Advantages of a High-Powered Ultrasonic Vibration Cutting Device for Orthognathic Surgeries.

This study aimed to evaluate the advantages of using a high-powered ultrasonic vibration cutting device (HP-UVCD) in orthognathic surgeries. We analyzed 22 consecutive patients who underwent Le FortⅠosteotomy and bilateral sagittal split osteotomies for cleft lip and palate. We used conventional power instruments, such as reciprocating saws and rotating burrs in the first 10 patients, and an HP-UVCD in the remaining 12 patients. Surgical time, intraoperative blood loss, and postoperative inferior alveolar nerve affection were retrospectively investigated. The surgical time in the ultrasonic group (223±12.217 min) was significantly shorter than that in the conventional group (278±11.153 min, P =0.008). The amount of intraoperative blood loss in the ultrasonic group was an average of 230±45.154 g, and that in the conventional group was an average of 343±49.463 g. Although the blood loss in the ultrasonic group was reduced compared with that in the conventional group, this difference was not statistically significant ( P =0.118). All patients in both groups recovered normal sensation by 6 months postoperatively. Our findings suggest that the HP-UVCD can be used in place of a reciprocating saw or rotating burrs in orthognathic surgeries, resulting in reduced surgical time and minimal blood loss. The use of an ultrasonic bone-cutting device may allow for a safer and less invasive orthognathic surgery.

Impact of palatoplasty techniques on tympanic membrane findings and hearing prognosis in children with cleft palate.

OBJECTIVE: Children with cleft palate (CP) are at high risk of developing otitis media with effusion (OME) due to Eustachian tube (ET) dysfunction. Palatoplasty has been reported to decrease the frequency of middle ear disease and improve ET function, and although various techniques have been developed, there is no consensus on the differences in the impact of different techniques on the middle ear. The purpose of this study was to determine the differential effects of palatoplasty on middle ear function and hearing. METHODS: We performed a retrospective observational survey of pediatric patients who underwent palatoplasty for CP between June 2010 and October 2018 at Tohoku University Hospital. Cases were divided into three groups depending on the palatoplasty procedures performed: the push-back palatoplasty group, the two-flap palatoplasty group, and the Furlow double-opposing Z-plasty group. We examined the differences in clinical characteristics between patients who underwent each procedure. The primary outcome variable was tympanic membrane (TM) findings, and the secondary outcome was hearing test results. RESULTS: Children who underwent the two-flap palatoplasty had a higher tympanostomy tube (TT) insertion rate and a higher total number of TT insertions than those who underwent the Furlow double-opposing Z-plasty or the push-back palatoplasty. The TM retraction rate tended to be lower in the Furlow double-opposing Z-plasty group than in the push-back palatoplasty group or the two-flap palatoplasty group. The hearing test results at the last visit were not significantly different among the three groups. CONCLUSIONS: Children who underwent the two-flap palatoplasty had a higher rate of TT insertions, potentially increasing the risk of TM perforation. In contrast, the Furlow double-opposing Z-plasty group had a lower tendency for TM regression, possibly due to improved ET function and reduced incidence of OME. It is important to understand the advantages and disadvantages of each technique before selecting one suitable for the child's cleft and arch width. Additionally, it is important to conduct regular follow-up of TM findings and hearing test results even after palatoplasty.

Magnetoencephalographic evaluation of repaired lip sensation in patients with cleft lip.

BACKGROUND: Cleft lip is the most common congenital anomaly worldwide. Nevertheless, lip somatosensory characteristics of patients with cleft lip after cheiloplasty have not yet been determined. The present study used magnetoencephalography to objectively evaluate the lip sensation in patients with unilateral cleft lip to establish a new objective evaluation method. METHODS: Participants were 15 patients with unilateral cleft lip after cheiloplasty (UCL group), and 30 healthy young subjects (control group). Five points of the upper and lower lips were stimulated electrically to measure somatosensory evoked magnetic fields (SEFs). The sources of the magnetic fields were modeled as single equivalent current dipoles (ECDs). ECDs located on the central sulcus by superimposition on magnetic resonance images were analyzed. Latency and intensity at 50-75 ms (cP60m) observed in the UCL group were compared with those in the control group. Thresholds of tactile stimuli in both groups were obtained using Semmes-Weinstein monofilaments for subjective sensory evaluation. RESULTS: No significant difference was found in the intensity of the cP60m or subjective evaluation between the groups. However, the latency of the cP60m was significantly longer in the upper lip of the UCL group than in the control group. CONCLUSIONS: SEFs showed a difference in lip sensation between the UCL group and the control group, suggesting that longer latency might be caused by the effects of surgical scarring on the neurotransmission pathway. These results suggest SEFs as useful for the objective evaluation of lip sensations. This study might improve future surgical procedures and lip functions of patients with cleft lip.

Somatosensory evoked magnetic fields induced by electrical palate stimulation in patients with unilateral cleft lip and palate after palatoplasty.

Palatal sensation is important for articulation, feeding, and swallowing. However, palatal sensation in patients with cleft palate (CP) after palatoplasty has been investigated only inadequately because of the complexity and high costs of objective evaluation. This study compared the somatosensory evoked magnetic fields (SEFs) induced by electrical stimulation of the palates of patients with CP after palatoplasty and the palatal sensory thresholds (PSTs) of the stimulation with those of healthy (control) subjects. The CP group comprised 12 patients with unilateral cleft lip and palate (UCLP). The control group comprised 31 control subjects. No significant difference in intensity was found between them. Nevertheless, the PSTs in the UCLP group were significantly higher than those in the control group at all sites (p < 0.05). We infer that the electrical signals transmitted from palatal sensory receptors of patients with CP might be amplified by a compensation mechanism in the central nervous system. SEFs provide an effective method for objective evaluation of palatal sensation in patients with CP after palatoplasty. Evaluation of SEFs during palatal sensory stimulation in patients with CP after palatoplasty might lead to better corrective surgical methods that also preserve palatal sensation.

Reliability of Ultrasound-Guided One-Point Fixation for Zygomaticomaxillary Complex Fractures.

This study aimed to analyze the precision and postoperative stability of ultrasound guided 1-point fixation on the zygomaticomaxillary buttress for the treatment of zygomaticomaxillary complex (ZMC) fractures. The authors analyzed 24 consecutive patients who underwent ultrasound-guided 1-point fixation for ZMC fractures without separation of the fracture at the frontal process of the zygomatic bone. The authors used titanium plates in the first 6 cases, and biodegradable plates in the remaining 18 cases. The authors obtained computed tomography images preoperatively, and again the first day after surgery (T1) and 6 months after the surgery (T2). The authors calculated vertical change (VC) and horizontal change (HC) of the zygoma on computed tomography. Precision was evaluated with T1 images. Stability was evaluated from T1 to T2, and titanium and biodegradable plates were compared. From T1 images, the mean VC and HC was 0.22° (range, 1.60°-1.08°) and 0.33° (range, 1.86°-1.03°), respectively. From T1 to T2, the mean VC and HC was 0.08° and 0.28°, respectively. Comparing the types of plates, the mean HC in the biodegradable plate group was 0.39°, which was significantly greater than that in the titanium plate group (mean -0.10°). However, as the degree of change was relatively small, this did not pose any clinical problems. Our findings suggest that ultrasound-guided 1-point fixation on the zygomaticomaxillary buttress provides accurate reduction on ZMC fractures without the separation of the frontal process of the zygomatic bone fracture. Sufficient stability was obtained, even with the use of biodegradable plates.

Initial organ distribution and biological safety of Mg2+ released from a Mg alloy implant.

Magnesium (Mg) alloys are considered promising materials for biodegradable medical devices; however, the initial effects and distribution of released Mg2+ ions following implantation are unclear. This is addressed in the present study, using two types of Mg alloys implanted into rats. An in vitro immersion test was first carried out to quantify Mg2+ ions released from the alloys at early stages. Based on these data, we performed an in vivo experiment in which large amounts of alloys were subcutaneously implanted into the backs of rats for 1, 5, 10, and 25 h. Mg2+ accumulation in organs was measured by inductively coupled plasma mass spectrometry. In vivo, blood and urine Mg2+ concentrations were higher in rats receiving the implants than in controls after 1 h; however, the levels were within clinically accepted guidelines. The Mg2+ concentration in bone was significantly higher in the 25 h implanted group than in the other groups. Our results suggest that homeostasis is maintained by urinary excretion and bone accumulation of released Mg2+ ions in response to sudden changes in Mg2+ ion concentration in the body fluid in a large number of Mg alloy implants at the early stages.

Midfacial Changes Through Anterior Maxillary Distraction Osteogenesis in Patients With Cleft Lip and Palate.

Maxillary hypoplasia is a major issue in cleft lip and palate patients, and predictable surgical maxillary advancement is required. In the present study, the changes and stability of the maxilla and soft tissue profile achieved after the application of anterior maxillary distraction osteogenesis (AMDO) using intraoral expander in unilateral cleft lip and palate and isolated cleft palate patients were investigated by comparing to the Le Fort I osteotomy (LFI) and maxillary distraction osteogenesis (DO) with rigid external distraction (RED) system.Ten patients who underwent orthognathic treatment with AMDO were examined (AMDO group). Changes in the positions of soft and hard tissue landmarks were calculated from the lateral cephalograms taken before the distraction, at the end of the distraction, and 1 year after the surgery. They were compared with the changes in 7 other unilateral cleft lip and palate patients who underwent LFI (LFI group) and 6 others who underwent DO with RED (RED group).The mean maxillary advancement of the AMDO group was similar to that of the RED group, judged by the change of point A. During DO, the AMDO group showed less clockwise rotation of mandible compared to the RED group. The soft tissue advancement of the upper lip and nose in the AMDO group was similar to that in the RED group, which was significantly larger than that in the LFI group.Our results indicate that AMDO can be surgical option to cleft lip and palate patients with less invasive but excellent improvement in both midfacial skeletal and soft tissue similar to DO-RED.