Dental and skeletal components of Class II open bite treatment with a modified Thurow appliance.
BACKGROUND
Due to the lack of studies that distinguish between dentoalveolar and basal changes caused by the Thurow appliance, this clinical study, carried out by the School of Dentistry--State University of São Paulo/Araraquara, aimed at assessing the dental and skeletal changes induced by modified Thurow appliance.


METHODS
The sample included an experimental group comprising 13 subjects aged between 7 and 10 years old, with Class II malocclusion and anterior open bite, and a control group comprising 22 subjects similar in age, sex and mandibular plane angle. Maxillary/mandibular, horizontal/vertical, dental/skeletal movements (ANS, PNS, U1, U6, Co, Go, Pog, L1, L6) were assessed, based on 14 landmarks, 8 angles (S-N-ANS, SNA, PPA, S-N-Pog, SNB, MPA, PP/MPA, ANB) and 3 linear measures (N-Me, ANS-Me, S-Go).


RESULTS
Treatment caused significantly greater angle decrease between the palatal and the mandibular plane on the experimental group, primarily due to an increase in the palatal plane angle. ANB, SNA and S-N-ANS angles significantly decreased more in patients from the experimental group. PNS was superiorly remodeled. Lower face height (ANS-Me) decreased in the experimental group and increased in the control group.


CONCLUSIONS
The modified Thurow appliance controlled vertical and horizontal displacements of the maxilla, rotated the maxilla and improved open bite malocclusion, decreasing lower facial height.
Helder Baldi
HB
Jacob
Ary
A
dos Santos-Pinto
Peter H
PH
Buschang
D000539:Alveolar Process / Q000473:pathology; D059925:Anatomic Landmarks / Q000473:pathology; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D002648:Child; D002680:Chin / Q000473:pathology; D005115:Extraoral Traction Appliances; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy*; D008334:Mandible / Q000473:pathology; D008335:Mandibular Condyle / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology; D009295:Nasal Bone / Q000473:pathology; D024343:Open Bite / Q000473:pathology / Q000628:therapy*; D016382:Orthodontic Appliance Design; D010155:Palatal Expansion Technique / Q000295:instrumentation; D010159:Palate / Q000473:pathology; D012189:Retrospective Studies; D012399:Rotation; D012658:Sella Turcica / Q000473:pathology; D014087:Tooth Movement Techniques / Q000295:instrumentation; D014716:Vertical Dimension
Angle Class II malocclusion; Open bite; Orthopedics