Helical distraction is superior to linear and circular distraction in mandibular distraction osteogenesis: an in silico study.

Helical mandibular distraction is theoretically better than linear or circular distraction. However, it is not known whether this more complex treatment will result in unquestionably better outcomes. Therefore, the best attainable outcomes of mandibular distraction osteogenesis were evaluated in silico, given the constraints of linear, circular, and helical motion. This cross-sectional kinematic study included 30 patients with mandibular hypoplasia who had been treated with distraction, or to whom this treatment had been recommended. Demographic information and the computed tomography (CT) scans showing the baseline deformity were collected. The CT scans of each patient were segmented and three-dimensional models of the face created. Then, the ideal distraction outcomes were simulated. Next, the most favorable helical, circular, and linear distraction movements were calculated. Finally, errors were measured: misalignment of key mandibular landmarks, misalignment of the occlusion, and changes in intercondylar distance. Helical distraction produced trivial errors. In contrast, circular and linear distractions resulted in errors that were statistically and clinically significant. Helical distraction also preserved the planned intercondylar distance, while circular and linear distractions led to unwanted changes in the intercondylar distance. It is now evident that helical distraction offers a new strategy to improve the outcomes of mandibular distraction osteogenesis.

Clinical feasibility of deep learning-based automatic head CBCT image segmentation and landmark detection in computer-aided surgical simulation for orthognathic surgery.

The purpose of this ambispective study was to investigate whether deep learning-based automatic segmentation and landmark detection, the SkullEngine, could be used for orthognathic surgical planning. Sixty-one sets of cone beam computed tomography (CBCT) images were automatically inferred for midface, mandible, upper and lower teeth, and 68 landmarks. The experimental group included automatic segmentation and landmarks, while the control group included manual ones that were previously used to plan orthognathic surgery. The qualitative analysis of segmentation showed that all of the automatic results could be used for computer-aided surgical simulation. Among these, 98.4% of midface, 70.5% of mandible, 98.4% of upper teeth, and 93.4% of lower teeth could be directly used without manual revision. The Dice similarity coefficient was 96% and the average symmetric surface distance was 0.1 mm for all four structures. With SkullEngine, it took 4 minutes to complete the automatic segmentation and an additional 10 minutes for a manual touchup. The results also showed the overall mean difference between the two groups was 2.3 mm for the midface and 2.4 mm for the mandible. In summary, the authors believe that automatic segmentation using SkullEngine is ready for daily practice. However, the accuracy of automatic landmark digitization needs to be improved.

Clinical feasibility evaluation of digital dental articulation for three-piece maxillary orthognathic surgery: a proof-of-concept study.

Digital dental articulation for three-piece maxillary orthognathic surgery is challenging. The purpose of this proof-of-concept study was to evaluate the clinical feasibility of a newly developed mathematical algorithm to digitally establish the final occlusion for three-piece maxillary surgery. Five patients with jaw deformities who had undergone a three-piece double-jaw surgery that was planned virtually were randomly selected for this study. The final occlusion had been hand-articulated using stone casts, scanned into the computer and used in the surgery. These hand-articulated occlusions served as the control group. To form the experimental group, the three-piece maxillary dental arch was articulated again automatically from the patient's original occlusion using the mathematical algorithm. The hand- and algorithm-articulated occlusions were then evaluated qualitatively by two experienced orthodontists. A quantitative evaluation was also performed. The results of the qualitative evaluation showed that all of the three-piece occlusions, hand- and algorithm-articulated, were clinically acceptable based on the American Board of Orthodontics grading system. When compared, two of the algorithm-articulated occlusions were clearly better (40%), one was the same (20%), and two were slightly worse (40%) than the hand-articulated occlusions. All of the quantitative measurements were comparable between the two articulation methods. In conclusion, the results of this study demonstrate that it is clinically feasible to digitally articulate the three-piece maxillary arch to the intact mandibular dental arch.

[One case of Pott's puffy tumor: inverted papilloma of nasal sinus postoperative complications].

A 45 years old male patient presented with recurrent abscess of the nasal root and right periorbital tissue. The incision and drainage were performed repeatedly, and anti-infection had poor effect of treatment. Previous history of sinusitis surgery. Nasal cavity and frontal sinus infections and abscesses were treated in other hospitals. CT showed enhanced patchy foci and abscesses on the right temporal side, frontal, periorbital and nasal roots. Repeated discharge of purulent secretions during hospitalization in our hospital prompted Klebsiella pneumoniae infection. After the patient was discharged from the hospital, he was diagnosed with Pott's tumor by repeated consultation with the literature.

The effect of recombinant human erythropoietin in treating the anemia of prematurity.

Anemia of prematurity (AOP) has been conventionally treated with erythrocyte transfusions. Recent investigations have reported the use of recombinant human erythropoietin (rHuEPO) as an alternative for treating AOP. The potential of rHuEPO in increasing erythropoiesis implies its clinical usefulness. The effect of rHuEPO on reticulocyte count as well as other parameters of blood cells was examined in 14 premature babies with AOP. The average birth body weight and gestational age of these premature babies were 1533.71 +/- 61.66 g (Mean +/- SEM) and 31.36 +/- 0.49 weeks respectively. They received the first dose of rHuEPO at age 26.14 +/- 2.03 days with a hemoglobin level by 9.40 +/- 0.27 g/dL and hematocrit level of 28.20 +/- 0.81%. They were given rHuEPO 200 U/kg subcutaneously every other day for 10 doses, and iron 3 mg/kg and vitamin E 25 IU/kg per os every day. Average erythropoietin level of the patients on entry into this study was low (7.66 +/- 1.10 mu/mL). After treatment with rHuEPO for 20 days, the corrected reticulocyte count increased from 0.64 +/- 0.10% to 1.68 +/- 0.42% on Day 5 (P < 0.05), 1.96 +/- 0.41% on Day 12 (P < 0.05), 1.77 +/- 0.43% on Day 20 (P < 0.05), and hematocrit increased from 28.2 +/- 0.81% to 29.58 +/- 1.02% (p < 0.05) on Day 20. Bone marrow aspirates on Day 10 for 9 infants revealed moderate to high cellularity, mostly with erythroblasts (47.89 +/- 1.78%); the M/E ratio was low (0.57 +/- 0.05). The granulocyte series and megakaryocyte could be well visualised.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal volvulus caused by a persistent omphalomesenteric band: report of one case.

Persistent omphalomesenteric band is a rare cause of volvulus or intestinal obstruction. A 7-month-old male infant was brought to this Emergency Room after having shown poor appetite for three days, frequent bilious vomiting, and fever for half a day. Physical examination revealed the infant was dehydrated and had slight abdominal distension as well as hypoactive bowel sounds with a tender, ill-defined mass over right lower quadrant. Radiography and sonography were consistent with distal small bowel obstruction. Emergent laparotomy was done and a fibrous band found extending from the anti-mesenteric border of the ileum to the posterior wall of the umbilicus. Small bowel volvulus had occurred around the band and dilated small bowel was noted. An understanding of the embryologic development of these structures and their normal disappearance may assist pediatricians and surgeons to make the correct diagnosis and select the right pathoanatomic approach in surgery.

Hematuria due to nutcracker phenomenon of left renal vein: report of a case.

The nutcracker phenomenon refers to compression of the left renal vein between the aorta and the superior mesenteric artery, which leads to painless intermittent gross hematuria. An 11-year-old girl presented with a two-year history of recurrent painless hematuria. Physical examination and routine laboratory examinations were noncontributory. Renal ultrasonographic study, selective left renal angiography and retrograde left renal venography showed evidence of compression of the left renal vein where it crossed between the aorta and the superior mesenteric artery. A needle biopsy of the right kidney revealed no abnormal histologic change. These results led to a diagnosis of the nutcracker phenomenon; to the best of our knowledge, this may be the first case reported in Taiwan. Herein, we present our experience with this case and discuss the diagnostic options.

Clinical use of single-dose surfactant TA therapy for premature infants with severe respiratory distress syndrome.

A single dose of surfactant TA was given as rescue therapy to four small premature infants with severe respiratory distress syndrome requiring mechanical ventilation. Birth weights ranged from 810 to 1200 gm. The dose of 100-120 mg/kg was given at the mean age of 5 hours, with range of 3 to 7 hours. Following surfactant therapy, there was a significant improvement (p < 0.05) in a/APO2 (raising from 0.11 +/- 0.05 before treatment to 0.34 +/- 0.19 at 6 hours after treatment). There was also a significant reduction in the severity of respiratory distress syndrome at 24 hours post-therapy. One baby died of sepsis at 40 hours of life; one survived without complications. The other two cases developed severe bronchopulmonary dysplasia later. We concluded that early use of exogenous surfactant is beneficial in small premature infants with severe respiratory distress syndrome.