Three-dimensional analysis techniques--Part 1: Three-dimensional soft-tissue analysis of 24 adult cleft palate patients following Le Fort I maxillary advancement: a preliminary report.

The three-dimensional, facial soft-tissue changes of 24 patients with various cleft types following transpalatal Le Fort I osteotomy were measured using laser scanning techniques, radial measurements, and a color millimetric scale. There was a varying degree of midface retrusion in the different cleft groups, and a very similar pattern of retrusion over the nasal complex. Each group of patients showed a varying degree of relapse postsurgically, but there was a failure in all the cleft groups to correct the lack of nasal projection.

Three-dimensional analysis techniques--Part 2: Laser scanning: a quantitative three-dimensional soft-tissue analysis using a color-coding system.

New methods for measuring and averaging three-dimensional soft-tissue morphology and change from laser scans using a color millimetric scale are described. The techniques were employed to measure facial differences between a group of Class I skeletal males and females. The surgical change in one patient following bimaxillary surgery is also illustrated. The combination of the laser scanning technique and the new color coding system probed to be a simple, noninvasive, effective, and easily interpreted method for measuring three-dimensional soft-tissue differences and change across the facial complex.

Three-dimensional analysis techniques--Part 3: Color-coded system for three-dimensional measurement of bone and ratio of soft tissue to bone: the analysis.

A new color-coded method of illustrating three-dimensional changes in the bone and the ratio of soft tissue to bone movement is described. The technique is illustrated by superimposing preoperative and 1-year postoperative CT scans of three patients following bimaxillary surgery. The method has proved to be a very simple, effective, and readily interpreted method of quantifying both bone and the ratio of movement of the overlying soft tissues across the face following surgery.

Three-dimensional analysis techniques--Part 4: Three-dimensional analysis of bone and soft tissue to bone ratio of movements in 24 cleft palate patients following Le Fort I osteotomy: a preliminary report.

The three-dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 24 cleft palate patients following Le Fort I osteotomy. CT scans were taken for each patient preoperatively and 1 year postoperatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate color scales. In all of the groups, there was a fairly consistent pattern of movement over the mandible. The soft tissues moved in a 1.25:1 ratio over the chin and canine regions, and reduced to 1:1 over the body. In the maxilla, there was a 1:1 movement in the midline increasing to 1.25:1 bilaterally over the alar bases for both the bilateral clefts and clefts of the secondary palate groups. In the unilateral cleft group, however, there was a greater degree of movement over the cleft than over the noncleft side.

Three-dimensional nasal changes following maxillary advancement in cleft patients.

Three-dimensional laser surface scanning of the face was performed before and after Le Fort I maxillary advancement in 24 patients with replaced clefts of the lip and palate. The surgery resulted in advancement of the upper lip and para-alar tissues and an increase in the relative prominence of the nose within the face. These changes were produced at the expense of an increase in nasal width and a reduction in nasal tip protrusion. The changes in nasal morphology showed significant variation among patients.

A three-dimensional soft tissue analysis of fifteen patients with Class II, Division 1 malocclusions after bimaxillary surgery.

A three-dimensional soft tissue study of the results of surgery in a group of 15 women with Class II, Division I malocclusions after orthognathic surgery was performed with laser scans. A group of 30 women with Class I malocclusions ages between 19 and 25 years were used as controls. Laser scans were taken before surgery, 3 months after surgery, and at least 1 year after retention. The skeletal 2 patients were shown to have a narrowing of the face over the maxillary complex, checks, the nose, as well as around the alar bases, the so called "adenoid facies." There was also the expected mandibular deficiency. The effects of the bimaxillary surgery were not simply confined to the maxilla and the mandible, with soft tissue changes extending as far as the outer canthi of the eyes. There was very little relapse in the group as a whole from the third month to 1 year after surgery. This technique has proved to be a simple noninvasive method of measuring three dimensionally. It has proven to be a very useful tool in auditing surgical outcome and measuring surgical relapse.

A three-dimensional analysis of bone and soft tissue to bone ratio of movements in 17 Skeletal II patients following orthognathic surgery.

The three-dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 17 Skeletal II patients following orthognathic surgery. CT scans were taken for each patient pre-operatively and 1 year post-operatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate colour scales. There was a constant ratio of movement over the maxillae with the central part of the upper lip being moved in a 1:1 ratio, increasing to a 1.25:1 ratio over the canine regions and 1.5:1 ratio over the paranasal areas. In the mandible there was a constant ratio of 1.25:1 over the chin, mentalis, and canine regions bilaterally. The ratio reduced to 1:1 over the body of the mandible.

Le Fort I maxillary osteotomy: is it possible to accurately produce planned pre-operative movements?

The planned preoperative maxillary movements for five groups of patients requiring orthognathic surgery were prospectively compared to the actual surgical movements achieved in the operating theatre. There was a very poor success rate in achieving predicted movements in all the patient groups. There is a need to test and implement a reliable method of assisting the surgeon in spatially orientating the jaws on the operating table.

A three dimensional analysis of soft and hard tissue changes following bimaxillary orthognathic surgery in skeletal III patients.

The three dimensional changes in the bone and the ratio of soft tissue to bone movement were investigated in a group of 16 Skeletal III patients following orthognathic surgery. Computerised tomogram scans were taken for each patient pre-operatively and 1 year postoperatively. The scans were superimposed, radial measurements calculated, and the changes illustrated by two separate colour scales. There was no constant pattern of movement in the maxilla or mandible in these patients. However, following a Le Fort 1 osteotomy there was commonly a 1:1 ratio in the midline which increased to 1.25:1 at the alar bases and over the canine regions bilaterally. There was also a 1.25:1 ratio or greater over the chin and mentalis regions following mandibular set back.

A three-dimensional soft tissue analysis of 16 skeletal class III patients following bimaxillary surgery.

A three-dimensional soft tissue study of the results of surgery in a group of 16 skeletal Class III adult patients following orthognathic surgery was carried out using laser scans (Arridge et al., 1985). The patient group was compared to a control group of the same population. Laser scans were taken prior to surgery, 3 months post-surgery, and at least 1 year after retention. Preoperative comparison to the control groups revealed that the facial disproportion related to both the maxilla and the mandible. Le Fort I advancements resulted in broadening of the lateral aspects of the nose, advancement of the dorsum, and overcorrection of the alar bases. There was a degree of change over the cheeks bilaterally, because of alterations in the general drape of the soft tissues. There was a degree of overcorrection in the female group following mandibular set back but the male group were still more prognathic, when compared to the control group. There was a marked degree of relapse in the mandible from 3 months to 1 year postoperatively, with a resultant anterior movement of the maxillary arch. Laser scanning has proved to be a simple non-invasive method of measuring three-dimensionally, and is a very useful tool in auditing surgical outcome and measuring surgical relapse.

Stability of surgical correction of patients with Skeletal III and Skeletal II anterior open bite, with increased maxillary mandibular planes angle.

The surgical correction of eleven Class III patients and 10 Class II patients with a long face, increased maxillary mandibular planes angle and anterior open bite was undertaken using bimaxillary surgical procedures. Lateral skull radiographs were examined pre-operatively, 48 hours, and 1 year post-operatively, to quantify the amount and direction of surgical change achieved and the subsequent stability. There was no consistent pattern in the actual movements achieved in either group of patients in the maxillae or the mandibles. Some of the cases being impacted and continuing to impact, others impacting then relapsing. In the Class III patients some of the mandibular set backs remained stable others relapsing and some continuing to move posteriorly. However, despite these inconsistent patterns, there was a 7-degree reduction in the maxillary mandibular planes angle which relapsed by 1.7 degrees over the first year. The overbite was increased from -6 mm to +3.1 mm post-operatively and this relapsed at the 1 year stage to +2.4 mm. The overjet reduced from -4 to 1.7 mm and continued to improve to -0.9 mm at the 1-year stage. In the Class II patients some of the mandibular advancements remained stable others relapsing and some continuing to advance. However, despite these inconsistent patterns there was a 9-degree reduction in the maxillary mandibular planes angle which reduced by a further degree at the 1 year stage. The overbite was increased from -4.6 to -1.6 mm post-operatively and this remained stable at the 1 year stage.(ABSTRACT TRUNCATED AT 250 WORDS)

A study model analysis of adult unoperated Sri Lankans with unilateral cleft lip and palate.

The maxillary arch-form of 41 Sri Lankan adults with unoperated complete unilateral cleft lip and palate (8 female and 33 male) were compared to a control group of 100 normal Sri Lankan adults (45 female and 55 male). The teeth in the cleft group were smaller than their equivalents in the control group, the most marked difference being found in the central and lateral incisors. Arch widths of the cleft groups were reduced, more anteriorly than posteriorly, resulting in more V-shaped arches. No differences were found in the arch length or chord lengths between the groups. Crossbites occurred in 19.5 percent of the cleft group as compared to none of the controls. The overjet was greater in the cleft group than in the controls. A higher percentage of missing teeth was recorded in the cleft group.