A Comparison of Synovial Fluid Pressure After Immediate Versus Gradual Mandibular Advancement in the Miniature Pig

Bone Density of the Condyle of Children with Craniofacial Microsomia and its Correlation with Condylar Resorption After Mandible Distraction Osteogenesis

OBJECTIVE

To investigate condylar bone density (BD) in children with craniofacial microsomia (CFM) and identify factors that contribute to early stage condylar resorption (CR) after mandibular distraction osteogenesis (MDO).

DESIGN

Retrospective study.

SETTING

Craniofacial department of a plastic surgery hospital.

PATIENTS

Fifty-one children with CFM classified as Pruzansky IIa based on complete pre-(T0) and post-MDO (T1) computed tomography (CT) data.

INTERVENTION AND MAIN OUTCOME MEASUREMENTS

Mimic 21.0 (Materialise Inc., Belgium) was used to measure bilateral BD and condylar height (CH) and volume (CV) of affected side. Children were split into groups based on either affected side BD or the distraction length (DL,25 mm as cutoff) .Bilateral BD was compared using a paired t-test in each group. The CH and CV of affected side at T0 and T1 were compared. The relative values of the CH and CV (CH ratio) and the volume (CV ratio) of the affected side were compared across the groups.

RESULTS

The BD was lower on affected side than on unaffected side. Regarding BD, CH and CV decreased after MDO in group I, while the CH ratio and CV ratio of group I was lower than that of groups II and III. Regarding DL, the CV ratio was lower in Group L than Group S.

CONCLUSIONS

The condylar bone quality on affected side is compromised in type IIa CFM. A low BD in combination with a larger distraction distance may increase the risk of CR; therefore, MDO in patients with such characteristics should be postponed.

Mandibular surgery: technologic and technical improvements

The ability of surgeons to use advanced techniques can significantly improve both surgical outcome and patient satisfaction. Surgical evolution in mandibular orthognathic surgery is no exception, because advancements have aided both surgical planning and technique. It is important for clinicians to be aware of the historical progression of improvements in this technique and appreciate the technologic advancements as they are happening. Computer-driven surgical planning is becoming increasingly popular, providing surgeons and patients with the ability to adjust to intraoperative and postoperative variations. By using these capabilities, clinicians are now able to give patients the best possible outcomes.

Pressure and inflammatory stimulation induced increase of cadherin-11 is mediated by PI3K/Akt pathway in synovial fibroblasts from temporomandibular joint

OBJECTIVE

The goal of the study was to investigate the expression of cadherin-11 in synovial fibroblasts (SFs) under mechanical or inflammatory stimuli, and its potential relationship with PI3K/Akt signaling pathway.

METHODS

SFs separated from rat temporomandibular joint (TMJ) were treated with hydrostatic pressures (HP) of 30, 60, 90, and 120 kPa, as well as tumor necrosis factor-α (TNF-α) for 12, 24, 48, and 72 h. The location of cadherin-11 was observed by immunofluorescence microscopy, and its expression was detected by real-time PCR and Western blot. We also studied the activation of PI3K/Akt signaling pathway in SFs with HP or TNF-α stimulation.

RESULTS

The results showed that increased expression of cadherin-11 could be found in the cell-cell contact site of SFs in response to HP and inflammatory stimulation. The mRNA and protein expression of cadherin-11 was positively correlated with the intensity of HP and the duration time of TNF-α treatment. Increased expression of vascular endothelial growth factor-D (VEGF-D) and activation of Akt were also found. Treatment with PI3K inhibitor LY294002 attenuated the pressure or inflammatory cytokine induction increases of cadherin-11, VEGF-D, and FGF-2 both in mRNA and protein levels.

CONCLUSIONS

These findings suggest that cadherin-11 may play important roles in SFs following exposure to mechanical loading and inflammatory stimulation. In addition, PI3K/Akt pathway was associated with pressure or inflammation-induced cadherin-11 expression, which may involve in the pathogenesis of temporomandibular diseases.

Vertical fracture of the mandibular posterior ramus border secondary to the stress of the rigid internal fixation material

A unique case of a vertical fracture of the mandibular posterior ramus border secondary to the stress of the rigid internal fixation material is described in this study. We think that the surgeon's experience and awareness play a key role in avoidance of such a complication.

Treatment of maxillomandibular deformities with internal curvilinear distraction

Internal curvilinear distraction is successful in achieving clinically significant distraction with stable occlusion in our patient population of infants, adolescents, and adults. When distracting the mandible, the curve of the distractor, the position of the distractor, and the osteotomy site are accountable for the final result. The curved distractor can mimic part of the natural logarithmic growth of the maxillomandibular complex. In addition, the result is predictable based on this design and the internal nature of the distractor, which can be left in place longer than other distractor types. Distraction can be combined with orthognathic surgery in certain cases resulting in increased benefit. This new procedure is called distraction orthognathics.

Deslocamentos esqueléticos associados à cirurgia de avanço mandibular: avaliação quantitativa tridimensional

OBJETIVO: avaliar através de imagens tridimensionais os deslocamentos dos ramos, côndilos e mento resultantes da cirurgia de avanço mandibular. MÉTODOS: este estudo prospectivo utilizou tomografias computadorizadas de feixe cônico das fases pré-cirúrgica e pós-cirúrgica de 27 indivíduos apresentando Classe II esquelética com padrão normocefálico ou braquicefálico. Uma técnica de superposição automatizada da base do crânio permitiu a avaliação de alterações esqueléticas em regiões anatômicas de interesse, e os deslocamentos foram visualizados e quantificados a partir da técnica dos mapas coloridos de superfícies. A estatística descritiva consistiu de valores médios, mínimo e máximo, e desvios-padrão. Mudanças maiores do que 2mm foram consideradas clinicamente relevantes e classificadas através de categorização dos valores. As tendências direcionais dos movimentos estruturais foram exibidas em valores positivos ou negativos. Coeficientes de correlação de Pearson foram aplicados com nível de significância de 95%, testando se deslocamentos em determinadas regiões foram associados com outras áreas. RESULTADOS: o mento apresentou deslocamento anteroinferior médio de 6,81±3,2mm, enquanto a porção inferior dos ramos apresentou movimento lateral com a cirurgia (esquerdo = 2,97±2,71mm; direito = 2,34±2,35mm). Outras regiões anatômicas mostraram deslocamento médio menor que 2mm, mas com evidente variabilidade individual. Correlações estatisticamente significativas foram positivas e moderadas. Os côndilos, bordo posterior e porção superior dos ramos apresentaram correlação bilateral, enquanto as porções superior e inferior dos ramos mostraram correlação ipsilateral. CONCLUSÃO: o método 3D utilizado permitiu uma precisa visualização e quantificação dos resultados cirúrgicos, destacando-se o movimento anteroinferior do mento e o deslocamento lateral da porção inferior dos ramos mandibulares, mas com considerável variabilidade individual em todas as regiões anatômicas avaliadas.