Vertical components of overbite change: a mathematical model.

The purpose of this study was to better understand the multidimensional nature of overbite changes that occur during adolescence. The study used longitudinal cephalograms of 181 untreated children (102 males, 79 females) taken at ages 10 and 15. Four major components that directly affect overbite were measured: (1) maxillary vertical displacement, (2) mandibular vertical displacement, (3) upper incisor vertical change within the bone, (4) lower incisor vertical change within the bone. Cranial base, maxillary, and mandibular superimpositions were performed for each subject to assess the vertical changes that occurred in these 4 components and to assess overbite. A multiple regression analysis was used to develop a mathematical model describing the relationships of these components to changes in overbite. The model was validated with an independent subsample and a comparison of subjects whose overbites decreased and those whose overbites increased. The results showed that overbite changed minimally (0.2 mm) over the 5-year period; variation ranged from a 2.4 mm decrease to a 5.6 mm increase. The regression model indicated that the mandibular skeletal changes were twice as important as the mandibular dental changes and about 2.5 times as important as the maxillary changes in effecting overbite change. Within the mandibular skeletal component, vertical growth was more important than mandibular rotation in determining overbite change. The model demonstrated that a multivariate approach is necessary to understand overbite changes. More effective orthodontic treatment might be achieved by focusing on the primary components effecting overbite change, especially those with the greatest potential for therapeutic modification.     

Increased overbite and craniomandibular disorders--a clinical approach

This study investigated the effect of a maxillary fixed lingual arch with anterior bite plane on adult patients with craniomandibular disorders (CMD) and increased overbite. The sample comprised 11 patients with an increased overbite (greater than 5 mm) and a normal or Class II molar relationship. The main CMD symptoms were daily tension headache in the region of anterior temporal muscles and/or pain or clicking in the temporomandibular joint. Previous treatment with stabilization splints, removal bite plates, or occlusal grinding had not given satisfactory results. When the maxillary lingual arch with anterior bite plane was fitted, molar separation was approximately 4 mm, and occlusal contact occurred only between the acrylic bite plane and the lower six anterior teeth. The permanent appliance could be removed only by the orthodontist. All patients reported relief of CMD symptoms 1 to 2 weeks after initiation of treatment. After a mean time of 3 months, a flatter curve of Spee, molar contact, and reduced overbite could be seen in all cases. The excessive overbite had decreased approximately 3.4 mm. Subsequent treatment involved orthodontic or prosthetic therapy to normalize and stabilize the sagittal and vertical dimensions. After an average posttreatment observation period of 2 years, all patients remained free of CMD pain.     

Stability and relapse of mandibular anterior alignment: a cephalometric appraisal of first-premolar-extraction cases treated by traditional edgewise orthodontics

Assessment at least 10 years postretention of fifty-four cases previously treated in the permanent-dentition stage with first-premolar extractions, traditional edgewise mechanotherapy, and retention revealed considerable variation among patients. The long-term response to mandibular anterior alignment was unpredictable; no cephalometric parameters, such as maxillary and mandibular incisor proclination, horizontal and vertical growth amounts, mandibular plane angle, etc., were useful in establishing a prognosis. Few associations of value were found between cephalometric parameters and dental-cast measurements, such as overbite, arch length, intercanine width, and overjet. Only a slight tendency was found for incisor inclination to return toward the pretreatment value during the postretention period. It was possible to predict, on the basis of an analysis of pre- and posttreatment cephalometric records, those cases which had greater than 4 mm deepening of overbite postretention as well as those cases which had decreases of 3 mm or more in arch-length postretention. The practical use of these predictions were of limited clinical value, however.     

Effects of intrusion combined with anterior retraction on apical root resorption

This study evaluated the influence of intrusion mechanics combined with anterior retraction on root resorption of the maxillary incisors. A sample of 56 patients was divided into two groups: group 1 comprised 28 patients (12 females and 16 males), presenting with an increased overjet and deep overbite (6.48 and 4.78 mm, respectively) treated with reverse curve of Spee intrusion mechanics and group 2 comprised 28 patients (12 females and 16 males) with an increased overjet of 5.67 mm and a normal overbite of 1.12 mm. The initial mean ages for groups 1 and 2 were 13.41 and 13.27 years, respectively. Pre- (T1) and post- (T2) treatment periapical radiographs were used to evaluate root resorption. The groups were compared using the Mann-Whitney U-test. Correlation between root resorption and tooth movement was investigated with Spearman's correlation coefficient. The subjects in group 1 had statistically greater root resorption (P < 0.05) than those in group 2. The initial overbite severity and the amount of correction had significant positive correlations with root resorption (r = 0.324 and r = 0.320, respectively). The combination of anterior retraction with intrusive mechanics causes more root resorption than anterior retraction of the maxillary incisors alone.     

Periodontal diseases in adult Kenyans

This study comprised 1131 persons who constitute a stratified random sample of the entire population aged 15-65 years in Machakos District, Kenya. Each person was examined for tooth mobility, plaque, calculus, gingival bleeding, loss of attachment and pocket depth on the mesial, buccal, distal and lingual surface of each tooth. The oral hygiene was poor with plaque on 75-95% and calculus on 10-85% of the surfaces depending on age. Irrespective of age, pockets greater than or equal to 4 mm was seen on less than 20% of the surfaces, whereas 10-85% of the surfaces had loss of attachment greater than or equal to 1 mm. The proportion of surfaces per individual with loss of attachment greater than or equal to 4 mm or greater than or equal to 7 mm, and pocket depths greater than or equal to 4 mm or greater than or equal to 7 mm, respectively, showed a pronounced skewed distribution, indicating that in each age group, a subfraction of individuals is responsible for a substantial proportion of the total periodontal breakdown. The individual teeth within the dentition also showed a marked variation in the severity of periodontal breakdown. Our findings provide additional evidence that destructive periodontal disease should not be perceived as an inevitable consequence of gingivitis which ultimately leads to considerable tooth loss. A more specific characterization of the features of periodontal breakdown in those individuals who seem particularly susceptible is therefore warranted.     

Surgical versus orthodontic correction of skeletal Class II malocclusion in adolescents: effects and indications.

To clarify the effects of orthodontic versus surgical treatment and to distinguish more clearly those Class II patients who can be treated successfully with orthodontics alone, we compared three groups of adolescents: forty patients treated successfully with orthognathic surgery, 40 patients treated successfully with orthodontics alone, and 21 patients whose orthodontic treatment was judged to be unsuccessful. Successful surgical treatment was accomplished largely by bringing the mandible forward, but this involved vertically repositioning the maxilla, alone or in combination with advancing the mandible, in 40% of the patients. Successful orthodontic treatment resulted from a combination of retraction of the maxillary incisors and protraction of the mandibular incisors; most of the successfully treated group also had significant vertical growth, and 40% had greater than 2 mm anteroposterior growth. The unsuccessfully treated orthodontic patients initially had greater overjet, more severe mandibular deficiency, and greater anterior facial height than those treated successfully; they also had less retraction of the maxillary incisors and less growth during treatment. In Class II adolescents beyond the growth spurt, surgery is likely to be needed for successful correction of the malocclusion if the overjet is greater than 10 mm, especially if the distance from pogonion to nasion perpendicular is 18 mm or more, mandibular body length is less than 70 mm, or facial height is greater than 125 mm.     

Long-term stability of anterior open bite closure corrected by surgical-orthodontic treatment

In adults, superior repositioning of posterior maxilla with or without mandibular surgery has become the treatment method of choice to close anterior open bite. Study aim was to examine the long-term stability of anterior open bite closure by superior repositioning of maxilla or by combining maxillary impaction with mandibular surgery. The sample comprised 24 patients who underwent anterior open bite closure by superior repositioning of maxilla (maxillary group, n = 12, mean age 29.3 years) or by maxillary impaction and mandibular osteotomy (bimaxillary group, n = 12, mean age 30.8 years). Lateral cephalograms were studied prior to surgery (T1), the first post-operative day (T2) and in the long term (T3, maxillary group mean 3.5 years; bimaxillary group mean 2.0 years). Paired and two-sample t-tests were used to assess differences within and between the groups. The vertical incisal bite relations were -2.6 and -2.2 mm at T1; 1.23 and 0.98 mm at T2; and 1.85 and 0.73 mm at T3 in the maxillary and bimaxillary groups. At T3, all subjects had positive overbite in the maxillary group, but open bite recurred in three subjects with bimaxillary surgery. For both groups, the maxilla relapsed vertically. Significant changes in sagittal and vertical positions of the mandible occurred in both groups. In the bimaxillary group, the changes were larger and statistically significant. In general, the maxilla seems to relapse moderately vertically and the mandible both vertically and sagittally, particularly when both jaws were operated on. Overbite seems to be more stable when only the maxilla has been operated on.     

上颌快速扩弓联合固定矫治器治疗的稳定性研究

目的 观察患者接受上颌快速扩弓联合直丝弓矫治器治疗后覆牙合、覆盖及上牙弓宽度的变化。方法 选择2003年2月—2008年1月于青岛市口腔医院进行治疗的患者37例（男19例,女18例）,将患者分为4个不同的时期进行测量（N1:治疗前;N2:进行上颌快速扩弓后;N3:固定治疗后;N4:保持1年后）。分别测量每位患者的上颌尖牙间宽度、前磨牙间宽度、磨牙间宽度,并对前牙覆盖和覆牙合进行测量。患者的平均年龄（11.3±1.4）岁（10.2～15.3岁）。结果 治疗全部结束后、尖牙间宽度、前磨牙间宽度、磨牙间宽度、覆盖、覆牙合分别增加（2.6±2.3）mm、（3.7±2.1）mm、（5.2±2.5）mm、（0.3±0.6）mm、（-0.1±1.6）mm,患者复发率在尖牙宽度为47%,前磨牙间宽度为21％,磨牙间宽度为10%,覆盖复发率为9%,覆牙合为13%。结论 患者经过上颌快速扩弓后,在固定矫治阶段复发明显,保持阶段也有一定程度的复发。 上颌快速扩弓能够减小覆牙合,增加覆盖。     

Postretention assessment of deep overbite correction in Class II Division 2 malocclusion

The purposes of this study were to evaluate the long-term stability of deep overbite correction in Class II Division 2 malocclusion and to search for predictors of postretention overbite. The sample of 62 (31 males, 31 females) was limited to Class II Division 2 patients with initial deep overbite and successful orthodontic treatment as judged clinically at the end of treatment. Study models and cephalograms were analyzed before treatment, after treatment, and out of retention (average 15 years). The sample was divided into two groups according to the degree of postretention overbite: Group 1 (N=33; overbite > or = 4.0 mm at T3, mean = 5.17 +/- 0.87) and group 2 (N=29; overbite <4.0 mm at T3, mean = 2.95 +/- 0.87). The results showed that patients with very upright pretreatment maxillary and mandibular incisors tended to have deeper initial overbite and a tendency to return to their original relationship by the postretention stage. Posttreatment vertical growth contributed to maintenance of overbite correction. By stepwise multiple regression analysis, initial overbite was selected as the most important predictor of postretention overbite. Initial overbite was positively related with postretention overbite.     

Patterns of occlusion in 3-year-old Danish children

Occlusion and spacing patterns are described for 1,624 3-year-old children living in Gladsaxe, a suburb of Copenhagen. Normal transversal relations were found in 1,396 children, while 214 had crossbite, and 14 had scissors-bite. The sagittal and vertical occlusion were significantly different in the three groups. The sagittal occlusion characters were to a large extent identical in the second primary molar, the canine and the incisor regions in the individual child. Open bite was much more frequent in children with maxillary overjet greater than 4 mm than in children with maxillary overjet greater than or equal to 4 mm. Definite mandibular overjet was diagnosed in three children but 19 had a tendency towards mandibular overjet. The number of dummy suckers was very high and significantly higher among children with crossbite than amoung children with normal transversal relations. Crowding was found in the incisor regions, but very seldom, while total spacing existed in 34.5% of the maxillary and 24.3% of the mandibular arches.     

Retrospective Analysis of Casts to Assess Cervical Headgear Treatment in the Presence of Vertical Growth Pattern

Abstract Objective: Does molar distalization as effected by cervical headgear increase the vertical dimension of occlusion in patients with vertical growth pattern? Materials and Methods: A sample of 86 patients with neutral and vertical growth pattern in the late mixed dentition stage underwent headgear treatment. Their initial and intermediary casts were retrospectively analyzed for occlusal relationships at the maxillary first molars and degrees of overjet and overbite. The only cases included were those in which headgear treatment was carried on for at least 6 months, achieving a minimum distalization of 4 mm. The intermediary casts were fabricated after headgear treatment had been completed and prior to the initiation of multiband treatment.Patients were divided into three groups (N, V1 and V2) according to the degrees of vertical growth pattern, which were determined based on y-axis angle values. Results: Grouped by degrees of vertical growth, the data revealed occlusal relationship changes of 6–8 mm and overjet reductions of 0.6–1.2 mm. The overbite changes were unexpectedly small (0–0.04 mm).Grouped by degrees of overbite, the data revealed that headgear treatment increased the vertical dimension of occlusion in deep-bite patients (> 4 mm), while giving rise to decreases in patients with overbites of < 3 mm.     

The association between incisor trauma and occlusal characteristics in individuals 8–50 years of age

Abstract –  To explore the association between incisal trauma and occlusal characteristics using oral examination and health interview data from the Third National Health and Nutrition Examination Survey 1988–1994 (NHANES III). Incisal trauma examinations were performed on 15 364 individuals 6–50 years of age using an ordinal scale developed by the National Institute of Dental and Craniofacial Research. Occlusal examinations were performed on 13 057 individuals 8–50 years of age. We fitted separate multivariate logistic regression models for maxillary and mandibular incisor trauma adjusting for socio-demographic variables (age, gender, race-ethnicity) and occlusal characteristics (overbite, overjet, open bite). 23.45% of all individuals evidenced trauma on at least one incisor, with trauma more than four times more prevalent on maxillary (22.59%) than on mandibular incisors (4.78%). Males (OR = 1.67) had greater odds of trauma than females; Whites (OR = 1.37) and non-Hispanic Blacks (OR = 1.37) had greater odds of trauma than Mexican–Americans. The odds of trauma increased with age, peaked from age 21 to 30 (OR = 2.92), and declined. As overjet increased, so did the odds of trauma. Compared to individuals with ≤0-mm overjet, odds of trauma increased from 1–3 mm (OR = 1.42) to 4–6 mm (OR = 2.42) to 7–8 mm (OR = 3.24) to >8 mm (OR = 12.47). Trauma to incisors is prevalent but mostly limited to enamel. Trauma to maxillary incisors is associated with overjet, gender, race-ethnicity, and age, while trauma to mandibular incisors is associated with gender, age, and overbite.     

Predictability of upper lip soft tissue changes with maxillary advancement

To improve predictability of the esthetic (soft tissue) results after maxillary advancement surgery, a better understanding of the relationships between the dental osseous movement and overlying soft tissue response is essential. Twenty-one adult patients who underwent isolated maxillary advancement via LeFort I osteotomies without adjunctive nasal soft tissue procedures and/or V-Y closure of the vestibular incision were studied. Homogeneity of the patient population was ensured by selecting cases with less than 2 mm vertical change. The mean maxillary advancement and mean change in Sn was calculated for these 21 patients. Additionally, the 21 patients were subdivided into two groups based on lip thickness: group 1 (lips between 10 and 17 mm thick) and group 2 (greater than 17 mm thick). In each patient group a linear regression (LR) was determined on the magnitude of maxillary advancement (MMA) to the change in soft tissue subnasale (Sn) and on the ratio of Sn change to bone move. The results using mean data showed that the relationships produce significantly high standard deviations; thus, a general correlation between change in soft tissue position to bony advancement cannot be made. Individuals with thin lips (12 to 17 mm) had a good correlation between the magnitude of bony move and amount of soft tissue change. However, increased lip thickness (greater than 17 mm) produced a less predictable correlation between soft and hard tissue changes. All lips thinned around 2 mm when compared with preoperative values. Lip thickness stabilized at approximately 6 months postoperatively.     

Stability following superior repositioning of the maxilla by LeFort I osteotomy

Cephalometric data from 61 patients who had undergone superior repositioning of the maxilla via LeFort I osteotomy by means of the downfracture technique were analyzed to evaluate stability of skeletal and dental landmarks at various time intervals up to 1 year. None of these patients had concurrent mandibular ramus or body osteotomy except genioplasty and all had at least 2 mm intrusion at the maxillary incisor or molar. In approximately 20% of the patients, there was 2 mm (critical value) or more postsurgical movement of skeletal or dental landmarks. During the first 6 weeks postoperatively, the maxilla showed a strong tendency to move farther upward in the patients in whom it was not stable. The posterior maxilla was vertically stable in 90% of the patients, the anterior maxilla in 80%. Horizontally, skeletal landmarks were stable in 80%, but when changes occurred, there was a tendency for the anterior maxilla to move back when it had been advanced. After the first 6 weeks, the posterior maxilla was stable vertically in all patients, but in 20% anterior maxillary landmarks moved downward, opposite to the direction of movement during fixation. In 11 of the 15 patients who demonstrated vertical changes postsurgery, the movement from fixation release to 1 year follow-up was opposite and approximately equal to the initial change, so that the net movement after 1 year was less than 2 mm. Only 6.5% (four patients) demonstrated 2 mm or greater net vertical movement for any of the variables studied 1 year after surgical treatment. There was no indication that the amount of presurgical orthodontic movement of incisors, the presence of multiple segments at surgery, the age of the patient, the presence or absence of genioplasty, or the presence or absence of suspension wires was a risk factor for instability.     

Gender Differences in the Amount of Gingival Display During Smiling Using Two Intraoral Dental Biometric Measurements

Purpose: The aims of this study were to compare gender differences in the width and length of the maxillary right central incisor and the horizontal and vertical overlap of the anterior teeth and to determine the relationships of these two intraoral dental biometric measurements with the amount of gingival display during smiling. Materials and Methods: A total of 61 men and 66 women were included in this study. For each participant, the gingival tissue display during smiling was judged to be either visible or not, and the maximum mesiodistal and incisogingival dimensions of the maxillary right central incisor were measured, along with the amount of horizontal and vertical overlap of anterior teeth using a digital caliper. Gender differences in these parameters and the relationship between subjects showing gingival display when smiling and the two intraoral dental biometric measurements were determined. Statistical analyses of data were performed using SPSS (V11) software. The mean scores for gender were calculated, and a Student's t‐test was used to identify significant differences between both groups. Significance level was set to 0.05. Results: The age of the participants ranged between 23 and 52, with a mean of 33.47 ± 9.07 years. A relatively small percentage of the subjects (22.05%) displayed gingiva when smiling. More women displayed gingiva when smiling than men, with a 2:1 female:male ratio. Men exhibited significantly (p < 0.05) wider (8.76 ± 0.66 mm) and longer (10.28 ± 0.88 mm) central incisors compared to women (7.92 ± 0.72 mm; 9.27 ± 0.93 mm width and length, respectively). No gender differences were found in the width‐to‐length ratio. Subjects with gingival display had significantly more horizontal (4.28 ± 1.21 mm; p < 0.001), and vertical (3.52 ± 0.66 mm; p < 0.05) overlap of anterior teeth compared to those who did not display gingiva when smiling (2.40 ± 1.03 and 2.30 ± 0.93 mm, respectively). Conclusions: Significantly more women displayed gingiva in smiling. Men had significantly wider and longer central incisors. No differences were recorded between men and women relative to both the horizontal and vertical anterior tooth overlap. Subjects who displayed gingiva when smiling had more horizontal and vertical overlap of anterior teeth.     

Dentoalveolar and skeletal changes associated with the pendulum appliance.

The purpose of the study was to examine the dentoalveolar and skeletal effects of the pendulum appliance in Class II patients at varying stages of dental development and with varying facial patterns (high, neutral, and low mandibular plane angles). Specifically, the amount and nature of the "distalization" of the maxillary first molars and the reciprocal effects on the anchoring maxillary first premolars and incisors were studied, as were skeletal changes in the sagittal and vertical dimensions of the face. Pretreatment and posttreatment cephalometric radiographs obtained from 13 practitioners were used to document the treatment of 101 patients (45 boys and 56 girls). The average maxillary first molar distalization was 5.7 mm, with a distal tipping of 10.6 degrees. The anchoring anterior teeth moved mesially, as indicated by the 1.8-mm anterior movement of the upper first premolars, with a mesial tipping of 1.5 degrees. The maxillary first molars intruded 0.7 mm, and the first premolars extruded 1.0 mm. Lower anterior facial height increased 2.2 mm; there was no significant difference in lower anterior facial height increase between patients of high, neutral, or low mandibular plane angles. In patients with erupted maxillary second molars, there was a slightly greater increase in lower anterior face height and in the mandibular plane angle and a slightly greater decrease in overbite in comparison to patients with unerupted second molars. Similar findings were observed in patients with second premolar anchorage versus those with second deciduous molar anchorage. The results of this study suggest that the pendulum appliance is effective in moving maxillary molars posteriorly during orthodontic treatment. For maximum maxillary first molar distalization with minimal increase in lower anterior facial height, this appliance is used most effectively in patients with deciduous maxillary second molars for anchorage and unerupted permanent maxillary second molars, although significant bite opening was not a concern in any patient in this study.     

Craniofacial development in obese adolescents

The purpose of this study was to investigate craniofacial morphology in obese adolescents and to compare the morphological data with those of normal adolescents. The study was based on measurements of lateral cephalometric roentgenograms of adolescents who had been diagnosed as obese. Linear and angular measurements were obtained from cephalometric tracings of 27 females (mean age 15.6 +/- 0.83 years) and 23 males (mean age 13.9 +/- 0.98 years). The data were compared with corresponding measurements of gender and age matched controls. The results showed that both males and females in the obesity group exhibited significantly larger mandibular and maxillary dimensions than the controls. On average, mandibular length (Cd-Pgn) was 10 mm greater in males and 8 mm greater in females. Maxillary length (Pm-A) was 3.5 mm greater in males and 3 mm greater in females. When considering vertical dimensions, lower anterior (Ans-Gn) and posterior (S-Go) face height were 4 and 5 mm greater in the obese males, respectively, while in the obese females both these distances were 4 mm greater compared with the controls. Both maxillary (SNA) and mandibular (SNB, SNPg) prognathism were more pronounced in the obesity group than in the control group. This also influenced the average soft tissue profile, which was less convex in the obesity groups. The mandibular plane angle (ML/SN) was smaller in the obesity group than in the control group. Craniofacial morphology differs between obese and normal adolescents. In general, obesity was associated with bimaxillary prognathism and relatively greater facial measurements.     

A follow-up case report of Actinobacillus actinomycetemcomitans in human periodontal disease

The purpose of this investigation was to compare clinical and microbial parameters in a follow-up case report of adult subjects harboring Actinobacillus actinomycetemcomitans (Aa) with clinically matched subjects who did not have detectable Aa. 16 subjects with Aa and 16 subjects without Aa at the baseline examination were re-examined at an average of 46 months following collection of baseline data. Clinical measurements were recorded and subgingival plaque sampled and evaluated for microbial flora from each maxillary first molar. In 16 subjects with Aa at baseline, 4 sites in 3 subjects had detectable actinobacilli at the follow-up appointment. 26 sites in 13 individuals with Aa at baseline had a significantly increased gingival index at the follow-up visit (p less than or equal to 0.05), but there was no significant increase in probing depth or attachment loss. 32 sites in the 16 subjects without Aa at baseline still did not have detectable levels of this microorganism at the follow-up examination nor was there any significant difference between baseline and the follow-up appointment for the gingival index, probing depth and attachment level measurements. In subjects with Aa at baseline, 1 of 12 teeth without Aa and 5 of 20 teeth with Aa had been extracted prior to the follow-up visit. In this population group, having sites where Aa was detected, 6 of 9 teeth which had a probing depth greater than or equal to 5 mm were lost before the follow-up data collection appointment. In the control group, which did not have detectable Aa at baseline, 9 teeth with probing depths greater than or equal to 5 mm were not lost. These observations, although not proving, suggest in this population group, that deeper probing depths taken together with the presence of Aa may have placed an individual at greater risk of tooth loss.     

Total maxillary advancement with and without bone grafting.

Computer morphometrics was used to analyze 21 adult patients who underwent total maxillary advancement; ten had bone grafting behind the tuberosity and 11 did not. Each group was subclassified as those with idiopathic maxillary deficiency and those with cleft lip and cleft palate; all patients were treated by the same basic operative technique. The results of the study indicate that those patients who had bone grafts had optimum stability. However, individuals with maxillary deficiency who undergo minimal advancements (less than 0.5 mm) can have overcorrections at surgery and, therefore, do not require bone grafts for good stability.     

Accuracy of a LeFort I maxillary osteotomy

An optimal outcome of combined surgery and orthodontics involving the maxilla is dependent on many factors. Accurate placement of the maxilla by the surgical team is ultimately of paramount importance. The aim of this retrospective study was to evaluate the accuracy of LeFort I maxillary osteotomy with respect to the presurgical prediction. The sample comprised 42 patients (33 females, nine males) who had undergone LeFort I osteotomy procedure alone or in combination with a mandibular osteotomy with or without genioplasty. Tracings of presurgical and immediate postsurgical lateral cephalograms and surgical predictions were digitized and compared using Quick Ceph software analysis. Vertical and horizontal measurements to various skeletal landmarks were used to assess the discrepancy between the predicted maxillary position and the actual postsurgical result. Statistically significant differences were found between the predicted and actual postsurgical maxillary molar vertical position, and significant differences were also found for the palatal plane angular measurements. Two surgical teams were compared, and surgical team 1 had significantly less variation in the surgical outcomes than did surgical team 2. When single-jaw and bimaxillary surgery were compared, no significant differences were found. Similarly, there were no statistically significant differences found when assessing the primary direction of movement (impaction vs downgraft vs advancement). Overall, 66% of the results were within two mm of prediction and 26% of the results were within one mm of prediction. A LeFort I maxillary osteotomy can be an accurate procedure with a wide range of discrepancy.