Estudio retrospectivo de 544 timpanoplastias con cartílago y pericondrio: resultados anatómicos y funcionales / A retrospective study of 544 tympanoplasty with cartilage and perichondrium: anatomical and functional results

Introducción: el cierre de las perforaciones timpánicas se realiza con diferentes materiales, entre ellos el cartílago y el pericondrio. En este estudio se compararon los resultados anatómicos y funcionales obtenidos con ambos materiales, y se evaluaron posibles factores asociados con los buenos resultados. Material y métodos: estudio retrospectivo en pacientes intervenidos de timpanoplastia sin mastoidectomía entre el 1 de enero de 2001 y el 31 de diciembre de 2018. Resultados: se incluyeron 544 timpanoplastias. En la mayoría se utilizó cartílago (78,5 %) y en el resto pericondrio. El cartílago se utilizó con mayor frecuencia en los menores de 18 años (p=0,001), perforaciones totales y subtotales (p=0,000) y timpanoplastias secundarias y terciarias (p=0,008). No hubo diferencias en el tiempo de seguimiento (15,68 ± 22,18 meses frente al 12,86 ± 14,9 meses, p=0,169). La tasa de éxito anatómico fue mayor en el grupo de cartílago, sin diferencias en los resultados auditivos (82 % con cartílago y 78,3 % con pericondrio). El éxito anatómico se relacionó con la técnica utilizada para la reconstrucción con cartílago, mientras que los resultados auditivos se asociaron significativamente con el estado de la mucosa del oído medio y la cadena de huesecillos en el momento de la cirugía y el éxito anatómico posquirúrgico. Conclusiones: con el cartílago se consiguieron mejores resultados anatómicos que con el pericondrio, sin diferencias a nivel funcional. Sin embargo, los resultados funcionales empeoraron si había patología a nivel del oído medio y en ausencia de restauración anatómica.

Introduction: Different materials are used to close tympanic perforations. This stu-dy aimed to compare anatomical results obtained with cartilage and perichondrium and evaluate factors associated with successful results. Material and method: Re-trospective study of patients who underwent tympanoplasty without mastoidectomy between January 1, 2001, and December 31, 2018. Demographic data, ear pathology, surgical intervention, and anatomical and functional results were collected. Results:544 tympanoplasty were included. Cartilage was the most used (78.5%). Cartilage was used more frequently in children under 18 years (p = 0.001), to reconstruct total and subtotal perforations (p = 0.000) and in secondary and tertiary tympanoplasty (p = 0.008). Follow-up time did not differ between the two groups (15.68 ± 22.18 months vs. 12.86 ± 14.9 months, p = 0.169). The anatomical success rate was higher in the cartilage group, with no significant differences in hearing outcomes (82% with cartilage and 78.3% with perichondrium). Anatomical success was related to the technique used for cartilage reconstruction (monoblock or palisade). Hearing re-sults were significantly associated with the state of middle ear mucosa at the time of surgery, the state and mobility of the ossicle chain, and post-surgical anatomical suc-cess. Conclusions: Cartilage achieved better anatomical results than perichondrium. Both materials were comparable on a functional level. However, the functional re-sults worsen if there is pathology of the middle ear (mucosa or chain of ossicles) and anatomical restoration is not achieved.

Molecular nanoribbon gels.

Herein, we show that twisted molecular nanoribbons with as many as 322 atoms in the aromatic core are efficient gelators capable of self-assembling into ordered π-gels with morphologies and sol-gel transitions that vary with the length of the nanoribbon. In addition, the nanoribbon gels show a red fluorescence and also pseudoconductivity values in the same range as current state-of-the-art π-gels.

Mandibular osteoma as a cause of ankylosis and progressive trismus.

Osteomas are benign tumours of bone tissue restricted to the craniofacial skeleton. The aim of this article is to present and discuss the demographic and clinical aspects and the management of craniomaxillofacial osteomas. When the patient was submitted from primary care to our hospital, he was 68 years old, and he had ankylosis of the temporomandibular joint for the previos 4 years. A CT scan was performed, finding a giant mandibular osteoma. Conservative treatment and radiological follow-up were carried out with clinical stability. Osteomas more often are seen in the paranasal sinuses and in young adults, with no differences in gender. Most are asymptomatic, but they can cause local problems. For its diagnosis, CT is usually performed. Treatment options are conservative management and follow-up or surgery. Although rarely, they can recur. Mandibular peripheral osteoma is a rare entity. Depending on the symptoms, a conservative or surgical treatment can be chosen. A clinical and radiological follow-up is necessary to detect possible recurrences or enlargement.

Crystalline supramolecular organic frameworks via hydrogen-bonding between nucleobases.

We report a crystalline supramolecular framework assembled by H-bonding interactions between covalently fused monomers equipped with two guanine-cytosine nucleobase pairs.

Elucidating Noncovalent Reaction Mechanisms: G-Quartet as an Intermediate in G-Quadruplex Assembly.

In analogy to covalent reactions, the understanding of noncovalent association pathways is fundamental to influence and control any supramolecular process. Following an approach that is reminiscent of covalent methodologies, we study here, for the first time, the mechanism of G-quadruplex formation in organic solvents. Our results support a reaction pathway in which the cation shifts the equilibrium towards a G-quartet transient intermediate, which then acts as a template in the formation of the G-quadruplex product.

Uracil grafted imine-based covalent organic framework for nucleobase recognition.

An imine-based covalent organic framework (COF) decorated in its cavities with uracil groups has shown selective recognition towards adenine in water. These results show how the confinement of the base-pair inside the COF's pores allows a remarkable selective recognition in aqueous media.

Thermodynamic and Kinetic Stabilities of G-Quadruplexes in Apolar Solvents.

In contrast to more polar media, G-quadruplex assembly reveals remarkably high thermodynamic and kinetic stability in toluene solutions. Depending on the substituents installed at the lipophilic guanosine, either a dodecamer or an octamer complex is formed in the presence of K+ or Na+ salts that resist conditions of high dilution and elevated temperatures without exhibiting significant dissociation. Moreover, kinetic exchange between complexed and uncomplexed G is slow enough in NMR to monitor G-quadruplex formation along a day time scale.