Lokesh Suri

Surgically assisted rapid palatal expansion: A literature review

Transverse maxillomandibular discrepancies are a major component of several malocclusions. Orthopedic and orthodontic forces are used routinely to correct a maxillary transverse deficiency (MTD) in a young patient. Correction of MTD in a skeletally mature patient is more challenging because of changes in the osseous articulations of the maxilla with the adjoining bones. Surgically assisted rapid palatal expansion (SARPE) has gradually gained popularity as a treatment option to correct MTD. It allows clinicians to achieve effective maxillary expansion in a skeletally mature patient. The use of SARPE to treat MTD decreases unwanted effects of orthopedic or orthodontic expansion. Our aim in this article is to present a comprehensive review of the literature, including indications, diagnosis, guidelines for case selection, a brief overview of the surgical techniques, orthodontic considerations, complications, risks, and limitations of SARPE to better aid the clinician in the management of MTD in skeletally mature patients.

Influence of patient head positioning on measured axial tooth inclination in panoramic radiography

Objective Panoramic radiographs are routinely used to assess the mesiodistal axial inclination of teeth (MDAI) in orthodontic treatment. These radiographs are sensitive to minor deviations from standard head position that result in image distortions. The aim of this study is to measure and quantify the changes in MDAI on panoramic radiograph resulting from changes in patient head position. Materials and Methods The testing devise was a human skull with guide wires placed on the facial surface of the teeth and alveolar process along the long axis of each tooth. Panoramic radiographs were captured digitally with the orientation of the skull in Frankfurt horizontal plane parallel to the floor and with 1°, 2°, 5°, 7°, and 10° both superior and inferior rotations. The mesiodistal tooth angulations were determined using MIPAC software (DentalEye and LEAD Technologies, Inc. 2005). Results The more distal the position of the tooth in the arch the greater the change in MDAI with a change in vertical head position. A maximum change of approximately 10 degrees was observed in MDAI of both the maxillary and mandibular molars with a corresponding superior head tilt of 10 degrees. The Mandibular anteriors displayed significant inconsistencies in MDAI with both superior and inferior head tilt. A superior head tilt produced a greater change in mesiodistal angulation than did an inferior head tilt. Conclusions Accurately taken panoramic radiographs can serve as a convenient tool for evaluating the MDAI before, during and after orthodontic treatment. Additional radiographs are recommended for the mandibular anteriors.

Expression of MMP-13 (collagenase-3) in long-term cultures of human dental pulp cells

UNLABELLED Matrix metalloproteinase-13 (MMP-13 or collagenase-3) is a member of the family of matrix metalloproteinases (MMPs) produced in high amounts by cells with mineralising potential. Human dental pulp has been shown to express high levels of MMP-13 RNA. OBJECTIVE Since human dental pulp derived cells (HDPC) are known to possess osteoprogenitor properties, we investigated the pattern of expression of MMP-13 in long-term cultures of those cells under conditions that support mineralisation in vitro. DESIGN Impacted teeth or teeth extracted for orthodontic purposes were used to obtain dental pulp explants and HDPC were cultured for approximately 5 weeks. Pro- and active MMP-13 levels were determined in the cell culture supernatants by means of enzyme-linked immunosorbent assay (ELISA). Cell growth was evaluated through DNA content and osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity and Alizarin Red staining. RESULTS Mineralising cultures of HDPC produced significantly higher levels of pro-MMP-13 compared to control cultures. Both pro- and active MMP-13 levels displayed a characteristic peak that was found to coincide with the peak in alkaline phosphatase activity and the onset of mineralisation. Once mineralisation was firmly established, MMP-13 expression was significantly reduced. CONCLUSIONS Evidence from this study suggests a role for MMP-13 in the transition of human dental pulp cells to a mature mineralising phenotype and points to MMP-13 as a possible marker in HDPC differentiation.

Cephalometric findings in patients with Papillon-Lefèvre syndrome.

INTRODUCTION Literature regarding oral conditions in patients with Papillon-Lefèvre syndrome (PLS) often covers the periodontal aspects, but no literature was found describing specific craniofacial findings in this group. The aim of this retrospective study was to investigate the cephalometric findings of patients with PLS. METHODS Lateral cephalograms of 8 patients with PLS were traced, and hard- and soft-tissue variables were analyzed. RESULTS Class III skeletal relationship was evident (ANB angle, 2 degrees +/- 3.1 degrees ; Wits appraisal, -9.1 mm +/- 3.7 mm). Other findings include maxillary retrognathia, decreased lower facial height, retroclined mandibular incisors, and upper lip retrusion. CONCLUSIONS Patients affected with PLS have a Class III skeletal pattern. These findings can be of clinical value not only for diagnosis, but also for proper treatment planning.

Ask us. Long-term stability of maxillary expansion.

AThere is only second-level evidence that maxillary expansion obtained with fixed expansion appliances is stable in the long term. There is only weak indirect evidence of long-term expansion stability with the use of removable maxillary expansion appliances. Maxillary expansion, with fixed or removable expansion appliances, is a common orthodontic treatment. It is primarily used for the correction of posterior crossbites as a result of reduced maxillary width. Maxillary expansion is particularly important in eliminating mandibular functional shift, a finding commonly associated with deficient maxillary arch width in early dentition development that can have undesirable consequences on facial symmetry, and possibly temporomandibular joint function, if left untreated. Other applications suggested in the orthodontic literature include increasing arch perimeter in the absence of posterior crossbite to facilitate nonextraction edgewise treatment, and improving Class II interarch relationships by a spontaneous mandibular growth or positioning response to maxillary expansion. The increase in the transverse dimension of the maxillary arch by using expansion appliances is indisputable. The short-term treatment effects are both dental and skeletal, resulting in significant gains in maxillary intermolar width and maxillary perimeter arch width postexpansion. The longterm change in the maxillary transverse dimension posttreatment (ie, the amount of expansion remaining with time) is less well established, particularly in relation to expected transverse changes with growth in untreated persons with normal occlusion. Systematic reviews and meta-analyses are evidencedbased tools that use systematic literature searches, quality assessments and data extraction measures to summarize the literature for a particular treatment effect. They reduce bias in data interpretation. The Council on Scientific Affairs (COSA) used an evidence-based approach to the question of long-term stability of the maxillary transverse dimension changes associated with fixed or removable expansion appliances. A search of the literature for meta-analyses and systematic reviews via PubMed and Google Scholar, with the key words palate expansion, maxillary expansion, rapid maxillary expansion, and slow maxillary expansion, was conducted. Eight articles that surveyed the literature between 1979 and January 2005 were found.