Comparison of the skeletal stability after mandibular counter-clockwise rotation in three surgical procedures.

The treatment of mandibular deformities with an anterior open bite is challenging. In this study, skeletal stability after mandibular osteotomies was evaluated to determine the best treatment for mandibular prognathism with an anterior open bite in three procedures: intraoral vertical ramus osteotomy (IVRO), conventional sagittal split ramus osteotomy (conv-SSRO), and SSRO without bone fixation (nonfix-SSRO). Patients who underwent mandibular osteotomy to correct skeletal mandibular protrusion were included. Changes in skeletal and soft tissues were assessed using lateral cephalograms taken before (T1), 3 ± 2 days (T2), and 12 ± 3 months (T3) after surgery. Thirty-nine patients were included: nine in the IVRO group and 11 and 19 in the conv- and nonfix-SSRO groups, respectively. The mandibular plane angles (MPAs) of the T2-T1 were - 2.7 ± 2.0 (p = 0.0040), - 3.7 ± 1.7 (p < 0.0001), and - 2.3 ± 0.7 (p < 0.0001) in the IVRO, conv-SSRO, and nonfix-SSRO groups, respectively. The skeletal relapse of the MPAs was not related to the MPA at T2-T1, and it was approximately 1.3° in the conv-SSRO group. The skeletal relapse of the MAPs was significantly correlated with the MPA of T2-T1 in the IVRO (p = 0.0402) and non-fix-SSRO (p = 0.0173) groups. When the relapse of the MPAs was less than 1.3°, the MPA of T2-T1 was calculated as 2.5° in the nonfix-SSRO group. When the MPA of T2-T1 is less than 2.5°, non-fix SSRO may produce a reliable outcome, and when it is more than 2.5°, conv-SSRO may produce better outcomes.

Clockwise torque results in higher reoperation rates in left-sided femur fractures.

PURPOSE: Effects of clockwise torque rotation onto proximal femoral fracture fixation have been subject of ongoing debate: fixated right-sided trochanteric fractures seem more rotationally stable than left-sided fractures in the biomechanical setting, but this theoretical advantage has not been demonstrated in the clinical setting to date. The purpose of this study was to identify a difference in early reoperation rate between patients undergoing surgery for left- versus right-sided proximal femur fractures using cephalomedullary nailing (CMN). MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program was queried from 2016-2019 to identify patients aged 50 years and older undergoing CMN for a proximal femoral fracture. The primary outcome was any unplanned reoperation within 30 days following surgery. The difference was calculated using a Chi-square test, and observed power calculated using post-hoc power analysis. RESULTS: In total, of 20,122 patients undergoing CMN for proximal femoral fracture management, 1.8% (n=371) had to undergo an unplanned reoperation within 30 days after surgery. Overall, 208 (2.0%) were left-sided and 163 (1.7%) right-sided fractures (p=0.052, risk ratio [RR] 1.22, 95% confidence interval [CI] 1.00-1.50), odds ratio [OR] 1.23 (95%CI 1.00-1.51), power 49.2% (α=0.05). CONCLUSION: This study shows a higher risk of reoperation for left-sided compared to right-sided proximal femur fractures after CMN in a large sample size. Although results may be underpowered and statistically insignificant, this finding might substantiate the hypothesis that clockwise rotation during implant insertion and (postoperative) weightbearing may lead to higher reoperation rates. LEVEL OF EVIDENCE: Therapeutic level II.

Association between electrocardiographic QRS transition zone and mortality from all causes and cardiovascular diseases: A systematic review and meta-analysis.

AIMS: To investigate whether clockwise rotation (CWR) and counterclockwise rotation (CCWR) of electrocardiographic QRS transition zone is associated with mortality from all causes and cardiovascular diseases (CVD). METHODS: Studies were identified from searching of PubMed, EMBASE and the reference lists of relevant papers. Summary multivariate-adjusted hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) and 95% prediction intervals (PIs) were computed through meta-analysis. RESULTS: A total of five observational cohort studies fulfilled the inclusion criteria, which included 47,252 participants from the general population (8.8% CWR; 44.1% CCWR). Pooling data revealed that CWR was significantly associated with the increased risk of all-cause mortality (HR, 1.18; 95% CI: 1.12-1.24; 95% PI: 1.03-1.37) and CVD mortality (HR, 1.18; 95% CI: 1.08-1.29; 95% PI: 0.98-1.42) compared to NR pattern, with low heterogeneity among studies (P = 0.29, I2 = 20%; P = 0.37; I2 = 7%; respectively). However, CCWR was inversely associated with the risk of all-cause mortality (HR, 0.92; 95% CI: 0.89-0.95; 95% PI: 0.80-1.05) with low heterogeneity (P = 0.14; I2 = 43%), while no significant association existed between CCWR and CVD mortality (HR, 0.89; 95% CI: 0.77-1.02; 95% PI: 0.53-1.48) with high heterogeneity (P < 0.01; I2 = 78%). CONCLUSION: Our meta-analysis demonstrated CWR was positively associated with higher risk of mortality from all-cause and CVD, while CCWR was negatively associated with the risk of all-cause mortality and no significant association with CVD mortality. These findings suggested that QRS transition zone carries important prognostic value, more attention should be paid in clinical practice.

QRS transitional zone rotations and the risk of atrial fibrillation: the Suita Study.

ECG screening can detect people at risk of developing atrial fibrillation (AF). Recent literature indicated that QRS transitional zone rotations could predict several cardiovascular events. Herein, we investigated the association between QRS transitional zone rotations and the future risk of AF. This prospective cohort study included 6794 participants (3178 men and 3616 women), aged 30-84 years, from the urban Japanese city of Suita. QRS transitional zone rotations were diagnosed by ECG during baseline, while AF was diagnosed by ECG, hospital records, and checkups during follow-up. The Cox regression was used to compute the sex-specified hazard ratios (HRs) and 95% confidence intervals (CIs) of incident AF for participants with counterclockwise and clockwise QRS transitional zone rotations compared to those with normal rotation. Within a median follow-up period of 14.6 years, 311 participants (206 men and 105 women) developed AF. Counterclockwise rotation was associated with the reduced risk of AF among men, but not women, in the age-adjusted model: HR (95% CI) = 0.66 (0.44, 0.98) and the multivariable-adjusted model: HR (95% CI) = 0.65 (0.43, 0.97). Clockwise rotation was not associated with AF risk in either sex. To the best of our knowledge, this is the first study to indicate that counterclockwise rotation could be associated with the reduced risk of AF in men. More studies are needed to confirm our findings and elucidate possible mechanisms.

Electrocardiographic QRS axis shift, rotation and COVID-19.

Background: In patients with coronavirus disease-2019 (COVID-19), severe dyspnea is the most dramatic complication. Severe respiratory difficulties may include electrocardiographic frontal QRS axis rightward shift (Rws) and clockwise rotation (Cwr). Aim: This study investigated the predictability of advanced lung tomography findings with QRS axis shift and rotation. Patients and Methods: This was a retrospective analysis of 160 patients. Patients were divided into the following two groups: normal (n = 80) and low (n = 80) oxygen saturation. These groups were further divided into four groups according to the rightward and leftward axis shift (Lws) on the electrocardiographic follow-up findings. These groups were compared in terms of electrocardiographic rotation (Cwr, counterclockwise rotation, or normal transition), tomographic stage (CO-RADS5(advanced)/CO-RADS1-4), electrocardiographic intervals, and laboratory findings. Results: In patients with low oxygen saturation, the amount of QRS axis shift, Cwr, and tomographic stage were significantly higher in the Rws group than in the Lws group. There were no differences in the above parameters between the Rws and Lws groups in patients with normal oxygen saturation. Logistic regression analysis revealed that the presence of Cwr and Rws independently increased the risk of CO-RADS5 by 18.9 and 4.6 fold, respectively, in patients with low oxygen saturation. Conclusion: In COVID-19 patients who have dyspnea with low oxygen saturation, electrocardiographically clockwise rotation with a rightward axis shift demonstrated good sensitivity (80% [0.657-0.943]) and specificity (80% [0.552->1]) for predicting advanced lung tomographic findings. ClinicalTrialsgov Identifier: NCT04698083.

Surgical Orthodontic Treatment in Case of Severe High Angle Skeletal Class II Malocclusion and Mandibular Retrusion.

This report describes a patient with severe high angle class II malocclusion and mandibular retrusion in whom surgical orthodontic treatment to prevent an increase in ramus height resulted in a significant improvement in esthetics and long-term stability. The patient was a woman aged 30 years 5 months who presented with the chief complaint of maxillary protrusion. She had a convex facial type, a chin button on lip sealing, and a gummy smile. Cephalometric analysis revealed a normal maxilla anterior-posterior position, but significant mandibular retrusion with pronounced clockwise rotation. The anterior maxillary tooth axis was standard, but labially inclined in the mandible. Based on these findings, the diagnosis was skeletal class II high angle malocclusion and mandibular retrusion. The proposed treatment plan comprised 2-jaw surgery with premolar extraction. Le Fort I osteotomy, in particular, was planned in the maxilla to move the ANS upward by 3.0 mm and the PNS downward by 3.0 mm. Sagittal split ramus osteotomy (SSRO) was planned to adjust the mandible and move the mandible forward by 10.0 mm. To prevent postoperative relapse, the short lingual split method was used in performing the SSRO. The mandible was split to minimize stretching of the median pterygoid muscle. Postoperatively, the ANS, PNS, and pogonion showed movement of 2.0 mm upward, 3.0 mm downward, and 8.0 mm forward, respectively. Additionally, lip closure was now natural, and the gummy smile had markedly improved. At 6 years postoperatively, there has been no change skeletally or dentally. Follow-up is being continued to monitor further progress.

Microtornillos como método de control vertical en desprogramación muscular / Vertical control with miniscrews in muscular deprogramming treatment

Una de las consecuencias de la desprogramación neuromuscular es la rotación mandibular en sentido horario, evidenciando el punto prematuro de contacto y aumentando la dimensión vertical del paciente. En pacientes clase II con componente vertical, es un problema realizar este tipo de tratamiento, ya que por lo general este efecto de posterorrotación mandibular hace el perfil más convexo, y en algunos casos genera mordida abierta anterior, la cual se debe corregir posteriormente con el tratamiento de ortodoncia, cirugía o prótesis, lo que alarga el tiempo total de tratamiento por la necesidad de control vertical. El presente caso se trata de una mujer de 45 años de edad, dolicofacial, con tendencia a mordida abierta, mordida dual, sobremordida vertical y horizontal disminuidas, motivo de consulta dolor articular, el cual no le permite continuar con sus labores diarias, el tratamiento realizado fue desprogramación neuromuscular con un guarda oclusal inferior con el propósito de aliviar sintomatología articular y control vertical con microtornillos palatinos previo a tratamiento ortodóncico (AU)

One of the effects of the neuromuscular deprogramming treatment is the mandibular clockwise rotation, making the light premature occlusal contact more evident and increasing the patient vertical dimension. In Class II patients with vertical component is difficult to treat them due to profile worsening as an effect of the clockwise rotation creating in some patient's anterior open bite, this has to be corrected later in treatment with orthodontic intrusion, surgery or prosthodontic treatment, increasing the total time of treatment with the vertical control necessity. This case report is a 45 years old patient, dolichofacial, with anterior open bite tendency, dual bite, decreased overjet and overbite, her chief complaint was temporomandibular joint dysfunction which dont allow her to do her daily duties, the treatment for her was neuromuscular deprogramming splint for the temporomandibular joint pain, and vertical control with temporary anchorage devices (miniscrews) before the orthodontic treatment (AU)

A combined orthodontic / orthognathic approach in the management of obstructive sleep apnoea: Balancing treatment efficacy and facial aesthetics.

Obstructive sleep apnoea (OSA) is a prevalent condition and has been extensively managed with orthognathic surgery using a variety of surgical techniques. This case report describes the successful management of a 56-year-old Caucasian woman with a bimaxillary retrusive profile and macroglossia complicated by OSA and the combined use of orthodontics and orthognathic surgery to improve Apnoea-Hypopnoea Index while maintaining facial aesthetics. The non-extraction treatment plan included: (1) pre-surgical orthodontic treatment to maximise aesthetics and functional occlusion after surgery; (2) maxillomandibular advancement using down fracture of the maxilla (Le Fort 1 osteotomy) with counter-clockwise rotation as well as bilateral sagittal split osteotomy with septoplasty to aid increase in airway function; and (3) post-surgical orthodontic finishing and alignment with self-ligating fixed appliances. Optimum aesthetic and functional results as well as an increase in the airway volume were achieved, without compromising facial aesthetics, with the cooperation of two specialties and the use of state-of-the-art technology during the surgical planning stages.

Release of syngnathia by anticlockwise rotation and mandibular advancement using bilateral alloplastic temporomandibular joint prostheses: a new approach.

We describe a new approach to the planning of treatment and subsequent operation on a patient with syngnathia and severe mandibular retrognathism. To facilitate a large mandibular advancement we applied alloplastic temporomandibular joint (TMJ) prostheses to the coronoid processes after anticlockwise rotation of the mandible. To the best of our knowledge this is the first documented case of its kind.

Análise biomecânica de diferentes tipos de fixação em osteotomia sagital do ramo após diferentes avanços e alterações do plano mandibular: um estudo com elementos finitos / Biomechanical analysis of different types of fixation in sagittal ramus osteotomy after different advances and changes in the mandibular plane: a study with finite elements

O objetivo deste trabalho foi avaliar, por meio de um estudo com análise em elementos finitos, as tensões de superfície presentes na cortical óssea mandibular e no material de síntese, assim como avaliar a resistência da fixação ao deslocamento após a osteotomia sagital do ramo mandibular (OSRM) quando da realização de diferentes avanços mandibulares com e sem alteração do plano mandibular. Foram obtidos modelos virtuais tridimensionais de uma mandíbula e planejados avanços de 6 e 12mm com avanço linear, assim como associados ao giro horário e anti-horário do plano mandibular. Cada conjunto foi, então, fixado com uma ou duas placas monocorticais do sistema 2.0 dispostas horizontalmente com 4 parafusos em cada placa. Ao todo, foram construídos 12 modelos que foram então submetidos a uma carga vertical linear na região de incisivos centrais em incrementos de 50N até o limite máximo de 500N. Os resultados demonstraram que os avanços de 12mm estão associados a maiores tensões nas corticais ósseas e no material se síntese. Também foi possível concluir que os modelos fixados com duas placas apresentaram valores menores de tensão no material de síntese em comparação aos modelos fixados com uma placa. A mudança do plano mandibular no sentido anti-horário nos avanços de 6 mm, fixados com 1 ou 2 placas, aumentou a tensão no material de síntese, o que não ocorreu nos avanços de 12 mm. Esses resultados podem auxiliar os cirurgiões na tomada de decisão clínica diária (AU).

The aim of the present paper was to evaluate, via a finite element analysis, the tensions on the cortical bone and the plating system, as to evaluate mandibular resistance after the sagittal split ramus osteotomy with different mandibular advancements and mandibular plane movements. 3D mandibular models were obtained and a 6mm and 12mm advancement was planned associated with linear, clockwise or counter clockwise rotation of the mandibular plane angle. Each model was then fixed with one or two plates of the 2.0mm system and held with 4 monocortical screws at each side. A total of 12 models were built and they were subjected to a vertical load in the incisors region ranging from 50N to 500N in 50N increments. Results have shown that the 12mm advancement was associated with a higher tension in the cortical bone and plate surface. It was also concluded that the models fixed with 2 plates presented lower values of tension on the plates in comparison with the models fixed with a single plate. Counter clockwise rotation of the mandibular plane angle in the 6mm advancement, fixed with 1 or 2 plates, brought more tension to the plates, which did not occur in the 12mm advancements. These results may aid surgeons with decision making on a daily basis (AU).

Cardiac structural and functional profile of patients with delayed QRS transition zone and sudden cardiac death.

AIMS: Delayed QRS transition zone in the precordial leads of the 12-lead electrocardiogram (ECG) has been recently associated with increased risk of sudden cardiac death (SCD), but the underlying mechanisms are unknown. We correlated echocardiographic findings with ECG and clinical characteristics to investigate how alterations in cardiac structure and function contribute to this risk marker. METHODS AND RESULTS: From the ongoing population-based Oregon Sudden Unexpected Death Study (catchment population ∼1 million), SCD cases with prior ECG available (n = 627) were compared with controls (n = 801). Subjects with delayed transition at V5 or later were identified, and clinical and echocardiographic patterns associated with delayed transition were analysed. Delayed transition was present in 31% of the SCD cases and 17% of the controls. These subjects were older and more likely to have cardiovascular risk factors and history of myocardial infarction. Delayed transition was associated with increased left ventricular (LV) mass (122.7 ± 40.2 vs. 102.9 ± 33.7 g/m2; P < 0.001), larger LV diameter (53.3 ± 10.4 vs. 49.2 ± 8.0 mm; P < 0.001), and lower LV ejection fraction (LVEF) (46.4 ± 15.7 vs. 55.6 ± 12.5%; P < 0.001). In multivariate analysis, delayed transition was independently associated with myocardial infarction, reduced LVEF, and LV hypertrophy. The association between delayed transition and SCD was independent of the LVEF (OR 1.57; 95% CI 1.04-2.38; P = 0.032). CONCLUSION: The underpinnings of delayed QRS transition zone extend beyond previous myocardial infarction and reduced LVEF. Since the association with sudden death is independent of these factors, this novel marker of myocardial electrical remodelling should be explored as a potential risk predictor of SCD.

Abnormal electrocardiographic QRS transition zone and risk of mortality in individuals free of cardiovascular disease.

AIMS: We examined the prognostic significance of abnormal electrocardiographic QRS transition zone (clockwise and counterclockwise horizontal rotations) in individuals free of cardiovascular disease (CVD). METHODS AND RESULTS: A total of 5541 adults (age 53 ± 10.4 years, 54% women, 24% non-Hispanic black, 25% Hispanic) without CVD or any major electrocardiogram (ECG) abnormalities from the US Third National Health and Nutrition Examination Survey were included in this analysis. Clockwise and counterclockwise horizontal rotations were defined from standard 12-lead ECG using Minnesota ECG Classification. Mortality and cause of death were assessed through 2006. At baseline, 282 participants had clockwise rotation and 3500 had counterclockwise rotation. During a median follow of 14.6 years, 1229 deaths occurred of which 415 were due to CVD. In multivariable-adjusted Cox proportional hazard analysis and compared with normal rotation, clockwise rotation was significantly associated with increased risk of all-cause mortality {hazard ratio (HR) [95% confidence interval (CI)]: 1.43 (1.15-1.78); P = 0.002} and CVD mortality [HR (95% CI): 1.61 (1.09, 2.37) P = 0.016]. In contrast, counterclockwise rotation was associated with significantly lower risk of all-cause mortality [HR (95% CI): 0.86 (0.76, 0.97); P = 0.017] and non-significant association with CVD mortality [HR (95% CI): 1.07 (0.86, 1.33); P = 0.549]. These results were consistent in subgroup analysis stratified by age, sex, and race. CONCLUSION: In a diverse community-based population free of CVD and compared with normal rotation, clockwise rotation was associated with increased risk of all-cause and CVD mortality while counterclockwise rotation was associated with lower risk of all-cause mortality and non-significant association with CVD mortality. These findings call for attention to these often neglected ECG markers, and probably call for revising the current definition of normal rotation.

Delayed QRS transition in the precordial leads of an electrocardiogram as a predictor of sudden cardiac death in the general population.

BACKGROUND: QRS transition zone is related to the electrical axis of the heart in the horizontal plane and is easily determined from the precordial leads of a standard 12-lead ECG. However, whether delayed QRS transition, or clockwise rotation of the heart, carries prognostic implications and predicts sudden cardiac death (SCD) is unclear. OBJECTIVE: The purpose of this study was to study whether delayed transition is associated with mortality and SCD. METHODS: We evaluated 12-lead ECGs of 10,815 Finnish middle-aged subjects from the general population (52% men, mean age 44 ± 8.5 years) and followed them for 30 ± 11 years. Main end-points were mortality and SCD. RESULTS: Delayed QRS transition at lead V4 or later occurred in 1770 subjects (16.4%) and markedly delayed transition at lead V5 or later in 146 subjects (1.3%). Delayed transition zone was associated with older age, male gender, higher body mass index, hypertension, baseline cardiovascular disease, leftward shift of the frontal QRS axis, wider QRS-T angle, and ECG left ventricular hypertrophy. After adjusting for several clinical and ECG variables, delayed transition was associated with overall mortality (hazard ratio [HR] 1.15, 95% confidence interval [CI] 1.07-1.22, P < .001) and SCD (HR 1.23, 95% CI 1.03-1.47, P = .029). Markedly delayed transition at V5 or later predicted significantly SCD (HR 1.89, 95% CI 1.18-3.03, P = .008) and all-cause mortality (HR 1.30, 95% CI 1.07-1.58, P = .01). However, further adjustments for repolarization abnormalities attenuated this effect. CONCLUSION: Delayed QRS transition in the precordial leads of an ECG seems to be a novel ECG risk marker for SCD. In particular, markedly delayed transition was associated with significantly increased risk of SCD, independent of confounding factors.

Contributing factors to intraoperative clockwise rotation of the proximal segment as a relapse factor after mandibular setback with sagittal split ramus osteotomy.

The aims of this study were to analyze possible contributing factors to intraoperative clockwise rotation (CWR) of the proximal segment (PS), which is known to be a primary factor for relapse after mandibular setback with sagittal split ramus osteotomy (SSRO) and to evaluate the correlation between the CWR of the PS and relapse tendency. The sample was comprised of 47 patients who underwent SSRO for mandibular setback. Lateral cephalograms were analyzed. The vertical difference between the inferior borders of the PS and the distal segment at the vertical osteotomy line for SSRO after setback of the distal segment (vertical bony step, VBS) was the most predictable factor for CWR of the PS (p < 0.001), and it correlated significantly with the gonial angle, the surgical change in SNB, and the downward movement of the maxilla (p < 0.05). Patients with large CWR of the PS showed a greater tendency in horizontal relapse than patients with small CWR of the PS (p < 0.05). Such relapse patterns could be prevented with adequate surgical planning designed to reduce the VBS, such as maxillary posterior impaction or the intentional guidance of the PS to maintain the original position of the PS without CWR.

Cyclic fatigue resistance of newly manufactured rotary nickel titanium instruments used in different rotational directions.

The aim of this study was to investigate whether cyclic fatigue resistance is increased for nickel titanium instruments manufactured with improved heating processes in clockwise or counterclockwise continuous rotation. The instruments compared were produced either using the R-phase heat treatment (K3XF; SybronEndo, Orange, CA, USA) or the M-wire alloy (ProFile Vortex; DENTSPLY Tulsa Dental Specialties, Tulsa, OK, USA). Tests were performed with a specific cyclic fatigue device that evaluated cycles to failure of rotary instruments in curved artificial canals. Results indicated no significant difference in resistance to cyclic fatigue when rotary nickel titanium instruments are used in clockwise or counterclockwise continuous rotation. In both directions of rotation, size 04-25 K3XF showed a significant increase (P < 0.05) in the mean number of cycles to failure when compared with size 04-25 ProFile Vortex.

Post-operative Stability of Counter Clockwise Rotation of the Mandibular Plane in Skeletal CIII with Anterior Openbite Patients

3degrees).CONCLUSION: This study evaluated the amount of horizontal relapse, and the degree of relapse. Stable results were obtained. Although there was no statistical significance between the degree of openbite and the amount of horizontal relapse, the group with a greater amount of openbite had a greater amount of relapse.