GRANULATION TISSUE FORMATION

Granulation tissue formation is composed of three important steps: fibroplasia, wound contraction and angiogenesis.

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RE-EPITHELIALIZATION

This process involves replication and movement of the epidermal cells from the wound edges in order to reconstitute an organized, keratinized, stratified squamous epithelium. Increased mitotic activity within the basal cells of the wound edges occurs within 12 hours of wounding. Initially, migration of epidermal cells creates a delicate covering over the raw area, a process also known as ‘epiboly’. These cells then migrate, usually as a sheet, by extending lamellipodia (from the Latin lamina – thin sheet, pod – foot) from the free edge of the cut epidermis, across the defect. This process of migration is dependent on the oxygen tension present in the wound and is most rapid in hyperbaric conditions.7 ‘Contact inhibition’ prevents movement when epithelial sheets meet. Gradually, a continuous squamous cell epithelium is restored.

Costen’s Syndrome

The TMJ dysfunction could cause subtle alterations in middle-ear biomechanics, and hypothesised that these could be attributable to anatomical links between the TMJ and the middle ear, including the discomalleolar ligament, the anterior malleolar ligament and the tendon between the tensor tympani and tensor veli palatini muscles. Changes in tension on these structures in TMJ dysfunction could be transmitted to the malleus, thereby altering the stapes position. The latter could cause a pressure change in inner-ear fluids and alter the polarisation state of cochlear and vestibular hair cells, thereby contributing to symptoms of ear fullness, tinnitus, subjective hearing loss and vertigo. Subtle changes in inner-ear fluid pressure have been detected by multiple frequency tympanometry.

The cause of hearing loss associated with temporomandibular disorder can only be speculated upon. Recently, a hypothesis was proposed linking temporomandibular disorders, Eustachian tube dysfunction and inner-ear dysfunction. Irritation in the TMJ region was hypothesised to result in the release of inflammatory mediators in the Eustachian tube via an axon reflex, which could further activate the anterior cervical sympathetic system. The latter would enhance neurogenic inflammation in the Eustachian tube, resulting in reduced middle-ear ventilation. The imbalance between middle-ear and inner-ear pressure could alter the polarisation state of cochlear hair cells, thereby causing sensorineural hearing loss. In this context, another recent study reported multiple system dysregulation (especially affecting the sensory, autonomic and inflammatory domains) in patients with painful temporomandibular disorders. This hypothesis may help explain the various types of hearing loss observed in patients with various categories of temporomandibular disorder.

Ley de Poiseuille

Poiseuille’s law explains that the flow of a fluid, in this case air through the nasal cavity, is inversely proportional to the fourth power of the radius of the lumen. As a result, even small modifications to the cross-sectional area of the nasal airway can produce dramatic effects on airflow, particularly through the internal nasal valve.

Ley de Bernoulli

La ley de Bernoulli dice que un incremento en la velocidad está asociado a una disminución de la presión intraluminal. La presión diferencial resultante induce al colapso del tejido blando circundante y empeoramiento de la obstrucción nasal.

Sífilis

Debido a que la sífilis adquirida después del nacimiento puede manifestarse como hipoacusia neurosensorial progresiva y vértigo, debe considerarse el diagnóstico en cualquier paciente sexualmente activo que presenta hipoacusia de instauración reciente y/o vértigo.

Síndrome de Loeys Dietz


El síndrome de Loeys-Dietz (SLD) es un trastorno del tejido conectivo autosómico dominante, causado por mutaciones en los genes TGFBR1 (9q33-q34) y TGFBR2 (3p22). Se caracteriza típicamente por la tríada de hipertelorismo, paladar hendido o úvula bífida, y aneurismas y/o tortuosidad arterial. El 75 % de los pacientes presentan hallazgos dismórficos faciales típicos; es entonces cuando se d
enomina síndrome de Loeys-Dietz tipo1. El síndrome de Loeys-Dietz tipo 2 es usado para describir a un grupo de pacientes sin afectación craneofacial mayor, pero con manifestaciones cutáneas. Ambos tipos pueden ser producidos por alteraciones en los genes descritos. De hecho, actualmente se piensa que ambos tipos de SLD forman un continuum clínico.

Tympanic Inervation

The external surface of the tympanic membrane is innervated
by the auriculotemporal nerve and the auricular branch of the
vagus nerve, whereas the inner surface is supplied by Jacobson’s
nerve, a branch of the glossopharyngeal nerve.

Regulación del ciclo nasal

Regulación de la Microvasculatura Nasal

Inervación Simpática: Provee el tono vasoconstrictor a las arterias y venas de capacitancia, mediado por la Norepinefrina (neurotransmisor primario), Neuropéptido Y (un débil neurotransmisor, refuerza los efectos de la Norepinefrina), y un Polipéptido Aviario Pancreático (APP).

Inervación Parasimpática: Controla las secreciones y dilata los vasos de resistencia mediado a través de la Acetilcolina (neurotransmisor primario), Péptido Intestinal Vasoactivo (VIP), y Péptido Histamina Isoleucina (PHI).

Síndrome de Alagille

El síndrome de Alagille es una enfermedad multiorgánica secundaria a la mutación del gen JAG1. Las manifestaciones otológicas incluyen otitis media crónica, malformaciones del hueso temporal y sordera. La característica de este síndrome en oído es la hipoplasia de los  canales semicirculares posteriores que terminan en fondo de saco y son visibles en estudios por TC.

 

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