An adjustable brush (100, 200, 700) comprising: a brush head (104, 204, 704), the brush head (104, 204, 704) including: a first plurality of teeth (106, 206, 706) extending along a rotation axis (111, 606, 1105); and a second plurality of teeth (108, 208, 708) extending along the rotation axis (111, 606, 1105), the second plurality of teeth (108, 208, 708) being rotatable independently of the first plurality of teeth (106, 206, 706) about the rotation axis (111, 606, 1105); and a handle (108, 202, 702) extending from the brush head (104, 204, 704); characterized in that the brush head (104, 204, 704) includes a plurality of arms (212, 710) extending from the handle (108, 202, 702), wherein the arms (212, 710) define a receptacle for receiving at least a portion of a carriage (110, 216, 714) from which the first and second pluralities of teeth (108, 208, 708) extend; wherein the carriage (110, 216, 714) is rotatably coupled to the brush head (104, 204, 704), wherein a rotation of at least a portion of the carriage (110, 216, 714) causes a corresponding rotation in at least one of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708); wherein the brush head (104, 204, 704) includes a first knob (218, 716), wherein the rotation of at least a portion of the carriage (110, 216, 714) corresponds to a rotation of the first knob (218, 716), wherein the rotation of the first knob (218, 716) causes a corresponding rotation of at least one of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708); wherein a rotation of the first knob (218, 402, 716, 718) in a first rotation-direction causes the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708) to transition into a retracted position from an extended position, wherein when in the retracted position, at least a portion of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708) are disposed within the receptacle defined by the arms (212, 710). a brush head (104, 204, 704), the brush head (104, 204, 704) including: a first plurality of teeth (106, 206, 706) extending along a rotation axis (111, 606, 1105); and a second plurality of teeth (108, 208, 708) extending along the rotation axis (111, 606, 1105), the second plurality of teeth (108, 208, 708) being rotatable independently of the first plurality of teeth (106, 206, 706) about the rotation axis (111, 606, 1105); and a first plurality of teeth (106, 206, 706) extending along a rotation axis (111, 606, 1105); and a second plurality of teeth (108, 208, 708) extending along the rotation axis (111, 606, 1105), the second plurality of teeth (108, 208, 708) being rotatable independently of the first plurality of teeth (106, 206, 706) about the rotation axis (111, 606, 1105); and a handle (108, 202, 702) extending from the brush head (104, 204, 704); characterized in that the brush head (104, 204, 704) includes a plurality of arms (212, 710) extending from the handle (108, 202, 702), wherein the arms (212, 710) define a receptacle for receiving at least a portion of a carriage (110, 216, 714) from which the first and second pluralities of teeth (108, 208, 708) extend; wherein the carriage (110, 216, 714) is rotatably coupled to the brush head (104, 204, 704), wherein a rotation of at least a portion of the carriage (110, 216, 714) causes a corresponding rotation in at least one of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708); wherein the brush head (104, 204, 704) includes a first knob (218, 716), wherein the rotation of at least a portion of the carriage (110, 216, 714) corresponds to a rotation of the first knob (218, 716), wherein the rotation of the first knob (218, 716) causes a corresponding rotation of at least one of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708); wherein a rotation of the first knob (218, 402, 716, 718) in a first rotation-direction causes the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708) to transition into a retracted position from an extended position, wherein when in the retracted position, at least a portion of the first and/or second plurality of teeth (106, 206, 706; 108, 208, 708) are disposed within the receptacle defined by the arms (212, 710).