Bone Reconstruction Planning Using Computer Technology for Surgical Management of Severe Maxillomandibular Atrophy

Application of computer-aided design and 3D-printed template for accurate bone augmentation in the aesthetic region of anterior teeth

PURPOSE

To explore the outcomes of bone augmentation in the aesthetic zone of the anterior teeth using computer-aided design and a 3D-printed template.

METHODS

Ten patients with severe bone defects in the aesthetic zone of anterior teeth were included in the study; CT data were collected before surgery. The design of the osteotomy line in the bone defect area was determined under computer simulation. The position parameters and osteotomy line of the free bone were determined via virtual surgery. A 3D-printed template was prepared to guide the accurate placement of the bone graft. Reexamination was conducted to evaluate the position of the bone graft immediately after the operation and the resorbed capacity of the bone graft before implant restoration.

RESULTS

The position of the bone graft was consistent with the preoperative design. The amount of bone graft resorbed was within the acceptable range three months after the operation, and the effect of implant restoration was satisfactory.

CLINICAL SIGNIFICANCE

Use of computer-aided design and a 3D-printed template can be an effective approach for accurate bone augmentation in the aesthetic zone of the anterior teeth.

Contemporary Smile Design: An Orthodontic Perspective

Orthodontists play a vital role in the smile design of individuals. There are a variety of orthodontic goals and tooth movements that can be achieved to obtain the ideal smile that ultimately leads to the optimum esthetic outcomes. In this article, some methods and appliance systems to control and achieve the desired tooth movements are described and illustrated.

An Evaluation of Jaw Tracking Movements in Patients with Total Joint Replacements versus a Control Group

Background and Objectives: One form of treatment for degenerative temporomandibular joint diseases such as osteoarthritis, rheumatic arthritis, TMJ ankylosis, and condylar resorption is total joint replacement. The aim of this study was to examine the function of the temporomandibular joint after prosthetic joint replacement. Materials and methods: Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via a SICAT JMT+ device. This non-invasive system measures 3D position and linear movements in all degrees of freedom and allows undisturbed functional mandibular movements to provide a quantitative evaluation. In addition, a TMJ questionnaire consisting of the subjective symptoms was also obtained. To date, no similar studies have been cited in the literature. Results: Mandibular movements after prosthetic joint replacement were recorded during opening, closing, protrusion, and lateral excursive movements and were all significantly decreased compared to those of controls. In the treatment group, the maximum incisal opening was 33.46 ± 5.47 mm, left lateral movement was 1.91 ± 2.7 mm, right lateral movement was 1.74 ± 1.74 mm, and protrusive movement was 2.83 ± 2.05 mm. The p-value comparison study and control group indicated significant difference (p < 0.0001) between the two groups. The study group stated a high level of satisfaction with the total joint replacement. Conclusion: Within the limitations of the study, the following conclusions can be drawn: (1) TMJ replacement patients showed significantly limited jaw movements compared to the control group; (2) a small percentage of TMJ replacement patients still present low levels of pain but improved chewing ability and quality of life.

Advances in the Resection and Reconstruction of Midfacial Tumors Through Computer Assisted Surgery

Curatively intended oncologic surgery is based on a residual-free tumor excision. Since decades, the surgeon’s goal of R0-resection has led to radical resections in the anatomical region of the midface because of the three-dimensionally complex anatomy where aesthetically and functionally crucial structures are in close relation. In some cases, this implied aggressive overtreatment with loss of the eye globe. In contrast, undertreatment followed by repeated re-resections can also not be an option. Therefore, the evaluation of the true three-dimensional tumor extent and the intraoperative availability of this information seem critical for a precise, yet substance-sparing tumor removal. Computer assisted surgery (CAS) can provide the framework in this context. The present study evaluated the beneficial use of CAS in the treatment of midfacial tumors with special regard to tumor resection and reconstruction. Therefore, 60 patients diagnosed with a malignancy of the upper jaw has been treated, 31 with the use of CAS and 29 conventionally. Comparison of the two groups showed a higher rate of residual-free resections in cases of CAS application. Furthermore, we demonstrate the use of navigated specimen taking called tumor mapping. This procedure enables the transparent, yet precise documentation of three-dimensional tumor borders which paves the way to a more feasible interdisciplinary exchange leading e.g. to a much more focused radiation therapy. Moreover, we evaluated the possibilities of primary midface reconstructions seizing CAS, especially in cases of infiltrated orbital floors. These cases needed reduction of intra-orbital volume due to the tissue loss after resection which could be precisely achieved by CAS. These benefits of CAS in midface reconstruction found expression in positive changes in quality of life. The present work was able to demonstrate that the area of oncological surgery of the midface is a prime example of interface optimization based on the sensible use of computer assistance. The fact that the system makes the patient transparent for the surgeon and the procedure controllable facilitates a more precise and safer treatment oriented to a better outcome.

Comparison of the condyle-fossa relationship and resorption between patients with and without Juvenile Idiopathic Arthritis (JIA)

INTRODUCTION

The most common disease in pediatric rheumatology is juvenile idiopathic arthritis (JIA). JIA is considered to be an autoimmune disease with an onset before the age of 16. The temporal mandibular joint (TMJ) has been reported to be involved in up to 87% of patients with JIA. Even though substantial research has been conducted on JIA, limited research has studied to understand its effect on the condyle-fossa relationship and to evaluate resorption amount on condyle by using a scoring system.

AIM

The purpose of this study was 1) to compare condyle - fossa relationships in the temporomandibular joint (TMJ), 2) was to score condylar resorption by using a TMJ indexing system in patients with JIA and without JIA.

METHODS

The present retrospective cross-sectional study included cone-beam computed tomography (CBCT) images obtained from the sagittal, coronal, and axial slices. In the multidisciplinary Pediatric Rheumatology Outpatient Clinic at The University of Alabama at Birmingham (UAB) children with JIA are also examined by a group of orthodontists working in the same institute from October 2018 to July 2019. The predictor variable consists of patients with JIA and without JIA. The primary outcome variables are the depth of the mandibular fossa, joint spaces, axial angles, medio-lateral width, and condyle resorption. Other study variables were age and sex. In this study, the measurements obtained from 2 different groups (with JIA and without JIA) are compared using a t-test, where Tukey is utilized to adjust for multiple comparisons. The left and right joints are analyzed separately as the paired t test conducted showed a significant difference between the 2 joints (P < .05).

RESULTS

The study was comprised of 34 patients diagnosed with JIA and 34 healthy subjects. The depth of the mandibular fossa, the anterior joint spaces, the axial angles, and the resorption index showed statistically significant differences between the JIA and healthy groups in both left and right sides (P < .05). However, there was no statistically significant difference in the posterior joint spaces and mediolateral width between JIA and healthy groups in both sides (P > .05).

CONCLUSIONS

The results of our study presented the destructive potential of juvenile idiopathic arthritis by using CBCT. CBCT scanning is a helpful tool in the evaluation of the radiographic result of TMJ.

A randomized trial on the effects of root resorption after orthodontic treatment using pulsating force

Background

An orthodontic device that moves teeth with pulsating force was invented and underwent a single center, controlled, clinical trial to test its safety and efficacy for treatment. The device has a custom-made thermo-plastic mouthpiece which fits over the teeth with an inflatable silicone element. A console that measures and controls the pulsating force level in real-time controls the air pressure that delivers a pulsating force. In this study, the effect of the device on root resorption during orthodontic treatment was evaluated using 3D cone beam computed tomography and compared with a control group of patients who received Invisalign treatment.

Methods

Twenty-eight subjects were enrolled in the investigational arm and 15 in the control group. Subjects were followed until the average score of the mandibular and maxillary teeth achieved a Little’s Irregularity Index of 1.5 mm or less.

Results

There were no adverse events reported throughout the study for either treatment arm. No clinically significant root resorption was observed for either group. The investigational device did not cause root resorption greater than the control group. Both devices produced a safety profile compared to current orthodontic techniques.

Conclusion

The investigational device did not produce more root resorption than similar conventional orthodontic appliances.

Trial registration

ClinicalTrials.gov, NCT03421886. Registered 12 January 2018 - Retrospectively registered.

Contemporary management of an orthodontic-orthognathic patient with limited time availability in an orthodontic office setting: Case report

INTRODUCTION

This case report describes the treatment of a 21-year-old man who presented in an orthodontic office for treatment but lived in a city 100 miles away and wanted the orthognathic surgery in another state in America. The patient presented with an anterior open bite and skeletal Class III relationship.

METHODS

The treatment plan included: (1) effective and careful communication of the treatment plan with the patient, orthodontist and oral and maxillofacial surgeon; (2) pre-surgical alignment and levelling of the teeth in both arches with Invisalign; (3) a long-distance communication between the orthodontist and the surgeon for surgical plan with virtual surgical planning (VSP Orthognathics; 3D Systems, www.3Dsystem.com) online; (4) maxillary advancement (LeFort I osteotomy) with mandibular set-back (bilateral sagittal split osteotomy); (5) postsurgical correction of the malocclusion with clear brackets and aligners; and (6) retention and final small tooth movement adjustments with aligners/clear retainers.

RESULTS

The anterior open bite was treated, crowding was eliminated in the upper and lower anterior segment, correction of skeletal and dental Class III malocclusion was obtained, mandibular plane angle was reduced and facial profile improved.

CONCLUSIONS

The results suggest that aesthetic and functional results can be achieved with long-distance communication of two specialties and with the combined use of clear aligners and clear fixed appliances.

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.

A Cross-Sectional Study to Understand 3D Facial Differences in a Population of African Americans and Caucasians

Objective The purpose of this cross-sectional retrospective study was to use three-dimensional surface imaging to determine gender dimorphism and facial morphological changes from adolescence to adulthood in African American and Caucasian populations.

Materials and Methods Three-dimensional images were captured and the total sample size included 371 subjects. Images were combined using Rapidform 2006 Plus Pack 2 software to produce a male and female facial average for each population. Comparisons were conducted within the following categories: (1) gender comparison within each race, (2) adult and adolescent comparison within each race, and (3) adult and adolescent comparison between the races.

Results Adolescent gender comparisons within each race showed high percentages of similarity. However, adult females in both races showed more prominent periorbital, malar, and nasolabial regions and less prominent lower forehead, nose, and lower face compared with adult males of the same race. African American adult females showed increase in length and width of the face, increased nasal tip projection, and decreased periorbital regions compared with African American adolescent females. Welsh adult females had an increase in the nose and chin projection compared with Welsh adolescent females. Adult males of both races had increase in nose and chin projection, increase in length and width of the face, and decreased periorbital, malar, and nasolabial regions compared with adolescent males of the same race. African American adolescents had a wider alar base, more protrusive lips, and periorbital regions, and less prominent nose and chin compared with the Welsh adolescents. African American adults also had a wider alar base; more protrusive lips and periorbital regions; a broader face; and more retrusive chin, nose, nasolabial region; and lower forehead compared with Welsh adults.

Conclusions Few differences were noted between genders within the same racial groups during adolescence. However, changes became more distinct in adulthood. From adolescence to adulthood, facial morphologies were similarly matched within the gender for females; however, there were significant changes for males. Lastly, facial morphology patterns tend to be established early in life.