are shown in Fig. 9.2 and, also, the lines that are then drawn between some of these landmarks. The angles be­tween these can then be compared with standard values to indicate facial skeletal variations from normal. Digital pho­tographic images may also be superimposed on the radio­graphic images and surgical predications carried out with the computer software.

For dentofacial anomalies, the diagnosis will describe the maxillary and mandibular base relationship relative to the skull together with a description of the dental occlusion and comments about general condition of the dentition and oral hygiene. The mandible and maxilla may be de­scribed as prognathic, hypoplastic or asymmetrical. The effect of these may be to produce a long face, open bite or short face. The chin may also be described using various classifications of excess (macrogenia), hypoplasia (micro­genia) and asymmetry. For craniofacial anomalies, the diagnosis will also describe the orbits, eyes, ears and other

The chin may be reduced or undergo augmentation as an isolated procedure or as part of a mandibular or maxillary orthognathic operation. Genioplasty may be undertaken via an intraoral approach and fixation with mini-plates is usual (Fig. 9.4).

The surgical techniques used for maxillary surgery are generally described by the Le Fort classification used for fracture description (see Chapter 8). The higher-level osteotomies are obviously more complicated surgical operations. The most common maxillary osteotomy is the Le Fort I (Fig. 9.5). This operation is very versatile and enables movement of maxilla in any direction. Access is by an intraoral approach and bone cuts are made with a saw and chisels. Fixation is with mini-plates. Higher-level maxillary osteotomies may require access via discrete skin incisions about the face or these may be avoided by a bicoronal approach. In the latter, a scalp incision is made across the vertex of the skull from ear to ear. This approach provides excellent access to the upper facial skeleton and a scar that is concealed beneath hair unless the patient develops hair loss.

Surgical airway management with a tracheostomy is usually unnecessary for orthognathic surgery other than high-level maxillary procedures. However, close clinical and electrome­chanical observation with pulse oximetry is necessary to check that the patient does not become hypoxic as the result of soft tissue swelling following surgery. The level of nursing supervision required means that the first postoperative 24 hours are usually spent in a high-dependency or intensive care unit. A nasopharyngeal airway is well tolerated in con­scious patients and may be left in situ postoperatively to safeguard the airway during the first night. This will require frequent suction to maintain a clot-free patent airway.

Various ‘Z’ and ‘W’ plasties and local flap techniques may be used to disguise facial scars.

Used to remove superficially embedded foreign bodies from dirty facial abrasions and allow to heal without tattooing. Also used to treat acne scarring.

Corrects periorbital skin wrinkling and orbital fat herniation.

d. False. The mandible develops in the normal way. The