بررسي درمان خارج كردن يك طرفه بر تقارن قوس دنداني ماگزيلا در بيماران كلاس دو subdivision

Evaluation of the role of unilateral tooth extraction treatment on maxillary arch symmetry in Class II subdivision cases

ﯾﮑﻄﺮﻓﻪ ﮐﺸﯿﺪن دﻧﺪان ﺑﻪ ﻋﻨﻮان ﯾﮏ ﮔﺰﯾﻨﻪ درﻣﺎﻧﯽ ﺑﺎﻟﻘﻮه ﺑﺮاي اﺻﻼح ﻣﺎل اﮐﻠﻮژن ﮐﻼس دو subdivision ﭘﯿﺸﻨﻬﺎد ﺷﺪه اﺳﺖ، ﺗﺎ از اﮐﺜﺮ ﻋﻮارض ﺟﺎﻧﺒﯽ ﻣﺮﺗﺒﻂ ﺑﺎ ﻣﮑﺎﻧﯿﮏ ﻧﺎﻣﺘﻘﺎرن اﺟﺘﻨﺎب ﮐﺮد، اﻣﺎ ﺷﮑﻞ ﻗﻮس ﭘﺲ از درﻣﺎن ﻣﻤﮑﻦ اﺳﺖ ﻣﺘﻘﺎرن ﻧﺒﺎﺷﺪ. ﻫﺪف از اﻧﺠﺎم اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ دﻗﯿﻖ اﯾﻦ ﻧﺎﻗﺮﯾﻨﮕﯽ در ﺗﻤﺎﻣﯽ اﺑﻌﺎد و ﺗﻌﯿﯿﻦ اﺛﺮات ﭘﺲ از درﻣﺎن ﮐﺸﯿﺪن ﭘﺮﻣﻮﻟﺮ ﯾﮏ ﻃﺮﻓﻪ ﺑﺮ روي ﻗﻮس دﻧﺪاﻧﯽ ﻓﮏ ﺑﺎﻻ در ﻣﺎل اﮐﻠﻮژن ﻫﺎي ﮐﻼس دو subdivision اﺳﺖ. ﻣ اد و روش ﻫﺎ: در اﯾﻦ ﻣﻄﺎﻟﻌﻪ cohort ﮔﺬﺷﺘﻪ ﻧﮕﺮ، 34 ﺑﯿﻤﺎر ﮐﻪ داراي ﻣﺎل اﮐﻠﻮژن ﮐﻼس دو subdivision و ﺗﺤﺖ درﻣﺎن ارﺗﻮدﻧﺴـﯽ ﺛﺎﺑـﺖ در ﺑﯿﻤﺎران ﺑﺰرﮔﺴﺎل ﺑﺎ ﮐﺸﯿﺪن دﻧﺪان ﻗﺮار ﮔﺮﻓﺘﻪ ﺑﻮدﻧﺪ، اﻧﺘﺨﺎب ﺷﺪﻧﺪ. ﭘﺲ از اﯾﻦ ﮐﻪ اﯾﻦ اﻓﺮاد از ﻧﻈﺮ ﺳﻦ و ﺟﻨﺲ match ﺷﺪﻧﺪ ﺑﻪ دو ﮔﺮوه درﻣـﺎن ﺷﺪه ﺑﺎ ﮐﺸﯿﺪن ﯾﮏ ﻃﺮﻓﻪ و ﮐﺸﯿﺪن دو ﻃﺮﻓﻪ در ﻓﮏ ﺑﺎﻻ ﺗﻘﺴﯿﻢ ﮔﺸﺘﻪ و ﺗﻘﺎرن ﻗﻮس دﻧﺪاﻧﯽ در اﯾﻦ دو ﮔﺮوه ﺑـﺎ اﺳـﺘﻔﺎده از ﻗﺎﻟﺐ ﻫـﺎي ﺳـﻪ ﺑﻌـﺪي دﯾﺠﯿﺘﺎل ﻓﮏ ﺑﺎﻻ ارزﯾﺎﺑﯽ ﺷﺪ. ﺗﻐﯿﯿﺮات ﻗﺪاﻣﯽ-ﺧﻠﻔﯽ، ﻋﻤﻮدي و ﻋﺮﺿﯽ ﻗﻮس دﻧﺪاﻧﯽ و ﻣﯿﺰان ﺟﺎﺑﺠﺎﯾﯽ دﻧﺪان ﻫﺎي ﻣﻮﻟﺮ و ﮐﺎﻧﯿﻦ ﺛﺒﺖ ﺷﺪ و ﺗﻐﯿﯿـﺮات اﯾﻨﮑﻠﯿﻨﺸﻦ دﻧﺪان ﻫﺎي اﯾﻨﺴﺎﯾﺰورﻫﺎ ﻧﯿﺰ در رادﯾﻮﮔﺮاﻓﯽ ﻟﺘﺮال ﺳﻔﺎﻟﻮﻣﺘﺮي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺖ. ﺑـﺮاي ﻫـﺮ ﺷـﺎﺧﺺ ﺑـﺎ ﺗﻮزﯾـﻊ ﻧﺮﻣـﺎل از از آزﻣـﻮن test-T و k^2 و ﺑﺮاي داده ﻫﺎي ﺧﺎص ﺑﺎ ﺗﻮزﯾﻊ ﻏﯿﺮﻋﺎدي از آزﻣﻮن Mann-u Whitney اﺳﺘﻔﺎده ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﻣﯿﺰان ﻋﺪم ﺗﻘﺎرن دﻧﺪاﻧﻬﺎي ﻣﻮﻟﺮ در ﮔﺮوه ﮐﺸﯿﺪن ﯾﮏ ﻃﺮﻓﻪ در ﺑﻌﺪ ﻗﺪاﻣﯽ ﺧﻠﻔﯽ 4/55 ﻣﯿﻠﯽ ﻣﺘﺮ و در ﺑﻌﺪ ﻋﺮﺿﯽ 0/15 ﻣﯿﻠﯽ ﻣﺘﺮ ﺑﯿﺸﺘﺮ از ﮔﺮوه ﮐﺸﯿﺪن دوﻃﺮﻓﻪ ﺑﻮد ﮐﻪ از ﻧﻈﺮ آﻣﺎري ﻣﻌﻨﯽ دار ﺑﻮد.)0/001 p≤(. اﻣﺎ در ﺑﻌﺪ ﻋﻤﻮدي ﻣﻮﻟﺮﻫﺎ از ﻧﻈﺮ آﻣﺎري ﺗﻔـﺎوت ﻣﻌﻨـﯽ داري ﻧﺸـﺎن ﻧﺪادﻧـﺪ. ﻣﯿﺰان ﻋﺪم ﺗﻘﺎرن دﻧﺪاﻧﻬﺎي ﮐﺎﻧﯿﻦ در ﮔﺮوه ﮐﺸﯿﺪن ﯾﮏ ﻃﺮﻓﻪ در ﺑﻌﺪ ﻗﺪاﻣﯽ-ﺧﻠﻔﯽ 0/60ﻣﯿﻠﯿﻤﺘﺮ، در ﺑﻌﺪ ﻋﻤﻮدي 0/58 ﻣﯿﻠـﯽ ﻣﺘـﺮ و ﻋﺮﺿـﯽ 0/18 ﻣﯿﻠﯽ ﻣﺘﺮ ﺑﯿﺸﺘﺮ از ﮔﺮوه ﮐﺸﯿﺪن دوﻃﺮﻓﻪ ﺑﻮد ﮐﻪ از ﻧﻈﺮ آﻣﺎري ﻣﻌﻨﯽ دار ﺑﻮد )0/0001 p≤(. ﺗﻔﺎوت ﺷﯿﺐ دﻧﺪان ﻫﺎي ﻗﺪاﻣﯽ ﺑﺎﻻ در دو ﮔـﺮوه ﻧﯿـﺰ از ﻧﻈﺮ آﻣﺎري ﻣﻌﻨﯽ دار ﺑﻮد. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: در ﮔﺮوه ﮐﺸﯿﺪن ﯾﮏ ﻃﺮﻓﻪ، ﻣﯿﺰان ﺟﺎ ﺑﻪ ﺟﺎﯾﯽ دﻧﺪان ﻣﻮﻟﺮ در ﺳﻤﺖ ﮐﺸﯿﺪن ﻧﺴﺒﺖ ﺑﻪ ﺳﻤﺖ ﻧﮑﺸﯿﺪن از ﻟﺤﺎظ آﻣﺎري ﺑـﻪ ﻃـﻮر ﻣﻌﻨـﯽ داري در ﺟﻬﺖ ﮐﺎﻧﺴﺘﺮﯾﮑﺸﻦ، اﯾﻨﺘﺮوژن و ﺣﺮﮐﺖ ﻗﺪاﻣﯽ ﺑﯿﺸﺘﺮ ﺑﻮد؛ ﻫﻤﭽﻨﯿﻦ ﺟﺎﺑﺠﺎﯾﯽ دﻧﺪاﻧﯽ ﮐﺎﻧﯿﻦ در ﺳﻤﺖ ﮐﺸﯿﺪن از ﻟﺤﺎظ آﻣﺎري ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داري در ﺟﻬﺖ ﺧﻠﻔﯽ، اﯾﻨﺘﺮوژن و ﮐﺎﻧﺴﺘﺮﯾﮑﺸﻦ ﺑﯿﺸﺘﺮ ﺑﻮد.

Asymmetric extractions have been proposed as potential treatment options to correct Class II subdivision malocclusion, suggesting that most side effects associated with asymmetrical mechanics can be avoided, however the post-treatment arch form may not be symmetrical. Therefore, the aim of this study was to determine the post-treatment effects of unilateral premolar extraction on the maxillary dental arch in Class II subdivision malocclusions. Material and Methods: Thirty-four patients with Class II subdivision malocclusion were treated for tooth extraction were selected. Patients were divided into two groups treated with unilateral and bilateral extractions in the maxilla. Dental arch symmetry was assessed using maxillary digital 3D casts and anterior-posterior, vertical and transverse changes of upper dental arch was calculated. The amount of displacement of the molars and canines were recorded and the changes in inclination of incisors was also measured on lateral cephalography. The T-test and test was used for each index with normal distribution and Mann-u Whitney test was used for specific data with abnormal distribution. Results: The amount of molars asymmetry in the unilateral extraction group in the transverse dimension was 0.15 mm and in anterior-posterior dimension 4.55 mm more than bilateral extraction group which was statistically significant (p≤0.001). However, in the vertical plane, the molars showed statistically insignificant differences. The amount of canines’ asymmetry in the unilateral extraction group in the transverse, vertical and anterior-posterior dimension was 0.18 mm, 0.58 mm and in 0.60 mm respectively, when compared with bilateral extraction group which was statistically significant (p≤0.0001). The difference in the inclination of the upper anterior teeth at the end of treatment was also statistically significant. Conclusion: The effect of unilateral premolars extraction on the symmetry of the dental arch form is significantly different from bilateral premolars extraction. Asymmetry of the molars at the end of treatment, the amount of anterior displacement of the molars on the extraction side and the amount of posterior canine displacement on the traction side were clinically significant.