Clinical feasibility evaluation of digital dental articulation for three-piece maxillary orthognathic surgery: a proof-of-concept study.

Digital dental articulation for three-piece maxillary orthognathic surgery is challenging. The purpose of this proof-of-concept study was to evaluate the clinical feasibility of a newly developed mathematical algorithm to digitally establish the final occlusion for three-piece maxillary surgery. Five patients with jaw deformities who had undergone a three-piece double-jaw surgery that was planned virtually were randomly selected for this study. The final occlusion had been hand-articulated using stone casts, scanned into the computer and used in the surgery. These hand-articulated occlusions served as the control group. To form the experimental group, the three-piece maxillary dental arch was articulated again automatically from the patient's original occlusion using the mathematical algorithm. The hand- and algorithm-articulated occlusions were then evaluated qualitatively by two experienced orthodontists. A quantitative evaluation was also performed. The results of the qualitative evaluation showed that all of the three-piece occlusions, hand- and algorithm-articulated, were clinically acceptable based on the American Board of Orthodontics grading system. When compared, two of the algorithm-articulated occlusions were clearly better (40%), one was the same (20%), and two were slightly worse (40%) than the hand-articulated occlusions. All of the quantitative measurements were comparable between the two articulation methods. In conclusion, the results of this study demonstrate that it is clinically feasible to digitally articulate the three-piece maxillary arch to the intact mandibular dental arch.

Fluctuating asymmetry of the normal facial skeleton.

The purpose of this study was to produce reliable estimations of fluctuating facial asymmetry in a normal population. Fifty-four computed tomography (CT) facial models of average-looking and symmetrical Chinese subjects with a class I occlusion were used in this study. Eleven midline landmarks and 12 pairs of bilateral landmarks were digitized. The repeatability of the landmark digitization was first evaluated. A Procrustes analysis was then used to measure the fluctuating asymmetry of each CT model, after all of the models had been scaled to the average face size of the study sample. A principal component analysis was finally used to establish the direction of the fluctuating asymmetries. The results showed that there was excellent absolute agreement among the three repeated measurements. The mean fluctuating asymmetry of the average-size face varied at each anthropometric landmark site, ranging from 1.0mm to 2.8mm. At the 95% upper limit, the asymmetries ranged from 2.2mm to 5.7mm. Most of the asymmetry of the midline structures was mediolateral, while the asymmetry of the bilateral landmarks was more equally distributed. These values are for the average face. People with larger faces will have higher values, while subjects with smaller faces will have lower values.

There is variability in our perception of the standard head orientation.

The purposes of this study were to determine: (1) whether an observer's perception of the correct anatomical alignment of the head changes with time, and (2) whether different observers agree on the correct anatomical alignment. To determine whether the perception of the correct anatomical alignment changes with time (intra-observer comparison), a group of 30 observers were asked to orient, into anatomical alignment, the three-dimensional (3D) head photograph of a normal man, on two separate occasions. To determine whether different observers agree on the correct anatomical alignment (inter-observer comparison), the observed orientations were compared. The results of intra-observer comparisons showed substantial variability between the first and second anatomical alignments. Bland-Altman coefficients of repeatability for pitch, yaw, and roll, were 6.9°, 4.4°, and 2.4°, respectively. The results of inter-observer comparisons showed that the agreement for roll was good (sample variance 0.4, standard deviation (SD) 0.7°), the agreement for yaw was moderate (sample variance 2.0, SD 1.4°), and the agreement for pitch was poor (sample variance 15.5, SD 3.9°). In conclusion, the perception of correct anatomical alignment changes considerably with time. Different observers disagree on the correct anatomical alignment. Agreement among multiple observers was bad for pitch, moderate for yaw, and good for roll.

Accuracy, intra- and inter-rater reliability of three scoring systems for the glottic view at videolaryngoscopy.

An accurate and reproducible recording of laryngoscopic view at tracheal intubation is an important aspect of anaesthetic practice. Unlike direct laryngoscopy, in which the view achieved by the line of sight directly relates to the ease of intubating the trachea, videolaryngoscopy can create a situation in which the view is good, but intubation difficult or impossible. Communicating this to a subsequent anaesthetist is important. We compared three scoring systems: Cormack and Lehane; POGO (percentage of glottic opening); and the Fremantle score, as used by 74 critical care doctors rating 30 anonymised videos of videolaryngoscopic intubations. Accuracy (degree of agreement of score with an expert panel assessment) was higher for POGO (75.5%) and the Fremantle score (73.9%) than for Cormack and Lehane (65.4%; p < 0.001). Intra-rater reliability (mean free marginal Kappa for ordinal scores and mean Cronbach's Alpha for continuous score) was higher for Fremantle score (0.796) and Cormack and Lehane (0.773) than POGO (0.693). Inter-rater reliability for Fremantle score (0.618) and POGO (0.614) were similar and higher than the inter-rater reliability of Cormack and Lehane 0.464 (p < 0.001). The higher accuracy and inter-rater reliability of POGO and the Fremantle score suggest they are preferable to Cormack and Lehane for use when documenting videolaryngoscopy. The additional information about ease of intubation conveyed by the Fremantle score may support its routine use in recording videolaryngoscopic intubation.

Evaluation of three-dimensional root surface changes and resorption following rapid maxillary expansion: a cone beam computed tomography investigation.

OBJECTIVES: To evaluate root surface changes and resorption following toothborne rapid maxillary expansion (RME) using cone beam computed tomography (CBCT). SETTING AND SAMPLE POPULATION: The Department of Orthodontics at The University of Texas Health Science Center. Twenty-four consecutively treated patients (mean age: 12.8 years) requiring maxillary expansion. MATERIAL AND METHODS: An observational cohort included 48 CBCT images collected prior to (T1) and 4.8 months after (T2) RME from the study sample. Maxillary (study group) and mandibular (control group) first molars (n=48) and first premolars (n=48) were segmented and digitally registered using a 'best-fit' algorithm. Linear surface and volumetric changes between the study and control groups were compared using independent sample t-tests. Additionally, individual root length measurements were compared between the T1 and T2 images in each group using paired t-tests. RESULTS: All study teeth had significant changes for the evaluation of maximum linear surface area and volumetric changes as compared to control teeth (p<0.05). On average, premolars and molars in the study group experienced a root shortening of 0.36-0.52 mm (p<0.05). Color-coded diagrams demonstrated thinning and resorption occurring primarily at the apex and buccal aspects of the roots. Severity of these changes was individual-specific, as root resorption patterns were non-uniform. CONCLUSION: Significant volume loss, linear surface area changes, and thinning/shortening of maxillary first molar and premolar roots were common findings with the use of toothborne RME therapy.

Symptom differences and pretreatment asymptomatic interval affect outcomes of stenting for intracranial atherosclerotic disease.

BACKGROUND AND PURPOSE: Different types of symptomatic intracranial stenosis may respond differently to interventional therapy. We investigated symptomatic and pathophysiologic factors that may influence clinical outcomes of patients with intracranial atherosclerotic disease who were treated with stents. MATERIALS AND METHODS: A retrospective analysis was performed of patients treated with stents for intracranial atherosclerosis at 4 centers. Patient demographics and comorbidities, lesion features, treatment features, and preprocedural and postprocedural functional status were noted. χ(2) univariate and multivariate logistic regression analysis was performed to assess technical results and clinical outcomes. RESULTS: One hundred forty-two lesions in 131 patients were analyzed. Lesions causing hypoperfusion ischemic symptoms were associated with fewer strokes by last contact [χ(2) (1, n = 63) = 5.41, P = .019]. Nonhypoperfusion lesions causing symptoms during the 14 days before treatment had more strokes by last contact [χ(2) (1, n = 136), 4.21, P = .047]. Patients treated with stents designed for intracranial deployment were more likely to have had a stroke by last contact (OR, 4.63; P = .032), and patients treated with percutaneous balloon angioplasty in addition to deployment of a self-expanding stent were less likely to be stroke free at point of last contact (OR, 0.60; P = .034). CONCLUSIONS: More favorable outcomes may occur after stent placement for lesions causing hypoperfusion symptoms and when delaying stent placement 7-14 days after most recent symptoms for lesions suspected to cause embolic disease or perforator ischemia. Angioplasty performed in addition to self-expanding stent deployment may lead to worse outcomes, as may use of self-expanding stents rather than balloon-mounted stents.

Stent-assisted coiling versus coiling alone in unruptured intracranial aneurysms in the matrix and platinum science trial: safety, efficacy, and mid-term outcomes.

BACKGROUND AND PURPOSE: Stent-assisted coiling may result in less aneurysm recanalization but more complications than coiling alone. We evaluated outcomes of coiling with and without stents in the multicenter Matrix and Platinum Science Trial. MATERIALS AND METHODS: All patients in the Matrix and Platinum Science Trial with unruptured intracranial aneurysms treated per protocol were included. Baseline patient and aneurysm characteristics, procedural details, neurologic outcomes, angiographic outcomes, and safety data were analyzed. RESULTS: Overall, 137 of 361 (38%) patients were treated with a stent. Stent-coiled aneurysms had wider necks (≥4 mm in 62% with stents versus 33% without, P < .0001) and lower dome-to-neck ratios (1.3 versus 1.8, P < .0001). Periprocedural serious adverse events occurred infrequently in those treated with and without stents (6.6% versus 4.5%, P = .39). At 1 year, total significant adverse events, mortality, and worsening of mRS were similar in treatment groups, but ischemic strokes were more common in stent-coiled patients than in coiled patients (8.8% versus 2.2%, P = .005). However, multivariate analysis confirmed that at 2 years after treatment, prior cerebrovascular accident (OR, 4.7; P = .0089) and aneurysm neck width ≥4 mm (OR, 4.5; P = .02) were the only independent predictors of ischemic stroke. Stent use was not an independent predictor of ischemic stroke at 2 years (OR, 1.1; P = .94). Stent use did not predict target aneurysm recurrence at 2 years, but aneurysm dome size ≥10 mm (OR, 9.94; P < .0001) did predict target aneurysm recurrence. CONCLUSIONS: Stent-coiling had similar outcomes as coiling despite stented aneurysms having more difficult morphology than coiled aneurysms. Increased ischemic events in stent-coiled aneurysms were attributable to baseline risk factors and aneurysm morphology.

Comparison of facial morphologies between adult Chinese and Houstonian Caucasian populations using three-dimensional imaging.

The objective of this study was to compare the facial morphologies of an adult Chinese population to a Houstonian white population. Three-dimensional (3D) images were acquired via a commercially available stereophotogrammetric camera system, 3dMDface™. Using the system, 100 subjects from a Houstonian population and 71 subjects from a Chinese population were photographed. A complex mathematical algorithm was performed to generate a composite facial average (one for males and one for females) for each subgroup. The computer-generated facial averages were then superimposed based on a previously validated superimposition method. The facial averages were evaluated for differences. Distinct facial differences were evident between the subgroups evaluated. These areas included the nasal tip, the peri-orbital area, the malar process, the labial region, the forehead, and the chin. Overall, the mean facial difference between the Chinese and Houstonian female averages was 2.73±2.20mm, while the difference between the Chinese and Houstonian males was 2.83±2.20mm. The percent similarity for the female population pairings and male population pairings were 10.45% and 12.13%, respectively. The average adult Chinese and Houstonian faces possess distinct differences. Different populations and ethnicities have different facial features and averages that should be considered in the planning of treatment.

Delayed transcutaneous extrusion of embolic coils after embolization of facial artery pseudoaneurysm.

External carotid artery (ECA) pseudoaneurysm is a known complication of treatment for head and neck cancer. We report a case of facial artery pseudoaneurysm arising after irradiation and salvage surgery for advanced tonsillar cancer, that was treated with endovascular embolization. The case was complicated by delayed transcutaneous extrusion of embolization coils through the skin of the anterior neck. We review the literature for related cases of coil extrusion in the head and neck, and discuss the implications for pseudoaneurysm surveillance.

The development and preliminary evaluation of a proposed new scoring system for videolaryngoscopy.

Clear documentation of anaesthetic technique, difficulties and complications is an essential part of good anaesthetic practice, particularly in the area of airway management. The current convention of describing intubation using a videolaryngoscope only in terms of a Cormack and Lehane score is at best unhelpful and at worst dangerous. In an attempt to address the inadequacy of a Cormack and Lehane score to describe videoscopic intubation, we propose a three part scoring system: view, ease and device - the 'Fremantle Score'. Preliminary evaluation of this system in a diverse group of anaesthetists utilising four available videolaryngoscopes in a simulated normal and difficult airway manikin has demonstrated that the system is easy to use, easy to understand and relevant. In three of the eight device and manikin combinations studied, the videolaryngoscopic view correlated with the ease of intubation. This highlights the need for an alternative tool to describe intubation with a videolaryngoscope. We consider this development of a specific videoscopic scoring system a first step in better describing intubation by a videolaryngoscope and improving patient care.

Pediatric intracranial nongalenic pial arteriovenous fistulas: clinical features, angioarchitecture, and outcomes.

BACKGROUND AND PURPOSE: NGAVFs are rare vascular malformations usually presenting in infancy or childhood. We sought to identify clinical and angiographic predictors of clinical outcome for these lesions. MATERIALS AND METHODS: Retrospective review of a neurointerventional data base identified 386 pediatric patients with intracranial AVFs and AVMs, from which a cohort of 25 patients with NGAVF were selected for medical record and imaging analysis. RESULTS: NGAVFs constituted 7.3% of pediatric intracranial vascular lesions with a nondural arteriovenous shunt. Seven of 8 patients who presented in the first month of life had CHF and harbored large, complex fistulas with multiple sites of arteriovenous shunting. Single-hole fistulas predominated later in childhood and more frequently presented with seizures, hemorrhage, or focal neurologic deficits. More treatment procedures were performed in subjects presenting at ≤ 2 years of age compared with older children (median = 3 versus 2, P = .041), and in those harboring a multi-hole fistula versus those with a single-hole fistula (median = 3 versus 2, P = .003). Eighteen patients (72%) had complete posttreatment elimination of NGAVF shunting. Compared with patients presenting at >2 years of age, patients presenting in the first 2 years of life were more likely to have a multi-hole fistula (100% versus 25%, P = .0001) and to have a poor clinical outcome (54% versus 0%, P = .0052), defined as a pediatric mRS of ≥ 3. CONCLUSIONS: The morbidity of NGAVF appears higher than previously reported despite a somewhat higher rate of angiographic cure. Poor clinical outcome occurred primarily in patients with multi-hole NGAVFs presenting at ≤ 2 years of age.

Pediatric intracranial aneurysms: new and enlarging aneurysms after index aneurysm treatment or observation.

BACKGROUND AND PURPOSE: Children with brain aneurysms may be at higher risk than adults to develop new or enlarging aneurysms in a relatively short time. We sought to identify comorbidities and angiographic features in children that predict new aneurysm formation or enlargement of untreated aneurysms. MATERIALS AND METHODS: Retrospective analysis of the University of California-San Francisco Pediatric Aneurysm Cohort data base including medical records and imaging studies was performed. RESULTS: Of 83 patients harboring 114 intracranial aneurysms not associated with brain arteriovenous malformations or intracranial arteriovenous fistulas, 9 (8.4%) developed new or enlarging brain aneurysms an average of 4.2 years after initial presentation. Comorbidities that may be related to aneurysm formation were significantly higher in patients who developed new aneurysms (89%) as opposed to patients who did not develop new or enlarging aneurysms (41%; RR, 9.5; 95% CI, 1.9%-48%; P = .0099). Patients with multiple aneurysms at initial presentation were more likely than patients with a single aneurysm at presentation to develop a new or enlarging aneurysm (RR, 6.2; 95% CI, 2.1%-185; P = .0058). Patients who initially presented with at least 1 fusiform aneurysm were more likely to develop a new or enlarging aneurysm than patients who did not present with a fusiform aneurysm (RR, 22; 95% CI, 3.6%-68%; P = .00050). Index aneurysm treatment with parent artery occlusion also was associated with higher risk of new aneurysm formation (RR, 4.2; 95% CI, 1.3%-13%; P = .024). New aneurysms did not necessarily arise near index aneurysms. The only fatality in the series was due to subarachnoid hemorrhage from a new posterior circulation aneurysm arising 20 months after index anterior circulation aneurysm treatment in an immunosuppressed patient. CONCLUSIONS: Patients who presented with a fusiform aneurysm had a significantly greater incidence of developing a new aneurysm or enlargement of an index aneurysm than did those who presented with a saccular aneurysm. In our patient cohort, 8 of the 9 children who eventually developed new or enlarging brain aneurysms initially presented with fusiform aneurysm morphology. Other comorbidities or multiple aneurysms were also common in these patients at initial presentation.

Facial morphology of Finnish children with and without developmental hip dysplasia using 3D facial templates.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a condition that affects the femoral head and the acetabulum and leads to hip subluxation and dislocation. Infants with DDH are usually treated using splints that immobilize their hip joint and are forced on their back for long periods of time. The link between positioning and facial asymmetries is poorly understood. OBJECTIVE: To compare the facial morphologies of children with DDH to a group of healthy controls. SUBJECTS AND METHODS: Fifty-six Finnish patients born with DDH were matched on the basis of gender and age to a control group. Three-dimensional surface images were captured using the 3dMDface system. Using RF6 PP2 software, anthropometric landmarks were plotted and used to calculate asymmetry based on 3D co-ordinates in a reference framework. RESULTS: There was statistically significant difference between all paired facial shells. Relative to the control group, DDH boys and girls presented a chin-point deviation to the right, a more prominent left orbital ridge, a more protrusive nose and upper lip. The gender-specific subgroups show a similarity of 66.54 and 65.22% in girls and boys, respectively. CONCLUSIONS: Patients with DDH present a facial asymmetry when compared to healthy controls. Gender characteristics are marked whether subjects are affected with DDH or not. Three-dimensional surface imaging is a powerful diagnostic and research tool.

Long-term outcome in the repair of spinal cord perimedullary arteriovenous fistulas.

BACKGROUND AND PURPOSE: The natural history of PMAVFs, also known as type IV spinal cord AVFs, is incompletely understood. Both open surgical and endovascular approaches have been described as treatment modalities for this disease. The goal of this study was to evaluate the long-term outcome of patients with PMAVFs treated at a single tertiary care institution. MATERIALS AND METHODS: We conducted a retrospective study of 32 patients with PMAVFs, evaluated between 1983 and 2009. Data were gathered by reviewing outpatient clinic notes, operative and radiologic reports, and spinal angiograms. The PMAVFs were categorized into 1 of 3 types based on the angiographic imaging criteria. Pretreatment and posttreatment ambulation and micturition symptoms were quantified by using the ALS. RESULTS: Thirty patients underwent corrective procedures, 4 by embolization alone, 11 by surgery alone, and 15 with a combination of the 2. Twenty-eight patients underwent follow-up spinal angiography, with residual shunt noted in 6 patients. The mean follow-up period was 54 months (range, 1-228 months). Analysis of the ALS scores revealed that treatment of PMAVFs, independent of technique, resulted in significant improvement in ambulation but inconsistent changes in micturition. In addition, residual fistula at the time of the follow-up angiogram was associated with worsened neurologic status or lack of improvement. Outcome analysis based on fistula type showed dramatic improvement in ALS ambulation scores (62%) for type 3 fistulas, compared with types 1 and 2 (26% and 27%, respectively). CONCLUSIONS: Significant improvement in ambulation but in not micturition was observed following treatment. Residual fistula on follow-up angiography was associated with progressive worsening or lack of improvement in neurologic function. Patients with type 3 fistulas were shown to benefit most from treatment, with marked improvement in posttreatment ambulation scores. As endovascular and surgical techniques continue to evolve, further studies are warranted.

Endovascular treatment of medically refractory cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: CV following aneurysmal SAH is a significant cause of morbidity and mortality. We review our experiences using PTA and IA verapamil infusion for treating medically refractory cases. MATERIALS AND METHODS: We performed a retrospective review of patients with SAH admitted from July 2003 to January 2008. RESULTS: Of 546 patients admitted within 72 hours of symptom onset, 231 patients (42%) developed symptomatic CV and 189 patients (35%) required endovascular therapy. A total of 346 endovascular sessions were performed consisting of 1 single angioplasty, 286 IA verapamil infusions, and 59 combined treatments. PTA was performed on 151 vessel segments, and IA verapamil was infused in 720 vessel segments. IA verapamil doses ranged from 2.0 to 30.0 mg per vessel segment and from 3.0 to 55.0 mg per treatment session. Repeat treatments were necessary in 102 patients (54%) for persistent, recurrent, or worsening CV. There were 6 treatment-related complications, of which 2 resulted in clinical worsening. No deaths were attributable to endovascular therapy. At follow-up, 115 patients (61%) had a good outcome and 55 patients (29%) had a poor outcome. Sixteen patients died from causes related to SAH, while 3 died from other medical complications. CONCLUSIONS: Endovascular treatments are an integral part of managing patients with medically refractory CV. In our experience, PTA and IA verapamil are safe, with a low complication rate, but further studies are required to determine appropriate patient selection and treatment efficacy.

Calcification of the interclinoid and petroclinoid ligaments of sella turcica: a radiographic study of the prevalence.

OBJECTIVES: The purpose of this study was to evaluate the prevalence of calcifications of the sella turcica, in particular, calcification of the interclinoid and petroclinoid ligaments (PCL). DESIGN: Radiographic analysis of preoperative cephalometric film images. SETTING AND SAMPLE POPULATION: Lateral cephlometric radiographs of 255 subjects presenting for orthodontic evaluation were reviewed. The number of subjects selected for this study was determined by power analysis. EXPERIMENTAL VARIABLE: Two calibrated raters reviewed cephalometric projections and scored the films using a standardized rating scale. OUTCOME MEASURE: The rating scale classified interclinoid ligaments (ICL) into one of four categories depending on the degree of calcification and PCLs as either, no calcification, partial or complete calcification. RESULTS: Of all subjects, calcification of the ICL ranged from 39% rated as more than half calcified to 8% completely calcified. Petroclinoid analysis revealed 67% with no calcification, 23% with partial calcification and 9% completely calcified. Spearman's correlations were computed between age and the degree of calcification and between the degree of calcification for these two ligaments with a significant association between age and degree of calcification in the PCL, r = 0.185 (p = 0.003) and a significant association between the degree of calcification in the petroclinoid and ICLs, r = 0.186 (p = 0.003). In addition, chi-squared tests demonstrated statistically significant associations between the presence of calcification in the PCL to the distribution of age (p = 0.041) and between the presence of calcification in the ICL to the distribution of age (p = 0.045). CONCLUSION: As calcification of these ligaments has suggestive associations with disease entities, their recognition as a variant of normal anatomy should be evaluated when assessing cephalometric radiographs.

A new method of evaluating posterior occlusion and its relation to posttreatment occlusal changes.

The purpose of this study was to assess the relationship between posterior occlusion and posttreatment changes in other occlusal variables. Pretreatment (T1), posttreatment (T2), and postretention (T3) records were obtained for 49 Class I (n = 23) and Class II (n = 26) extraction cases. Overbite, overjet, mandibular incisor irregularity, right and left molar deviations, midline deviation, and mandibular arch length were measured, and occlusal registrations were made of each set of dental casts. The proximity of posterior occlusal surfaces was measured as the contact or near-contact areas at or below 300 microm thickness, based on the optical densities of scanned images of the posterior occlusal registrations. The treatment changes for overbite, overjet, right and left molar deviation, and arch length were significantly greater in the Class II group, and the reductions in incisor irregularity were greater in the Class I group. No other class differences were found. Overbite, overjet, and incisor irregularity increased after treatment, and arch length continued to decrease, with no significant class differences. Contact and near-contact areas at or below 300 microm constituted 7% of the functional occlusal table for both classes at the end of treatment, having decreased significantly in both groups (21% in Class I and 29% in Class II) during treatment. Because contact and near-contact areas increased in some patients and decreased in others, there were no significant posttreatment changes. Negative correlations were found between contact and near-contact areas at T2 and changes in overjet from T2 to T3, and between contact and near-contact areas at T3 and changes in overbite from T2 to T3. No relationships were found between posterior contact and near-contact area and incisor irregularity. We concluded that (1) the area of actual and near contacts at or below 300 microm decreased significantly with treatment, indicating that, despite excellent treatment results by conventional standards, the proximity of posterior occlusal surfaces lessened; (2) the proximity of the posterior occlusal surfaces should not be expected to increase posttreatment; (3) posttreatment contact and near-contact areas may be factors in overbite and overjet stability; and (4) posttreatment contact and near-contact areas are not related to incisor irregularity.

Predicting upper lip response to 4-piece maxillary LeFort I osteotomy.

The purpose of this retrospective study was to understand and predict the multidimensional changes in upper lip morphologic features after segmental (4-piece) maxillary Le Fort I advancement/impaction with VY closure and alar base cinch sutures. The study evaluated longitudinal lateral cephalograms of 57 patients (42 women, 15 men) 27.5 +/- 11.2 years of age before surgery. Lateral cephalograms with teeth in occlusion and lips in repose were taken 2 weeks before surgery and at least 6 months after the operation. Mean postsurgical duration was 15.5 months. The upper lip predictably moved anteriorly in a graduated fashion, from 50% (subnasale) to 90% (labrale superius) the amount of the underlying osseous anterior movement, and showed a slight lengthening (0.73 +/- 1.9 mm) from subnasale to upper lip stomion. The upper lip surface contour was also straightened as a result of the surgical movement. Multiple regression models showed that the anterior changes in the landmarks prosthion and facial surface of the upper incisor were the most important variables in predicting upper lip response. The prediction equations for horizontal movements explained 86% to 94% of the variation, with errors of the estimates that range between 1.27 mm and 1.65 mm. The models, when applied to an independent validation sample of 14 subjects, explained between 86% and 94% of the total variation. The conclusion is that upper lip response after 4-piece Le Fort I advancement/impaction (VY closure and alar base cinch suture) can be accurately predicted.