Team approach in the management of revision surgery to correct bilateral temporomandibular joint replacements.

This case report describes the successful second surgical treatment of a 26-year-old white female patient with a retrognathic mandible and previous bilateral total joint prostheses placement. The patient had previously presented with bilateral idiopathic condylar resorption (ICR) which caused clockwise mandibular rotation and resulted in anterior open bite and a retrognathic mandible. The patient had undergone definitive corrective for the ICR where condylectomies were performed bilaterally. In addition, total joint prostheses using 'stock joints' were used to restore the condyle and glenoid fossa on both sides. Although the previous surgery corrected the anterior open bite and restored the condyles, the patient was still suffering from joint symptoms (significant pain), restricted mandibular movements, increased overjet (12 mm) and a retrognathic mandible. The treatment plan included a combined orthodontic surgical approach: (1) bimaxillary orthognathic surgery: a surgical procedure on the mandible to reposition the prosthetic joints and correct the mandible position, and a segmental LeFort I to expand the maxilla; and (2) post-surgical orthodontics treatment to detail the occlusion. At the end of the treatment, good aesthetic and functional results were obtained with the cooperation of two specialties. This case emphasises the importance of three-dimensional planning and multidisciplinary treatment when addressing complex jaw movements. It also emphasises the importance orthodontic planning and collaboration with the orthodontist.

Evaluation of temporomandibular joint function after orthognathic surgery using a jaw tracker.

OBJECTIVE: It has been reported that temporomandibular joint (TMJ) function after orthognathic surgery differs from normal patients. Dysfunction of the joints occurs often even in the general public, with an incidence in the range of 20%-25%. Population-based studies among adults report that approximately 10%-15% have symptoms of pain and 5% of them had a perceived need for treatment. To date, no studies have reported on the evaluation of TMJ function after orthognathic surgery through the use of four-dimensional jaw tracking. DESIGN AND SETTING: This study evaluated TMJ function using such a device and information from a TMJ questionnaire. Sixteen orthognathic surgery patients and 17 controls were included in this study. Four-dimensional jaw tracking information was obtained using the SiCAT JMT device. Clinical signs and jaw function were evaluated. RESULTS: Within the limitations of the study, the following results were seen using the SICAT JMT+ jaw tracking device: (1) no significant differences were found in any of the millimetric measurements between the surgery patients and controls; (2) no significant difference was found in subjective reported symptoms of pain, clicking, crepitation, locking, stiffness, headaches and migraines between the groups; and (3)there was a significant difference in the popping of the joints for surgery and non-surgery groups. CONCLUSION: Jaw tracking did not detect significant differences in jaw function, but some clinical symptoms were present.

A combined orthodontic / orthognathic approach in the management of obstructive sleep apnoea: Balancing treatment efficacy and facial aesthetics.

Obstructive sleep apnoea (OSA) is a prevalent condition and has been extensively managed with orthognathic surgery using a variety of surgical techniques. This case report describes the successful management of a 56-year-old Caucasian woman with a bimaxillary retrusive profile and macroglossia complicated by OSA and the combined use of orthodontics and orthognathic surgery to improve Apnoea-Hypopnoea Index while maintaining facial aesthetics. The non-extraction treatment plan included: (1) pre-surgical orthodontic treatment to maximise aesthetics and functional occlusion after surgery; (2) maxillomandibular advancement using down fracture of the maxilla (Le Fort 1 osteotomy) with counter-clockwise rotation as well as bilateral sagittal split osteotomy with septoplasty to aid increase in airway function; and (3) post-surgical orthodontic finishing and alignment with self-ligating fixed appliances. Optimum aesthetic and functional results as well as an increase in the airway volume were achieved, without compromising facial aesthetics, with the cooperation of two specialties and the use of state-of-the-art technology during the surgical planning stages.

Comprehensive treatment approach for bilateral idiopathic condylar resorption and anterior open bite with customized lingual braces and total joint prostheses.

This case report describes the successful treatment of a 14-year-old girl with severe bilateral idiopathic condylar resorption and resultant mandibular retrusion, increased overjet, and anterior open bite. The nonextraction treatment plan included (1) aligning and leveling the teeth in both arches, (2) performing Le Fort I maxillary osteotomy, bilateral condylectomy, and mandibular joint replacement, and (3) postsurgical correction of the malocclusion. The orthodontic treatment was initiated with the use of custom lingual appliances followed by orthognathic surgery planned with virtual surgical planning. Patient-fitted and customized temporomandibular joint implants were designed and manufactured based on the patient's stereolithic bone anatomic model. Treatment was concluded with detailed orthodontic finishing. Optimum esthetic and functional results were achieved with the cooperation of 2 specialties and the use of state-of-the-art technology.

Virtual surgical planning: Balancing esthetics, practicality, and anticipated stability in a complex Class III patient.

The treatment of skeletal Class III malocclusion with anterior open bite is a complex and challenging aspect of orthodontics. Facial esthetic factors, practicality and the anticipated stability of a provisional surgical plan must all be factored into the final decision of the actual orthodontic-orthognathic treatment. This case report presents the multidisciplinary treatment of a 39-year-old female patient with skeletal Class III, severe open bite with first dental contact being on the second molars, lateral crossbite, and crowding in both arches. The nonextraction treatment started with aligning and leveling of the teeth in both arches followed by an initial surgical plan based on the clinical evaluation of the smile esthetics. Precise surgical planning information was imported into the Virtual Surgica (VSP Orthognathics) workflow to visualize the direction and amount of movement necessary. The final plan was adjusted because of anticipated practical limitations of the surgery as well as to insure the stability. LeFort I, bilateral sagittal split osteotomies, and setback genioplasty were thus performed. After the surgery, the treatment concluded with the fine adjustment of the occlusion. In the end, good esthetic and functional outcomes with long-term stability were achieved as a result of this delicate multidisciplinary approach.

Comprehensive treatment approach for condylar hyperplasia and mandibular crowding with custom lingual braces and 2-jaw surgery.

We report on the successful treatment of a 32-year-old woman with condylar hyperplasia and severe mandibular crowding. In addition, her maxilla was canted to the right, her mandibular midline and chin point deviated to the left, and her maxillary canines were missing. The treatment plan included (1) aligning and leveling the teeth in both arches, (2) correcting overbite and overjet, (3) performing LeFort I osteotomy and bilateral split osteotomies, and (4) correcting the malocclusion postsurgically. The orthodontic treatment was performed with custom lingual braces and clear brackets, and virtual surgical planning techniques were used to plan the orthognathic surgery. The condylar hyperplasia and the mandibular crowding were corrected. At the end of treatment, the patient's face appeared symmetrical. The results suggest that esthetic and functional results can be achieved with the cooperation of 2 specialties and the use of state-of-the-art technology.

Anthropometric Analysis of the Face.

BACKGROUND: Facial anthropometric analysis is essential for planning cosmetic and reconstructive facial surgery, but has not been available in detail for modern Greeks. In this study, multiple measurements of the face were performed on young Greek males and females to provide a complete facial anthropometric profile of this population and to compare its facial morphology with that of North American Caucasians. MATERIALS AND METHODS: Thirty-one direct facial anthropometric measurements were obtained from 152 Greek students. Moreover, the prevalence of the various face types was determined. The resulting data were compared with those published regarding North American Caucasians. RESULTS: A complete set of average anthropometric data was obtained for each sex. Greek males, when compared to Greek females, were found to have statistically significantly longer foreheads as well as greater values in morphologic face height, mandible width, maxillary surface arc distance, and mandibular surface arc distance. In both sexes, the most common face types were mesoprosop, leptoprosop, and hyperleptoprosop. Greek males had significantly wider faces and mandibles than the North American Caucasian males, whereas Greek females had only significantly wider mandibles than their North American counterparts. CONCLUSIONS: Differences of statistical significance were noted in the head and face regions among sexes as well as among Greek and North American Caucasians. With the establishment of facial norms for Greek adults, this study contributes to the preoperative planning as well as postoperative evaluation of Greek patients that are, respectively, scheduled for or are to be subjected to facial reconstructive and aesthetic surgery.

Surface analysis of study models generated from OrthoCAD and cone-beam computed tomography imaging.

INTRODUCTION: The purpose of this research was to determine the accuracy of digital models generated by cone-beam computed tomography and compare it with that of OrthoCAD models (Cadent, Carlstadt, NJ) for orthodontic diagnosis and treatment planning by using surface area analysis. MATERIALS: Two sets of maxillary and mandibular digital models of 30 subjects were obtained. The models were made from impressions scanned with OrthoCAD and by conversion of related cone-beam computed tomography files. Each patient's matched pairs of maxillary and mandibular models were superimposed by using a software program and a best-fit algorithm; surface-to-surface analysis was then performed. The average linear differences between the 2 files at all points on the surfaces were measured, and tolerance levels of 0.25, 0.5, 0.75, 1.0, 1.25, and 1.5 mm were set to determine the surface correlation amounts between the 2 files. Additionally, 6 linear measurements from predetermined landmarks were also measured and analyzed. RESULTS: The average maxillary model linear difference was 0.28 to 0.60 mm, whereas the average mandibular model linear difference ranged between 0.34 and 0.61 mm. Greater than a 90% surface correlation was obtained on average at 1.00 mm in the maxillary models and at 1.25 mm in the mandibular models. The mean differences obtained from the linear measurements of the maxillary and mandibular models were 0.071 and 0.018 mm, respectively. CONCLUSIONS: Surface-to-surface analysis of OrthoCAD and digital models generated by cone-beam computed tomography pointed to a fair overlap between the protocols. The accuracy of digital models generated by cone-beam computed tomography is adequate for initial diagnosis and treatment planning in orthodontics.

Occlusal asymmetries in children with congenital hip dislocation.

Developmental dysplasia of the hip (DDH) has been associated with other congenital postural deformities and associated with asymmetric features in the body. The aim of this study was to examine the associations between developmental DDH and malocclusions in preschool and school children. The subjects were 60 children (40 girls and 20 boys) born during 1997-2001 in Northern Ostrobothnia Hospital District and having developmental DDH and treated by Von Rosen method. The control group consisted of 71 Finnish children (46 girls and 25 boys) matched by age and gender. Children participated the cross-sectional study at the age of 5-10 years; the mean age of the DDH children was 8.0 (SD 1.4) and controls 7.9 (SD 1.4) years. Dental examinations, intra-oral photographs, and clinical examination including growth measurements were carried out. The DDH children had significantly more lateral crossbites than controls (30/9.9 per cent; P < 0.003). Overall, 77.8 per cent of cases were unilateral crossbites and found more on the right side (50 per cent) compared to the left side (22.2 per cent). Girls had more crossbite compared to boys (77.8/22.2 per cent; odds ratio 2.53). Children with congenital hip dislocation are more predisposed to the asymmetric growth of occlusion and the development of crossbite. The genetic and environmental factors including intrauterine conditions in addition to the splint therapy may be possible influencing factors. This study will give additional information of the development of occlusal asymmetries and the multifactorial nature of the aetiology of lateral malocclusions.

The KPG index--a novel 3D classification system for maxillary canine impactions.

INTRODUCTION: Advancements in Cone Beam Computed Tomography (CBCT) have improved localization of impacted canines. The KPG index is the first 3-D classification system for classifying the position of canines based on their distance from the norm (1). The aim of this study was to determine if this index provides an estimate of the time necessary to treat an impacted canine using closed eruption. MATERIALS AND METHODS: CBCT scans of 28 impacted canines at The University of Texas School of Dentistry at Houston Department of Orthodontics were classified using the KPG index. The scores and categories were compared to the time from surgical exposure to proper positioning. RESULTS: Four canines were classified as "Easy," 11 as "Moderate," 9 as "Difficult," and 4 as "Extremely Difficult." Average treatment times associated in months were: "Easy"--11.23, "Moderate"--11.36, "Difficult"--12.76, and "Extremely Difficult"--13.23. CONCLUSIONS: The KPG index currently cannot be confirmed as an accurate means of estimating treatment time for an impacted canine. Further verification studies should include larger sample sizes and compare differing mechanics. However, there are limitations to 2-D imaging; therefore, the 3-D CBCT images and the KPG index, with further validation, will become increasingly valuable to orthodontists.

Is Orthognathic Correction with TMJ Preservation A Stable Treatment Option for Patients with Juvenile Idiopathic Arthritis?

Purpose: The purpose of this study was to evaluate the long-term skeletal stability of orthognathic correction of dentofacial deformities secondary to juvenile idiopathic arthritis (JIA) in individuals without total alloplastic joint reconstruction. Materials and Methods: The investigators designed and implemented a retrospective case series of patients diagnosed with JIA who underwent bimaxillary orthognathic surgery. To evaluate the long-term skeletal changes, the maxillary palatal plane to mandibular plane angle, anterior facial height, and posterior facial height measurements were evaluated through cephalograms. Results: Six patients met inclusion criteria. All subjects were female (mean 16.2 years). Four patients demonstrated < 1° of change of the palatal plane to mandibular plane angle, and all patients had < 2° of change. Three patients had < 1% change in the anterior to posterior facial height ratio. Three patients demonstrated relative posterior facial shortening compared to anterior facial height (< 4%). No patients developed postoperative anterior open-bite malocclusion. Conclusion: Orthognathic correction of the JIA DFD deformity with TMJ preservation is a viable modality to improve facial esthetics, occlusion, upper airway and speech swallowing and chewing mechanisms in select patients. The measured skeletal relapse did not affect the clinical outcome.

Outcome study of computer-aided surgical simulation in the treatment of patients with craniomaxillofacial deformities.

PURPOSE: The purpose of this study was to determine whether the surgical outcomes achieved with computer-aided surgical simulation (CASS) are better than those achieved with traditional methods. MATERIALS AND METHODS: Twelve consecutive patients with craniomaxillofacial (CMF) deformities were enrolled. According to the CASS clinical protocol, a 3-dimensional computer composite skull model for each patient was generated and reoriented to the neutral head posture. These models underwent 2 virtual surgeries: 1 was based on CASS (experimental group) and the other was based on traditional methods 1 year later (control group). Once the 2 virtual surgeries were completed, 2 experienced oral and maxillofacial surgeons at 2 different settings evaluated the 2 surgical outcomes. They were blinded to the planning method used on the virtual models and each other's evaluation results. The primary outcome was overall CMF skeletal harmony. The secondary outcomes were individual maxillary, mandibular, and chin harmonies. Statistical analyses were performed. RESULTS: Overall CMF skeletal harmony achieved with CASS was statistically significantly better than that achieved with traditional methods. In addition, the maxillary and mandibular surgical outcomes achieved with CASS were significantly better. Furthermore, although not included in the statistical model, the chin symmetry achieved by CASS tended to be better. A regression model was established between mandibular symmetry and overall CMF skeletal harmony. CONCLUSION: The surgical outcomes achieved with CASS are significantly better than those achieved with traditional planning methods. In addition, CASS enables the surgeon to better correct maxillary yaw deformity, better place proximal/distal segments, and better restore mandibular symmetry. The critical step in achieving better overall CMF skeletal harmony is to restore mandibular symmetry.

A new method to orient 3-dimensional computed tomography models to the natural head position: a clinical feasibility study.

PURPOSE: The purpose of this study was to evaluate the clinical feasibility of a new method to orient 3-dimensional (3D) computed tomography models to the natural head position (NHP). This method uses a small and inexpensive digital orientation device to record NHP in 3 dimensions. This device consists of a digital orientation sensor attached to the patient via a facebow and an individualized bite jig. The study was designed to answer 2 questions: 1) whether the weight of the new device can negatively influence the NHP and 2) whether the new method is as accurate as the gold standard. PATIENTS AND METHODS: Fifteen patients with craniomaxillofacial deformities were included in the study. Each patient's NHP is recorded 3 times. The first NHP was recorded with a laser scanning method without the presence of the digital orientation device. The second NHP was recorded with the digital orientation device. Simultaneously, the third NHP was also recorded with the laser scanning method. Each recorded NHP measurement was then transferred to the patient's 3D computed tomography facial model, resulting in 3 different orientations for each patient: the orientation generated via the laser scanning method without the presence of the digital orientation sensor and facebow (orientation 1), the orientation generated by use of the laser scanning method with the presence of the digital orientation sensor and facebow (orientation 2), and the orientation generated with the digital orientation device (orientation 3). Comparisons are then made between orientations 1 and 2 and between orientations 2 and 3, respectively. Statistical analyses are performed. RESULTS: The results show that in each pair, the difference (Δ) between the 2 measurements is not statistically significantly different from 0°. In addition, in the first pair, the Bland-Altman lower and upper limits of the Δ between the 2 measurements are within 1.5° in pitch and within a subdegree in roll and yaw. In the second pair, the limits of the Δ in all 3 dimensions are within 0.5°. CONCLUSION: Our technique can accurately record NHP in 3 dimensions and precisely transfer it to a 3D model. In addition, the extra weight of the digital orientation sensor and facebow has minimal influence on the self-balanced NHP establishment.

Comparison of dental arch forms created from assessment of teeth, alveolar bone, and the overlying soft tissue.

OBJECTIVE: The objective of this study was to determine whether there are differences among the arch forms created from assessments of tooth surfaces, alveolar bone, and overlying soft tissue. MATERIALS AND METHODS: This study included 18 individuals who presented with a class I malocclusion, mild crowding, and a cone beam computed tomography (CBCT) image of good diagnostic quality. The facial axis point was chosen to create the arch form from teeth, the Bowman-Kau (BK) point was used to establish the arch form from alveolar bone, and the WALA ridge was used to calculate the soft tissue arch form. A predetermined algorithm was then used to create five separate arch forms per patient. These arch forms were categorized according to shape and were superimposed. The distances between the tooth-, bone-, and soft tissue-derived arch forms were calculated. RESULTS: The calculated distances between all arch forms were significantly different. The distances between the tooth- and bone-derived arch forms were larger for the mandible compared to the maxilla (mean 3.30 vs. 2.48 mm, respectively). The larger distances seemed to be located more posteriorly in the arch than anteriorly. The distance between tooth- and soft tissue-derived arch forms was largest for the second premolar (2.35 ± 1.59 mm), first molar (2.86 ± 0.63 mm), and second molar (3.25 ± 0.87 mm). There were no significant differences in the distance between the tooth- and either bone- or soft tissue-derived arch forms with regard to sex. CONCLUSIONS: The arch form shapes obtained from the teeth, alveolar bone, and soft tissue are correlated and show the same general shape. Although future large-scale studies are needed for confirmation, our results suggest that evaluating the easily visualized external features, including the WALA ridge, can adequately predict the underlying bone shape, and thus the desired arch form. Nevertheless, the shapes vary significantly between patients, so the final treatment plan should be individualized rather than relying on over-simplified general wire shapes.

Effectiveness of impacted and supernumerary tooth diagnosis from traditional radiography versus cone beam computed tomography.

PURPOSE: The purpose of this study was to determine if cone beam computed tomography (CBCT) is more effective than traditional radiography (TR) in diagnosing pediatric dental clinical cases involving impacted and supernumerary teeth. METHODS: Surveys were given to 10 pediatric dental faculty and 10 pediatric dental residents after viewing 8 clinical cases in either CBCT or TR in which the patient presented with pathology (impaction or supernumerary) in the anterior maxilla. The surveys asked for pathology diagnosis, location, and identification of root resorption, as well as questions about the usefulness of the radiographic mode in treatment planning. RESULTS: A statistically significant difference in CBCT vs. TR viewed cases was found with CBCT statistically better (P<0.05) for pathology location, determining root resorption, usefulness, adequacy in treatment planning, and was the overall recommended mode. More faculty were able to correctly identify the pathology location (P=0.034), while more residents believed they could determine presence of root resorption P=0.029). For impacted versus supernumerary cases, more pathology was correctly located when viewed in CBCT mode (P<0.05). No statistical significance in diagnosing the presence of pathology for all cases was found. CONCLUSIONS: CBCT and TR were effective in the initial diagnosis of pathology in the cases presented. CBCT, however, provides more information on the location of pathology, the presence of root resorption, and treatment planning. The pediatric dental community can benefit from the amount of additional information provided by CBCT. The benefits of CBCT imaging must be weighed against the radiation risk to the pediatric patient and the complexity of the pathology.

A Comparison of 3D Facial Features in a Population from Zimbabwe and United States.

OBJECTIVES: The purpose of this study was to determine the differences in three-dimensional (3D) facial features in a population from Zimbabwe and the United States. In addition, this study seeks to establish an average facial template of each population allowing clinicians to treat patients according to their cultural esthetic perceptions. MATERIALS AND METHODS: Three hundred one subjects from Zimbabwe and the United States were carefully selected and recruited for the study. Each subject presented with a normal facial profile, no asymmetries, and normal body mass index. The 3D images were captured using the 3dMD cameras. All images were further separated into male and female groups of the respective populations and imported to a dedicated software for analysis. STATISTICAL ANALYSIS: The 3D facial images were constructed using Rapidform 6 software to recreate a composite facial average for each group representing a male and female average 3D face of Zimbabwean (Zim) and United States origin. RESULTS: The linear measurements showed that the maximum average distance between the Zim-M and Zim-F was 1.24 mm and the minimum distance between the African American (AA)-M and AA-F was 0.24 mm. This was the absolute distance. When the signed linear measurements were taken into consideration, the maximum average distance between Zim-F and AA-M was 1.22 mm and the least average distance between the Zim-M and AA-M was 0.22 mm. The absolute color histograms showed greatest similarity between the Zim-M and AA-M at 58% and the Zim-F had a 25 and 27% similarity with the AA-F and Zim-M, respectively. CONCLUSION: The Zim-F showed the most variable features with a broader face, prominent forehead, and retruded alar base compared with their male counterparts and the Zim-M showed a wider prominent malar/zygomatic region, and prominent lateral supraorbital regions. There was a high similarity of 58% between the Zim-M and the AA-M, with the Zim-M showing a more protrusive superciliary arches, and a lateral zygomatic region tapering to the root of the nose.

Quantifying changes in incisor inclination before and after orthodontic treatment in class I, II, and III malocclusions.

BACKGROUND: This study was designed to determine if orthodontic treatment significantly changes the upper incisor position in Class I, II, and III dental and skeletal malocclusions. METHODS: Ninety nonextraction-treated patients were included in this retrospective cohort study and divided into three groups: Class I, Class II, and Class III. All cephalometric measurements (ANB, Wits, U1-PP, U1-SN, U1-NA, U1 perpendicular to FH and U1-L1) were taken using the Dolphin Management and Imaging Software, Version 05.05.5070.221436 (United States and Canada). RESULTS: The posttreatment values of ANB, Wits appraisal, U1-NA mm, U1-FH mm, IMPA and U1-L1° are statistically significant (P < 0.05) among the Class I, II, and III when compared with the normal values. Also ANB° changes after orthodontic treatment in Class I, II, and III were statistically significant with the greater changes in Class III malocclusion. CONCLUSIONS: There is a significant amount of dento-alveolar compensation for the maxillary incisors not only in patients with Class II and III but also in Class I malocclusions that underwent nonextraction treatments.

Orthodontic-Orthognathic Management of a patient with skeletal class II with bimaxillary protrusion, complicated by vertical maxillary excess: A multi-faceted case report of difficult treatment management issues.

This case reports the unsuccessful first treatment and the subsequent retreatment of a 35-year old Asian female with a skeletal class II with bimaxillary protrusion, complicated by a deep bite and vertical maxillary excess. This case report highlights the multiple facets of a challenging treatment plan and discusses the ramifications of treatment when treatment does not go as planned. The initial treatment plan consisted of a surgical approach with a maxillary Le Fort I surgery to correct the malocclusion as per the patient's requests without mandibular surgery due to the inherent risk of paraesthesia. The second treatment plan consisted of a bimaxillary surgery with genioplasty. The surgical treatment utilized virtual surgical planning (VSP). The orthodontic treatment was concluded with a corrected overjet and overbite achieving optimum function and balancing the facial profile aesthetically. This case report highlights the need for clear communication of the treatment plan and also the unpredictability of certain treatment outcomes especially when the literature does not provide for definitive conclusions. In addition, it sheds light on the challenge of unpredictable response of soft tissue after surgical treatment and the importance of patient expectations of outcomes. It is hoped that the paper provides a platform for future discussions of difficult malocclusions.