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Subtraction radiography is a way to measure differences in landmark positions between cephalometric films without using tracings that introduce another source of error. This method was used to evaluate the reproducibility of head positioning in 54 pairs of cephalometric films taken within hours of each other, before and after splint removal in orthognathic surgery patients. There were no statistically significant changes in two cranial and four maxillary landmarks; the expected changes in mandibular landmark served to validate the method. The results suggest that patient positioning is not a major contributor to the error of cephalometric methods.

Postsurgical changes in 24 patients who had rigid internal fixation (RIF) of the mandible with screws after combined superior repositioning of the maxilla and mandibular advancement were compared with 53 patients who underwent the same surgery but who had intraosseous wire fixation, skeletal suspension wires, and 8 weeks of maxillomandibular fixation (MMF). During the first 8 weeks after surgery, the mean posterior relapse of the mandible was greater in the MMF group than in the RIF group (for example, -1.1 mm versus 0.15 mm at B point), and the percentage of patients with clinically significant vertical and horizontal changes was greater in the MMF group. By 1 year, there had been slight additional mean relapse in the MMF group (-1.5 mm net relapse at B point, with 42% of the patients showing 2 mm or more relapse). In the RIF group, the mandible was more likely to be repositioned forward than posteriorly (net mean change at B point, 0.7 mm forward; 33% had 2 mm or more forward movement). In the RIF group, all but one of the patients (96%) were judged to have an excellent clinical result; in the MMF group, the corresponding figure was 60%.

The treatment outcome for skeletal Class II malocclusion was reviewed in 33 nongrowing patients who were treated with orthodontics alone (by premolar extraction and tooth movement to camouflage the skeletal problem) and in 57 patients treated for similar problems with surgery and orthodontics (with mandibular advancement and with tooth movement to reduce rather than increase dental compensation for the skeletal deformity). Cephalometric and dental cast changes were scored to quantitate treatment effects. Two approaches were used to determine the treatment efficacy (the relative success of treatment): (1) whether the final value for a measurement criterion (such as an overjet and an ANB angle) fell within the normal range, and (2) the quantitative amount of correction produced relative to an "ideal" value. In addition, a panel of judges was used to rate esthetic changes from pretreatment and posttreatment facial slides. Both orthodontic treatment and surgical-orthodontic treatment improved the malocclusion as judged from dental casts. Surgery resulted in greater reduction of overjet and greater improvement in most cephalometric skeletal, dental, and soft tissue criteria. Before treatment, the surgical patients had lower esthetic ratings than the orthodontics-only patients. After treatment, the esthetic ratings for the orthodontic patients were unchanged. The surgical patients had improved but not to the pretreatment level of the orthodontics patients.