Nasrin Farhadian; Amirfarhang Miresmaeili; Vahid Mollabashi
Abstract
Introduction: Complications to force eruption of impacted teeth may arise from several reasons including ankylosis, dilaceration, and/or some barriers in the eruption pathway. Treatment time prolongation without obvious clinical progress gradually decreases the patient compliance. In this paper we present ...
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Introduction: Complications to force eruption of impacted teeth may arise from several reasons including ankylosis, dilaceration, and/or some barriers in the eruption pathway. Treatment time prolongation without obvious clinical progress gradually decreases the patient compliance. In this paper we present a non-conventional method to forced eruption of an impacted maxillary canine.
Case Presentation: A-21-year old girl presented with missing of teeth No 17, 12, 22, 27, 38, 37, 47, 48 and labially impaction of both maxillary canine was prepared for treatment through apically position flap for exposure of the both canines. Using standard edgewise 0.18 appliance and conventional elastic traction the right maxillary canine erupted to its normal position after about 18 months but the other tooth had not responded favorably to this technique. There was no signs of ankylosis, a titanium bone screw was placed in the labial cortical bone and mesial of the malposed canine. A spring is made of 0.017” × 0.025” SS wire with two helixes that delivered about 100 g force and 400 gr.mm activation moment to labial bracket on malposed canine crown. The force exerted on mini implant will be balanced with a force and moment on malposed tooth very similar to type IV Burston classification. After about 5 months the tooth had reached to its final occlusal position.
Conclusions: The appliance used for this patient brought the impacted canine into the arch without any more force on the neighbor teeth. Two point contact of the spring arm by bending the wire over the head of the mini implant made it possible to apply buccolingual crown torque.
Shahriar Shahab; Amirfarhang Miresmaeili; Mehdi Esmaeili; Vahid Mollabashi; Nasrin Farhadian
Abstract
Aim: The main objective of this preliminary study was to introduce a new approach for the estimation of nasal cavity volume using two dimensional measurements in serial sections, as an alternative to planimetry volume measurements.
Materials and Methods: Ten CBCT images were studied in the coronal plane ...
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Aim: The main objective of this preliminary study was to introduce a new approach for the estimation of nasal cavity volume using two dimensional measurements in serial sections, as an alternative to planimetry volume measurements.
Materials and Methods: Ten CBCT images were studied in the coronal plane and the 4-mm thick sections were selected between Anterior and Posterior Nasal Spine. Real estimation of nasal cavity volume was computed using Cavalieri principle in conjunction with planimetry method. The outline of each slice was digitized and the resulted surface area was computed by AutoCAD software. In alternative method, a surface area estimate was measured by multiplying maximum width and maximum height in each slice. The sum of slices area in each method was named as Total Nasal Cavity Area (TNCA). Nasal cavity volume = TNCA × thickness of tomography slice. TNCA1 based on planimetry method, was compared with TNCA2 using to coordinates with linear regression analysis.Results: Regression analysis showed a powerful correlation between two methods measurements (r = 0.951). The following formula was proposed for volume estimation using the coordinate method: TNCA1 = 85.6±1.53 TNCA2.
Conclusions: In this pilot study, we substituted successfully two linear measurements instead of planimetry to estimate nasal cavity volume. This may help investigators to overcome inherent problems appearing in measurements of nasal cavity volume.
