and Raja Mohan, MD
When considering surgery to correct craniofacial abnormalities in a patient, a thorough facial analysis is paramount before an operative plan is designed. Surgical intervention alongside orthodontic treatment helps achieve an optimal and predictable result.
First, the patient’s perspective and desires should be discussed when performing the initial evaluation. Often, the patient’s perceptions differ from those of the surgeon. In addition, a detailed history of the patient’s current and previous medical problems should be gathered. Family history is also pertinent since siblings may have similar facial abnormalities. It is important to consider the history of speech problems or congenital craniofacial abnormalities.1
Comorbidities such as preexisting cardiac or renal dysfunction require consultation with a specialist to obtain advice for perioperative management. Patients with diabetes or those who are immunocompromised are at a greater risk for infection and may have complications with wound healing. Lastly, patients with bleeding tendencies or who bruise easily should be evaluated for any coagulation disorders such as Von Willebrand’s disease.2,3 Patients with coagulation disorders may not be aware of their condition and might require treatment intraoperatively for adequate hemostasis. Controlling blood pressure, whether it is high or low, is also key in preventing complications associated with bleeding, such as hematoma. As for any surgical procedure, patients should discontinue nonsteroidal anti-inflammatory medications and aspirin-containing products before the procedure.
3.2 Dental History and Examination
A detailed dental history is important in patients considering maxillofacial surgery. Any history of periodontal disease, tooth extractions, or previous dental procedures should be recorded; a current evaluation by a dentist is also essential. Patients who have had prolonged orthodontic treatment could have root resorption, which would render further orthodontic work imprudent.4 Sometimes, patients undergo orthodontic treatment for what is in fact a skeletal problem and will actually require surgical treatment. The changes induced by the orthodontic treatments should be reversed before surgical intervention.4
The alignment of the teeth, location of the palatal vault, and shape of the arch should also be examined. Crowding indicates the inability of the dental arch to accommodate the teeth. Assessment of oral hygiene and periodontal disease are vital to the success of orthognathic surgery since their presence precludes orthodontic treatment, and surgery without orthodontic intervention should almost never be considered. One of the most important parts of the intraoral examination is assessing the patient’s occlusion. Any overbite, overjet, or crossbite should be noted, and the angle classification should be determined. Details regarding angle classification and occlusion can be found in other sections of this book. Placing a tongue blade and asking the patient to bite down is a simple maneuver to assess the patient’s occlusal canting and determine if there is any asymmetry.
Any history of temporomandibular joint (TMJ) dysfunction should be recorded. Patients with this condition may experience symptoms such as clicking, pain, locking, ear pain, bruxism, or headaches. Preoperative imaging can assist with determining the presence and severity of the TMJ conditions. The masticatory function and tenderness of the muscles should be evaluated. The interincisal dimension, lateral excursion, and protrusive excursion should all be measured. A normal mandibular opening is 40 to 56 mm, and the normal range of lateral movement at 10 mm and protrusion is 9 to 13 mm.5
3.3 Psychological Assessment
Before the procedure, one must have a detailed discussion with the patient, parents, or legal guardians about the intended facial changes and potential risks and outcomes so that they understand the changes that can occur. Often, significant alterations in facial appearance are to be expected, and it may take time for the patient to adjust to these changes. The treatment plan and expected outcome should ultimately be based on the patient’s desires. Even though the postoperative changes may be anatomically or “cephalometrically” correct, the patient may still be dissatisfied with the result. It is important to avert this scenario as much as possible.
3.4 Facial Analysis
A systematic approach to the face concentrating on the relationships of craniofacial, skeletal, and soft tissue components is suggested. The patient’s skin is examined first to assess thickness, color, and consistency and is evaluated for its susceptibility to forming hypertrophic scars or keloids. Patients with red hair, light or freckled skin, and blue eyes are more susceptible to bleeding and developing hypertrophic scars.
The face may be divided into three different zones: upper, middle, and lower (Figure 3.1). The upper zone extends from the hairline to the glabella. The middle zone extends from the glabella to the subnasale. The third zone extends from the subnasale to the menton. The frontal view of the face can be split into five equal, vertical segments. Two segments are occupied by the eyes, extending from the lateral canthus to the medial canthus. One segment extends from one medial canthus to the other and contains the nose, and the last two segments extend from the lateral canthi to the lateral border of the ipsilateral temple. Any asymmetry in these segments should be noted.
Figure 3.1. Lines passing through eyebrows and subnasale divide the face into three equal zones. Reprinted with permission from Elsevier (Guyuron B. Patient assessment. In: Guyuron B, Eriksson E, Persing JA. Plastic Surgery: Indications and Practice. Vol. 2. Philadelphia, PA: WB Saunders; 2009:1343–1351). Copyright © 2009 Elsevier.
A top-down approach allows one to evaluate the entire face in a thorough manner. The forehead is examined for its length and width as well as for any irregularities. Wrinkles in the forehead are best assessed by asking the patient to close his or her eyes tightly and then gently open them.6 This maneuver allows the forehead to relax. Vertical frown lines can be due to overactive corrugators and procerus muscles.7 The eyebrows are examined for their symmetry and relationship to adjacent structures. The brows are arched with the peak located at the level of the lateral limbus. Ideally, the lateral ends of the brow are cephalad to the medial ends. The brow is usually 1 cm above the superior orbital rim in women and at the level of the rim in men. A vertical line should connect the medial brow to the ipsilateral alar base, while an oblique line drawn from the lateral canthus to the alar base should extend and connect to the lateral brow.8
When analyzing the middle zone of the face, the size and shapes of the eyes are checked (Figure 3.2