Non-surgical aesthetic techniques, p. 332).
• Blepharospasm: 25 units in 10 divided doses to medial and lateral lids.
• Frey’s syndrome: 5 units intradermally at 1cm distances.
• Masseteric hypertrophy: 25 units into masseter.
• Sialorrhoea/drooling: to submandibular/parotid glands up to 70 units total.
• TMJ pain dysfunction/dislocation: into lateral pterygoid muscles ± temporalis, up to 80 units each side.
• Post-operative sialocoele: parotidectomy—emerging evidence.
• Migrainous headaches.
• Cervical dystonia (torticollis).
• Doses relate to Botox® (Allergan).
Sensitivity and specificity
How good a test is at identifying those who have the disease.
How good a test is at identifying those who do not have the disease.
• True positives: those with a positive test result who do have the disease.
• True negatives: those with a negative test result who do not have the disease.
• False positives: those with a positive test result who do not have the disease.
• False negatives: those with a negative test result who do have the disease.
• A sensitive test will therefore have few false negatives.
• A specific test will have few false positives.
For example, MRI of the neck in detection of nodal metastasis:
• Sensitivity is 75–80% (i.e. not very sensitive). It therefore has a significant number of false negatives. These are the nodes with micrometastasis that do not show up on MRI.
• Specificity is 90–100%. It has few false positives, i.e. those nodes that fit the radiological criteria for metastatic disease nearly always show disease at histology.
Sensitivity = No. true positives/(No. true positives + No. false negatives)
Specificity = No. true negatives/(No. true negatives + No. false positives)
• The positive predictive value is the proportion of patients with positive test results who are correctly diagnosed:
PPV = No. true positives/(No. true positives + No. false positives)
• The infratemporal fossa is an irregularly shaped cavity, situated below and medial to the zygomatic arch.
• Previously called the pterygomaxillary space.
Consist of the following structures:
• Anteriorly: by the infratemporal surface of the maxilla and the ridge, which descends from its zygomatic process.
• Posteriorly: by the articular eminence of the temporal bone and the spinal angularis of the sphenoid bone.
• Superiorly: by the greater wing of the sphenoid below the infratemporal crest and the under-surface of the squamous temporal bone.
• Inferiorly: by the alveolar border of the maxilla.
• Medially: by the lateral pterygoid plate.
• Laterally: by the ramus of mandible.
• It has no floor.
• The lower part of the temporalis muscle.
• Lateral and medial pterygoid muscle.
• The internal maxillary vessels, consisting of the maxillary artery originating from the external carotid artery and its branches.
• Internal maxillary branches found within the infratemporal fossa including:
• middle meningeal artery;
• inferior alveolar artery;
• deep temporal artery;
• buccal artery;
• pterygoid venous plexus.
Mandibular nerve, inferior alveolar nerve, lingual nerve, buccal nerve, chorda tympani nerve, and otic ganglion.