Stockholders' Equity - Additional Information (Detail) - USD ($)																			12 Months Ended
	Jan. 02, 2016	Dec. 31, 2015	Aug. 12, 2015	Jul. 13, 2015	Jun. 23, 2015	Mar. 09, 2015	Jan. 02, 2015	Nov. 07, 2014	Aug. 27, 2014	Jul. 22, 2014	Jul. 13, 2014	Feb. 10, 2014	Dec. 19, 2013	Sep. 23, 2013	Jul. 12, 2013	Jun. 06, 2013	Apr. 26, 2013	Nov. 08, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Nov. 30, 2014	Jul. 26, 2013	Apr. 18, 2013	Mar. 23, 2013	Dec. 31, 2012
Stockholders Equity [Line Items]
Preferred stock, shares authorized		1,000,000																	1,000,000	1,000,000	1,000,000
Preferred stock, shares outstanding		0																	0	0	0
Common stock, shares issued		58,228,000																	58,228,000	58,115,000
Common stock, shares outstanding		58,228,000																	58,228,000	58,115,000	37,422,753
Common stock, shares authorized		100,000,000																	100,000,000	100,000,000
Proceeds from equity offering, net of expenses								$ 34,800,000		$ 11,500,000		$ 4,800,000								$ 51,118,000	$ 5,201,000
Maximum stock offering price																							$ 5,000,000
Dividend Declared																			$ 0
Warrants and rights outstanding		0																	0
Minimum required closing price of common stock on the NASDAQ in order to exercise																									$ 6.00
Allocated Share-based Compensation Expense																			$ 3,350,000	$ 1,233,000	$ 1,609,000
Common stock issued pursuant to options exercised																			38,000	153,000	343,000
Options outstanding		4,493,000																	4,493,000	3,475,000	4,441,000					3,860,000
Expected term (years)																			5 years 9 months 18 days	3 years 9 months 29 days	3 years 7 months 24 days
Volatility																			90.00%	94.00%	84.00%
Risk-free interest rate																			1.64%	1.66%	1.04%
Coo
Stockholders Equity [Line Items]
Stock options granted to COO																350,000
Stock options granted at an exercise price																$ 4.00
Stock options vesting beginning date																Jun. 06, 2014
Unvested stock options forfeited																				306,250
Stock options expiration date																			Feb. 28, 2016
Chief Executive Officer
Stockholders Equity [Line Items]
Shares vested and exercised consecutive term				36 months
Chief Financial Officer | Vest on January 2, 2016
Stockholders Equity [Line Items]
Stock options granted						523,026
Share based compensation arrangement by share Based payment award fair value price						$ 1.48
Expected term (years)						6 years 1 month 6 days
Volatility						88.79%
Risk-free interest rate						1.83%
Chief Financial Officer | CFO Grant Award Tranche Two
Stockholders Equity [Line Items]
Stock options granted						348,684
Shares vested and exercisable date						Mar. 09, 2025
Share based compensation arrangement by share Based payment award fair value price						$ 1.70
Expected term (years)						10 years
Volatility						87.87%
Risk-free interest rate						2.19%
Option shares vested and exercised		100,000
2002 Stock Incentive Plan
Stockholders Equity [Line Items]
Plan expiration date																			May 05, 2019
Common stock authorized for issuance under the 2002 Plan		11,550,000																	11,550,000
Common stock issued pursuant to options exercised																			3,068,000
Options outstanding		4,493,000																	4,493,000
Options available for future grant		3,989,000																	3,989,000
Non-qualified Stock Options
Stockholders Equity [Line Items]
Options available for future grant											172,282
Stock options granted at an exercise price											$ 1.98
Exercise Price of Stock Options							$ 2.64
Non-qualified Stock Options | Officers
Stockholders Equity [Line Items]
Stock options granted							1,365,702
Options expiration period							10 years
Options vesting description																			(i) as to 50% of the options, one-fourth on the one year anniversary of the grant date and the remaining three-fourths, ratably over the next 36 month period, commencing on the thirteenth month from grant date over a requisite service period of four years, and (ii) as to 50% of the options, upon achievement of specific annual Company performance criteria with a requisite service period of one year.
Non-qualified Stock Options | Consultants
Stockholders Equity [Line Items]
Stock options granted							86,000
Options expiration period							5 years
Non-qualified Stock Options | Officers And Consultant | Two Thousand Fifteen Compensation Plan
Stockholders Equity [Line Items]
Decrease in fair value awards			$ 661,000
Additional compensation expense related to modification																			$ 154,000
Shares issued for settlement																			122,038
Non-qualified Stock Options | Officers And Consultant | Two Thousand Fifteen Compensation Plan | Subsequent Event
Stockholders Equity [Line Items]
Number of warrant vesting upon early termination	488,170
Non-qualified Stock Options | Officers And Consultant | Two Thousand Fifteen Compensation Plan | Vest on January 2, 2016 | Subsequent Event
Stockholders Equity [Line Items]
Percentage on performance optional vesting	80.00%
Non-qualified Stock Options | Chief Executive Officer
Stockholders Equity [Line Items]
Stock options granted at an exercise price				$ 1.64
Stock options granted				870,000
Exercise Price of Stock Options				$ 1.64
Options expiration period				10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				4 years
Non-qualified Stock Options | Chief Financial Officer
Stockholders Equity [Line Items]
Stock options granted at an exercise price						$ 1.99
Stock options granted						871,710
Options expiration period						10 years
Restricted Stock Units (RSUs)
Stockholders Equity [Line Items]
Options available for future grant											37,879
Exercise Price of Stock Options											$ 1.98
Restricted Stock Units (RSUs) | One Independent Directors
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period									9,217
Restricted Stock Units (RSUs) | Four Independent Director
Stockholders Equity [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period									37,000
Share-based compensation arrangement by share-based payment award, equity instruments other than options, value per share									$ 2.17
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									12 months
One Year Anniversary | Chief Executive Officer
Stockholders Equity [Line Items]
Option shares vested and exercised				217,500
One Year Anniversary | Chief Financial Officer | Vest on January 2, 2016
Stockholders Equity [Line Items]
Option shares vested and exercised						130,757
Shares vested and exercised consecutive term						35 months
Shares vested and exercisable date						Mar. 09, 2016
Thirty Six Month Anniversary | Chief Financial Officer | Vest on January 2, 2016
Stockholders Equity [Line Items]
Option shares vested and exercised						10,909
Shares vested and exercisable date						Mar. 09, 2019
Options Vesting And Becoming Exercisable Each Month | Chief Executive Officer
Stockholders Equity [Line Items]
Option shares vested and exercised				18,125
Options Vesting And Becoming Exercisable Each Month | Chief Financial Officer | Vest on January 2, 2016
Stockholders Equity [Line Items]
Option shares vested and exercised						10,896
Ten Year Anniversary | Chief Financial Officer | CFO Grant Award Tranche Two
Stockholders Equity [Line Items]
Option shares vested and exercised					100,000
Shares vested and exercisable date					Mar. 09, 2025
Option shares vested and exercised					248,684
Sun Dental Warrant
Stockholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights																	$ 5.90
Stock-based compensation																			$ 0	$ 0
Plan expiration date																				Apr. 24, 2014
Sun Dental Warrant vesting rate per assisted sale																	1,000
2013 IR Warrant
Stockholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights																								$ 5.10
Stock-based compensation																			0	$ 0	$ 0
Minimum required closing price of common stock on the NASDAQ in order to exercise																								$ 7.50
CMR Warrant
Stockholders Equity [Line Items]
Stock-based compensation																			$ 0	$ 0	0
2012 IR Warrant
Stockholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights																		$ 2.50
Minimum required closing price of common stock on the NASDAQ in order to exercise																		$ 7.00
Number of warrant vesting upon early termination																		25,000
Allocated Share-based Compensation Expense																					$ 64,000
Stock based compensation, shares issued																					9,296
Warrants
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																						9,205,862
Class of Warrant or Right, Exercise Price of Warrants or Rights																						$ 4.00
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period																			0	9,205,862	1,025,000
Northland Securities Inc
Stockholders Equity [Line Items]
Issuance of stock, net, shares														2,688,172
Common stock issued, price per share														$ 1.86
Proceeds from equity offering, gross														$ 5,000,000
Payments of stock issuance costs														408,000
Proceeds from equity offering, net of expenses														$ 4,600,000
Valam First Tranche
Stockholders Equity [Line Items]
Warrants issued to purchase common stock															165,000
Class of Warrant or Right, Exercise Price of Warrants or Rights															$ 4.00
Vesting of Valam warrant															30,000
Warrants and rights outstanding																				30,000	30,000
Stock-based compensation																				$ 41,000	$ 41,000
Valam | Original Agreed Price
Stockholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights															$ 6.00
Plan expiration date																				Jul. 14, 2020
FDA Clearance
Stockholders Equity [Line Items]
Vesting of Valam warrant															55,000
Second Ent Laser
Stockholders Equity [Line Items]
Vesting of Valam warrant															40,000
ENT laser revenues required during a 12-month period																					5,000,000
Third Ent Laser
Stockholders Equity [Line Items]
Vesting of Valam warrant															40,000
ENT laser revenues required during a 12-month period																					10,000,000
Oracle Group
Stockholders Equity [Line Items]
Issuance of stock, net, shares														340,000
Common stock issued, price per share													$ 1.80
Proceeds from equity offering, gross													$ 612,000
Payments of stock issuance costs													30,000
Proceeds from equity offering, net of expenses													$ 582,000
2014 Common Stock Issuances
Stockholders Equity [Line Items]
Issuance of stock, net, shares								14,162,873		6,250,000		1,945,525
Common stock issued, price per share								$ 2.39		$ 1.92		$ 2.57
Warrants issued to purchase common stock								9,205,862
Class of Warrant or Right, Exercise Price of Warrants or Rights								$ 4.00
Proceeds from equity offering, gross								$ 35,000,000		$ 12,000,000		$ 5,000,000
Payments of stock issuance costs								235,000		462,000		188,000
Proceeds from equity offering, net of expenses								$ 34,800,000		$ 11,500,000		$ 4,800,000
Warrants exercisable								May 07, 2015
Warrants issued for term								3 years
Maximum
Stockholders Equity [Line Items]
Preferred stock, shares authorized																				1,000,000
Maximum | Sun Dental Warrant
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																	500,000
Stock-based compensation																					$ 1,000
Maximum | 2013 IR Warrant
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																								60,000
Maximum | CMR Warrant
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																									100,000
Maximum | CMR Warrant | First Tranche
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																									50,000
Class of Warrant or Right, Exercise Price of Warrants or Rights																									$ 4.50
Maximum | CMR Warrant | Mar. 23, 2013 Maximum Second Tranche CMR Warrant Cancelled Dec 2013
Stockholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights																									$ 4.50
Maximum | CMR Warrant Cancelled Dec 2013 | First Tranche
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																				50,000
Maximum | CMR Warrant Cancelled Dec 2013 | Mar. 23, 2013 Maximum Second Tranche CMR Warrant Cancelled Dec 2013
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																					50,000
Maximum | 2012 IR Warrant
Stockholders Equity [Line Items]
Warrants issued to purchase common stock																		50,000
Series B Junior Participating Cumulative Preferred Stock
Stockholders Equity [Line Items]
Preferred stock, shares authorized																				500,000