Davide Farronato

Ten-point 3D cephalometric analysis using low-dosage cone beam computed tomography

OBJECTIVE The aim of this study was to combine the huge amount of information of low dose Cone Beam CT with a cephalometric simplified protocol thanks to the latest informatics aids. Lateral cephalograms are two-dimensional (2-D) radiographs that are used to represent three-dimensional (3-D) structures. Cephalograms have inherent limitations as a result of distortion, super imposition and differential magnification of the craniofacial complex. This may lead to errors of identification and reduced measurement accuracy. The advantages of CBCT over conventional CT include low radiation exposure, imaging quality improvement, potentially better access, high spatial resolution and lower cost. MATERIALS AND METHODS This study assessed cephalometric 2D and 3D measurements and the analysis of CBCT cephalograms of the volume and centroid of the maxilla and mandible, in 10 clinical cases. RESULTS With a few exceptions the linear and angular cephalometric measurements obtained from CBCT and from conventional cephalograms did not differ statistically (p>0.01). There was a correlation between the variation in the skeletal malocclusion and growth direction of the jaws, and the variation in the spatial position (x, y, z) of the centroids and their volumes (p<0.01). CONCLUSIONS The 3D cephalometric analysis is easier to interpret than 2D cephalometric analysis. In contrast to those made on projective radiographies, the angular and linear measurements detected on 3D become real, moreover the fewest points to select and the automatic measurements made by the computer drastically reduced human error, for a much more reliable reproducible and repeatable diagnosis.

Orthodontic Treatment in a Patient with Cleidocranial Dysostosis

Cleidocranial dysostosis is a rare congenital skeletal disorder, associated with clavicular hypoplasia or aplasia, delayed closure of cranial fontanels, brachycephalic skull, delayed exfoliation of primary dentition, eruption of permanent teeth, and multiple supernumerary and morphologic abnormalities of the maxilla and mandible. The disorder is caused by mutation in the CBFA1 gene, on the short arm of chromosome 6p21. The prevalence of cleidocranial dysostosis is estimated one per million, without sex or ethnic group predilection. The purpose of this paper is to describe the orthodontic treatment in a patient with cleidocranial dysostosis. Therapy may include removal of supernumerary teeth, surgical exposure of impacted teeth, and orthodontic treatment.

Orthodontic movement of a dilacerated maxillary incisor in mixed dentition treatment

Dilaceration is a dental deformity characterized by an angulation between crown and root causing non-eruption of the tooth. It generally occurs following trauma to the deciduous dentition the apices of which lie close to the permanent tooth buds. Surgical extraction used to be the first choice in treating the severely dilacerated teeth. In this case report, it is described how a dilacerated central incisor was successfully moved into alignment in a young patient with proper surgical and orthodontic management avoiding use of prosthetic/implant devices. The panoramic radiograph after the traumatic injury is compared with the one at the end of treatment. The results were sustainable over long-term in both periodontal and aesthetic terms.

Assessment of inter- and intra-operator cephalometric tracings on cone beam CT radiographs: comparison of the precision of the cone beam CT versus the latero-lateral radiograph tracing

BackgroundIn this study we aimed at quantifying the possible errors which may occur when assessing specific reference planes and linear derivants on cephalometric radiographs traced manually and digitally. Furthermore, we have compared the precision of the tracings according to both the two- and three-dimensional (2D and 3D respectively) techniques and between clinicians.FindingsWe have obtained via cone beam computed tomography (CBCT) archive of the orthodontics department of the University of Milan 20 cone beam CT radiographs from which we have obtained 20 latero-lateral radiographs. Five independent clinicians referred to as A, B, C, D, E have been randomly selected to trace both radiographs maintaining the same working and lighting conditions to minimize the possibility of operator- and environment-dependent errors from occurring. The results have been statistically assessed by Student’s t test. The comparison of the data gathered from the tracings in 2D and 3D shows that certain measurements have statistically significant differences. Particularly, the difference in the measurements of the sagittal dimension of the mandible and the anterior and posterior nasal spines has resulted to be statistically significant. The results of the intra-operator comparison proved that the 3D technique is extremely precise.ConclusionOur study determines that the 3D technique allows to obtain more precise results and with several advantages when compared to the conventional technique such as a true representation of the anatomical structures, less risk of errors occurring due to clinician skills and absence of overlapping anatomical structures.

Mandibular condylar hyperplasia: clinical, histopathological, and treatment considerations.

Abstract Condylar hyperplasia is a rare disorder characterized by an increased volume of the condyle, ramus, and mandibular body leading to facial asymmetry. We present three cases of condylar hyperplasia: two women and one man, age range 27 to 34. Clinically, all three patients showed a deviation of the mandible to the opposite side and a protruded position of the chin, hypertrophy of the lower border of the mandible, combined with an elongation of the mandibular ramus, open-bite on the deformed side, and cross-bite on the opposite side. In all three cases, scintigraphy showed an increased uptake. Radiography and CT scanning confirmed the clinical diagnosis and patients were subjected to surgery, comprising high condylectomy on the affected side with access in the pre-tragus area. The surgical piece sent to the Institute of Pathological Anatomy for histological examination revealed a nonuniform picture, in terms of both the depth of cartilage islands and the thickness of the fibrous layer covering the joint surface. Common to all three cases, however, was the apparent evolution of fibrous tissue to cartilage, and of this to compact bone tissue. At two-four years, all cases have maintained a good occlusal response. The asymmetric deformity of the mandible resulting from the rare condition of hemimandibular hyperplasia is presented and the clinical, histopathological and therapeutic aspects discussed.

Long‐term results of early condylar fracture correction: case report

Condylar fractures in childhood occur frequently, often with minimal pain and discomfort and therefore the diagnosis is not made at the time of injury. Management may be surgical or non-surgical. Non-surgical therapy in children is the method of choice if the condyle can translate normally. In fact, there is an excellent chance of regeneration and continued normal development after fracture in growing patients. The purpose of this article is to describe the long-term clinical and radiological evaluation of a conservatively treated unilateral condylar fracture, a result of trauma, in a 6-year-old patient. In addition, she presented a congenitally missing lower incisor ipsilateral to the fracture and a class II malocclusion. She was treated with functional jaw orthopedics using a splint and an activator and subsequent orthodontic treatment with fixed appliances [J Orofac Orthop5 (2002) 429]. The remodeling process of the condylar head and neck is clearly observed in the panoramic radiographs of the 12-year follow-up records presented.

Immediate loading of mandibular overdentures supported by one-piece, direct metal laser sintering mini-implants: a short-term prospective clinical study.

BACKGROUND Only a few studies have dealt with immediately loaded, unsplinted mini-implants supporting ball attachment-retained mandibular overdentures (ODs). The aim of this study is to evaluate treatment outcomes of ball attachment-retained mandibular ODs supported by one-piece, unsplinted, immediately loaded, direct metal laser sintering (DMLS) mini-implants. METHODS Over a 4-year period (2009 to 2012), all patients referred to the Dental Clinic, University of Varese, and to a private practice for treatment with mandibular ODs were considered for inclusion in this study. Each patient received three or four DMLS mini-implants. Immediately after implant placement, a mandibular OD was connected to the implants. At each annual follow-up session, clinical and radiographic parameters were assessed, including the following outcome measures: 1) implant failures; 2) peri-implant marginal bone loss; and 3) complications. Statistical analysis was conducted using a life-table analysis. RESULTS A total of 231 one-piece DMLS mini-implants were inserted in 62 patients. After 4 years of loading, six implants failed, giving an overall cumulative survival rate of 96.9%. The mean distance between the implant shoulder and the first visible bone-to-implant contact was 0.38 ± 0.25 and 0.62 ± 0.20 mm at the 1- and 4-year follow-up examinations, respectively. An incidence of 6.0% of biologic complications was reported; prosthetic complications were more frequent (12.9%). CONCLUSIONS Within the limits of this study, it can be concluded that the immediate loading of one-piece, unsplinted, DMLS titanium mini-implants by means of ball attachment-supported mandibular ODs is a successful treatment procedure. Long-term follow-up studies are needed to confirm these results.

Temporary lip paresthesia during orthodontic molar distalization: Report of a case

Lip paresthesia during mandibular molar orthodontic distalization is rare. When it occurs, it is often related to excessive dimensions of the mandibular second molar roots. In this clinical report, we describe a patient who developed lip paresthesia during orthodontic treatment. The paresthesia was relieved by immediate interruption of the forces applied to the mandibular second molars and pharmacologic therapy. Before fixed orthodontic treatment proceeds in patients with large tooth roots, it is important to diagnose the relationship between the roots and the mandibular canal to prevent nerve numbness and damage.

A Four-Year Survival Rate Multicenter Prospective Clinical Study on 377 Implants: Correlations Between Implant Insertion Torque, Diameter, and Bone Quality.

The purpose of this study was to evaluate the survival rate and incidence of prosthetic complications in 377 implants with a double octagon connection. Furthermore, the correlations among implant dimensions (diameter and length), bone quality, and insertion torque were investigated. A 4-year multicenter prospective clinical study was designed to evaluate the survival rate of 377 dental implants inserted in 189 patients between January 2004 and April 2010. After an average follow-up of 46 months, the implant survival rate was 99.7%, and the incidence of complication was 0.53%. Moreover, insertion torque was statistically related in a significant way to implant diameter. The connection system seemed to reduce the risk that the prosthetic component screw would loosen. Within the limits of this study, it was observed that a wider diameter corresponded to a higher implant primary stability. Implant length did not seem to be critical in obtaining higher primary stability.

Rapid maxillary expansion in growing patients. Hyrax versus transverse sagittal maxillary expander: a cephalometric investigation

The aim of this retrospective study was to cephalometrically evaluate and compare the skeletal and dental effects of a transverse sagittal maxillary expander (TSME) and a Hyrax-type expander (RME) in children with maxillary hypoplasia. Fifty subjects (26 males and 24 females), aged from 6 to 15 years, with a maxillary crossbite caused by basal apical narrowness, were divided into two equal groups. Twenty-five were treated with a TSME and the other 25 with a RME. For each patient, a lateral cephalogram was obtained before treatment (T0) and at the end of the retention period (T1). Changes in the two groups during the observation period were calculated, compared, and statistically analysed with a paired samples t -test. In the TSME group, SNP-A, I SN, and I FH and in the RME group SN-SNP.SNA, N-Me, and U6.PP displayed a statistically significant increase (P < 0.05). The increase in SNP-A, I SN, and I FH in the TSME group was significantly greater following treatment than in the RME group. The results support the use of the TSME to produce skeletal changes and dentoalveolar modification and to correct maxillary hypoplasia. It was also demonstrated that in patients with an anterior open bite, the use of the TSME is not contraindicated as the anterior vertical dimension did not increase significantly.