Parametrizing the genioplasty: a biomechanical virtual study on soft tissue behavior

Purpose

Sliding genioplasty is used to surgically correct a retruded or misaligned chin: in this procedure, an osteotomy is performed and the bony segment is repositioned. In this study we investigate the effect of surgical parameters (bony segment movement, osteotomy design) on postop soft tissue changes in a patient cohort.

Methods

Seven patients were retrospectively recruited. Cone beam computed tomography data were obtained and soft tissue and bone shape reconstructions were performed. 3D models were created and surgical cuts were replicated according to postop scans. Each model was imported in ANSYS 2019R1 (Ansys Inc, USA) for simulation: the effect of variation in osteotomy plane as well as extent of bony segment movement were assessed by means of design of experiment: surgical parameters were varied in a surgically acceptable range and the soft tissue predictions were evaluated as displacement output of five craniometric landmarks.

Results

Simulation results show the overall changes of the lower third of the face are sensitive to changes in horizontal and vertical displacement of the bony segment as well as segment rotation. No significant changes in the soft tissue response were to attribute to the osteotomy design.

Conclusions

Our results are consistent with experimental findings reported in the literature: when planning genioplasty in orthognathic surgery, particular focus on the segment movement (horizontal translation, vertical translation and rotation), rather than on the design of the osteotomy itself, should be considered.

3D computed tomographic evaluation of the upper airway space of patients undergoing mandibular distraction osteogenesis for micrognathia

Mandibular distraction osteogenesis (MDO) is currently an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. To date one of the unsolved problems is how to assess the quantitative increase of mandible length needed to achieve a significant change in the volume of the posterior airway space (PAS) in children with mandibular micrognathia following distraction osteogenesis. The purpose of this study is to present quantitative volumetric evaluation of PAS in young patients having distraction osteogenesis for micrognathia using 3D-CT data sets and compare it with pre-operative situation. In this observational retrospective study, we report our experience in five consecutive patients who underwent MDO in an attempt to relieve severe upper airway obstruction. Each patient was evaluated before treatment (T0) and at the end of distraction procedure (T1) with computer tomography (CT) in axial, coronal, and sagittal planes and three-dimensional CT of the facial bones and upper airway. Using parameters to extract only data within anatomic constraints, a digital set of the edited upper airway volume was obtained. The volume determination was used for volumetric qualification of upper airway. The computed tomographic digital data were used to evaluate the upper airway volumes both pre-distraction and post-distraction. The mean length of distraction was 23 mm. Quantitative assessment of upper airway volume before and after distraction demonstrated increased volumes ranging from 84% to 3,087% with a mean of 536%. In conclusion, our study seems to show that DO can significantly increase the volume of the PAS in patients with upper airway obstruction following micrognathia, by an average of 5 times. Furthermore, the worse is the starting volume, the greater the increase in PAS to equal distraction.

Bladder Leiomyoma: Case Report

The author describes a case of bladder leiomyoma that is particularly interesting for the rarity of the tumour and especially for its dimensions which required a subtotal cystectomy with enlargement ileocystoplasty.

The Ballistic Lithotrite in Ureteral Calculosis

The Authors describe their experience regarding 120 cases of ureteral calculosis treated with the ballistic lithotrite. Fragmentation of the stones proved effective in all cases, the ureter being freed of obstruction in only one session. The ballistic lithotrite may therefore be considered a valid alternative to electrohydraulic lithotripsy and laser, or even the best choice in terms of effectiveness, easy application and reduced purchasing and maintenance costs for the endourological treatment of ureteral calculosis.

Octylonium bromide in the treatment of the irritable bowel syndrome: a clinical-functional study

We investigated the effect of octylonium bromide on a number of symptoms and functional aspects of the irritable bowel syndrome. Seventy-two patients complaining mainly of abdominal pain were studied in a double-blind trial (octylonium bromide 40 mg tid for 4 weeks or placebo). Clinical parameters were: abdominal pain, bloating and bowel frequency. Sigmoid manometry with simultaneous recording of the thresholds for distension and/or pain upon graded inflation of an endoluminal balloon was performed before and at the end of treatment. In contrast to placebo, octylonium bromide significantly reduced pain and bloating, and significantly increased (p < 0.02) the pain threshold throughout the treatment period. However, comparison with the placebo group failed to show any relevant differences. Neither treatment influenced the frequency of bowel movement. Sigmoid motility during distension was significantly reduced after octylonium bromide (p < 0.05), but it did not change after placebo. In conclusion, octylonium bromide is capable of reducing symptoms and motor reactivity of the sigmoid in patients with irritable bowel syndrome.

Clinical and functional evaluation of the efficacy of otilonium bromide: a multicenter study in Italy

Seventy-two patients complaining of abdominal pain were studied in a double blind trial with otilonium bromide (OB) (40 mg tid or placebo). In our patients we performed, before and after the treatment, a clinical evaluation (symptom variations) and functional studies (sigmoid manometry during bowel distension). As regards clinical parameters, otilonium bromide significantly reduced abdominal pain and bloating and significantly increased (p less than 0.02) the pain threshold. However the comparison with the placebo group did not show any difference between the two groups. Sigmoid motility during distension was significantly reduced (p less than 0.05) in OB group, whereas it did not change in the placebo group. We can conclude that, in irritable bowel syndrome (IBS) patients, OB is able to improve symptoms and to reduce stimulated motor activity of the sigmoid.

[Nephro-colic fistula: a clinical case]

The authors discuss a case of nephro-colic fistula recently observed. The patient, treated by radical cystectomy for diffuse bladder carcinoma, had a nephrostomic drainage. Clinical and diagnostic considerations are reported.