Larry M. Wolford D.M.D.

Obelenis Ryan, D. P., J. Bianchi, J. Ignacio, L. M. Wolford and J. R. Goncalves (2019). “Cone-beam computed tomography airway measurements: Can we trust them?” Am J Orthod Dentofacial Orthop 156(1): 53-60.

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INTRODUCTION: Pharyngeal airway space (PAS) assessment has been used in the past for a better understanding of orthodontic and surgical outcomes; however, this analysis could be unreliable. Our objective was to evaluate possible changes in the PAS reading in the same patient from their consecutive cone-beam computed tomography (CBCT) scans. METHODS: We evaluated a total of 27 patients’ CBCT scans obtained at 2 time points with the use of a standardized acquisition protocol. The mean age at T0 was 31 years (range 17-62 years) and the follow-up records (T1) were taken after 4-6 months. Dolphin Imaging software was used to measure the volumes of the nasopharynx, oropharynx, and hypopharynx. We also evaluated the craniocervical position with the use of a lateral cephalogram. RESULTS: The variables exhibited high intraclass correlation coefficients (ICCs) when measuring the same CBCT scan twice (T0 and T0). However, The ICC between the measurements performed on the first and second CBCT scans (T0 and T1) showed that the only variable with high reproducibility between the 2 scans was cranial base, with an ICC >0.97. Average differences of 682.1 mm(3), 2255.3 mm(3), and 517.4 mm(3) were found for the nasopharynx, oropharynx, and hypopharynx, respectively. Regarding the cephalometric angles, average differences between T0 and T1 scans were 0.6 degrees , 2.7 degrees , and 0.4 degrees for OPT.CVT, OPT.SN, and cranial base, respectively. CONCLUSIONS: Different CBCT exams with equal scanning and patient positioning protocols can result in different 3D PAS readings. A more careful interpretation of CBCT volumetric data to achieve adequate conclusions of the clinical outcomes is necessary.

Tappa, K., U. Jammalamadaka, J. A. Weisman, D. H. Ballard, D. D. Wolford, C. Pascual-Garrido, L. M. Wolford, P. K. Woodard and D. K. Mills (2019). “3D Printing Custom Bioactive and Absorbable Surgical Screws, Pins, and Bone Plates for Localized Drug Delivery.” J Funct Biomater 10(2): E17.

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Additive manufacturing has great potential for personalized medicine in osseous fixation surgery, including maxillofacial and orthopedic applications. The purpose of this study was to demonstrate 3D printing methods for the fabrication of patient-specific fixation implants that allow for localized drug delivery. 3D printing was used to fabricate gentamicin (GS) and methotrexate (MTX)-loaded fixation devices, including screws, pins, and bone plates. Scaffolds with different infill ratios of polylactic acid (PLA), both without drugs and impregnated with GS and MTX, were printed into cylindrical and rectangular-shaped constructs for compressive and flexural strength mechanical testing, respectively. Bland PLA constructs showed significantly higher flexural strength when printed in a Y axis at 100% infill compared to other axes and infill ratios; however, there was no significant difference in flexural strength between other axes and infill ratios. GS and MTX-impregnated constructs had significantly lower flexural and compressive strength as compared to the bland PLA constructs. GS-impregnated implants demonstrated bacterial inhibition in plate cultures. Similarly, MTX-impregnated implants demonstrated a cytotoxic effect in osteosarcoma assays. This proof of concept work shows the potential of developing 3D printed screws and plating materials with the requisite mechanical properties and orientations. Drug-impregnated implants were technically successful and had an anti-bacterial and chemotherapeutic effect, but drug addition significantly decreased the flexural and compressive strengths of the custom implants.

Galiano, A., L. Wolford, J. Goncalves and D. Goncalves (2019). “Adolescent internal condylar resorption (AICR) of the temporomandibular joint can be successfully treated by disc repositioning and orthognathic surgery, part 2: Treatment outcomes.” Cranio 37(2): 111-120.

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OBJECTIVE: To evaluate treatment outcomes for patients with TMJ adolescent internal condylar resorption (AICR) treated by a specific surgical protocol, including: (1) Removal of bilaminar tissue surrounding the condyle, (2) Articular disc repositioning with Mitek anchor technique, and (3) Concomitant orthognathic surgery. METHODS: This study evaluated 24 AICR patients treated by the specific surgical protocol with clinical subjective and objective examinations and lateral cephalogram assessments for surgical changes and long-term outcomes. RESULTS: Mean age at diagnosis was 16.5 years, and mean follow-up was 30.3 months. All 24 patients had significant reduction in TMJ pain, facial pain, and headaches, with improvement in jaw function, diet, and disability. Cephalometric analysis showed significant surgical changes but good long-term occlusal and skeletal stability. CONCLUSION: Patients with AICR treated with the specific surgical protocol demonstrated good skeletal and occlusal stability as well as improvement in TMJ pain, headaches, jaw function, diet, and disability.

Gomes, L. R., L. H. Soares Cevidanes, M. R. Gomes, A. Carlos de Oliveira Ruellas, D. P. Obelenis Ryan, B. Paniagua, L. M. Wolford and J. R. Goncalves (2018). “Three-dimensional quantitative assessment of surgical stability and condylar displacement changes after counterclockwise maxillomandibular advancement surgery: Effect of simultaneous articular disc repositioning.” Am J Orthod Dentofacial Orthop 154(2): 221-233.

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INTRODUCTION: In this study, we quantitatively assessed 3-dimensional condylar displacement during counterclockwise maxillomandibular advancement surgery (CMMA) with or without articular disc repositioning, focusing on surgical stability in the follow-up period. METHODS: The 79 patients treated with CMMA had cone-beam computed tomography scans taken before surgery, immediately after surgery, and, on average, 15 months postsurgery. We divided the 142 condyles into 3 groups: group 1 (n = 105), condyles of patients diagnosed with symptomatic presurgical temporomandibular joint articular disc displacement who had articular disc repositioning concomitantly with CMMA; group 2 (n = 23), condyles of patients with clinical verification of presurgical articular disc displacement who had only CMMA; and group 3 (n = 14), condyles of patients with healthy temporomandibular joints who had CMMA. Presurgical and postsurgical 3-dimensional models were superimposed using voxel-based registration on the cranial base. Three-dimensional cephalometrics and shape correspondence were applied to assess surgical and postsurgical displacement changes. RESULTS: Immediately after surgery, the condyles moved mostly backward and medially and experienced lateral yaw, medial roll, and upward pitch in the 3 groups. Condyles in group 1 showed downward displacement, whereas the condyles moved upward in groups 2 and 3 (P

Rodrigues, D. B., P. S. F. Campos, L. M. Wolford, J. Ignacio and J. R. Goncalves (2018). “Maxillary Interdental Osteotomies Have Low Morbidity for Alveolar Crestal Bone and Adjacent Teeth: A Cone Beam Computed Tomography-Based Study.” J Oral Maxillofac Surg 76(8): 1763-1771.

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PURPOSE: Maxillary segmentation involving interdental osteotomies can have an adverse effect on the interdental crestal bone and adjacent teeth. The purpose of the present study was to evaluate the effect of interdental osteotomies on surrounding osseous and dental structures, including adjacent teeth, using cone beam computed tomography (CBCT), in patients who underwent segmental maxillary osteotomies. PATIENTS AND METHODS: The present retrospective cohort study evaluated interdental osteotomy (IDO) sites between the lateral incisors and canines in patients treated with 3-piece Le Fort I osteotomies. CBCT scans were assessed using Kodac Dental Imaging software at specific intervals: T0 (before surgery), T1 (immediately after surgery), and T2 (a minimum of 11 months after surgery). The statistical analysis using a linear regression model was adjusted to compare the variables at the different intervals. Injury to the dental structures was assessed by radiological evidence of dental damage, the requirement for endodontic treatment, or tooth loss. RESULTS: We evaluated 94 IDO sites in 47 patients in the present study. The mean inter-radicular distance at T0 was 2.5 mm. A statistically significant increase was seen in the inter-radicular distance (between T1 and T0) of 0.72 mm, with a reduction of the alveolar bone crest height (between T2 and T0) of 0.19 mm (P < .001) for the group that underwent IDO. A weak correlation was found for this increase in the inter-radicular distance, with changes in the alveolar crest bone height. The potential complications associated with interdental osteotomies such as iatrogenic damage to the tooth structure, the need for endodontic treatment, and tooth loss were not encountered in any patients. CONCLUSIONS: We found very low morbidity for the interdental alveolar crest and the integrity of teeth adjacent to interdental osteotomies for patients who underwent maxillary segmentation between the lateral incisors and canines.