JOURNAL ARTICLE

Anchorage efficacy of palatally-inserted miniscrews in molar distalization with a periodontally/miniscrew-anchored distal jet

Gero Kinzinger, Norbert Gülden, Faruk Yildizhan, Benita Hermanns-Sachweh, Peter Diedrich
Journal of Orofacial Orthopedics 2008, 69 (2): 110-20
18385957

AIM: As a clinical pilot study using the skeletonized, periodontally/miniscrew-anchored Distal Jet appliance, this study aimed to verify the positional stability of the palatally-inserted paramedian miniscrews when subjected to loading for several months, hence to assess the efficacy of the supporting anchorage design.

MATERIAL AND METHOD: Sixteen miniscrews (8-9 mm in length, 1.6 mm in diameter, polished surface) were inserted in the anterior region of the palate at paramedian locations. Once they had been in place for 1 week, skeletonized Distal Jets for bilateral molar distalization were anchored to the first premolars and necks of the miniscrews using composite. The appliances' coil spring systems were activated to a distalization force of 200-240 cN. The miniscrews were processed histologically after minimally-invasive explantation.

RESULTS: Forces acting reciprocally on the anchorage unit result in significant anchorage loss in the palatally-inserted titanium miniscrews used for added anchorage support: we observed ventral movement in the vicinity of the miniscrew heads of 0.95+/-0.82 mm (the mean; p = 0.005), and extrusion of 0.21+/-0.28 mm (p = 0.040). In the process they tipped 2.65 degrees +/-6.23 degrees in relation to the palatal plane and 2.15 degrees +/-5.76 degrees in relation to the anterior cranial base. We observed no evidence of direct screw-to-bone contact in any of the explanted miniscrews.

CONCLUSIONS: Titanium miniscrews with a polished surface, 1.6 mm in diameter and 8-9 mm long, do not provide stationary anchorage in molar distalization with the periodontally/miniscrew-anchored Distal Jet. When subjected for several months to load from forces that act in reciprocity to the force systems occurring during molar distalization, they fail to remain completely stationary in position in the palatal locations in which they were inserted. However, the combined anchorage setup is sufficient, intraorally and regardless of patient compliance, to largely compensate for the mesially-acting forces that occur reciprocal to molar distalization.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
18385957
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"