Hands of a Periodontist. Myths and truths about manual dexterity

A Periodontist’s Notebook - November 06, 2020

The first clinical patient – I do not think any of us will ever forget them.

If I am painfully honest and critical, I have always thought of myself as more of a brainy than a handy. Granted, I played a musical instrument, designed jewellery, sew, and learned how to wield a screwdriver and a french key alongside my dad way before I grew awareness of dental tools. I've been engaged in a number of activities that are known and recommended today for improvement of fine motor skills and hand-eye coordination. Experientially (and frustratingly), we all know some individuals that ace in specific manual tasks, having an innate ability to learn and perform them with easiness. However, I still, to this day, feel that I'm not a natural.

Having self-diagnosed myself, I was okay with the idea that, manually, clinical practice at dental school will be a developmental process. Being a brainy, however, I've never missed a single opportunity to come fully prepared. Very early on into university education, I had already been smitten by Atul Gawande who quickly became one of my favourite physician-writers ever. In one of his books, he discusses the importance of pre-planning and organisation in medicine (Gawande, 2011). By following this paradigm, I had gotten into a habit of learning different procedures by breaking them into steps, essentially making checklists for each and every dental procedure (and continue doing so even today). 

Going back to the memory of the first clinical patient, my first ever clinical task was to do a post-endodontic tooth restoration. I had mentally breezed through all of the key steps in the procedure and was feeling pretty self-confident. The hands, on the other hand (pun intended!), weren't following. Irrespective of the training on the phantom dental heads at the preclinic, what couldn't be simulated and tried out before the actual, real-life scenario was a fidgety patient, streams of saliva, steel bur accidentally touching enamel and loss of control over a contra-angle handpiece. While, in the end, no patient was harmed in the making of what turned out to be a more-than-decent restoration for a first-timer, the challenge of using my hands served as a reminder of the long road ahead.

Years later, now that I'm working as a clinical teacher in Periodontology, I witness the same challenges, doubts and sometimes even despair of my students. It might sound like a bold statement, and a biased one for sure, but I genuinely believe that Periodontology presumes manually mastering some of the most complex and elaborate procedures in the entire field of dentistry.
How do we (learn to) use our hands better?

Motor skills

Traditionally motor skills are divided dichotomously, into gross and fine. Gross motor skills are movements related to large muscles of the legs, arms and the trunk of the body, i.e. walking, sitting or sporting skills, and are developed from the earliest age. Fine motor skills are movements involving smaller muscle groups such as those of the wrists, hands, fingers, feet and toes, and are usually coordinated with eyes. Drawing, playing the piano and manipulating objects all require fine motor coordination with the highest precision. Very often a term manual dexterity is used for the fine motor skills of hands and fingers. 

In education-related literature, very often a term psychomotor skill is used interchangeably with technical and procedural skills. The term essentially highlights both the mental and motor activities which are required to execute a manual task. In medicine and dentistry, this process is explained by the "closed-looped theory" (Adams, 1987; Kovacs, 1997). Let's take an example of making a surgical knot. During the sole motor act of entering and passing the needle through a flap, we receive continuous sensory information. We might observe and perceive that the suture is too close to the margin of the flap (self-assessment), or receive such feedback from an observer, a tutor or a mentor. While tying a knot, the suture material easily cuts and tears through the thin band of tissue (knowledge of results). If one references this knowledge of results (tissue cutting) against the original movement (passing too close to the flap's margin), a future performance will be corrected and improved. Knowing the closed-looped theory only serves to confirm why education in small, individual-sized groups, under the observation and with timely feedback is essential in learning, correcting, and improving the performance of motor action. Otherwise, one is left to "trial and error" with self-assessment and knowledge of results gained through the retrospective analysis of the patient morbidity.

Manual dexterity

In medical disciplines, however, manual dexterity is (too) often times deemed crucial and sole factor influencing surgical performance. Actually, as suggested by research, it seems that visual-spatial ability, in particular, is related to competency and quality of results in complex surgery (Maan et al., 2012; Wanzel et al., 2002, 2003). Similar findings were also reported for the domain of periodontal plastic surgery (Burkhardt et al., 2019). Burkhardt and co-authors highlighted that successful clinical performance could be correlated and predicted through visual-spatial ability testing, however, in their study, the same correlation could not be found with regards to psychomotor skills. 

Psychomotor skills are even traditionally evaluated in the dental school admission process (Schwibbe et al., 2016). But are the results of admission tests what determines us as (future) dentists? Research on the population of dental students suggests that studying dentistry in general leads to the improvement of manual skills over time (Luck et al., 2000). Actually, for all of you out there, burdened with the idea of not being "talented" enough to excel in dentistry, even the manual abilities of students evaluated as poor upon admission to dental school, research suggests, is trained and improves significantly over time (Giuliani et al., 2007).

As mentioned above, psychomotor skills can be improved through repetitive practice. Luckily, however, we are not even limited solely to practical training. A significant and ever-growing body of evidence now suggests that mental training, visualisation and mental imagery, is a powerful tool for skill acquisition and improvement. Imagery practise presumes repetitive cognitive rehearsal of a physical action or a procedure without actually making any muscle movement (Hall, 2002). A method very often used among professional athletes and musicians proves to be an effective way of optimising the procedure outcomes both in medicine and dentistry (Immenroth et al., 2007; Jofré et al., 2019; Welk et al., 2007). After all, are we not performers as well?

Talent

What about talent? I have briefly skimmed on the phenomenon of being gifted or being a natural, a frequent subject of ongoing research, as much as non-scientific subjective opinions. The discussion is traditionally led whether talent in sports, music and games (all of which require fine manual skills) is consequential to the continuity of development or the dominance of genetic influences. One of the most frequently quoted studies, by Ericsson et al., soothes all of the sore spots of those that do not believe in talent – in fact, the authors conclude that the achievements of elite performers are the result of intense practice extended for a minimum of 10 years or 10000 hours (!!!!!) (Ericsson et al., 1993) In contrast, a recent, 2014 systematic review found that "deliberate practice explained only 26% of the variance in performance for games, 21% for music, 18% for sports, 4% for education, and less than 1% for professions" (Macnamara et al., 2014). All authors agree, though, attaining high levels of skills is not a matter of just black or white – or practice or talent. A combination of two also relies on motivation, environmental support and educators.

The science of touch in periodontology

Periodontology is, in many ways, a unique discipline in dentistry. One of its uniqueness lies in the "divorce "between the eyes and the hands, coordination of which is essential in the performance of many manual tasks. How much more exciting and challenging does that make it for the clinician? The clinical diagnostic, evaluation and non-surgical treatment procedures are done under the gum line, with no visual control whatsoever. What one relies on is the touch. Manikin/phantom based simulators are traditionally used in the learning process of performing dental procedures, but we may all agree that the reality of the experience is rightly questioned, especially in Periodontology. With the advances in technology, haptics-based simulators have been introduced in dental training (Khanna et al., 2015; Luciano et al., 2009; Steinberg et al., 2007). Haptic technology creates an experience of touch by applying forces, vibrations, or motions to the hand of the user. 


Modified pen grasp has many advantages over a standard pen grasp - increased tactile sensitivity being one of them.

In Periodontology, even the most basic act - the way we hold an instrument - is essential. The modified pen grasp is the recommended method for holding periodontal instruments. As its name suggests, it implies the modification of the grasp with which one usually holds a pen, through the placement of the middle finger on the instrument. This ensures better and more precise control and lessens the musculoskeletal stress to the fingers of the clinician. An even more important role is the improvement of tactile sensitivity. The middle finger, which rests very lightly at the very end of the handle and, in major part, on the shank of the instrument, feels the vibrations that are transmitted through the working end of the instrument, touching the surface of the tooth. Under our skin, we have a number of sensory mechanoreceptors, Pacini corpuscles, which are extremely sensitive to high-frequency vibration. They're particularly numerous in the human fingers - on average 350 per each finger vs 800 in the entire palm (Johnson et al., 2000). The extent of their function? In skilled operators using a probe or other probing instruments, through the transmitted vibrations they can perceive and discriminate the texture of the working surface as if the fingers were present at that surface (Klatzky & Lederman, 1999; Krueger, 1970). The probe, explorers and curettes, therefore, serve as an extension of our fingers and provide essential information upon which we base our clinical action.

Explorer 11/12 used for the exploration of the root's surface and the detection of subgingival hard deposits. Pacini's corpuscles in the fingertips detect the vibrations created by the contact of the instrument's working end with the rough surface of the root, transmitted through the working end and the terminal shank of the instrument.

A finishing thought

Being in charge of one's hands is, without a doubt, crucial for a dentist. But as Atul Gawande debates, there is much more to the education of surgeons than creating technical experts. In Periodontology, in particular, our clinical decision-making is very much founded in biology, and then there's an entire world of interpersonal skills, absolutely adamant in managing patients with a chronic disease such as periodontitis. 

Instead of being frightened of what should be attained, I suggest making a checklist and start conquering it one step at a time! 

 


Literature and suggested reads:

Adams, J. A. (1987). Historical Review and Appraisal of Research on the Learning, Retention, and Transfer of Human Motor Skills. Psychological Bulettin, 101(1), 41–74. https://doi.org/10.1037/0033-2909.101.1.41

Burkhardt, R., Hämmerle, C. H. F., & Lang, N. P. (2019). How do visual-spatial and psychomotor abilities influence clinical performance in periodontal plastic surgery? Journal of Clinical Periodontology, 46(1), 72–85. https://doi.org/10.1111/jcpe.13028

Ericsson, K. A., Krampe, R. T., & Tesch-Romer, C. (1993). The Role of Deliberate Practice in the Acquisition of Expert Performance. Psychological Review, 100(3), 363–406. https://doi.org/10.1037/0033-295X.100.3.363

Gawande, A. (2011). The Checklist Manifesto: How to Get Things Right. Profile Books.

Giuliani, M., Lajolo, C., Clemente, L., Querqui, A., Viotti, R., Boari, A., & Miani, C. M. (2007). Is manual dexterity essential in the selection of dental students? British Dental Journal, 203(3), 149–155. https://doi.org/10.1038/bdj.2007.688

Hall, J. C. (2002). Imagery practice and the development of surgical skills. American Journal of Surgery, 184(5), 465–470. https://doi.org/10.1016/s0002-9610(02)01007-3

Immenroth, M., Bürger, T., Brenner, J., Nagelschmidt, M., Eberspächer, H., & Troidl, H. (2007). Mental training in surgical education: A randomized controlled trial. Annals of Surgery, 245(3), 385–391. https://doi.org/10.1097/01.sla.0000251575.95171.b3

Jofré, J., Fuentes, J., Conrady, Y., Michel, M., Quintana, P., & Asenjo-Lobos, C. (2019). Improving Dental Students Fine Motor Skills by Visualization and Mental Imagery: A Pilot Randomized Clinical Trial. International Journal of Odontostomatology, 13(1), 69–74. https://doi.org/10.4067/S0718-381X2019000100069

Johnson, K. O., Yoshioka, T., & Vega-Bermudez, F. (2000). Tactile functions of mechanoreceptive afferents innervating the hand. Journal of Clinical Neurophysiology: Official Publication of the American Electroencephalographic Society, 17(6), 539–558. https://doi.org/10.1097/00004691-200011000-00002

Khanna, R., Sharma, S., & Rana, M. (2015). Haptics: The science of touch in periodontics. Digital Medicine, 1(2), 58. https://doi.org/10.4103/2226-8561.174768

Klatzky, R. L., & Lederman, S. J. (1999). Tactile roughness perception with a rigid link interposed between skin and surface. Perception & Psychophysics, 61(4), 591–607. https://doi.org/10.3758/BF03205532

Kovacs, G. (1997). Procedural skills in medicine: Linking theory to practice. The Journal of Emergency Medicine, 15(3), 387–391. https://doi.org/10.1016/s0736-4679(97)00019-x

Krueger, L. E. (1970). David Katz’s Der Aufbau der Tastwelt (The world of touch): A synopsis. Perception & Psychophysics, 7(6), 337–341. https://doi.org/10.3758/BF03208659

Luciano, C., Banerjee, P., & DeFanti, T. (2009). Haptics-based virtual reality periodontal training simulator. Virtual Reality, 13(2), 69–85. https://doi.org/10.1007/s10055-009-0112-7

Luck, O., Reitemeier, B., & Scheuch, K. (2000). Testing of fine motor skills in dental students: Fine motor skills. European Journal of Dental Education, 4(1), 10–14. https://doi.org/10.1034/j.1600-0579.2000.040103.x

Maan, Z. N., Maan, I. N., Darzi, A. W., & Aggarwal, R. (2012). Systematic review of predictors of surgical performance. The British Journal of Surgery, 99(12), 1610–1621. https://doi.org/10.1002/bjs.8893

Macnamara, B. N., Hambrick, D. Z., & Oswald, F. L. (2014). Deliberate practice and performance in music, games, sports, education, and professions: A meta-analysis. Psychological Science, 25(8), 1608–1618. https://doi.org/10.1177/0956797614535810

Schwibbe, A., Kothe, C., Hampe, W., & Konradt, U. (2016). Acquisition of dental skills in preclinical technique courses: Influence of spatial and manual abilities. Advances in Health Sciences Education: Theory and Practice, 21(4), 841–857. https://doi.org/10.1007/s10459-016-9670-0

Steinberg, A. D., Bashook, P. G., Drummond, J., Ashrafi, S., & Zefran, M. (2007). Assessment of Faculty Perception of Content Validity of PerioSim©, a Haptic-3D Virtual Reality Dental Training Simulator. Journal of Dental Education, 71(12), 1574–1582. https://doi.org/10.1002/j.0022-0337.2007.71.12.tb04434.x

Wanzel, K. R., Hamstra, S. J., Anastakis, D. J., Matsumoto, E. D., & Cusimano, M. D. (2002). Effect of visual-spatial ability on learning of spatially-complex surgical skills. Lancet (London, England), 359(9302), 230–231. https://doi.org/10.1016/S0140-6736(02)07441-X

Wanzel, K. R., Hamstra, S. J., Caminiti, M. F., Anastakis, D. J., Grober, E. D., & Reznick, R. K. (2003). Visual-spatial ability correlates with efficiency of hand motion and successful surgical performance. Surgery, 134(5), 750–757. https://doi.org/10.1016/s0039-6060(03)00248-4

Welk, A., Immenroth, M., Sakic, P., Bernhardt, O., Eberspächer, H., & Meyer, G. (2007). Mental training in dentistry. Quintessence International, 38(6), 489–497. https://pubmed.ncbi.nlm.nih.gov/17625632/