to play an innovative role in the adaptive radiation of cichlids fishes. It has also evolved in parallel across lakes in East Africa and Central America. Using gene expression profiling, we identified and validated a set of genes involved in nuchal hump formation in the Lake Malawi dolphin cichlid, Cyrtocara moorii. In particular, we found genes differentially expressed in the nuchal hump, which are involved in controlling cell proliferation (btg3, fosl1a and pdgfrb), cell growth (dlk1), craniofacial morphogenesis (dlx5a, mycn and tcf12), as well as regulators of growth-related signals (dpt, pappa and socs2). This is the first study to identify the set of genes associated with nuchal hump formation in cichlids. Given that the hump is a trait that evolved repeatedly in several African and American cichlid lineages, it would be interesting to see if the molecular pathways and genes triggering hump formation follow a common genetic track or if the trait evolved in parallel, with distinct mechanisms, in other cichlid adaptive radiations and even in other teleost fishes.

Cleft palate only: current concepts

Cleft palate only (CPO) is one of the most common congenital malformations worldwide. The etiopathogenesis of CPO is not completely understood. Environmental factors, such as smoking, alcohol consumption, intake of drugs during pregnancy, advanced paternal age, have been demonstrated to be a risk of CPO, but conflicting results have also been published. Insufficient intake of folic acid during the pregnancy has been suggested to increase the risk for CPO. The demonstrated risk for siblings and the higher risk for monozygotic twins suggest a genetic etiopathogenesis for CPO. In some cases of CPO a prevalent mode of inheritance has been reported, but oligogenic models with reduced penetrance, and the risk related to environmental factors have also been proved. One of the first manifestations associated with CPO is difficulty with feeding. Aerophagia is a problem in these infants with CPO and requires more frequent burping and slower feeding. The inability to generate intraoral breath pressure due to nasal air emission in CPO children frequently manifests as articulation difficulties, particularly consonant weakness, and unintelligible speech. Hearing disorders are prevalent among individuals with CPO, as a result of chronic otitis media with effusion due to eustachian tube dysfunction. A multidisciplinary team is essential to manage the many aspects of CPO. In treating CPO, the reconstructive surgeon works in cooperation with otolaryngologists, dentists and orthodontists, speech pathologists, audiologists, geneticists, psychiatrists, maxillofacial surgeons, social workers, and prosthodontists. CPO can be considered a genetically complex disease, but new knowledge and new therapeutic approaches have greatly improved the quality of life of these children. Prenatal diagnosis is an important step in the treatment of this disease.

New insights in orofacial cleft: epidemiological and genetic studies on italian samples

Cleft of the lip and/or palate (CL±P) is the most common congenital craniofacial anomaly affecting around 1 in 700 live births worldwide. Clefts of the human face can be classified anatomically as cleft lip only (CL), cleft palate only (CP), cleft lip and palate (CLP) or a combined group of cleft lip with or without cleft palate (CL±P), based on differences in embryologic development. CL±P has a genetic base and several linkage and association analyses have been performed in order to obtain important information about the role of candidate genes in its onset; not less important are gene-environment interactions that play an increasing role in its aetiology. In CL±P, several loci have been seen associated with the malformation, and, in some cases, a specific gene mapping in a locus has also been identified as susceptibility factor. In CP, one gene has been found, but many more are probably involved. In this short review the genetic studies carried out on CL±P, and the interaction with environmental factors (alcohol, smoking, drugs) are discussed.

Radiographic evaluation of regenerated bone following poly(lactic-co-glycolic) acid/hydroxyapatite and deproteinized bovine bone graft in sinus lifting

Although numerous biomaterials are used for maxillary sinus-lift surgery, the ideal material for such procedures has not yet been identified. Both heterologous and alloplastic bone substitutes have a solely osteoconductive effect and lack the osteoinductive properties of the bone morphogenetic proteins typical of autologous bone. Our group assessed a new alloplastic graft material, poly(lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA), implanted in a human model of maxillary sinus-lift surgery. For this prospective, random, double-blind trial, we used deproteinized bovine bone (DBB) as the comparison material. Radiographic bone vertical height and density were assessed at approximately 28 weeks after grafting using cone-beam computed tomography. The vertical dimension of the regenerated bone was equivalent between the 2 groups. The density of the bone regenerated using PLGA/HA was significantly lower than that obtained with DBB. Despite clinical assessments demonstrating that PLGA/HA has sufficient characteristics for use in sinus-lift surgery, DBB provided greater bone density and an equivalent vertical dimension of grafted bone. Further studies are needed to supplement the radiologic findings with histologic and micromorphometric examinations.

Piezosurgery versus conventional osteotomy in orthognathic surgery: a paradigm shift in treatment

The aim of the study was to compare in a randomized controlled clinical trial the use of the piezoelectric osteotomy as an alternative to the conventional approach in terms of surgery time, intraoperative blood loss, cut quality, nerve injury, and costs.One hundred ten patients who had orthognathic surgery procedures with bimaxillary osteotomy were divided into 2 groups: group A was treated with a piezosurgery device, and group B, with a reciprocating saw and bur.The piezosurgical bone osteotomy permitted individualized cut designs. The surgical time in group A was reduced, with a mean for the mandibular osteotomy (1 side) between 3 minutes 31 seconds and 5 minutes 2 seconds, whereas in group B, the surgical time was between 7 minutes 23 seconds and 10 minutes 22 seconds. The surgical time in group A for the Le Fort I osteotomy was between 5 minutes 17 seconds and 7 minutes 55 seconds in group A and between 8 minutes 38 seconds and 15 minutes 11 seconds in group B. All patients in group A had a low blood loss (<300 mL) versus patients of group B who had a medium to high blood loss (medium loss: 400 mL, high loss: >500 mL). Inferior alveolar nerve sensation was retained in 98.2% of group A versus 92.7% in group B at 6 months postoperative testing.Piezoelectric osteotomy reduced surgical time, blood loss, and inferior alveolar nerve injury in bimaxillary osteotomy. Absence of macrovibrations makes the instrument more manageable and easy to use and allows greater intraoperative control with higher safety in cutting in difficult anatomical regions.

Comparison of titanium and biodegradable plates for treating midfacial fractures

PURPOSE

The purpose of the present study was to evaluate the use of titanium plates and screws (TPSs) versus biodegradable plates and screws (BPSs) for fixation of midfacial fractures. In addition, complications related to the plates and rates of secondary surgery for plate removal were compared.

PATIENTS AND METHODS

From March 2005 to March 2012, 109 patients were enrolled in this study. Fifty-six patients with TPSs implanted to fix midfacial fractures (group A) and 53 patients with BPSs to treat midfacial fractures (group B) were evaluated. Patients' histories of plate-related nonunion, infection, displacement, pain, and palpability and secondary surgery for plate removal were checked.

RESULTS

None of the study participants developed nonunion issues related to the TPSs or BPSs. Six patients in group A developed complications associated with TPSs and 5 patients underwent secondary surgery for plate removal. One patient (1.8%) had a plate-related infection, 1 patient (1.8%) developed plate extrusion, 1 patient (1.8%) had plate-associated chronic pain, 2 patients (3.6%) complained of palpability, and 2 patients (3.6%) developed psychological problems (1 patient developed 2 complications). In contrast, only 1 patient in group B (2%) complained of temporary palpability, and this problem disappeared over time. None of the patients in group B complained of any other problems.

CONCLUSIONS

The results indicated that BPSs and TPSs have the potential for successfully treating midfacial fractures. BPSs are suitable for treating midfacial fractures and could serve as an alternative for TPSs in selected cases.

Orthodontic-surgical treatment: neuromuscular evaluation in open and deep skeletal bite patients

BACKGROUND

The aim of this study was to compare electromyographic data of two groups of patients (open and deep skeletal bite) before and after surgical orthodontic treatment.

METHODS

All patients who underwent orthognathic surgery at the Department of Orthodontics (University of Milan) were subjected to periodic electromyographic evaluation of the masticatory muscles (masseter and anterior temporal muscles) and to electrokinesiographic evaluation of mandibular movements. The sample comprised 72 patients (35 open skeletal bite patients and 37 deep skeletal bite patients) at the end of craniofacial growth. The electromyographic instruments used in the study included a Freely and a K6-I electromyograph. Statistical evaluation was carried out with Student's t tests for independent samples.

RESULTS

Lots of differences between open and deep skeletal bite patients have been underlined by the analysis of the electromyographic data obtained. These results have been obtained with both electromyographic systems. Muscular activity in microvolts is higher in deep skeletal bite patients at the beginning of the treatment than in open bite ones, but during the following phases of the treatment, the two values became similar.

CONCLUSIONS

Morphologic differences between open and deep bite patients can also be demonstrated by instrumental examinations, and their correction after surgical treatment is observable on electromyographic and electrognatographic exams.

Periodontal effects with self ligating appliances and laser biostimulation

Background:

Recently, various biostimulation's effects of low energy laser irradiation have been reported. The present study was designed to examine the effects of low-energy laser irradiation on alveolar bone remodelling during orthodontic tooth movement and finally on formation of new keratinized gingiva.

Materials and Methods:

22 patients and 27 teeth in vestibular mucosal without keratinized gingiva were selected. Every patient was treated with self ligating appliances. In every orthodontic session the patient was treated with Diode laser biostimulation. At the moment of debonding, 27 teeth involved in the research were evaluated in terms of quality and quantity of attached gingiva. BOP and CAL loss were investigated.

Results:

Every tooth considered at the end of orthodontic treatment showed an attached gingiva around the crown: The average of keratinized gingiva at the end of the study was 3.10 mm and the mean increasing at each month was 0,49 mm.

Conclusions:

The combination between self ligating appliances and laser's biostimulation could improve the differentiation of periodontal ligaments stem cells in fibroblasts, able to promote attached gingiva around the crown of the teeth erupted in oral vestibular mucosa.

Dental fragment embedded in the lower lip after facial trauma: Brief review literature and report of a case

Upper incisors are the most frequently involved teeth in traumatic dental injuries. Soft tissues (lips and/or oral mucosa) adjacent to incisal edge can receive direct and/or indirect traumas. Laceration of the lower lip is a not rare eventuality and teeth fragments could be embedded in labial soft tissue. The reattachment of these fragments, if possible, is the elective treatment choice, thanks to the modern adhesive and restorative techniques. The authors present a case of a white Caucasian 10-year-old child, who attended the dental clinic for the treatment of both upper central incisors’ crown fractures. The fragment of the left incisor was retrieved embedded in the lower lip. It was successfully surgically removed and reattached using a composite adhesive technique. A careful clinical and radiographic examination with the surgical removal of tooth fragments could prevent undesirable foreign body reaction, infection and scarring. The authors also reviewed the most relevant literature concerning tooth fragment reattachment after removal from oral soft tissues.

Comparison between Herbst appliances with or without miniscrew anchorage

Background:

Herbst appliance is largely used in orthodontics for the correction of Class II. The aim of this paper was to analyze dental and skeletal effects of a splints Herbst-miniscrews combined device in comparison to a mandibular splints Herbst appliance.

Materials and Methods:

Fifty Class II division 1 patients (27 males and 23 females with a mean age of 11.8 ± 1.7 years) were included in the study. Lateral headfilms of 25 patients with a mandibular resin splint and a miniscrew anchorage (test group) and of 25 patients with mandibular acrylic resin splints (control group) were analyzed before (T0) and after (T1) the Herbst treatment. The mean and standard deviation (SD) of each variable were calculated; paired t-test was used to evaluate statistical changes before and after the treatment, in each group and Student t-test was used to compare the two groups.

Results:

Significant differences were observed for P < 0.05. At the end of the Herbst treatment, mandibular incisor proclination was significantly lower in the test group (2.8°) in comparison to the control group (7.4°).

Conclusions:

The miniscrew-Herbst system, described in the present study, allows correction of Class II malocclusion, with a lower anchorage loss, in form of mandibular incisor proclination, during the treatment, in comparison to mandibular acrylic splints Herbst.

Picibanil (OK-432) in the treatment of head and neck lymphangiomas in children

BACKGROUND

Picibanil (OK-432) is a lyophilized mixture of group A Streptococcus pyogenes with antineoplastic activity. Because of its capacity to produce a selective fibrosis of lymphangiomas (LMs), it has been approved by Japanese administration in 1995 for the treatment of LMs.

MATERIALS AND METHODS

We treated 15 children (age range: 6-60 months) affected by head and neck macrocystic LMs with intracystic injections (single dose of 0.2 mL) of Picibanil (1-3 injections).

RESULTS

Complete disappearance of the lesion was noticed in eight (53.33%) cases, a marked (>50%) reduction of LMs was found five (33.33%) cases, while a moderate (<50%) response was recorded in two (13.33%) cases. Picibanil side effects included fever, local inflammation, and transitory increase of blood platelets' concentration; a single case of anemia was resolved with concentrated red blood cells transfusion.

CONCLUSIONS

Intracystic injection of Picibanil is an effective and safe treatment for macrocystic LMs in pediatric patients and may represent the treatment of choice in such cases, especially where surgical excision is associated with the risk of functional/cosmetic side effects.

Macrodontic maxillary incisor in alagille syndrome

This case report describes the surgical-orthodontic guided-eruption of a deeply impacted macrodontic maxillary central incisor in a 10-year-old patient with Alagille syndrome (ALGS). In the first stage, orthodontic treatment with fixed appliance on deciduous teeth allowed to create enough space for the eruption of the maxillary right central incisor. The second stage included closed surgical exposure and vertical traction. After impacted tooth erupted in the proper position, accessory periodontal treatment and dental reshaping procedures may be indicated to camouflage macrodontic incisor with the adjacent teeth. This is the first report that presents a patient with ALGS undergoing orthodontic and surgical treatment.

Occlus-o-Guide® versus Andresen activator appliance: neuromuscular evaluation

BACKGROUND

The aim of the present study was to assess the muscular variations at the electromyography (EMG) level for the anterior temporalis muscles and masseter muscles during treatment with Occlus-o-Guide® and Andresen activator appliances.

METHODS

Eighty-two patients (35 males and 47 females) aged between 8 and 12 years (mean age, 10.5±0.8 years) participated in the study. Fifty patients underwent treatment with an Occlus-o-Guide® and 32 patients with an Andresen activator. All patients underwent EMG examination using a Freely EMG (De Gotzen, Legnano, Italy) and surface bipolar electrodes when the appliances were worn for the first time (T0), and after 6 months (T1) and after 12 months (T2) of appliance use.

RESULTS

Statistical analysis showed that both at T0 and T2, the percent overlapping coefficient (POC) of the anterior temporalis muscles was not statistically different between the appliance groups. At T0, the POC of the masseter muscles was significantly lower for the Andresen appliance as compared to the Occlus-o-Guide® (p=0.02), while at T2 this significance was lost.

CONCLUSIONS

At insertion of an appliance, all patients show neuromuscular balance that does not correspond to orthognathic occlusion. Both appliances work by creating muscular imbalance. With the appliances in situ, EMG responses were generally analogous for the Occlus-o-Guide® and the Andresen activator; however, the imbalance was greater and the recovery of the orthological muscular balance was slower in patients under treatment with the Andresen activator as compared to those with the Occlus-o-Guide®.

Mandibular alterations and facial lower third asymmetries in unicoronal synostosis

PURPOSE

Maxillary and mandibular alterations in children affected by anterior synostotic plagiocephaly have, until today, received only scarce attention. The goal of this paper is to focus on the mandibular alterations, persisting after the early correction of anterior plagiocephaly during the first year of life.

METHODS

Maxillary and mandibular metric measurements were performed on high resolution, thin slices CT scans; all images were reconstructed into 3D models which were used to perform the metrical assessments.

RESULTS

Twelve patients were selected; all of them had been treated in early age with a neurosurgical intervention and had reached the end of maxillo-mandibular growth at the time of the evaluation. Significant discrepancies were documented between the two affected sides, with all measured distances being shorter on the synostotic side than the nonsynostotic one, the only exception being the vertical dimension of the mandibular ramus.

DISCUSSION

Mandibular alterations resulted to be characterized by lower jaw hypoplasia on the side of the affected suture and anterior displacement of the glenoid fossa; these two entities compensated each other uncompletely, ending in a rotation of the mandibula towards the synostotic side.

Orthodontic-surgical treatment: neuromuscular evaluation in skeletal Class II and Class III patients

OBJECTIVES

The aim of this study was the evaluation of the neuromuscular response to treatment according to diagnostic phases, as a follow-up of patients under surgical orthodontic treatment. The patient sample was subdivided into sub-samples, according to clinical characteristics.

MATERIALS AND METHODS

All of the patients who underwent orthognathic surgery in the Department of Orthodontics (University of Milan) were subjected to periodic electromyographic evaluation of the masticatory muscles (masseter and anterior temporal muscles), and to electrokinesiographic evaluation of the mandibular movements. The patient sample comprised 80 patients (37 males; and 43 females) at the end of growth. The electromyographic instruments used in the study included a Freely and a K6-I electromyography. Statistical evaluation was carried out with the Student's t-tests for independent samples.

RESULTS

There are many differences between the skeletal Class II and skeletal Class III patients that are shown through the analysis of these data obtained. In the beginning phases of the treatment the muscular activities were higher in the Class II patients than in the Class III patients. Nevertheless this difference was reversed at the end of the treatment. A similar difference could be found in the mandibular kinesiology, in fact the maximum mandibular opening movement was greater in the skeletal Class II patients than in the skeletal Class III patients at the beginning of the treatment. At the end of the treatment this difference was lost. At the beginning of the treatment the Class II patients showed a greater protrusive movement of the mandibular than the Class III patients. At the end the treatment however this gap was reduced without being reversed.

CONCLUSIONS

Functional evaluation in patients in surgical orthodontic therapy is an important element in the diagnostic-therapeutic recordings, so as to reduce as much as possible any incorrect neuromuscular activity that can result in relapse.

Bilateral pneumothorax after orthognatic surgery

Among complications in orthognathic surgery, the insurgence of pneumothorax is very rare. Pneumothorax is the presence of air or gas in the pleural cavity and it is rare complications in the postoperative oral and maxillofacial surgery patient. The clinical results are dependent on the degree of collapse of the lung on the affected side. Pneumothorax can impair oxygenation and/or ventilation. If the pneumothorax is significant, it can cause a shift of the mediastinum and compromise haemodynamic stability. While 10% of pneumothoraces are asymptomatic, patients often complain of acute chest pain and difficulty breathing. There is a reduction in vital capacity, tachycardia, tachypnoea and a decrease in partial pressure of oxygen with an inability to maintain oxygen saturations. We observed this unusual surgical consequence in a 28-year-old female with negative clinical history and instrumental evaluation after Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO). No further consequences, no neurological sequelae, no infections and no other osteotomies sequelae were seen. Sudden post-surgical dispnea associated to sub-cutaneous emphysema of the neck and of the thorax must be adequately observed with the aim of monitoring further severe sequelae. The anaesthetic management of the emergency difficult airway in any post-surgical orthognatic treatment can be extremely difficult requiring a multi-disciplinary approach.