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Objectives To investigate the skeletal and dental changes during chincup versus facemask treatment, to compare the long-term effects of the two appliances, and to document the impact of each on treatment success. Methods In all, 61 patients with Class III syndrome were retrospectively analyzed at three examination times: 7.8 ± 1.7 years of age (T0, pretreatment), 9.6 ± 2.4 years of age (T1, posttreatment), and around 15–20 years later (T2, long-term follow-up). Results Significant changes of specific cephalometric parameters for all treatment times: T0–T1 (SNA, interbase and gonial angle, Björk’s sum angle, maxillomandibular differential, and distance of upper lip to esthetic line), T1–T2 (NL-NSL, SNB, mandibular-body length, effective mandibular length, and effective maxillary length), and T0–T2 (mandibular-body length, effective mandibular length, effective maxillary length, maxillomandibular differential, SNB, ANB, gonial angle, Björk’s sum angle, and Wits appraisal). The T1–T2 results illustrate that in both treatment groups the typical Class III growth pattern often reappeared after treatment, including gains in SNB angle, condylion-gnathion length, and gonion-menton distance. Conclusions Either a facemask or a chincup may be effectively used to treat Class III malocclusion. There were differences in long-term stability. Maxillary development was similarly favorable in both groups of patients with successful outcome. The subgroup in whom chincup treatment had failed were mainly characterized by excessive mandibular growth, or lack of maxillary catch-up growth, with deterioration of the maxillomandibular relationship notably in the initial phase of treatment. Early chincup treatment did not have an adverse impact on the temporomandibular joints.

To assess early versus late treatment of Class III syndrome for skeletal and dental differences. Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Baseline data were obtained by reviewing pretreatment (T0) anamnestic records, cephalograms, and casts. The cases were assigned to an early or a late treatment group based on age at T0 (up to 9 years or older than 9 years but before the pubertal growth spurt). Both groups were further compared based on posttreatment data (T1) and long-term follow-up data collected approximately 25 years after treatment (T2). Early treatment was successful in 74% and late treatment in 67% of cases. More failures were noted among male patients. The late treatment group was characterized post therapeutically by significantly more pronounced skeletal parameters of jaw size relative to normal Class I values; in addition, a greater skeletal discrepancy between maxilla and mandible, higher values for mandibular length, Cond-Pog, ramus height, overjet, anterior posterior dysplasia indicator (APDI), lower anterior face height, and gonial angle were measured at T1. The angle between the AB line and mandibular plane was found to be larger at T0, T1, and T2, as well as more pronounced camouflage positions of the lower anterior teeth at T0. The early treatment group was found to exhibit greater amounts of negative overjet at T0 but more effective correction at T1. Early treatment of Class III syndrome resulted in greater skeletal changes with less dental compensation.

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 (T0) and posttreatment (T1) data, as well as long-term follow-up data collected approximately 25 years after treatment (T2). Each patient was assigned to a success or a failure group. Data were analyzed based on time (T0, T1, T2), 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 (T0, T1, T2) 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 T0 and T1. 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 T1 and T2. 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 T0. Even though this finding had been resolved by T1, it relapsed in 16% of the cases by T2. 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.

Ziel: dieser Arbeit war es, das Klasse-III-Syndrom nach morphologischen Kriterien einzuteilen und deren Haufigkeit und die Unterschiede zwischen den einzelnen Formen im Therapieverlauf zu ermitteln. Material und Methoden: Im Rahmen einer retrospektiven Analyse wurden 54 Patienten mit einem Klasse-III-Syndrom zu 3 Zeitpunkten nachuntersucht (Ausgangssituation mit 6–9 Jahren, Evaluierung nach Therapie und Langzeitkontrolle beim ausgewachsenen Patienten nach ca. 25 Jahren). Zur Einteilung nach morphologischen Kriterien wurden nur die Anfangsunterlagen (vor Therapiebeginn) herangezogen. Ergebnisse: In 40% der Falle war die Klasse III durch den Unterkiefer bedingt. Der Oberkiefer war in 11% der Falle fur das Entstehen des Klasse-III-Syndroms verantwortlich und in 49% lag eine Kombinationsform vor. Im Unterkiefer ist ein zu groser Unterkiefer (86,4%) die primare Ursache fur das Entstehen einer Klasse III, in 9,1% ist es die prognathe Lage des Unterkiefers und in 4,5% eine Kombination aus beiden. Im Oberkiefer ist hauptsachlich die retrognathe Lage des Oberkiefers fur die Fehlstellung verantwortlich (66,6%), gefolgt zu jeweils 16,7% von einem zu kleinen Oberkiefer und einer Kombination aus Mikrognathie und Retrognathie. Bei der Kombinationsform dominieren ein zu groser Unterkiefer und die retrognathe Lage der Maxilla, danach folgen ein zu groser Unterkiefer und ein zu kleiner Oberkiefer. Bei der Einteilung nach Progenieformen zeigten sich signifikante Unterschiede bezuglich der Normwerte im Therapieverlauf. Bei Therapiebeginn war dies der kleinere SNA-Wert bei maxillarer Retrognathie. Bei der Kontrolluntersuchung wies die Gruppe mit der Kombination beider Progeniearten die groste maxillo-mandibulare Differenz auf. Die maxillare Retrognathie war bei den Werten APDI und NSGn den Normwerten am nachsten und zeigte eine grosere untere Gesichtshohe. Im Vergleich dazu waren die Werte APDI bei den Gruppen der echten Progenie und der Kombinationsform deutlich erhoht und stiegen im Verlauf noch weiter an. Der Wert NSGn zeigte sich zu allen Zeitpunkten vor allem in der Gruppe der echten Progenie erhoht. Conclusio: Die Manifestationen des Klasse-III-Syndroms sind durch die erbliche Komponente sehr unterschiedlich. Durch genaue Diagnose konnen Therapieansatze modifiziert und gezielter eingesetzt werden.