Retrospective 25-year follow-up of treatment outcomes in Angle Class III patients Success versus failure

• Published in: Journal of orofacial orthopedics Vol. 78; no. 2; pp. 129 - 136
• Main Authors: Wendl, Brigitte, Kamenica, A., Droschl, H., Jakse, N., Weiland, F., Wendl, T., Wendl, M.
• Format: Journal Article
• Language: English
• Published: Munich Springer Medizin 01.03.2017
• Subjects: Adult; Age Distribution; Austria - epidemiology; Child; Child, Preschool; Comorbidity; Dentistry; Extraoral Traction Appliances - utilization; Female; Follow-Up Studies; Humans; Jaw Abnormalities - diagnosis; Jaw Abnormalities - epidemiology; Longitudinal Studies; Male; Malocclusion, Angle Class III - diagnosis; Malocclusion, Angle Class III - epidemiology; Malocclusion, Angle Class III - therapy; Medicine; Oral and Maxillofacial Surgery; Original; Original Article; Prevalence; Retrognathia; Retrospective Studies; Risk Factors; Sex Distribution; Treatment Failure; Treatment Outcome; Chincup; Prognostische Parameter; Klasse-III-Therapie; Therapieerfolg; Kopf-Kinn-Kappe; Class III therapy; Prognostic parameters; Treatment success
• ISSN: 1434-5293; 1615-6714
• DOI: 10.1007/s00056-016-0075-8

Objectives Despite recommendations for early treatment of hereditary Angle Class III syndrome, late pubertal growth may cause a relapse requiring surgical intervention. This study was performed to identify predictors of successful Class III treatment. Materials and methods Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Data were collected from the data archive, cephalograms, and casts, including pretreatment ( T 0) and posttreatment ( T 1) data, as well as long-term follow-up data collected approximately 25 years after treatment ( T 2). Each patient was assigned to a success or a failure group. Data were analyzed based on time ( T 0, T 1, T 2), deviations from normal (Class I), and prognathism types (true mandibular prognathism, maxillary retrognathism, combined pro- and retrognathism). Results Compared to Class I normal values, the data obtained in both groups yielded 11 significant parameters. The success group showed values closer to normal at all times ( T 0, T 1, T 2) and vertical parameters decreased from T0 to T2. The failure group showed higher values for vertical and horizontal mandibular growth, as well as dentally more protrusion of the lower anterior teeth and more negative overjet at all times. In adittion, total gonial and upper gonial angle were higher at T 0 and T 1. A prognostic score—yet to be evaluated in clinical practice—was developed from the results. The failure group showed greater amounts of horizontal development during the years between T 1 and T 2. Treatment of true mandibular prognathism achieved better outcomes in female patients. Cases of maxillary retrognathism were treated very successfully without gender difference. Failure was clearly more prevalent, again without gender difference, among the patients with combined mandibular prognathism and maxillary retrognathism. Crossbite situations were observed in 44% of cases at T 0. Even though this finding had been resolved by T 1, it relapsed in 16% of the cases by T 2. Conclusion The failure rate increased in cases of combined mandibular prognathism and maxillary retrognathism. Precisely in these combined Class III situations, it should be useful to apply the diagnostic and prognostic parameters identified in the present study and to provide the patients with specific information about the increased risk of failure.