Three-dimensional facial soft-tissue changes after surgical orthodontics in different vertical facial types of skeletal Class III malocclusion: A retrospective study

The study compared the soft-tissue response to hard-tissue movement among different Class III vertical facial types after orthognathic surgery (OGS). The study included 90 consecutive adult patients with skeletal Class III malocclusion who underwent two-jaw OGS. Patients were divided into three groups (high, medium, and low angle) based on the presurgical Frankfort-mandibular plane angle. Cone-beam computerized tomographs were taken before surgery and after debonding. Soft- and hard-tissue linear and angular measurements were performed using three-dimensional reconstruction images. One-way analysis of variance was used for intergroup comparisons. Soft tissue tended to respond more to hard-tissue movement in the lower lip area in patients with low angle (mean = 0.089, SD = 0.047, p = 0.023), whereas no significant difference was observed for other sites. Consistently, L1/Li thickness increased most significantly in the high-angle group (mean = 1.98, SD = 2.14, p = 0.0001), and B/Si thickness decreased most significantly after surgery (mean = 2.16, SD = 2.68, p = 0.016). The findings suggest that the high-angle group had a higher chance of undergoing genioplasty to enhance chin contour. Different OGS plans should be considered for different Class III vertical facial types.

Does cleft lip and palate affect the severity of malocclusion?

OBJECTIVE

The purpose of this study was to evaluate the 3D anatomical features of unilateral (UCLP) and bilateral (BCLP) complete cleft lip and palate with those of skeletal Class III dentofacial deformities.

MATERIALS AND METHODS

In total, 92 patients were divided into cleft and noncleft groups. The cleft group comprised 29 patients with UCLP and 17 patients with BCLP. The noncleft group comprised 46 patients with Class III dentofacial deformities. 3D anatomical landmarks were identified and the corresponding measurements were made on the cone-beam computed tomography (CBCT).

RESULTS

The differences between the affected and unaffected sides of the patients with UCLP were nonsignificant. The differences between the patients with UCLP and BCLP were nonsignificant except for the SNA angle. Significant differences between the patients with clefts and Class III malocclusion were identified for the SNA, A-N perpendicular, and A-N Pog line, indicating that the maxillae of the patients in the cleft group were more retrognathic and micrognathic. Relative to the noncleft group patients, the cleft group patients had a significantly smaller ramus height.

CONCLUSION

The affected and unaffected sides of the patients with UCLP did not exhibit significant differences. The maxillae of the patients with UCLP were significantly more retrognathic than those of the patients with BCLP. The maxillae and mandibles of the patients in the cleft group were more micrognathic and retropositioned relative to those of the noncleft Class III patients.

CLINICAL RELEVANCE

The maxillary and mandibular findings indicated greater deficiencies in the patients with UCLP or BCLP than in those with skeletal Class III malocclusion. Appropriate surgical design should be administered.

Does Clockwise Rotation of Maxillomandibular Complex Using Surgery-First Approach to Correct Mandibular Prognathism Improve Facial Appearance?

BACKGROUND

Facial aesthetics may be optimized based on a deeper understanding of soft tissue changes after orthognathic surgery.

PURPOSE

The purpose of the study was to delineate facial soft tissue changes after clockwise rotation (CWR) of the maxillomandibular complex (MMC) to correct mandibular prognathism using the surgery-first approach.

STUDY DESIGN, SETTING, SAMPLE

This prospective cohort study enrolled patients over 18 years of age with skeletal Class III malocclusion in the craniofacial center. The patients were excluded with previous history of craniofacial syndrome, orthognathic surgery trauma, infection at surgical sites, chin deviation (menton deviation ≥4 mm), 2 or more missing data points after surgery, or without informed consent. This study compared significant facial changes before (T0) and after orthodontic debonding (T1) in the CWR and control groups.

PREDICTOR VARIABLE

The patients were divided in accordance with maxillary occlusal plane change (OPC) after surgery into CWR (OPC >4°) and control (OPC ≤4°) groups.

MAIN OUTCOME VARIABLE

The primary outcome variable was frontal lip curvature (FLC: Right Cheilion-Stomion-Left Cheilion, degree) with or without upper lip curving upward at T1, where upper lip curving upward was considered more favorable.

COVARIATES

The covariates included age, sex, and various cephalometric measurements.

ANALYSES

The Mann-Whitney U test, paired, and independent t-test were implemented to compare the intragroup and intergroup differences. Statistical significance was indicated by P value <.05.

RESULTS

The study comprised 34 patients (21 women) in the control group and 37 (29 women) in the CWR group; their mean ages were 23.64 ± 4.38 and 24.21 ± 3.84 years, respectively (P value = .562). At T1, the CWR group had significant increased FLC (P value = .001), alar width (P value = .034), and lower vermilion height (P value = .018), and decreased lower lip length (P value = .004). The high FLC group had significant decreased upper lip projection (P value = .002) and increased nasolabial angle (P value = .013). The significant relationship between CWR and high FLC was supported by the χ2 test (P value = .018) and multiple logistic regression (P value = .017).

CONCLUSION

Greater CWR of the MMC increased FLC and lower vermilion height and reduced lower lip length. High FLC resulting from the CWR of the MMC improved facial appearance by moving the upper lip curve upward.

Clockwise versus counterclockwise rotation in bimaxillary surgery: 3D analysis of facial soft tissue outcomes

PURPOSE

This study aimed to compare facial 3D soft tissue changes in subjects with Class III deformities who underwent bimaxillary clockwise (CW) and counterclockwise (CCW) rotational orthognathic surgery.

METHODS

Asian Class III subjects who completed bimaxillary surgical orthodontic treatments were enrolled and categorized into CW and CCW groups based on maxillary occlusal plane alterations. Preoperative and 9-month follow-up cone-beam computed tomography (CBCT) and 3D stereophotogrammetry were obtained, superimposed, and quantified for skeletal movements and soft tissue changes in six facial regions. Inverse probability of treatment weighting (IPTW) adjusted for potential confounding factors.

RESULTS

Thirty-seven subjects were included (CW group, n = 20; CCW group, n = 17). Postsurgical chin volume significantly reduced in the CW group compared to the CCW group (mean difference 6362 mm3; p = 0.037), and intergonial width significantly decreased in the CW group (mean difference 6.2 mm; p = 0.005). The postoperative alar width increased by 1.04 mm and 1.22 mm in the CW and CCW groups, respectively (p = 0.70). However, these changes were not significantly correlated to the direction of MMC pitch.

CONCLUSION

Clockwise rotation of the bimaxillary complex demonstrated a significant advantage in reducing chin volume and intergonial width compared to counterclockwise rotation, leading to a reduced frontal lower face width among Asian Class III subjects.

Dental Occlusion Characteristics for Treatment Decision-Making Regarding Surgery-First Approach in Orthodontics

The surgery-first approach (SFA) is conducted to decrease the difficulty and duration of orthodontic treatment by correcting the skeletal discrepancy at the initial stage of treatment. However, the indication of the SFA has not been well defined yet. This study explored the dental occlusion characteristics for treatment decision-making regarding the SFA. A total of 200 skeletal Class III patients were consecutively collected and divided into two groups: the orthodontic-first approach (OFA) group and the SFA group. The pretreatment digital dental models and lateral cephalograms were measured. Logistic regression was completed and receiver operating characteristic (ROC) curves were obtained to predict the probability of the SFA. Results showed that the ROC model with L1-MP, upper and lower arch length discrepancy, overbite, and asymmetric tooth number as influencing factors revealed that the sensitivity and specificity for determining SFA were 83.0% and 65.0%, respectively; the accuracy of prediction was 75.0%. In conclusion, our findings indicate that the six measurements from digital dental models and lateral cephalograms can be effectively applied in treatment decision-making for the SFA with satisfactory accuracy.

Evaluation of pharyngeal airway space after orthodontic extraction treatment in class II malocclusion integrating with the subjective sleep quality assessment

Orthodontic treatment with premolar extractions is typically used to relieve dental crowding and retract anterior teeth for lip profile improvement. The aim of the study is to compare the changes in regional pharyngeal airway space (PAS) after orthodontic treatment with Class II malocclusion and to identify the correlations between questionnaire results and PAS dimensions after orthodontic treatment. In this retrospective cohort study, 79 consecutive patients were divided into normodivergent nonextraction, normodivergent extraction, and hyperdivergent extraction groups. Serial lateral cephalograms were used to evaluate the patients' PASs and hyoid bone positions. The Pittsburgh Sleep Quality Index and STOP-Bang questionnaire were used for sleep quality evaluation and obstructive sleep apnea (OSA) risk assessment, respectively, after treatment. The greatest airway reduction was observed in hyperdivergent extraction group. However, the changes in PAS and hyoid positions did not differ significantly among three groups. According to questionnaire results, all three groups had high sleep quality and low risk of OSA, with no significant intergroup differences. Moreover, pretreatment-to-posttreatment changes in PAS were not correlated with sleep quality or risk of OSA. Orthodontic retraction with premolar extractions nither exhibit significant reduction in airway dimensions nor increase their risk of OSA.

Surgical Stability After Proximal Segment Angle Alteration in Patients with Class III Facial Asymmetry

PURPOSE

Patients with facial asymmetry often seek improved symmetry in lower face contour resulting in transverse movement of the proximal segments. The study aimed to investigate the association between transverse change in the proximal segments and postoperative relapse after the surgical correction of skeletal Class III facial asymmetry.

METHODS

The retrospective cohort study included consecutive patients with skeletal Class III asymmetry who underwent 2-jaw orthognathic surgery. The primary predictor variable was ramus plane angle (RPA). The patients were grouped as small (S group, <4°) and large (L group, ≥4°) changes in RPA. The primary outcome was the positional change of B point, menton, and the intergonial width. Cone-beam computed tomography images were obtained before surgery (T0), 1 week after surgery (T1), and debond (T2). Intergroup comparison was conducted with independent t test. Correlations between the variables were estimated by Pearson correlation.

RESULTS

The study sample was composed of 60 subjects with 30 subjects in each study group. In the S group, the mean surgical changes of RPA were inward rotated 0.91° bilaterally. In the L group, the mean surgical changes of RPA were inward rotated 4.80° and 0.32° on the deviated and non-deviated side. After surgery, further minor inward adaptation of both sides was noted (<1 mm), and intergonial distance reduced with these changes in the proximal segments. By comparing the postsurgical stability between S and L group, the overall sagittal and vertical stability had no significant difference between 2 groups. However, the postsurgical transverse menton relapse (ΔMe in T2-T1) was significantly larger in L group (0.81 ± 1.40 mm) than S group (0.04 ± 1.32 mm) by 0.77 mm (P = .014).

CONCLUSION

Greater surgical changes in the proximal segments had minor clinical effect on transverse stability. Minor transvers overcorrection of 1 mm is recommended in cases with severe facial symmetry with extensive changes in the proximal segments.

Does the floor of the maxillary sinus affect tooth movement for premolar extraction space closure?

OBJECTIVE

The study investigated orthodontic tooth movement by comparing various horizontal and angular measures of the teeth having different sinus-root relationship (SRR) of patients undergoing first premolar extraction treatment protocols.

MATERIALS AND METHODS

This retrospective cross-sectional study included 45 Taiwanese adult patients, classified as the control group (n = 15) and the sinus group (n = 30) according to SRR. The control group had type I SRR (sinus floor above the level connecting the buccal and palatal root apices), whereas the sinus group included patients with type V SRR (the buccal and palatal root displayed apical protrusion into the sinus floor). Morphology was identified using pretreatment orthopantomograms. Lateral cephalometric measurements were conducted before treatment (T1) and at debonding (T2).

RESULTS

Post debonding, there were no statistically significant difference in the two groups. However, the incisors in the control group became marginally more upright than those of the sinus group, and the molars demonstrated tipping movement with minimal anchorage loss in the sinus group than in the control group. The total treatment time was not significantly different between the 2 groups.

CONCLUSION

The study revealed that the sinus-root relationship does not affect the orthodontic tooth movement. However, a more extensive 3-D study with larger sample size is strongly recommended before coming to any conclusion.

CLINICAL RELEVANCE

The lining of the floor of the maxillary sinus does not affect the orthodontic tooth movement.

Sequential digital occlusal analysis in patients with skeletal Class III malocclusion with orthognathic surgery: Surgery-first vs orthodontic-first approach

INTRODUCTION

This study compared changes in occlusal characteristics in patients with skeletal Class III malocclusion with surgery-first approach (SFA) and those with orthodontic-first approach (OFA) through digital occlusal analysis.

METHODS

In this prospective study, 90 consecutive subjects were divided into control, OFA, and SFA groups (30 per group). Force discrepancy, occlusal time, tooth contact, center of force, and force-time graph pattern were calculated for all samples using the T-Scan III system. Between-group differences were analyzed using a 1-way analysis of variance and generalized estimating equations. These parameters were calculated at the following time points: preoperatively, 1-month postoperatively (T1), 4-months postoperatively, and 1-year postoperatively (T3).

RESULTS

No significant differences were observed in the parameters between the experimental groups. The force discrepancy of the OFA and SFA groups decreased, approaching the value of controls at T3. The occlusal time significantly increased at T1 and progressively decreased at T3. The initial contact and maximum force were most frequently observed on molars, and its maximum force significantly decreased by 5.72% and 7.40% in the OFA and SFA groups at T3, respectively. The number of tooth contact was significantly reduced at T1 and gradually increased at T3. Moreover, after surgery, the force-time graph pattern was normalized, and the center of force tended to be more centric; however, the most frequent trajectory revealed premature contact during closing.

CONCLUSIONS

No significant difference was found in all parameters between the OFA and SFA groups. Occlusion deteriorated at 1 month postoperatively but gradually improved at 1 year postoperatively, approaching the controls.

Effects of maxillary advancement on maxillary incisor display in patients with skeletal Class III malocclusion and cleft lip and palate

INTRODUCTION

The information on the hard- and soft-tissue factors correlated with tooth display after LeFort I osteotomy, especially in the surgery-first approach (SFA), are limited. This study aimed to correlate different parameters with the maxillary incisor display in patients with skeletal Class III malocclusion and those with cleft lip and palate (CLP) in SFA.

METHODS

This study consisted of 35 patients with skeletal Class III malocclusion and 32 with cleft deformities who had undergone orthognathic surgery. Pretreatment and posttreatment lateral cephalometric analysis were obtained. Maxillary incisor display was measured in photographs. The intraclass correlation coefficient was used to assess the intraexaminer repeatability. The Student t test was used to compare the maxillary incisor display between 2 groups. Analysis of covariance was performed with pretreatment measurement as covariates, and the important determinants for maxillary incisor display were identified by adjusting the baseline measurements.

RESULTS

The mean increase of maxillary advancement at point A was 5.25 mm and 1.28 mm downward movement for skeletal Class III malocclusion, whereas it was 4.59 mm advancement and 2.16 mm downward movement for patients with CLP. The resulting maxillary incisor display was 2.86 mm for skeletal Class III malocclusion and 2.56 mm for patients with CLP. The covariates for maxillary incisor display before intervention was significantly associated with the maxillary incisor display after intervention (P <0.001). However, the interaction effect of groups was not seen (P = 0.933). The horizontal position of A, vertical position of ANS, and upper lip length were the most predictable parameters (P <0.001, P <0.001, P = 0.048, respectively) for maxillary incisor display in both groups.

CONCLUSIONS

Horizontal position of point A, vertical position of ANS, and upper lip length are the most important determinants for maxillary incisor display for patients with skeletal Class III malocclusion and those with CLP.

Comparison of 3-dimensional postoperative dental movement in Class III surgical correction with and without presurgical orthodontic treatment

Background

Surgery-first approach (SFA) is an emerging concept that surgically reposition the jaw bones without presurgical orthodontic treatment phase. The study investigated 3D dental movement in the postoperative orthodontic phase with orthodontic-first (OF) and SFA in orthognathic surgery (OGS).

Methods

This study included consecutive 40 patients (20, SF group; 20, OF group) skeletal Class III who underwent 2-jaw OGS correction. The data of cone-beam computed tomography were acquired at 3 stages with the scan of dental models to replace the dentition of the craniofacial images; at before OGS (T0), 1 week after OGS (T1) and at the completion of treatment (T2). The skeletal changes were obtained by overall superimposition. The post-operative dental movement was measured by 3D regional superimposition between T1 and T2.

Results

There were no significant difference in the postsurgical orthodontic movement in both groups except significant upper and lower molars extrusion by 2 mm in the SF group. Both groups exhibited no significant difference in mandibular stability in sagittal and vertical directions. The amount of extrusion in the molars was correlated with a postoperative sagittal mandibular forward movement. The total treatment duration was significantly shorter 230 days in the SF group.

Conclusion

The completion of the orthodontic treatment after OGS in the SFA was mainly accomplished through molar extrusive movement in both arches. The surgical setup of dental occlusion with 4 mm posterior open bite could be corrected during the postsurgical orthodontics in SFA through molar extrusion. The dental occlusion outcome was no different between OF and SFA.

Investigate the oral health impact and quality of life on patients with malocclusion of different treatment needs

Background

This study compared oral health impacts and QoL among patients with different malocclusion types and a normal population by using self-report questionnaires.

Methods

In this cross-sectional study, 214 healthy adults were divided into 3 groups: (1) Normal, control group; (2) ORTHO, patients who received orthodontic treatment; and (3) OGS group, patients who received orthognathic surgery (OGS). The timing of measurement were at the initial stage of the orthodontic therapy and before surgery. Two questionnaires and one additional item were used: the 36-item Short Form Health Survey (SF-36) for QoL, the 14-item Oral Health Impact Profile (OHIP-14) for oral health-related QoL (OHRQOL) and one additional item for aesthetic evaluation. Descriptive and inferential statistical analyses were used to compare the 3 groups. The effects of 3 malocclusion types, gender, age, and facial asymmetry in the OGS group were also evaluated.

Results

The ORTHO and OGS groups had higher negative impacts than did the Normal group in the OHIP-14, but not much difference in the SF-36. The item of aesthetics related to oral health impact was the lowest in the OGS group. The patients in the ORTHO group with a Class II malocclusion were most dissatisfied in the SF-36 and OHIP-14. In the OGS group, the women dissatisfied in the OHIP-14 and the aesthetic. The older patients had higher negative impacts in the OHIP-14 than the younger patients. The patients with facial asymmetry did not suffer higher negative impacts than did the patients with a symmetrical face in the SF-36 and OHIP-14.

Conclusions

The majority of the patients who required orthodontics or OGS reported a higher negative impact in the OHIP-14 compared with the normal controls, but not in the SF-36. Class II malocclusion suffered from highest psychological stress and aesthetic sensitivity than the other two subgroups in the ORTHO group.

Female Facial Attractiveness Assessed from Three-Dimensional Contour Lines by University Students

BACKGROUND

Three-dimensional (3D) images could provide more accurate evaluation for facial attractiveness than two-dimensional (2D) images. The 3D facial image could be simplified into gray scale 3D contour lines. Whether female facial attractiveness could be perceived in these simplified 3D facial contour lines should be determined.

METHODS

A series of 100 2D photographs (one frontal and two lateral views) and 3D contour lines extracted from 3D facial images of females were projected onto a screen. Each image presentation lasted 5 s, and the evaluators marked their impression of each image's facial attractiveness on a five-point Likert scale within 3 s of its presentation. The evaluation of the 3D contour lines was performed twice, 2 weeks apart. The evaluators were university students.

RESULTS

High consistency (r = 0.92) was found for the first and second evaluation of 3D facial contour lines for female facial attractiveness. The judgments of unattractive face were more consistent than the judgments of attractive face. Male students tended to give lower scores than female students in the evaluation of female facial attractiveness.

CONCLUSIONS

Female facial attractiveness could be evaluated by 3D facial contour lines. 3D facial contour lines should be one of the key factors of facial attractiveness.

Predicting need for orthognathic surgery in early permanent dentition patients with unilateral cleft lip and palate using receiver operating characteristic analysis

INTRODUCTION

The purpose of this study was to predict the need for orthognathic surgery in patients with unilateral cleft lip and palate (UCLP) in the early permanent dentition.

METHODS

In this retrospective cohort study, we included 61 patients with complete UCLP (36 male, 25 female; mean age, 18.47 years; range, 16.92-26.17 years). The subjects were grouped into an orthognathic surgery group and a nonsurgery group at the time of growth completion. Lateral cephalograms obtained at the age of 11 years were analyzed to compare the 2 groups. The receiver operating characteristic analysis was applied to predict the probability of the need for orthognathic surgery in early adulthood by using the measurements obtained at the age of 11 years.

RESULTS

SNB, ANB, SN, overbite, overjet, maxillary length, mandibular body length, and L1-MP were found to be significantly different between the 2 groups. For a person with a score of 2 in the 3-variable-based criteria, the sensitivity and specificity for determining the need for surgical treatment were 90.0% and 83.9%, respectively (ANB, ≤-0.45°; overjet, ≤-2.00 mm; maxillary length, ≤47.25 mm).

CONCLUSIONS

Three cephalometric variables, the minimum number of discriminators required to obtain the optimum discriminant effectiveness, predicted the future need for orthognathic surgery with an accuracy of 86.9% in patients with UCLP.

An integrated surgical protocol for adult patients with hemifacial microsomia: Methods and outcome

Background

Hemifacial microsomia (HFM) features hypoplasia and asymmetry in skeletal as well as soft tissue, and correction of the deformity is difficult in terms of aesthetic outcome. The purpose of this study is to examine the validity of an integrated treatment protocol for correction of this facial deformity.

Patients and methods

A retrospective study was performed on adult HFM patients who received two-jaw orthognathic surgery combined with facial contouring procedures in the first stage, and fat injection for the residual facial deficiency in the second stage. Inclusion criteria were patients treated by the same surgeon and follow-up at least 6 months. The demographic, perioperative, and follow-up data were collected. We defined a facial surface area discrepancy index (FDI) for objective assessment of the symmetry between the affected and non-affected side, and utilized visual analogue scale (VAS) for subjective evaluation of facial asymmetry before and after surgical treatment.

Results

A total of 14 patients were included. The mean age at orthognathic surgery was 21.7 years. Four patients were categorized as Pruzansky-Kaban type I, while the remaining 10 patients were type II (7 patients type IIA, 3 patients type IIB). Fat injection as a secondary procedure was performed in eleven cases (79%). The mean pre- and postoperative FDI was 87.6±6.3 and 95.4±5.2 with a significant advance for symmetry (p < 0.001). The pre- and postoperative VAS for asymmetry was 7.2±1.7 and 3.8±2.4 respectively, with a significant improvement (p = 0.002).

Conclusion

Our integrated approach using orthognathic surgery, facial contouring surgery and subsequent fat injection is satisfactory and obtain significant improvement of the facial deformity considering the complexity of HFM.

Effects of proximal grooves and abutment height on the resistance of resin-cemented crowns in teeth with inadequate resistance: An in vitro study

BACKGROUND

The resistance form is a key factor for a successful crown fabrication. This in vitro study evaluates the effects of proximal grooves and abutment height on the resistance of single cast crowns in molars with inadequate resistance.

METHODS

Sixty extracted human molars were prepared to possess 20° of total occlusal convergence for single crown fabrication. All of the prepared teeth were divided into six groups and prepared according to three axial heights (2, 3, and 4 mm) with or without preparing a pair of proximal grooves. Alloy metal copings of 5% titanium were casted and cemented. A self-adhesive modified-resin cement was used for cementation. A lateral dislodgement test was performed with an increasing external force applied at a 45° angulation on a universal testing machine. The force required to dislodge the crown from the tooth or to break the core was recorded.

RESULTS

Proximal grooves increased the dislodgement resistance in groups with an abutment height of 4 mm, whereas adding grooves made no significant differences in resistance in groups with abutment heights of 2 and 3 mm. The 2 mm groups exhibited worse performance than the other groups, whether they had proximal grooves or not.

CONCLUSION

An abutment height of 3 mm provided adequate resistance for single cast crowns when self-adhesive modified-resin cement was used. Preparing a pair of proximal grooves on abutments shorter than 4 mm had no significant influence on the resistance.

The effect of gingivoperiosteoplasty on facial growth in patients with complete unilateral cleft lip and palate

OBJECTIVE

Gingivoperiosteoplasty performed at the time of lip repair of cleft patients is one kind of alveolar repair. The purpose of this retrospective study was to evaluate the effect of gingivoperiosteoplasty on facial growth of patients with complete unilateral cleft lip and palate (UCLP).

DESIGN

Retrospective study.

PATIENTS

Sixty-two consecutive patients with nonsyndromic complete unilateral cleft lip/palate with 5-year-olds' record were included in this retrospective study.

INTERVENTIONS

All the patients had received nasoalveolar molding treatment before cheiloplasty at the age of 3 to 6 months. Twenty-six patients had gingivoperiosteoplasty performed at the time of cheiloplasty and function as the GPP group. Thirty-six patients did not have gingivoperiosteoplasty at the time of cheiloplasty and function as the non-GPP group.

MAIN OUTCOME MEASURES

Cephalometry was used to evaluate the facial growth at 5 years of age in the two groups of patients.

RESULTS

Gingivoperiosteoplasty had significant effects on the maxillary position (SNA), intermaxillary position (ANB), maxillary length (PMP-ANS), and maxillary alveolar length (PMP-A) at the age of 5 years. The SNA and ANB angles were larger in non-GPP group than in the GPP group by 3.0 degrees and 2.6 degrees , respectively. The maxillary length (PMP-ANS) and maxillary alveolar length (PMP-A) were larger in the non-GPP group than in the GPP group by 2.1 and 2.9 mm, respectively.

CONCLUSIONS

In patients with UCLP, the sagittal growth of the maxilla would be affected more adversely in the GPP group than in the non-GPP group at the age of 5 years.

An extraoral nasoalveolar molding technique in complete unilateral cleft lip and palate

SUMMARY

Although nasoalveolar molding is commonly performed before cleft lip surgery, customized palatal plate availability is limited for patients far from a hospital. This case report describes a preformed extraoral nasoalveolar molding (PENAM) appliance and treatment approach for presurgical nasoalveolar molding in newborns with complete unilateral cleft lip and palate. A 12-day-old boy presented with complete unilateral cleft lip and palate. The PENAM device was supported by an adhesive-taped upper lip, which consisted of a lip nasal stent made from a 0.5-mm stainless steel wire. The spring was activated monthly. The shape of the cartilaginous septum, alar cartilage tip, medial crus, lateral crus, and alveolar segments was molded to resemble the normal shape of these structures. The 9.3-mm alveolar gaps were reduced and approximated. The approximation mostly came from the major alveolus segment with approximately 6.4-mm movement. Cleft side nostril height increased 5.5 mm and deviation of the columella was corrected by 42°. PENAM can be helpful in infants with unilateral cleft lip and palate because it has benefits for long-term forced delivery, requires less frequent activations, and is suitable for patients who live far from a hospital.

Alteration of masticatory electromyographic activity and stability of orthognathic surgery in patients with skeletal class III malocclusion

PURPOSE

The purposes of this study were to 1) investigate longitudinal changes in electromyographic masticatory activity subsequent to orthognathic surgery (OGS) in patients with skeletal Class III malocclusion, and 2) compare masticatory muscle activity and skeletal factors in patients with stable versus relapsed mandibular positions after OGS.

MATERIALS AND METHODS

A consecutive series of patients with skeletal Class III malocclusion who underwent 2-jaw OGS (35 patients, 17 men and 18 women; age, 24.5 ± 5.0 yr) were included. Lateral cephalometric films were obtained preoperatively (T1), 1 month after OGS (T2), and at completion of orthodontic treatment (T3). Serial cephalometric tracings and analyses were obtained. Surface electromyograms of the anterior temporalis and masseter muscles were recorded at T1, T2, and T3 (6 mo after OGS). Resting tonus, maximum voluntary clench with habitual intercuspation and on cotton pads, and maximum muscle firing were evaluated. Percentage of overlapping coefficient and torque coefficient were calculated. Patients were categorized further into stable and relapse groups according to the sagittal relapse rate of mandibular setback. These surface electromyographic variables were compared between the 2 groups.

RESULTS

On average, the mandible showed a significant setback of 10.19 mm and a relapse of 1.12 mm (10.99%). Surgical relapse did not correlate with gender or genioplasty. Serial surface electromyographic data indicated a significant decrease from T1 to T2 that then recovered from T2 to T3. No significant difference between T1 and T3 was noted. Percentage of overlapping coefficient was significantly decreased after OGS. The torque coefficient did not differ significantly from T1 to T3. The relapse group (relapse, >11%; n = 15) had a greater resting tonus of the anterior temporalis muscle at T3, a larger percentage of overlapping coefficient at T1, and a greater maximum voluntary clench of the masseter muscles at all times than in the stable group (n = 20). The relapse group exhibited a greater decrease in facial height (2.18 mm) from T2 to T3 than did the stable group (0.5 mm).

CONCLUSION

A larger sagittal relapse of mandibular setback occurred in patients with greater masticatory muscle activity. Modifications in surgical design and overcorrection should be considered in patients with greater masticatory muscle activity before OGS.

Longitudinal observation of mandibular motion pattern in patients with skeletal Class III malocclusion subsequent to orthognathic surgery

PURPOSE

The aims of the present study were to delineate the characteristic patterns of 3-dimensional (3D) mandibular movement in patients with skeletal Class III malocclusion compared with normal individuals and to investigate the longitudinal changes in mandible and condylar motion after orthognathic surgery (OGS).

PATIENTS AND METHODS

The subjects in the present prospective study consisted of 2 groups. The OGS group included 24 patients with skeletal Class III who underwent OGS. The control group consisted of 25 patients who underwent orthodontic treatment only. The patient records included demographic data, lateral and posteroanterior cephalometric radiographs before treatment, and serial mandibular motion data. In the OGS group, the mandibular motion data were obtained before OGS (T1), 1 month after OGS (T2), and at least 6 months after OGS (T3). The differences in cephalometric measurements and mandibular movements between the 2 groups were compared. The Pearson correlation test was performed to assess the relationship between the cephalometric measurements and the mandibular movements. Serial changes in mandibular movement in the OGS group were also compared.

RESULTS

The skeletal pattern in the OGS group demonstrated retrusive maxilla and a protrusive mandible, with a larger mandibular plane angle. For the incisal range of motion, the OGS group's maximal mouth opening was larger than the control group's by 6.9 mm. In the OGS group, the condylar range of motion in retrusion and the Bennett angle were asymmetric. Skeletal Class III patients tended to have a smaller range of condylar retrusion. At 1 month after OGS, the maximal incisal range of motion decreased from 57.23 to 25.61 mm. Other variables, including laterotrusion, movement velocity, and angle and distance of condylar movement in protrusion, reduced significantly. The Bennett angle demonstrated increased symmetry on both sides. Six months after OGS, the condylar motion in opening demonstrated improvements, but to a lesser extent than at T1. The condylar motion in retrusion recovered totally. The maximum incisal range of motion reduced slightly, but remained similar in value to that of the control group. The variables, including laterotrusion, movement velocity, and angle and distance of condylar movement in protrusion, demonstrated total recovery. The mandibular movement variables at T3 were not significantly different from those of the control group.

CONCLUSIONS

Skeletal Class III patients demonstrated a larger maximal mouth opening than did the controls, along with similar laterotrusion, but with a smaller retrusive condylar range of movement. The range of incisor motion and condylar movement did not correlate. The deterioration in mandibular motion after OGS can recover totally within 6 months. At T3, the mandibular movement remained consistent with the amount in normal subjects.

The characteristics and distribution of dental anomalies in patients with cleft

BACKGROUND

Dental anomalies associated with different severities of cleft lip and palate have been rarely reported. This retrospective study investigates the characteristics of dental anomalies associated with different types of cleft, and compares the dental anomaly traits based on sex and severity of cleft.

METHODS

Cleft patients born in 1995 with qualified diagnostic records from 7 to 11 years were included for evaluation. Records were retrieved from database of Chang Gung Craniofacial Center, including panoramic radiographs and intraoral photographs. In total, 196 patients with complete records were included in the evaluation. This study compares the dental anomalies associated with each type of cleft.

RESULTS

The frequency of dental anomalies in the maxillary incisor area in the cleft palate (CP) group (20%) was significantly lower than that in other groups. The frequency of missing maxillary lateral incisors (MLIs) increased as the cleft severity increased. Supernumerary teeth and missing lower incisors exhibited the opposite trend. No sexual dimorphism appeared in terms of the frequencies of peg laterals and missing MLIs. The distribution patterns of missing MLIs and peg laterals in males, but not in females, were consistent for the three types of unilateral clefts.

CONCLUSION

Regarding the characteristics of dental anomalies among the three unilateral clefts, missing MLIs, supernumerary teeth, and missing lower incisors were found to be related to cleft severity. The maxillary lateral incisor was the most affected tooth in the cleft area. The frequency of missing MLIs and peg laterals was not sexual dimorphic, but the distribution pattern was different between the sexes.

Comparison of progressive cephalometric changes and postsurgical stability of skeletal Class III correction with and without presurgical orthodontic treatment

PURPOSE

This study compares 1) progressive dental and skeletal changes, 2) postsurgical stability, and 3) treatment efficacy of patients with skeletal Class III correction with and without presurgical orthodontic treatment.

PATIENTS AND METHODS

The study includes 53 patients who underwent orthognathic surgery (OGS) to correct skeletal Class III malocclusion. The patient grouping is based on presurgical orthodontics: surgical-first (SF) approach (n = 18) and modified-conventional (MC) approach (n = 35). This study divides the MC group into 2 groups based on whether patients underwent tooth extraction in the presurgical phase (Ext group) (n = 10) or not (Nxt group) (n = 25). Serial lateral cephalometric film measurements identify skeletal and dental changes before treatment (T1), before OGS (T2), 1 month after OGS (T3), and at completion of treatment (T4). This investigation reviews the medical charts for treatment progress and duration.

RESULTS

In the presurgical phase, the Ext group showed mild retraction of the upper incisors and more proclination of the lower incisors than the Nxt group. The skeletal sagittal parameters were similar from T1 to T4 in both the SF and MC groups. In the SF group, SN/U1 decreased 6.2° after surgery and was mildly proclined at T4; in the MC group, upper incisor inclination (SN/U1) increased 1.8° from T1 to T4, being 9.4° greater than that in the SF group at T4. The lower incisor inclination (MP/L1) was similar at T4 in both groups. In the MC group, the MP/L1 was shown to be proclined 4.5° before surgery, retroclined 1.9° after surgery, and further retroclined 4.5° until T4. The relapse rate of the mandibular setback was 14.3% in the SF group and 15.7% in the MC group without significant differences. The percentage of sagittal relapse less than 2 mm was 50% in the SF group and 54% in the MC group. The ratio was greater in the MC group with a relapse between 2 and 4 mm but lesser with a relapse greater than 4 mm. The Ext group showed a 3-month longer treatment duration than the Nxt group.

CONCLUSION

The amount of skeletal correction and postsurgical relapse, as well as treatment duration, were no different in Class III OGS patients with or without presurgical orthodontic treatment. The presurgical work of lower incisor proclination returned to an inclination similar to the initial status after completing treatment. The final outcome of patients evidenced no difference in lower incisor inclination, with or without presurgical orthodontics.

Comparison of transverse dimensional changes in surgical skeletal Class III patients with and without presurgical orthodontics

PURPOSE

To investigate transverse dimensional changes of dental arches in surgical skeletal Class III patients with and without presurgical orthodontics.

MATERIALS AND METHODS

Thirty-six patients with skeletal Class III were included and grouped into those with or without presurgical orthodontics. Eighteen patients (mean age, 22.3 +/- 3.8 years) with presurgical orthodontics (mean presurgical orthodontic treatment time, 176.3 +/- 38.3 days) were in the orthodontics-first (OF) group; the other 18 patients (mean age, 23.3 +/- 4.2 years) without presurgical orthodontics were in the surgery-first (SF) group. The posteroanterior cephalograms initially, before surgery, immediately after surgery, and 1 year after surgery were traced and analyzed. The inclination change of canines and molars was measured to interpret the changes of transverse dimension in both dental arches. Paired and unpaired t tests were performed to test intra- and intergroup differences (P < .05).

RESULTS

Dental changes in transverse planes demonstrated a similar trend in both groups. The maxillary canines were buccally tilted (SF vs OF group, 1.7 degrees vs 1.9 degrees), the maxillary molars were lingually tilted (SF group vs OF group, -4.7 degrees vs -1.0 degrees), the mandibular canines were lingually tilted (SF group vs OF group, 2.9 degrees vs 2.8 degrees), and the mandibular molars were buccally tilted (SF group vs OF group, -6.1 degrees vs -5.4 degrees).

CONCLUSION

The magnitude and trend of transverse dental changes in patients with surgical skeletal Class III were similar whether receiving presurgical orthodontics or not.

Surgical Approach to the Patient with Bimaxillary Protrusion

The patient who has bimaxillary protrusion often is treated using a combination of orthodontics and orthognathic surgery, and the general approach is dental extraction with retraction of the incisors. In certain cases, maxillary excess may be corrected solely with LeFort I osteotomy and setback and without dental extraction or anterior segmental osteotomies. This article discusses (1) treatment evaluation and planning and (2) the specific surgical techniques, primarily anterior segmental osteotomies and the technical details for setback of the LeFort I osteotomized segment (more than 5 mm), as they relate to the surgical approach of the patient who has bimaxillary protrusion.

The Inter-relationship Between Mandibular Autorotation and Maxillary LeFort I Impaction Osteotomies

The purposes of the present investigation were to: 1)locate the instantaneous rotation center of mandible autorotation during maxillary surgical impaction; 2) identify the discrepancies between the resultant mandibular position following by maxillary surgical impaction and presurgical predictions, which use the radiographic condylar center as the rotation center for mandibular autorotation; and 3)find the interrelation between the magnitude of maxillary surgical impaction and the sagittal change of mandible. Ten patients underwent maxillary LeFort I impaction without concomitant major mandibular ramus split osteotomies were included. The preoperative (T0) and postoperative (T1) lateral cephalograms were used to evaluate the surgical changes and locate the center of rotation of mandibular autorotation with Reuleaux method. Prediction errors were measured by comparing the predicted (Tp) and postoperative (T1) cephalometric tracings. The magnitude of the maxillary surgical impaction was compared to the positional changes of mandible after mandibular autorotation with correlation and regression analysis. The results demonstrated that the centers of mandibular autorotation located 2.5 mm behind and 19.6 mm below the radiographic condylar center of the mandible in average with large individual variations. By using the radiographic condylar center of the mandible to predict the mandibular autorotation would overestimate the horizontal position of chin by 2 mm and underestimate the vertical position of chin by 1.3 mm following an average of 5 mm surgical maxillary impaction. The magnitude of maxillary impaction was highly and positively correlated to the horizontal displacement of chin position. The rotation centers of mandibular autorotation following by maxillary LeFort I impaction osteotomies might not usually locate at the radiographic condylar center of the mandible also with large individual variations in their positions. Surgeons and orthodontists should be aware of the horizontal and vertical discrepancies of chin positions while planning a two-jaw surgery by using the radiographic center of mandibular condyle as the rotation center in mandibular autorotation.

Symmetry of the nose after presurgical nasoalveolar molding in infants with unilateral cleft lip and palate: a preliminary study

OBJECTIVE

To assess nostril symmetry and alveolar cleft width in infants with unilateral cleft lip and palate following presurgical nasoalveolar molding (NAM).

SAMPLE AND METHODS

Fifty-seven newborn patients underwent presurgical nasoalveolar molding. Magnified basal view facial photos were taken at four different times: initial visit (T1), before cheiloplasty (T2), 1 month after cheiloplasty (T3), and 1 year of age (T4). Direct measurements from the photos included: (1) nostril width on the affected and nonaffected side; (2) nostril height on the affected and nonaffected side; (3) columella-nasal base angle; and (4) width of the alveolar cleft. Nostril width and height data were used to calculate a ratio of affected to nonaffected side.

RESULTS

Effects of nasal symmetry after presurgical nasoalveolar molding were compared between the affected and nonaffected side. The nostril width ratio was 1.7, 1.2, 1.0, and 1.2 for T1 to T4. The nostril height ratio was 0.5, 0.8, 1.0, and 0.9 for T1 to T4. The angle of the columella was 53.3 degrees , 69.9 degrees , 91.2 degrees , and 86.9 degrees for T1 to T4. The average alveolar cleft width was 8.2 mm at T1 and closed down to 2.4 mm before cheiloplasty (T2) in cases with complete cleft.

CONCLUSIONS

Infants with presurgical nasoalveolar molding improved symmetry of the nose in width, height, and columella angle, as compared to their presurgical status. There was some relapse of nostril shape in width (10%), height (20%), and angle of columella (4.7%) at 1 year of age.

Cephalometric craniofacial characteristics in patients with temporomandibular joint ankylosis

BACKGROUND

The sequelae of temporomanibular joint (TMJ) ankylosis include limitation of jaw movement, interference of oral function and affects on the craniofacial growth. Analysis of the craniofacial form of TMJ ankylosis offers guidelines for managing this disease.

METHODS

Forty-five patients with intraarticular TMJ ankylosis were collected from the files at the Chang Gung Craniofacial Center. There were 21 male and 24 female patients, aged 3 to 47 years. Thirty-seven patients were unilaterally affected and eight had bilateral involvement. Patients were grouped according to gender and age. Both the medical history and onset of the disease were investigated in all patients. The pretreatment lateral cephalograms were used for analysis. The variables were compared with the Chinese norms with corresponding sex and age groups.

RESULTS

The etiology included 48.9% facial trauma history, 17.8% traumatic delivery or birth injury, 15.6% middle ear or dental infection, 2.2% chronic arthritis and 15.6% unknown causes. The onset of mouth opening limitation was under 16 years of age. The average total mandibular length was less than the norm by 30 mm. Each patient presented with a mandible that had backward rotation with chin recession. Accentuated antegonial notch and inferiorly located condyle were observed on the affected side. The maxilla was shorter and the ANB was larger than the norm by 10 degrees but the overbite and overjet were within normal ranges.

CONCLUSIONS

The facial growth was severely disturbed in terms of dimension, morphology and direction of growth in patients with TMJ ankylosis. Better management of mandibular fractures, good infection control and early treatment intervention are ways to reduce the influence on craniofacial growth.

The accuracy of video imaging prediction in soft tissue outcome after bimaxillary orthognathic surgery

PURPOSE

The purpose of the present study was to evaluate the accuracy of the outcome in soft tissue prediction through use of a computer imaging system after bimaxillary orthognathic surgery.

MATERIALS AND METHODS

The study sample consisted of 30 adults who had undergone orthognathic surgery that included the Wassmund and Köle procedures and optional genioplasty to correct bimaxillary protrusion. All the patients had lateral cephalometric radiographs and profile photographs taken within 6 months before surgery and at least 6 months after surgery. The computer-generated soft tissue image and the actual postsurgical profile were compared. The accuracy of this computer-generated profile image was evaluated.

RESULTS

The results indicated that the nasal tip, soft tissue A point, and upper lip presented the least predicted errors in sagittal plane. While the nasal tip presented higher reliability. Lower lip prediction was found to be the least accurate region and it tended to be located anterior to the actual position. In the vertical plane, most of the predictions revealed higher accuracy than those in the sagittal plane. There were no statistically significant differences between the predictions of the groups with and those without genioplasty.

CONCLUSIONS

Computer-generated image prediction was suitable for patient education and communication. However, efforts are still needed to improve the accuracy and reliability of the prediction program and to include the consideration of changes in soft tissue tension and muscle strain. The accuracy of this system in soft tissue prediction should be carefully interpreted.

Palatal surface area measurement: comparisons among different cleft types

The purpose of this study was to use three-dimensional imaging methods to measure the palatal surface of unrepaired cleft patients. The surface area of the palate was defined and measured on three-dimensional computed tomography images of dental plaster models in four different groups of cleft patients at 3 months of age. There were 30 unilateral complete cleft lips and palates (UCLP), 27 bilateral complete cleft lips and palates (BCLP), 23 isolated cleft palates of incomplete form (CP), and 19 unilateral cleft lips without cleft palates (UCL). These patients were nonsyndromic, unoperated, and without other major deformities. The dental casts were scanned, and the computed tomography data were transferred to an imaging laboratory for processing and reconstruction of three-dimensional images. Surface area of the palate was delineated, which was defined as within the alveolar crest and the line connecting both tuberosities. In UCLP and BCLP, the edge of cleft formed the medial boundary of the area for each palatal shelf, and the palatal surface area was the combination of both palatal shelves and the premaxillary area in BCLP group. The surface area was measured. Repeated definition and measurement tasks were performed for calculation of errors. The imaging data management and measurement were performed using the Analyze program (Biomedical Imaging Resource, Mayo Foundation, MN). In addition, linear distances were measured between the canine points on the alveolar crest (line C) and the tuberosity points (line T). The measurements were compared among the different groups. Analysis of variance and multiple comparisons were used for statistical analyses. The results showed that the mean error between repeated area definitions and measurements in this study was 1.86%. The bilateral complete cleft lip and palate (BCLP) and unilateral complete cleft lip and palate (UCLP) groups had significantly smaller palatal surface area than the unilateral cleft lip without cleft palate (UCL) and isolated cleft palate of incomplete form (CP) groups. There was no significant difference between the BCLP and UCLP groups. Line C and line T distances were significantly longer in BCLP and UCLP groups than in UCL and CP groups. The findings suggest that compared with UCL and CP patients, there is an intrinsic tissue deficiency in the palate/maxilla of BCLP and UCLP patients.