Abstract
Objective
This study investigated the skeletal and dentoalveolar changes after intrusion of maxillary posterior teeth using miniscrew implants during the treatment and posttreatment period.
Method
The subjects consisted of 11 adults (1 male, 10 females) whose open bites were treated by posterior teeth intrusion with miniscrew. The lateral cephalometric x-rays of pre-treatment, post-treatment, and the retention period were evaluated.
Results
The average intrusion of maxillary posterior teeth at the end of the treatment period was 2.22 mm (p < 0.001) and the average extrusion of maxillary posterior teeth at the end of the 17.4 month retention period was 0.23 mm (p = 0.359). The relapse rate was calculated at 10.36%. A decrease in overbite after the 17.4 month retention period was 0.99 mm (p < 0.05). The relapse rate was calculated at 18.10%. The skeletal changes and vertical height change of maxillary posterior teeth during the retention period was statistically insignificant, but there was a significant decrease in overbite (mean 0.99 mm, p < 0.05). The amount of intrusion and the overbite improvement from treatment significantly correlates to the degree of relapse.
Figures and Tables
![]() | Fig 1Appliance for intrusion of maxillary molars using miniscrew. A, Miniscrew insertion on buccal and palatal sides (buccal view); B, miniscrew insertion on buccal and palatal sides (palatal view); C, miniscrew insertion on the buccal side only, with a palatal rigid splint for preventing buccal tipping (transverse view); D, miniscrew insertion on the buccal side only, with a palatal rigid splint for preventing buccal tipping (palatal view). |
![]() | Fig 2Cephalometric landmarks and reference planes. S (Sella), N (nasion), Ar (articulare), P (porion), Go (gonion), Me (menton), Gn (gnathion), Po (pogonion), Or (orbitale), ANS (anterior nasal spine), PNS (posterior nasal spine), A (A point), B (B point), U1 (upper incisor tip), U6 (upper molar mesiobuccal cusp tip), L1 (lower incisor tip), L6 (lower molar mesiobuccal cusp tip), Pog' (soft tissue pogonion); SN (SN plane), a line through sella and nasion; FH (FH plane), a line through orbitale and porion; HP (horizontal reference plane), a line through nasion rotated 7° from sella-nasion line; VP (vertical reference plane), a line through sella and perpendicular line to HP; PP (palatal plane), a line through ANS and PNS; MP (mandibular plane), a line through menton and gonion. |
![]() | Fig 3Skeletal angular measurements. a, SN-GoMe; b, S-N-Pog; c, SNA, S-N-A angle; d, SNB, S-N-B angle; e, ANB difference, c-d; f, IMPA, mandibular incisor long axis to Mn. plane; g, FMA, FH-MP. |
![]() | Fig 4Skeletal and dental linear measurements. 1, N-Me, Anterior facial height; 2, VP-Pog, Antero-posterior location of pogonion; 3, U6-PP (mm), perpendicular distance between mesiobuccal cusp of Mx. first molar to palatal plane; 4, U1-PP (mm), perpendicular distance between Mx. incisor edge to palatal plane; 5, OB (mm), distance between incisal edges of maxillary and mandibular central incisors, perpendicular to horizontal reference plane; 6, OJ (mm), distance between incisal edges of maxillary and mandibular central incisors, perpendicular to vertical reference plane. |
Table 1
Cephalometric measurements before treatment (T1), after treatment (T2), and during retention period (T3)

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