| Field | Value |
|---|---|
| ID | OA-0197 |
| Type | component |
| Category | component |
| Fixed/removable | component in removable appliance |
| Primary function | retention of removable orthodontic appliances |
| Uses TADs | no |
The Adams clasp (arrowhead clasp) is the workhorse retention element of removable orthodontic appliances and functional appliances. Two arrowhead-shaped wire tags engage the mesio-buccal and disto-buccal undercuts of the tooth crown, while a connecting bridge crosses the buccal surface above the gingiva. Activating the arrowheads (bending inward) increases retention. Adams clasps are placed on first molars and/or premolars as the primary retention for Hawley retainers, removable expanders, habit appliances, and functional appliances (Twin Block, Bionator). Fabricated from 0.7 mm SS round wire.
The Adams clasp engages tooth structure through two arrowhead-shaped retentive tags that sit in the mesiobuccal and distobuccal undercuts of the crown. The bridge wire crosses the buccal surface above the free gingival margin. When the removable appliance is seated, the arrowheads are passively engaged; when activated (bent slightly inward), they grip the undercuts more tightly, increasing retention force. The clasp resists vertical displacement (removal) of the appliance but allows the patient to remove it by unseating the acrylic baseplate first.
Adams clasps are the standard retention element for nearly all removable orthodontic appliances: Hawley retainers, removable expanders, functional appliances (Twin Block, Bionator, Activator), bite plates, and habit appliances. They are placed on permanent first molars as the primary retention pair in most designs; additional clasps on premolars or primary molars are added when maximum retention is needed or when the appliance must resist heavy functional forces.
Tooth selection: First permanent molars are preferred — their large crown and pronounced undercuts provide maximum retention. When first molars are absent or erupting, premolars or primary second molars are used. Wire gauge: 0.7 mm (0.028") SS is standard; 0.6 mm for primary teeth. Activation: Fresh clasps are often over-retentive; the clinician adjusts bridge height and arrowhead position until seating force is appropriate — firm but not requiring patient discomfort to insert.
Adams clasps are ineffective on teeth with no buccal undercut (over-erupted teeth, teeth with heavy gingival recession, or primary teeth with spherical crowns). Poor bending technique — arrowheads not properly angled into the undercut — results in an appliance that feels retentive on the model but rocks or dislodges in the mouth. Over-activation causes appliance insertion pain and discourages wear.
Lab-bent from 0.7 mm SS wire on a dental stone model. The bridge and arrowheads are bent by hand or with Adams clasp-forming pliers, then embedded in the acrylic baseplate.
Appliances that incorporate this component. ★ = fabricated by Clear Fusion Lab.
Acrylic plate retainer
appliance
bite plane
— Removable habit appliance
appliance
appliance
molar, premolar, or canine
bridge for elastic or spring attachment
attachment point across midline
on teeth with poor undercuts
(0.6 mm) for primary dentition
Journal](https://www.nature.com/bdj)
al.](https://www.elsevier.com)