Vertical control of dolichofacial patient with an ACCO

Resumen

Introduction: Poor anteroposterior mandibular relations comprise the largest number of cases. In this group class II malocclusion is the most frequent. Orthodontists began using extraoral forces with modifi ed Hawley retainers many years ago. Margolis realized that removable appliances combined with extraoral forces could not only serve as good containers, but be used as effective correction mechanisms. He called his appliance ACCO (AC acrylic, CO cervico occipital anchorage). Objective: The objectives of the case hereby presented were maxillary growth control and try to protrude the mandible. Case presentation: A 10 year-3 month-old female patient attended the Orthodontics Clinic at the Division of Postgraduate Studies and Research at the National Autonomous University of Mexico. She presented a skeletal class II due to mandibular retrusion and maxillary protrusion, a vertical growth pattern, excessive growth of the nasomaxillary complex and protrusive incisors. Treatment: Orthopedic: ACCO with high traction and impact to retrude the maxilla and decrease vertical growth; with expansion screw (one turn a week). Headgear: nocturnal use and three to four hours in the afternoon. Active plate 24 hours and the patient was told to remove it for eating. Orthodontic treatment: .022 Roth fi xed appliances retention: bimaxillary appliance for nocturnal use. Results: After fi ve months of ACCO use, cephalometric tracings were performed again and the following values were obtained: maxillomandibular relationship: ANB 5o (initial 11o ), Wits 2 mm (initial 3 mm), Bimler overjet 9 mm (initial 10 mm) convexity 6 mm (initial 11 mm). Maxillary position: SNA 82o (initial 87o ) mandibular position: SNB: 78o (initial 76o ). Facial pattern: facial cone of 67o (61o initial dolichofacial). Vertical dimension: SN-mandibular 36.5o (initial 42o), FMA (Tweed) 35o (initial 43o), Goniac (Jarabak) 130o (initial 128o ). Incisor Inclination: UpI/SN 114o (initial 117o), LowI/Mand remained the same (95o). Conclusions: Orthopedics in conjunction with orthodontics harmonizes the maxilla and mandible and at the same time provides natural facial aesthetics, while maintaining proper functions: chewing, swallowing, phonation and breathing. It is vitally important to perform a timely diagnosis in order to intervene orthopedically, correct this kind of malocclusions and limit or prevent its severity.

Key words: ACCO, headgear, vertical control.