“It still looks a bit soupy in there, don’t you think?” The pack that had just filled the sinus, piriform aperture, and orbit now covered the Mayo stand, mute testimony to the enormous defect left by the rifle wound. “When should we operate?” the resident was asked.
It could be more than a shame, worse than just a “burned” donor site; it could be a catastrophe if we waited for too little … or too long a time.
“When?” is a fundamental question that underlies every surgical decision—when to intervene and when to observe, when to manage medically and when to operate, when to continue treatment and when to cease futile effort. In the practice of surgery, timing is critical.
Timing in Basic and Patient-Oriented Research
Timing in surgery is an important area for scientific inquiry. Among the many variables in clinical studies, timing is ubiquitous in its effect on the findings and conclusions of each investigation. When one examines clinical research that appears in JOMS, comparisons of clinical outcome studies depend upon when the study was performed, as well as the timing of interventions and observations. The reader should understand differences in timing as key to interpretation of results.
Timing of Intervention
For example, a comparison of 2 studies of open reduction for mandible fracture will vary with the timing of the surgical intervention from time of injury, duration of surgery, length of hospitalization, degree of fixation, and initiation and timing of antibiotic treatment, among others. Differing results may have less to do with more easily deciphered patient methods of the study (such as comparison of fixation methods) than with timing of interventions. Readers should know that outcomes attributed to differences in technique may be subsumed by the issues of “when” interventions occurred.
Timing of Observation
For example, an orthognathic outcome study that compares cephalometric tracings taken immediately postoperatively and at 6 weeks might offer different outcomes and conclusions than one that performs cephalometric tracings at 4 weeks and at 3 months. A study that shows only a modest benefit of therapy for bisphosphonate-associated osteonecrosis of the jaw after 1 year of observation might in the long run indicate that this is of greater therapeutic value than an intervention that shows complete success at a time of observation of 6 months. Readers should compare the timing of observations before concluding that one therapy demonstrates more positive effects than another.
Timing of Initiation and Completion of the Study
It has become accepted in many areas of clinical research that studies performed, however well, in the distant past may not have contemporary relevance. For example, studies on asthma or diabetes from the 1970s might have diminished contemporary relevance because of changes in society, environment, and diet that have ensued over the past 3 decades.
In contemporary clinical studies, the amount of time needed to recruit patients into randomized clinical trials or case series must be taken into account in the interpretation of results because time can alter associated interventions, can affect the skills and readiness of the clinical research team, and may have many other effects on study outcomes.
Assessment of Timing as a Guide to Clinical Practice
Clinical research can optimize the practice of surgery through the development of evidence to support appropriate timing. Outcome studies in particular often have much to add to the body of clinical knowledge about surgical timing if one takes into account the effect of timing on clinical outcome.
In this month’s JOMS, Susarla et al1 examined timing of lingual nerve repair and its effect on clinical outcome. This retrospective cohort study showed that early repair (fewer than 90 days postinjury) produced greater functional sensory recovery than late repair (93% early vs 63% late). Although these findings are compelling, they illustrate that even though timing is critical, timing is not everything.
Susarla et al wisely point out in their discussion the difficulties associated with offering conclusions about a therapy when a number of patients have dropped out because of spontaneous sensory recovery. Thus, patients who seek late repair might be exhibiting still unknown factors that make them inherently less likely to recover, whether operated on or not. To that point, Susarla et al examined neuroma formation as another time-dependent variable. In clinical research, the effect of time may insinuate confounding variables but may not always reveal them.
Some Critical Unanswered Questions of Timing
With many exciting investigations to come in JOMS, key effects of timing in oral and maxillofacial surgery practice await our readers’ insight. Issues of timing cover the gamut of our daily activities as surgeons.
When should a grafted site receive a dental implant?
When should implants be loaded?
What is the optimal age for third molar removal?
When should patients be discharged from anesthesia recovery?
At what age does mandibular advancement surgery produce the best results?
How should chemotherapy, radiation therapy, and surgery be timed to improve cancer survival?
When should cleft palate or alveolus repair be performed?
Perhaps you are reading this on your break from the timing decisions of the day. As you step back to the office to make clinical choices and perform surgery, try to identify a situation in which timing is critical. Examine a circumstance for which timing was not taken into account, and a clinical problem that resulted. Then again, perhaps there is no time to waste on that exercise. After all, it’s time to get back to work!
Reference
1. 1Susarla SM, Kaban LB, Donoff RB, et al.Does early repair of lingual nerve injuries improve functional sensory recovery?. J Oral Maxillofac Surg. 2007;65:1070. Abstract | Full Text |
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