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Tripod Mandibular Advancement Surgery Used in a Class II Malocclusion with Receding Lower Jaw
This report concerns a relatively simple and reliable method of managing a case of maxillary dental malocclusion combined with a minor underdeveloped and receding mandible.
The chief complaint of the patient was crowded upper anterior teeth and receding chin. After a thorough examination, the patient was diagnosed with a relatively normal maxilla with a slightly small mandible. Impacted upper left canine and missing lower central incisors were noted.
The main treatment goal was to combine surgery and orthodontics to gain the most benefit of treatment. Tripod mandibular advancing surgery (TMAS) plus genioplasty was used as a single-jaw intervention. Orthodontic mechanotherapy, devoid of temporary anchorage devices, was applied on the upper dentition first and then lower dentition, after the surgery until completion.
The choice of tooth removal had been made corresponding to the patient's upper left canine impaction and congenital missing of bilateral permanent lower central incisors. Impacted canine, upper right premolar and a retained primary lower central incisor were further extracted.
An auxiliary intrusion arch wire with tip-back bends was effective in managing the patient’s deep bite. Overerupted and upright upper incisors were leveled to gain appropriate torque and labial inclinations; consequently, dental arch coordination in both transverse and vertical dimensions was the focus of the treatment in preparation for subsequent TMAS.
TMAS enabled the early establishment of optimal overjet and overbite. A large degree of posterior tooth extrusion using vertical elastics and residual extraction space closure were then accomplished after surgery. Improved esthetic outcomes and stable occlusion were observed.
Wang, Yu-Ting; Cheng, Yu-Ling; Su, Ming-Jeaun; Tsai, Huei-Mei; and Liu, Yi-Min
"Tripod Mandibular Advancement Surgery Used in a Class II Malocclusion with Receding Lower Jaw,"
Taiwanese Journal of Orthodontics: Vol. 34:
1, Article 4.
https://doi.org/10.38209/2708-2636.1119 Available at: https://www.tjo.org.tw/tjo/vol34/iss1/4
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