Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Orthodontics

The aim of the present study was to assess the structural changes in the temporo-mandibular joint, skeletal and dental structures after deep bite treatment by upper incisors intrusion, in a group of growing class II female patients and to compare those changes with a matched control group. The participants were randomly divided into 23 treatment and 23 control subjects. In the treatment group, the upper anterior segment extending from the upper right to left canines was bonded. The mini-screws were inserted between the upper central and lateral incisors on both sides. The intrusive force was set at 60 gm at each mini-screw (about 20 gm for every tooth). The total treatment time was about 1 year, comprising 5 months of leveling and alignment and 7 months of intrusion, after which the post intervention cone beam C.T (CBCT) was acquired. Within the temporo-mandibular joints of the treated group, a significant posterior relocation of the mandibular condyle was evident with concomitant increase in the anterior joint space. Significant dimensional changes were evident in the mandibular base; where the treatment led to a significant increase in both mandibular effective length and body length, in the treatment group. There was also a significant mandibular positional change, where the chin point moved forward significantly in the treatment group. There was an improvement in the inter-arch skeletal relation in the treatment group. The upper incisors were intruded and proclined, while the lower incisors were only extruded in the treatment group significant skeletal and dental changes could be attained after bite opening in growing class II deep bite subjects

Issued also as CD