JDO Vol. 75
Editorial
Chris H. Chang
Reflections on 28 Years of AAO
AAO is indeed a grand institution, with a long history, but I often feel as if it’s like a family. This is most unique, especially in such a large association, having a feeling this close and intimate.
Whenever I have had the privilege of being invited to speak in the AAO annual meeting, the internal excitement starts as I prepare to show my friends and family what I have learned since we last met. This excitement continues to boil and intensifies to elevated levels during my delivery. Most importantly, I can still feel the rush when I talk to the audience and fellow delivery. Most importantly, I can still feel the rush when I talk to the audience and fellow participants long after my presentation has concluded. My excitement is basically all year round…
Pseudo-Class III Malocclusion with Anterior Crossbite and Bilateral Upper Transalveolar Impacted Canines: Four Premolar Extraction, Aligners, and Segmented Fixed Appliance
Chris Lin, Joshua S. Lin, Chris H. Chang, W. Eugene Roberts
History: An 18yr-11mo-old female presented with chief complaints of anterior crossbite, multiple missing teeth, and a protrusive chin.
Diagnosis: The patient was diagnosed with bimaxillary protrusion combined with an anterior crossbite, bilateral upper impacted canines, unerupted UR8, and missing UR7. The Discrepancy Index (DI) was 21.
Treatment: Four first premolars were extracted prior to Invisalign® treatment. The upper extraction spaces were maintained to allow the impacted canines to erupt. The lower extraction spaces were closed with aligners and segmental braces. The impacted UR3 erupted spontaneously, but the impacted UL3 and UR8 did not. Following surgical exposure, they were aligned using aligners, buttons, power chains (PCs), and elastics.
Results: After 43 months of active treatment, this malocclusion, with a Discrepancy Index of 21 points, was treated to a Cast-Radiograph Evaluation (CRE) score of 20 points and a Pink and White esthetic score of 2 points. The impacted canines were successfully aligned, with the impacted UR8 recovered and substituted for the missing UR7. The patient was pleased with the treatment outcome.
Conclusions: Careful treatment planning and clinical monitoring are prerequisites for treating challenging patients. Hybrid mechanics combining the strengths of segmented fixed appliances and clear aligner therapy are effective in correcting anterior crossbite, multiple impactions, and protrusive chin. (J Digital Orthod 2024;75:4-26)
Key words: Clear aligner therapy (CAT), fixed appliance (FA), segmental fixed appliances, clear aligner, bimaxillary protrusion, four premolars extraction, anterior crossbite, functional shift, impacted canine, U8 for U7 substitution, Invisalign®, pseudo-Class III
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Pseudo-Class III with Anterior Crossbite, Severe Crowding, and Retained Primary Teeth
Yung Hsin Yang, Chris H. Chang, W. Eugene Roberts
History: A 12yr-7mo-old female presented with a chief complaint (CC) of anterior crossbite and severe crowding.
Diagnosis: The patient had two retained primary teeth with impacted permanent teeth causing severe crowding and anterior crossbite. Functional shift was present. Cephalometric analysis revealed an ANB angle of 2°, SN-MP of 31.5°, and a protruded lower lip 5 mm to the E-line. The discrepancy index (DI) was 20 points.
Treatment: A Damon® system appliance with passive self-ligating brackets was applied to correct the dental malocclusion. Posterior and anterior bite turbos combined with Class III elastics were used to correct the anterior crossbite. Both retained primary teeth and 4 premolars were extracted to relieve the crowding. Bone screws were placed bilaterally in the mandibular buccal shelves to retract the mandibular arch. The active treatment time was 38 months.
Results: Retraction of the lower anterior segment and the lower lip was achieved to improve the profile. After 42 months of active treatment, the severe crowding was relieved, and the anterior crossbite was corrected with neither periodontal problems nor root resorption.
Conclusions: This case report demonstrates the use of a passive self-ligating appliance combined with temporary anchorage devices to effectively resolve a pseudo-Class III malocclusion with anterior crossbite and severe crowding. (J Digital Orthod 2024;75:32-47)
Key words: Class III malocclusion, non-surgical treatment, anterior crossbite, bite turbos, torque selection
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Class II Malocclusion with Impacted and Transposed Canines Treated with Modified Vertical Incision Subperiosteal Tunnel Access (VISTA) and Bone Screws
Joy Cheng, Chris H. Chang, W. Eugene Roberts
Introduction: A 11yr-8mo-old female presented with a chief complaint of unerupted bimaxillary right canines.
Diagnosis: The patient had a right end-on Class II and left full-cusp Class II dental malocclusion with an overjet of 8mm. A 100% impinging deep bite was also noted. This severe malocclusion was further complicated by an incompletely transposed and impacted maxillary right canine and a completely transposed and impacted mandibular right canine. The discrepancy index (DI) was 59.
Etiology: The cause of the severe impaction was a deviated path of eruption that may be related to over-retained primary canines.
Treatment: A right-sided infra-zygomatic crest (IZC) bone screw and a right-sided buccal shelf (BS) bone screw were used as anchorage for a modified vertical incision subperiosteal tunnel access (VISTA) submucosal procedure to retract unerupted bimaxillary right canines to their correct sagittal relationships, respectively. Bilateral IZC bone screws, Class II elastics, combined with anterior and posterior bite turbos (BTs) were used to correct the Class II malocclusion, excessive overjet, and deep bite.
Outcome: After 35 months of active treatment, this difficult malocclusion, with a Discrepancy Index of 59 points, achieved a Cast-Radiograph Evaluation score of 26 points and a Pink and White esthetic score of 4 points. The patient was very pleased with the treatment outcome. Final records were collected at the 1.5-year recall appointment. (J Digit Orthod 2024:75:54-74, reprinted with permission from Int J Orthod 2021;32(2):7-17)
Key words: Impaction, impacted and transposed maxillary canine, impacted and transposed mandibular canine, incompletely transposed impaction, completely transposed impaction, modified vertical incision subperiosteal tunnel access, VISTA, bone screw, closed eruption technique
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Taiwanese Lifestyle Through the Eyes of CC
Chapter 10A.
Regenerate the Land and Regenerate Myself
It is a well-known fact that resources are becoming increasingly limited; therefore, to obtain them sometimes relies on a favorable stroke of serendipity. Towards the end of April, 2023, one of the Chang family’s neighbors informed them that he was planning to move to Taipei and was looking to sell his property. This presented Dr. Chang with a great opportunity, which he just had to seize. And seize it he did! The very next day, Dr. Chang visited the neighbor to make him an offer. Without much further ado, the transaction was successfully completed, and the Changs had secured their third property in the neighborhood.
What really captured Dr. Chang’s heart, however, was not having one more house in his portfolio. Instead, what sealed the deal was that the property is encompassed by a 300-ping backyard (around 1,000 m2), which, to Dr. Chang’s discerning eye, looked like a diamond in the rough…