崇愛牙醫診所(資料重建中,歡迎新舊朋友)

• The premature loss of primary molars may require the placement of a space maintainer to prevent the
  migration of the adjacent teeth, depending upon the teeth present and the arch
  length. (乳大臼齒早失的案例,空間保持器可以防止相鄰牙的漂移,視尚有的存在牙齒與牙弓的長度)
• When loss of a primary canine occurs, the dental arch midline may be compromised and the arch
  length also may be reduced. The premature loss of primary canines may therefore
  require the placement of a space maintaining appliance to prevent midline
  deviation and/or loss of arch length, perimeter and/or circumference.
  (乳犬齒產生喪失,牙弓的中線可能重組偏移,牙弓長度會減少,因此,乳犬齒的早失,需要空間保持器來防止中線的偏移,與牙弓長度的減少,周界與口腔周圍環境的縮小)
   
• The premature loss of
  primary incisors does not usually require the placement of a dental appliance
  for the maintenance of space because mesial movement of the adjacent teeth is
  not generally expected.
  (乳切牙的早失,不一定需要空間保持器的置放,這是因為鄰牙的偏移較少會產生)

• A space maintainer is usually not necessary if there is
  a sufficient amount of space present to allow for eruption of permanent
  tooth/teeth. (如果替代的永久恆牙空間足夠,則不需間隙保持器的制作)
• A space maintainer may not be recommended if severe crowding exists, such that space maintenance is of
  minimal effect and  subsequent orthodontic intervention is indicated.
  (如果嚴重的齒列擁擠,是不適做保持器的,因為效果會不好,這時應是固定矯正器介入的適應症)
• A space maintainer may not be necessary if the
  succedaneous tooth will be erupting
  soon.(如果替代恆牙已快萌出,就不需要間隙保持器了)

(以下是各類間隙保持器的使用適應症與優缺點)

•  

  A)Band and Loop
  Space Maintainer

  
  
  
   

  Indications: Loss of first primary molar (乳大臼齒缺失) Advantages: Ease of fabrication for the clinician and ease of maintenance for the patient  (易操作) Disadvantages: Opposing tooth may supererupt(對咬牙會過萌出)

   

  B)Crown and Loop
  Space Maintainer

  
  
  
   

  Indications: Loss of first primary molar with significant loss of tooth substance of the abutment tooth  Advantages: Same as above  Disadvantages: More difficult to fabricate than band and loop(較不易操作)

   

  C)Distal Shoe
  (Intra-alveolar Space Maintainer)

  
  
  
   

  Indications: Loss of second primary molar prior to eruption of the first permanent molar  (乳第二大臼齒早失,在恆第一大臼齒尚未萌出前) Advantages: Maintains the second primary molar space(保持第二乳大臼齒的空間)  Disadvantages: Difficult to fabricate; contraindicated in some medically compromised patients, ie. pathological heart murmur (不易操作,有些如病理性的心雜音病人不適合做)

   

  Lower Lingual
  Holding Arch (LLHA)

  
  
  
   

  Indications: Loss of second primary molar in the mandible (counterpart to Nance)  (乳第二大臼齒早失) Advantages: Maintains the tooth space and the leeway space  Disadvantages: First permanent molars may be susceptible to decalcification; may be prone to breakage unless the patient is well-informed on maintenance(恆第一大臼齒易脫鈣)

   

  D)Nance

  
  
  
   

  Indications: Loss of second primary molar in the maxilla-counterpart to LLHA  Advantages: Maintains the tooth space and the leeway space  Disadvantages: Meticulous hygiene of the acrylic button is required

   

  E)Hawley
  Appliance / Removable Acrylic

  
  
  
   

  Indications: When multiple teeth are lost and the space maintenance and mastication are of concern  (多顆牙不見) Advantages: Can maintain space as well as aid in mastication  Disadvantages: Susceptible to fracture or loss